docs: clarify rsync compatibility roadmap

2026-08-15 12:49:07 +02:00
43 changed files with 1354 additions and 1602 deletions
@@ -58,7 +58,7 @@ endif()
 find_package(OpenSSL REQUIRED)

 file(GLOB SHARED_SRCS "src/shared/*.c")
-set(FILE_STORE_SRCS "${CMAKE_CURRENT_SOURCE_DIR}/src/shared/file_store.c")
+set(FILE_STORE_SRCS src/shared/file_store.c)
 list(REMOVE_ITEM SHARED_SRCS ${FILE_STORE_SRCS})
 file(GLOB SERVER_SRCS "src/server/*.c")
 set(SERVER_RECEIVER_SRCS src/server/receiver.c)
@@ -45,7 +45,7 @@ replacement for every rsync feature or protocol mode.

 - Recursive directory scanning.
 - Rsync-style source and destination arguments.
- SSH transport using `user@host:destination` paths below the remote authorized root.
+- SSH transport using `user@host:/path` destinations.
 - TCP client/server transfers.
 - Dry runs, excludes, includes, size filters, backups, statistics, and
  bandwidth limiting.
@@ -79,10 +79,8 @@ partial, alternate, and planned behavior.

 ### Build

-Requirements: C11 compiler, CMake 3.22 or newer, xxHash, zstd, OpenSSL,
-pthreads, and an SSH client for SSH transport. The first CMake configure fetches
-xxHash from GitHub, so network access is required unless the dependency is
-already cached.
+Requirements: C11 compiler, CMake 3.22 or newer, zstd, OpenSSL, pthreads,
+and an SSH client for SSH transport.

 ```bash
 cmake -B build -S .
@@ -100,13 +98,10 @@ cmake --build build -j$(nproc)
 ### SSH transfer

 The remote host must have `fastsync-server` available in `PATH`, or use
-`--fastsync-server-path`. SSH starts `fastsync-server --stdio` in its remote
-working directory, so use a destination below that directory unless the
-remote server is otherwise configured with a matching authorized root.
+`--fastsync-server-path`.

 ```bash
-ssh user@host 'mkdir -p destination'
-./build/client /path/to/source user@host:destination
+./build/client /path/to/source user@host:/path/to/destination
 ```

 ### TCP transfer
@@ -114,7 +109,7 @@ ssh user@host 'mkdir -p destination'
 Start the FastSync server:

 ```bash
-./build/server --destination-root /path/to -p 8080
+./build/server -p 8080
 ```

 Then run the client:
@@ -128,7 +123,7 @@ Then run the client:
 ### TLS transfer

 ```bash
-./build/server --destination-root /path/to --tls --cert server.pem --key server-key.pem -p 8443
+./build/server --tls --cert server.pem --key server-key.pem -p 8443
 ./build/client --tls --cert client.pem --key client-key.pem --ca ca.pem \
  --server-host example.com --server-port 8443 \
  --source-dir /path/to/source --dest-dir /path/to/destination \
@@ -145,30 +140,30 @@ FastSync-native are optional performance or transport extensions.
 ./build/client /source/ /destination/

 # Archive-style synchronization (current FastSync archive behavior)
-./build/client -a /source/ user@host:destination/
+./build/client -a /source/ user@host:/destination/

 # Preview a transfer without changing the destination
 ./build/client -n /source/ /destination/

 # Exclude temporary and object files
 ./build/client --exclude '*.tmp' --exclude '*.o' \
-  /source/ user@host:destination/
+  /source/ user@host:/destination/

 # Remove destination entries not present in the source
-./build/client --delete /source/ user@host:destination/
+./build/client --delete /source/ user@host:/destination/

 # Skip unchanged files using size and modification time
-./build/client --incremental /source/ user@host:destination/
+./build/client --incremental /source/ user@host:/destination/

 # Verify content when size and time are not sufficient
-./build/client --incremental --checksum /source/ user@host:destination/
+./build/client --incremental --checksum /source/ user@host:/destination/

 # Preserve supported mode and timestamp metadata
-./build/client -M /source/ user@host:destination/
+./build/client -M /source/ user@host:/destination/

 # Keep backups of overwritten destination files
-./build/client --backup --backup-dir backups \
-  /source/ user@host:destination/
+./build/client --backup --backup-dir /backups \
+  /source/ user@host:/destination/
 ```

 ## FastSync Extensions
@@ -222,8 +217,8 @@ before FastSync can claim full rsync CLI compatibility.
 | `--backup` | Back up overwritten files. |
 | `--backup-dir <dir>` | Store backups under a separate directory. |
 | `--suffix <suffix>` | Set the backup filename suffix. |
-| `--partial` | Select partial-transfer handling. With `--partial-dir`, completed files are written there; resumable transfers are not implemented. |
-| `--partial-dir <dir>` | Set a relative partial-transfer directory below the server destination root; use with `--partial`. |
+| `--partial` | Keep received data under the configured partial location. Full resume semantics are planned. |
+| `--partial-dir <dir>` | Set the partial transfer directory. |
 | `--inplace` | Write directly to the destination instead of using a temporary file. |

 ### Metadata and links
@@ -274,7 +269,6 @@ before FastSync can claim full rsync CLI compatibility.
 | `--cert <path>` | TLS certificate file. |
 | `--key <path>` | TLS private key file. |
 | `--ca <path>` | CA file for peer verification. |
-| `--destination-root <path>` | Confine received files to this server-side root; defaults to the current directory. |
 | `--allow-delete` | Permit client delete manifests. Deletion is refused by default. |
 | `-v`, `--verbose` | Enable debug logging. |
 | `--help` | Print server usage. |
@@ -152,14 +152,14 @@ This document maps rsync's full feature set to FastSync's current implementation

 | Flag | Rsync Description | FastSync Status | Notes |
 |------|-------------------|-----------------|-------|
-| `-S`, `--sparse` | Sparse block handling | ⚠️ Partial | Flag is accepted, but full hole preservation is not implemented |
+| `-S`, `--sparse` | Sparse block handling | ✅ Implemented | `preserve_sparse` config field |
 | `--preallocate` | Allocate dest files before writing | ❌ Not Implemented | |

 ## 11. Checksum & Comparison

 | Flag | Rsync Description | FastSync Status | Notes |
 |------|-------------------|-----------------|-------|
-| `--checksum` | Skip based on checksum | ✅ Implemented | With `--incremental`, compares xxHash64 content checksums; `-c` remains compression |
+| `--checksum` | Skip based on checksum | ❌ Not Implemented | Removed because it had no effect; `-c` means compression |
 | `--checksum-choice=STR` | Choose checksum algorithm | ❌ Not Implemented | xxHash used internally |
 | `--compare-dest=DIR` | Compare dest files relative to DIR | ❌ Not Implemented | Removed because it had no effect |
 | `--copy-dest=DIR` | Include copies of unchanged files | ❌ Not Implemented | Removed because it had no effect |
@@ -11,7 +11,6 @@
 #include <errno.h>
 #include <limits.h>
 #include <stdbool.h>
-#include <stddef.h>
 #include <stdio.h>
 #include <stdlib.h>
 #include <string.h>
@@ -60,7 +59,7 @@ static bool parse_positive_int(const char* s, int* out_val) {
 static int set_string_option(char** dest, const char* value, const char* option_name) {
  char* dup = str_dup(value);
  if (!dup) {
-    log_message(LOG_LEVEL_ERROR, "memory allocation failed for %s", option_name);
+    fprintf(stderr, "Error: memory allocation failed for %s\n", option_name);
    return -1;
  }
  free(*dest);
@@ -71,7 +70,7 @@ static int set_string_option(char** dest, const char* value, const char* option_
 /* Parse a string as a positive integer into *dest. Returns true on success, false on error. */
 static int set_positive_int_option(int* dest, const char* value, const char* option_name) {
  if (!parse_positive_int(value, dest)) {
-    log_message(LOG_LEVEL_ERROR, "%s must be a positive integer", option_name);
+    fprintf(stderr, "Error: %s must be a positive integer\n", option_name);
    return -1;
  }
  return 0;
@@ -80,7 +79,7 @@ static int set_positive_int_option(int* dest, const char* value, const char* opt
 /* Parse a string as a non-negative integer into *dest. Returns true on success, false on error. */
 static int set_nonneg_int_option(int* dest, const char* value, const char* option_name) {
  if (!parse_nonneg_int(value, dest)) {
-    log_message(LOG_LEVEL_ERROR, "%s must be a non-negative integer", option_name);
+    fprintf(stderr, "Error: %s must be a non-negative integer\n", option_name);
    return -1;
  }
  return 0;
@@ -88,187 +87,105 @@ static int set_nonneg_int_option(int* dest, const char* value, const char* optio

 static int read_patterns_from_file(const char* filepath, char*** patterns, int* count);

-/* Parse a string as an unsigned long long. Returns 0 on success, -1 on error. */
-static int parse_ull_arg(const char* val, unsigned long long* out, const char* optname) {
-  char* end;
-  errno = 0;
-  unsigned long long v = strtoull(val, &end, 10);
-  if (errno != 0 || *end != '\0') {
-    log_message(LOG_LEVEL_ERROR, "%s must be a non-negative integer", optname);
-    return -1;
-  }
-  *out = v;
-  return 0;
-}
-
-/* Append a duplicated pattern to a growable pattern array. Returns 0 on success, -1 on error. */
-static int config_add_pattern(char*** patterns, int* count, const char* value,
-                              const char* optname) {
-  char** tmp = realloc(*patterns, (*count + 1) * sizeof(char*));
-  if (!tmp) {
-    log_message(LOG_LEVEL_ERROR, "memory allocation failed for %s", optname);
-    return -1;
-  }
-  *patterns = tmp;
-  char* dup = str_dup(value);
-  if (!dup) {
-    log_message(LOG_LEVEL_ERROR, "memory allocation failed for %s", optname);
-    return -1;
-  }
-  (*patterns)[(*count)++] = dup;
-  return 0;
-}
-
-typedef enum {
-  OPT_FLAG,
-  OPT_STRING,
-  OPT_POS_INT,
-  OPT_NONNEG_INT,
-  OPT_ULL,
-} OptKind;
-
-typedef struct {
-  const char* name;
-  const char* alias;
-  OptKind kind;
-  size_t offset; /* offsetof of the target field in Config */
-} OptionEntry;
-
-/* Options that map directly onto a Config field with no side effects. */
-static const OptionEntry OPTION_TABLE[] = {
-    {"--dry-run", "-n", OPT_FLAG, offsetof(Config, dry_run)},
-    {"--delete", NULL, OPT_FLAG, offsetof(Config, use_delete)},
-    {"--incremental", NULL, OPT_FLAG, offsetof(Config, use_incremental)},
-    {"--delta", NULL, OPT_FLAG, offsetof(Config, use_delta)},
-    {"--save-to-disk", NULL, OPT_FLAG, offsetof(Config, save_to_disk)},
-    {"--progress", NULL, OPT_FLAG, offsetof(Config, show_progress)},
-    {"--tls", NULL, OPT_FLAG, offsetof(Config, use_tls)},
-    {"--backup", NULL, OPT_FLAG, offsetof(Config, backup)},
-    {"--stats", NULL, OPT_FLAG, offsetof(Config, stats)},
-    {"--partial", NULL, OPT_FLAG, offsetof(Config, partial)},
-    {"--links", "-l", OPT_FLAG, offsetof(Config, follow_symlinks)},
-    {"--copy-links", NULL, OPT_FLAG, offsetof(Config, copy_links)},
-    {"--safe-links", NULL, OPT_FLAG, offsetof(Config, safe_links)},
-    {"--copy-unsafe-links", NULL, OPT_FLAG, offsetof(Config, copy_unsafe_links)},
-    {"--sparse", "-S", OPT_FLAG, offsetof(Config, preserve_sparse)},
-    {"--inplace", NULL, OPT_FLAG, offsetof(Config, inplace)},
-    {"--checksum", NULL, OPT_FLAG, offsetof(Config, checksum)},
-
-    {"--source-dir", NULL, OPT_STRING, offsetof(Config, send_directory)},
-    {"--dest-dir", NULL, OPT_STRING, offsetof(Config, receive_root_directory)},
-    {"--server-host", NULL, OPT_STRING, offsetof(Config, server_host)},
-    {"--cert", NULL, OPT_STRING, offsetof(Config, tls_cert)},
-    {"--key", NULL, OPT_STRING, offsetof(Config, tls_key)},
-    {"--ca", NULL, OPT_STRING, offsetof(Config, tls_ca)},
-    {"--backup-dir", NULL, OPT_STRING, offsetof(Config, backup_dir)},
-    {"--fastsync-server-path", NULL, OPT_STRING, offsetof(Config, fastsync_server_path)},
-    {"--partial-dir", NULL, OPT_STRING, offsetof(Config, partial_dir)},
-    {"--suffix", NULL, OPT_STRING, offsetof(Config, suffix)},
-
-    {"--timeout", NULL, OPT_POS_INT, offsetof(Config, timeout)},
-    {"--contimeout", NULL, OPT_POS_INT, offsetof(Config, contimeout)},
-    {"--max-depth", NULL, OPT_NONNEG_INT, offsetof(Config, max_depth)},
-
-    {"--max-size", NULL, OPT_ULL, offsetof(Config, max_size)},
-    {"--min-size", NULL, OPT_ULL, offsetof(Config, min_size)},
-};
-
-static bool opt_is(const char* arg, const char* name, const char* alias) {
-  return strcmp(arg, name) == 0 || (alias && strcmp(arg, alias) == 0);
-}
-
-static const OptionEntry* find_table_option(const char* arg) {
-  for (size_t i = 0; i < sizeof(OPTION_TABLE) / sizeof(OPTION_TABLE[0]); i++)
-    if (opt_is(arg, OPTION_TABLE[i].name, OPTION_TABLE[i].alias))
-      return &OPTION_TABLE[i];
-  return NULL;
-}
-
-static int apply_table_option(Config* config, const OptionEntry* entry, const char* value) {
-  void* field = (char*)config + entry->offset;
-  switch (entry->kind) {
-  case OPT_FLAG:
-    *(bool*)field = true;
-    return 0;
-  case OPT_STRING:
-    return set_string_option((char**)field, value, entry->name);
-  case OPT_POS_INT:
-    return set_positive_int_option((int*)field, value, entry->name);
-  case OPT_NONNEG_INT:
-    return set_nonneg_int_option((int*)field, value, entry->name);
-  case OPT_ULL: {
-    unsigned long long v;
-    if (parse_ull_arg(value, &v, entry->name) != 0)
-      return -1;
-    *(unsigned long long*)field = v;
-    return 0;
-  }
-  }
-  return -1;
-}
-
 /* Parse CLI arguments into config. Returns 0 on success, -1 on error, 1 for help/clean-exit. */
 int parse_args(Config* config, int argc, char* argv[], int* positional_args,
               int* positional_count) {
  for (int i = 1; i < argc; i++) {
-    const OptionEntry* entry = find_table_option(argv[i]);
-    if (entry) {
-      if (entry->kind != OPT_FLAG) {
-        if (i + 1 >= argc) {
-          log_message(LOG_LEVEL_ERROR, "missing argument for %s", entry->name);
-          return -1;
-        }
-        if (apply_table_option(config, entry, argv[++i]) != 0)
-          return -1;
-      } else if (apply_table_option(config, entry, NULL) != 0) {
-        return -1;
-      }
-      continue;
-    }
-
-    if (opt_is(argv[i], "--help", NULL)) {
+    if (strcmp(argv[i], "--help") == 0) {
      print_usage();
      return 1;
-    } else if (opt_is(argv[i], "-V", "--version")) {
+    } else if (strcmp(argv[i], "-V") == 0 || strcmp(argv[i], "--version") == 0) {
      printf("fastsync version %s\n", PROTOCOL_VERSION);
      return 1;
-    } else if (opt_is(argv[i], "-a", "--archive")) {
+    } else if (strcmp(argv[i], "-a") == 0 || strcmp(argv[i], "--archive") == 0) {
      config->use_compression = true;
      config->use_multithreading = true;
      config->use_metadata = true;
      log_message(LOG_LEVEL_INFO, "Enabled archive mode (-c -m -M)");
-    } else if (opt_is(argv[i], "-p", NULL) && i + 1 < argc) {
+    } else if (strcmp(argv[i], "-n") == 0 || strcmp(argv[i], "--dry-run") == 0) {
+      config->dry_run = true;
+    } else if (strcmp(argv[i], "-p") == 0 && i + 1 < argc) {
      if (set_positive_int_option(&config->ssh_port, argv[++i], "-p") != 0)
        return -1;
      if (config->ssh_port > 65535) {
-        log_message(LOG_LEVEL_ERROR, "SSH port must be 1-65535");
+        log_message(LOG_LEVEL_ERROR, "SSH port must be 1-65535\n");
        return -1;
      }
-    } else if (opt_is(argv[i], "--exclude", NULL) && i + 1 < argc) {
-      if (config_add_pattern(&config->exclude_patterns, &config->exclude_count, argv[++i],
-                             "--exclude") != 0)
+    } else if (strcmp(argv[i], "--delete") == 0) {
+      config->use_delete = true;
+    } else if (strcmp(argv[i], "--exclude") == 0 && i + 1 < argc) {
+      char** tmp = realloc(config->exclude_patterns, (config->exclude_count + 1) * sizeof(char*));
+      if (!tmp) {
+        fprintf(stderr, "Error: memory allocation failed for --exclude\n");
        return -1;
-    } else if (opt_is(argv[i], "--include", NULL) && i + 1 < argc) {
-      if (config_add_pattern(&config->include_patterns, &config->include_count, argv[++i],
-                             "--include") != 0)
+      }
+      config->exclude_patterns = tmp;
+      char* dup = str_dup(argv[++i]);
+      if (!dup) {
+        fprintf(stderr, "Error: memory allocation failed for --exclude\n");
        return -1;
-    } else if (opt_is(argv[i], "--delta-block", NULL) && i + 1 < argc) {
-      unsigned long long val;
-      if (parse_ull_arg(argv[++i], &val, "--delta-block") != 0)
+      }
+      config->exclude_patterns[config->exclude_count++] = dup;
+    } else if (strcmp(argv[i], "--include") == 0 && i + 1 < argc) {
+      char** tmp = realloc(config->include_patterns, (config->include_count + 1) * sizeof(char*));
+      if (!tmp) {
+        fprintf(stderr, "Error: memory allocation failed for --include\n");
        return -1;
+      }
+      config->include_patterns = tmp;
+      char* dup = str_dup(argv[++i]);
+      if (!dup) {
+        fprintf(stderr, "Error: memory allocation failed for --include\n");
+        return -1;
+      }
+      config->include_patterns[config->include_count++] = dup;
+    } else if (strcmp(argv[i], "--max-size") == 0 && i + 1 < argc) {
+      char* end;
+      errno = 0;
+      unsigned long long val = strtoull(argv[++i], &end, 10);
+      if (errno != 0 || *end != '\0') {
+        fprintf(stderr, "Error: --max-size must be a non-negative integer\n");
+        return -1;
+      }
+      config->max_size = val;
+    } else if (strcmp(argv[i], "--min-size") == 0 && i + 1 < argc) {
+      char* end;
+      errno = 0;
+      unsigned long long val = strtoull(argv[++i], &end, 10);
+      if (errno != 0 || *end != '\0') {
+        fprintf(stderr, "Error: --min-size must be a non-negative integer\n");
+        return -1;
+      }
+      config->min_size = val;
+    } else if (strcmp(argv[i], "--incremental") == 0) {
+      config->use_incremental = true;
+    } else if (strcmp(argv[i], "--delta") == 0) {
+      config->use_delta = true;
+    } else if (strcmp(argv[i], "--delta-block") == 0 && i + 1 < argc) {
+      char* end;
+      errno = 0;
+      unsigned long long val = strtoull(argv[++i], &end, 10);
+      if (errno != 0 || *end != '\0') {
+        fprintf(stderr, "Error: --delta-block must be a positive integer\n");
+        return -1;
+      }
      if (val >= DELTA_BLOCK_SIZE_MIN && val <= DELTA_BLOCK_SIZE_MAX)
        config->delta_block_size = (uint32_t)val;
      else
-        log_message(LOG_LEVEL_WARNING, "--delta-block value %llu out of range, using default", val);
-    } else if (opt_is(argv[i], "--delta-max", NULL) && i + 1 < argc) {
-      unsigned long long val;
-      if (parse_ull_arg(argv[++i], &val, "--delta-max") != 0)
+        fprintf(stderr, "Warning: --delta-block value %llu out of range, using default\n", val);
+    } else if (strcmp(argv[i], "--delta-max") == 0 && i + 1 < argc) {
+      char* end;
+      errno = 0;
+      unsigned long long val = strtoull(argv[++i], &end, 10);
+      if (errno != 0 || *end != '\0') {
+        fprintf(stderr, "Error: --delta-max must be a positive integer\n");
        return -1;
+      }
      if (val >= DELTA_MIN_FILE_SIZE)
        config->delta_max_file_size = val;
      else
-        log_message(LOG_LEVEL_WARNING, "--delta-max value %llu too small, using default", val);
-    } else if (opt_is(argv[i], "-c", "-z")) {
+        fprintf(stderr, "Warning: --delta-max value %llu too small, using default\n", val);
+    } else if (strcmp(argv[i], "-c") == 0 || strcmp(argv[i], "-z") == 0) {
      config->use_compression = true;
      log_message(LOG_LEVEL_INFO, "Enabled Compression");
      if (i + 1 < argc) {
@@ -276,7 +193,7 @@ int parse_args(Config* config, int argc, char* argv[], int* positional_args,
        long level = strtol(argv[i + 1], &end_ptr, 10);
        if (*end_ptr == '\0') {
          if (level < 1 || level > 22) {
-            log_message(LOG_LEVEL_ERROR, "compression level must be 1-22");
+            fprintf(stderr, "Error: compression level must be 1-22\n");
            return -1;
          }
          config->compression_level = (int)level;
@@ -284,51 +201,91 @@ int parse_args(Config* config, int argc, char* argv[], int* positional_args,
          i++;
        }
      }
-    } else if (opt_is(argv[i], "-M", "--preserve")) {
+    } else if (strcmp(argv[i], "--source-dir") == 0 && i + 1 < argc) {
+      if (set_string_option(&config->send_directory, argv[++i], "--source-dir") != 0)
+        return -1;
+    } else if (strcmp(argv[i], "--dest-dir") == 0 && i + 1 < argc) {
+      if (set_string_option(&config->receive_root_directory, argv[++i], "--dest-dir") != 0)
+        return -1;
+    } else if (strcmp(argv[i], "--save-to-disk") == 0) {
+      config->save_to_disk = true;
+    } else if (strcmp(argv[i], "-M") == 0 || strcmp(argv[i], "--preserve") == 0) {
      config->use_metadata = true;
      log_message(LOG_LEVEL_INFO, "Enabled metadata preservation");
-    } else if (opt_is(argv[i], "-f", "--sendfile")) {
+    } else if (strcmp(argv[i], "-f") == 0 || strcmp(argv[i], "--sendfile") == 0) {
      config->use_sendfile = true;
      log_message(LOG_LEVEL_INFO, "Enabled sendfile");
-    } else if (opt_is(argv[i], "-m", NULL)) {
+    } else if (strcmp(argv[i], "-m") == 0) {
      config->use_multithreading = true;
      log_message(LOG_LEVEL_INFO, "Enabled Multithreading");
-    } else if (opt_is(argv[i], "-s", NULL)) {
+    } else if (strcmp(argv[i], "-s") == 0) {
      config->use_chunk_serialization = true;
      log_message(LOG_LEVEL_INFO, "Enabled Chunk Serialization");
-    } else if (opt_is(argv[i], "--server-port", NULL) && i + 1 < argc) {
+    } else if (strcmp(argv[i], "--server-host") == 0 && i + 1 < argc) {
+      if (set_string_option(&config->server_host, argv[++i], "--server-host") != 0)
+        return -1;
+    } else if (strcmp(argv[i], "--server-port") == 0 && i + 1 < argc) {
      if (!parse_positive_int(argv[++i], &config->server_port)) {
-        log_message(LOG_LEVEL_ERROR, "invalid --server-port value: %s", argv[i]);
+        fprintf(stderr, "Error: invalid --server-port value: %s\n", argv[i]);
        return -1;
      }
      if (config->server_port > 65535) {
-        log_message(LOG_LEVEL_ERROR, "server port must be 1-65535");
+        fprintf(stderr, "Error: server port must be 1-65535\n");
        return -1;
      }
-    } else if (opt_is(argv[i], "--bwlimit", NULL) && i + 1 < argc) {
-      unsigned long long kbps;
-      if (parse_ull_arg(argv[++i], &kbps, "--bwlimit") != 0)
-        return -1;
-      if (kbps == 0) {
-        log_message(LOG_LEVEL_ERROR, "--bwlimit must be a positive integer");
+    } else if (strcmp(argv[i], "--bwlimit") == 0 && i + 1 < argc) {
+      char* end;
+      errno = 0;
+      unsigned long long kbps = strtoull(argv[++i], &end, 10);
+      if (errno != 0 || *end != '\0' || kbps == 0) {
+        fprintf(stderr, "Error: --bwlimit must be a positive integer\n");
        return -1;
      }
      if (kbps > ULLONG_MAX / 1024) {
-        log_message(LOG_LEVEL_ERROR, "--bwlimit value too large");
+        fprintf(stderr, "Error: --bwlimit value too large\n");
        return -1;
      }
      io_set_bwlimit(kbps * 1024);
      log_message(LOG_LEVEL_INFO, "Set bandwidth limit to %llu KB/s", kbps);
-    } else if (opt_is(argv[i], "--chunk-size", NULL) && i + 1 < argc) {
-      unsigned long long val;
-      if (parse_ull_arg(argv[++i], &val, "--chunk-size") != 0)
-        return -1;
-      if (val == 0) {
-        log_message(LOG_LEVEL_ERROR, "--chunk-size must be a positive integer");
+    } else if (strcmp(argv[i], "--progress") == 0) {
+      config->show_progress = true;
+    } else if (strcmp(argv[i], "--chunk-size") == 0 && i + 1 < argc) {
+      char* end;
+      errno = 0;
+      unsigned long long val = strtoull(argv[++i], &end, 10);
+      if (errno != 0 || *end != '\0' || val == 0) {
+        fprintf(stderr, "Error: --chunk-size must be a positive integer\n");
        return -1;
      }
      config->chunk_size = val;
-    } else if (opt_is(argv[i], "--log-file", NULL) && i + 1 < argc) {
+    } else if (strcmp(argv[i], "--tls") == 0) {
+      config->use_tls = true;
+    } else if (strcmp(argv[i], "--cert") == 0 && i + 1 < argc) {
+      if (set_string_option(&config->tls_cert, argv[++i], "--cert") != 0)
+        return -1;
+    } else if (strcmp(argv[i], "--key") == 0 && i + 1 < argc) {
+      if (set_string_option(&config->tls_key, argv[++i], "--key") != 0)
+        return -1;
+    } else if (strcmp(argv[i], "--ca") == 0 && i + 1 < argc) {
+      if (set_string_option(&config->tls_ca, argv[++i], "--ca") != 0)
+        return -1;
+    } else if (strcmp(argv[i], "--timeout") == 0 && i + 1 < argc) {
+      if (set_positive_int_option(&config->timeout, argv[++i], "--timeout") != 0)
+        return -1;
+    } else if (strcmp(argv[i], "--contimeout") == 0 && i + 1 < argc) {
+      if (set_positive_int_option(&config->contimeout, argv[++i], "--contimeout") != 0)
+        return -1;
+    } else if (strcmp(argv[i], "--backup") == 0) {
+      config->backup = true;
+    } else if (strcmp(argv[i], "--backup-dir") == 0 && i + 1 < argc) {
+      if (set_string_option(&config->backup_dir, argv[++i], "--backup-dir") != 0)
+        return -1;
+    } else if (strcmp(argv[i], "--stats") == 0) {
+      config->stats = true;
+    } else if (strcmp(argv[i], "--max-depth") == 0 && i + 1 < argc) {
+      if (set_nonneg_int_option(&config->max_depth, argv[++i], "--max-depth") != 0)
+        return -1;
+    } else if (strcmp(argv[i], "--log-file") == 0 && i + 1 < argc) {
      if (config->log_file) {
        fclose(config->log_file);
        config->log_file = NULL;
@@ -336,29 +293,55 @@ int parse_args(Config* config, int argc, char* argv[], int* positional_args,
      }
      FILE* lf = fopen(argv[++i], "a");
      if (!lf) {
-        log_message(LOG_LEVEL_ERROR, "could not open log file '%s': %s", argv[i], strerror(errno));
+        fprintf(stderr, "Error: could not open log file '%s': %s\n", argv[i], strerror(errno));
        return -1;
      }
      config->log_file = lf;
      log_set_file(lf);
-    } else if (opt_is(argv[i], "--exclude-from", NULL) && i + 1 < argc) {
+    } else if (strcmp(argv[i], "--exclude-from") == 0 && i + 1 < argc) {
      if (read_patterns_from_file(argv[++i], &config->exclude_patterns, &config->exclude_count) !=
          0)
        return -1;
-    } else if (opt_is(argv[i], "--include-from", NULL) && i + 1 < argc) {
+    } else if (strcmp(argv[i], "--include-from") == 0 && i + 1 < argc) {
      if (read_patterns_from_file(argv[++i], &config->include_patterns, &config->include_count) !=
          0)
        return -1;
-    } else if (opt_is(argv[i], "-v", "--verbose")) {
+    } else if (strcmp(argv[i], "--partial") == 0) {
+      config->partial = true;
+    } else if (strcmp(argv[i], "--fastsync-server-path") == 0 && i + 1 < argc) {
+      if (set_string_option(&config->fastsync_server_path, argv[++i], "--fastsync-server-path") !=
+          0)
+        return -1;
+    } else if (strcmp(argv[i], "-v") == 0 || strcmp(argv[i], "--verbose") == 0) {
      set_log_level(LOG_LEVEL_DEBUG);
-    } else if (opt_is(argv[i], "-T", NULL) && i + 1 < argc) {
+    } else if (strcmp(argv[i], "-l") == 0 || strcmp(argv[i], "--links") == 0) {
+      config->follow_symlinks = true;
+    } else if (strcmp(argv[i], "--copy-links") == 0) {
+      config->copy_links = true;
+    } else if (strcmp(argv[i], "--safe-links") == 0) {
+      config->safe_links = true;
+    } else if (strcmp(argv[i], "--copy-unsafe-links") == 0) {
+      config->copy_unsafe_links = true;
+    } else if (strcmp(argv[i], "-S") == 0 || strcmp(argv[i], "--sparse") == 0) {
+      config->preserve_sparse = true;
+    } else if (strcmp(argv[i], "--inplace") == 0) {
+      config->inplace = true;
+    } else if (strcmp(argv[i], "--partial-dir") == 0 && i + 1 < argc) {
+      if (set_string_option(&config->partial_dir, argv[++i], "--partial-dir") != 0)
+        return -1;
+    } else if (strcmp(argv[i], "--suffix") == 0 && i + 1 < argc) {
+      if (set_string_option(&config->suffix, argv[++i], "--suffix") != 0)
+        return -1;
+    } else if (strcmp(argv[i], "-T") == 0 && i + 1 < argc) {
      if (set_positive_int_option(&config->timeout, argv[++i], "-T") != 0)
        return -1;
-    } else if (opt_is(argv[i], "--compress-level", NULL) && i + 1 < argc) {
+    } else if (strcmp(argv[i], "--checksum") == 0) {
+      config->checksum = true;
+    } else if (strcmp(argv[i], "--compress-level") == 0 && i + 1 < argc) {
      if (set_positive_int_option(&config->compression_level, argv[++i], "--compress-level") != 0)
        return -1;
      if (config->compression_level < 1 || config->compression_level > 22) {
-        log_message(LOG_LEVEL_ERROR, "--compress-level must be between 1 and 22");
+        fprintf(stderr, "Error: --compress-level must be between 1 and 22\n");
        return -1;
      }
    } else if (argv[i][0] == '-') {
@@ -381,7 +364,7 @@ int parse_args(Config* config, int argc, char* argv[], int* positional_args,
 static int read_patterns_from_file(const char* filepath, char*** patterns, int* count) {
  FILE* fp = fopen(filepath, "r");
  if (!fp) {
-    log_message(LOG_LEVEL_ERROR, "could not open pattern file '%s': %s", filepath, strerror(errno));
+    fprintf(stderr, "Error: could not open pattern file '%s': %s\n", filepath, strerror(errno));
    return -1;
  }
  char* line = NULL;
@@ -398,11 +381,22 @@ static int read_patterns_from_file(const char* filepath, char*** patterns, int*
      p[--len] = '\0';
    if (len == 0)
      continue;
-    if (config_add_pattern(patterns, count, p, "pattern file") != 0) {
+    char** tmp = realloc(*patterns, (*count + 1) * sizeof(char*));
+    if (!tmp) {
+      fprintf(stderr, "Error: memory allocation failed for pattern file\n");
      free(line);
      fclose(fp);
      return -1;
    }
+    *patterns = tmp;
+    char* dup = str_dup(p);
+    if (!dup) {
+      fprintf(stderr, "Error: memory allocation failed for pattern file\n");
+      free(line);
+      fclose(fp);
+      return -1;
+    }
+    (*patterns)[(*count)++] = dup;
  }
  free(line);
  fclose(fp);
@@ -420,7 +414,7 @@ int main(int argc, char* argv[]) {
  bool config_owned_by_pipeline = false;
  Config* config = config_create();
  if (!config) {
-    log_message(LOG_LEVEL_ERROR, "failed to allocate config");
+    fprintf(stderr, "Error: failed to allocate config\n");
    return 1;
  }
  config->save_to_disk = save_to_disk;
@@ -441,20 +435,20 @@ int main(int argc, char* argv[]) {
    free(config->receive_root_directory);
    config->send_directory = str_dup(argv[positional_args[0]]);
    if (!config->send_directory) {
-      log_message(LOG_LEVEL_ERROR, "memory allocation failed");
+      fprintf(stderr, "Error: memory allocation failed\n");
      exit_code = 1;
      goto cleanup;
    }
    config->receive_root_directory = str_dup(argv[positional_args[1]]);
    if (!config->receive_root_directory) {
-      log_message(LOG_LEVEL_ERROR, "memory allocation failed");
+      fprintf(stderr, "Error: memory allocation failed\n");
      exit_code = 1;
      goto cleanup;
    }
    config->save_to_disk = true;
    config_parse_ssh_dest(config);
  } else if (positional_count == 1) {
-    log_message(LOG_LEVEL_ERROR, "missing destination argument");
+    fprintf(stderr, "Error: missing destination argument\n");
    print_usage();
    exit_code = 1;
    goto cleanup;
@@ -462,7 +456,7 @@ int main(int argc, char* argv[]) {
    if (!config->send_directory && env_source) {
      config->send_directory = str_dup(env_source);
      if (!config->send_directory) {
-        log_message(LOG_LEVEL_ERROR, "memory allocation failed");
+        fprintf(stderr, "Error: memory allocation failed\n");
        exit_code = 1;
        goto cleanup;
      }
@@ -470,7 +464,7 @@ int main(int argc, char* argv[]) {
    if (!config->receive_root_directory && env_dest) {
      config->receive_root_directory = str_dup(env_dest);
      if (!config->receive_root_directory) {
-        log_message(LOG_LEVEL_ERROR, "memory allocation failed");
+        fprintf(stderr, "Error: memory allocation failed\n");
        exit_code = 1;
        goto cleanup;
      }
@@ -42,7 +42,7 @@ static ScannerOptions scanner_options_from_config(const Config* config, int num_
 static Client* connect_transfer_client(const Config* config) {
  if (config->transport == TRANSPORT_SSH) {
    if (config->use_sendfile) {
-      log_message(LOG_LEVEL_ERROR, "-f/--sendfile is not supported with SSH transport");
+      fprintf(stderr, "Error: -f/--sendfile is not supported with SSH transport\n");
      return NULL;
    }
    return client_connect_ssh(config->ssh_destination, config->ssh_port,
@@ -60,7 +60,6 @@ static Client* connect_transfer_client(const Config* config) {
    connected = client_connect(client, config->server_host, config->server_port);
  }
  if (!connected) {
-    client_disconnect(client);
    client_delete(client);
    return NULL;
  }
@@ -209,11 +208,8 @@ static int incremental_check(Client* client, File* file, const Config* config,

 static int send_delta(Client* client, File* file, DeltaSignature* sig, Config* config) {
  Delta* delta = delta_compute(file->data->data, file->data->size, sig, config->delta_block_size);
-  if (!delta) {
-    if (!send_status(client->file_descriptor, STATUS_NEXT))
-      return -1;
+  if (!delta)
    return 1;
-  }

  if (!delta_is_worthwhile(delta, file->data->size)) {
    delta_destroy(delta);
@@ -377,9 +373,8 @@ static int send_chunks_multithreaded(void* pipeline_context) {
  Client* client = connect_transfer_client(context->config);
  if (!client) {
    if (context->config->transport == TRANSPORT_TCP)
-      log_message(LOG_LEVEL_ERROR, "could not connect to server%s",
-                  context->config->use_tls ? " via TLS" : "");
-    pipeline_cancel(context);
+      fprintf(stderr, "Error: could not connect to server%s\n",
+              context->config->use_tls ? " via TLS" : "");
    mark_sender_done(context);
    return thrd_error;
  }
@@ -388,7 +383,6 @@ static int send_chunks_multithreaded(void* pipeline_context) {
  protocol_session_set_ssl(&session, (SSL*)client->ssl);
  protocol_session_bind(&session);
  if (!config_send(client->file_descriptor, context->config)) {
-    pipeline_cancel(context);
    disconnect_transfer_client(client);
    mark_sender_done(context);
    protocol_session_unbind();
@@ -400,13 +394,6 @@ static int send_chunks_multithreaded(void* pipeline_context) {
        context->queue_loader, &context->mutex_loader, &context->condition_not_empty_loader,
        &context->condition_not_full_loader, &context->loader_done);
    if (current_chunk == NULL) {
-      if (atomic_load(&context->cancelled)) {
-        pipeline_cancel(context);
-        disconnect_transfer_client(client);
-        mark_sender_done(context);
-        protocol_session_unbind();
-        return thrd_error;
-      }
      if (context->config->use_delete) {
        if (send_delete_manifest(client->file_descriptor, context->manifest) != 0)
          goto send_fail;
@@ -425,7 +412,7 @@ static int send_chunks_multithreaded(void* pipeline_context) {
      return thrd_error;
    }
    if (send_chunk(client, current_chunk, context->config) != 0) {
-      log_message(LOG_LEVEL_ERROR, "unexpected error while sending chunk");
+      fprintf(stderr, "Error: unexpected error while sending chunk\n");
      chunk_destroy(current_chunk);
      pipeline_cancel(context);
      disconnect_transfer_client(client);
@@ -519,10 +506,9 @@ static int load_files_multithreaded(void* pipeline_context) {
        if (f->data->size > STREAM_THRESHOLD)
          continue;
        if (!file_load_data(f)) {
-          log_message(LOG_LEVEL_ERROR, "Failed to load file data");
-          chunk_destroy(chunk);
-          pipeline_cancel(context);
-          return thrd_error;
+          log_message(LOG_LEVEL_ERROR, "Failed to load file data, skipping");
+          file_destroy(f);
+          chunk->items[i] = NULL;
        }
      }
    }
@@ -531,23 +517,14 @@ static int load_files_multithreaded(void* pipeline_context) {
                                            &context->condition_not_full_loader,
                                            &context->cancelled)) {
      chunk_destroy(chunk);
-      pipeline_cancel(context);
+      atomic_store(&context->cancelled, true);
+      cnd_broadcast(&context->condition_not_full_loader);
+      cnd_broadcast(&context->condition_not_empty_loader);
      return thrd_error;
    }
  }
 }

-/* Print a one-line transfer progress report to stderr. `suffix` ends the
-   line (e.g. "Done.\n") or is "" for in-place refresh. Shared by the
-   single-threaded loop and the multithreaded progress thread. */
-static void print_transfer_progress(unsigned long long total_bytes, time_t start,
-                                    const char* suffix) {
-  double elapsed = difftime(time(NULL), start);
-  double rate = elapsed > 0.0 ? total_bytes / (1048576.0 * elapsed) : 0.0;
-  fprintf(stderr, "\rSent %.1f MB  (%.1f MB/s)  %s", total_bytes / 1048576.0, rate, suffix);
-  fflush(stderr);
-}
-
 /* Progress-reporting thread for multithreaded send. Runs in parallel with
   the scanner/loader/sender threads and prints periodic progress to stderr. */
 static int progress_thread_fn(void* arg) {
@@ -562,14 +539,20 @@ static int progress_thread_fn(void* arg) {
    mtx_unlock(&context->mutex_progress);

    if (done) {
-      print_transfer_progress(total, start, "Done.\n");
+      time_t now = time(NULL);
+      double elapsed = difftime(now, start);
+      double rate = elapsed > 0.0 ? total / (1048576.0 * elapsed) : 0.0;
+      fprintf(stderr, "\rSent %.1f MB  (%.1f MB/s)  Done.\n", total / 1048576.0, rate);
      break;
    }

    time_t now = time(NULL);
    if (now - last_progress >= 1) {
      last_progress = now;
-      print_transfer_progress(total, start, "");
+      double elapsed = difftime(now, start);
+      double rate = elapsed > 0.0 ? total / (1048576.0 * elapsed) : 0.0;
+      fprintf(stderr, "\rSent %.1f MB  (%.1f MB/s)  ", total / 1048576.0, rate);
+      fflush(stderr);
    }

    struct timespec ts = {0, 100 * 1000000L}; /* 100 ms */
@@ -585,29 +568,36 @@ int send_files(Config* config) {
  Client* client = connect_transfer_client(config);
  if (!client) {
    if (config->transport == TRANSPORT_TCP)
-      log_message(LOG_LEVEL_ERROR, "could not connect to server%s",
-                  config->use_tls ? " via TLS" : "");
+      fprintf(stderr, "Error: could not connect to server%s\n", config->use_tls ? " via TLS" : "");
    return 1;
  }
  ProtocolSession session;
  protocol_session_init(&session, client->file_descriptor, client->file_descriptor);
  protocol_session_set_ssl(&session, (SSL*)client->ssl);
  protocol_session_bind(&session);
-  int ret = 1;
-  DirectoryScanner* scanner = NULL;
-  ArrayList* manifest = NULL;
-  if (!config_send(client->file_descriptor, config))
-    goto send_fail;
+  if (!config_send(client->file_descriptor, config)) {
+    disconnect_transfer_client(client);
+    protocol_session_unbind();
+    return 1;
+  }
  ScannerOptions scanner_options = scanner_options_from_config(config, 0);
-  scanner = directory_scanner_create_with_options(config->send_directory, &scanner_options);
-  manifest = create_transfer_manifest(config);
-  if (!scanner || (config->use_delete && !manifest))
-    goto send_fail;
+  DirectoryScanner* scanner =
+      directory_scanner_create_with_options(config->send_directory, &scanner_options);
  Chunk* current_chunk;
  unsigned long long total_bytes = 0;
  int total_files = 0;
  time_t last_progress = 0;
  time_t start = time(NULL);
+  ArrayList* manifest = create_transfer_manifest(config);
+  if (!scanner || (config->use_delete && !manifest)) {
+    if (scanner)
+      directory_scanner_destroy(scanner);
+    if (manifest)
+      array_list_delete(manifest);
+    disconnect_transfer_client(client);
+    protocol_session_unbind();
+    return 1;
+  }
  while ((current_chunk = directory_scanner_next(scanner)) != NULL) {
    unsigned long long chunk_bytes = 0;
    for (int i = 0; i < current_chunk->element_count; i++) {
@@ -619,21 +609,15 @@ int send_files(Config* config) {
      goto send_fail;
    }
    if (!config->use_sendfile) {
-      bool load_ok = true;
      for (int i = 0; i < current_chunk->element_count; i++) {
        File* f = current_chunk->items[i];
        if (f->data->size > STREAM_THRESHOLD)
          continue;
        if (!file_load_data(f)) {
          log_message(LOG_LEVEL_ERROR, "Failed to load file data");
-          load_ok = false;
-          break;
+          continue;
        }
      }
-      if (!load_ok) {
-        chunk_destroy(current_chunk);
-        goto send_fail;
-      }
    }
    if (send_chunk(client, current_chunk, config) != 0) {
      log_message(LOG_LEVEL_ERROR, "Failed to send chunk");
@@ -648,7 +632,10 @@ int send_files(Config* config) {
      time_t now = time(NULL);
      if (now - last_progress >= 1) {
        last_progress = now;
-        print_transfer_progress(total_bytes, start, "");
+        double elapsed = difftime(now, start);
+        double rate = elapsed > 0 ? total_bytes / (1048576.0 * elapsed) : 0;
+        fprintf(stderr, "\rSent %.1f MB  (%.1f MB/s)  ", total_bytes / 1048576.0, rate);
+        fflush(stderr);
      }
    }
    chunk_destroy(current_chunk);
@@ -658,33 +645,34 @@ int send_files(Config* config) {
  if (config->use_delete) {
    if (send_delete_manifest(client->file_descriptor, manifest) != 0) {
      array_list_delete(manifest);
-      manifest = NULL;
      goto send_fail;
    }
    array_list_delete(manifest);
    manifest = NULL;
  }
  bool ok = finalize_transfer(client);
-  if (config->show_progress)
-    print_transfer_progress(total_bytes, start, "Done.\n");
+  double elapsed_total = difftime(time(NULL), start);
+  if (config->show_progress) {
+    double rate = elapsed_total > 0 ? total_bytes / (1048576.0 * elapsed_total) : 0;
+    fprintf(stderr, "\rSent %.1f MB  (%.1f MB/s)  Done.\n", total_bytes / 1048576.0, rate);
+  }
  if (config->stats) {
-    double elapsed_total = difftime(time(NULL), start);
    double rate = elapsed_total > 0 ? total_bytes / (1048576.0 * elapsed_total) : 0;
    fprintf(stderr, "Stats: %d files, %.1f MB, %.1f MB/s\n", total_files, total_bytes / 1048576.0,
            rate);
  }
-  ret = ok ? 0 : 1;
-
-send_fail:
-  /* Single cleanup path for all exits. The manifest is intentionally deleted
-     here even on success without --delete, fixing a pre-existing leak. */
-  if (manifest)
-    array_list_delete(manifest);
-  if (scanner)
-    directory_scanner_destroy(scanner);
+  directory_scanner_destroy(scanner);
  disconnect_transfer_client(client);
  protocol_session_unbind();
-  return ret;
+  return ok ? 0 : 1;
+
+send_fail:
+  if (manifest)
+    array_list_delete(manifest);
+  directory_scanner_destroy(scanner);
+  disconnect_transfer_client(client);
+  protocol_session_unbind();
+  return 1;
 }

 int send_files_multithreaded(Config* config) {
@@ -720,10 +708,6 @@ int send_files_multithreaded(Config* config) {
  }
  if (config->use_delete)
    context->manifest = create_transfer_manifest(config);
-  if (config->use_delete && !context->manifest) {
-    pipeline_context_sender_destroy(context);
-    return 1;
-  }

  thrd_t scanner, loader, sender;
  bool scanner_created = false;
@@ -737,7 +721,7 @@ int send_files_multithreaded(Config* config) {
    sender_created = (thrd_create(&sender, send_chunks_multithreaded, context) == thrd_success);

  if (!scanner_created || !loader_created || !sender_created) {
-    log_perror("Error creating threads");
+    perror("Error creating threads.\n");
    pipeline_cancel(context);
    mtx_lock(&context->mutex_progress);
    context->sender_done = true;
@@ -757,7 +741,7 @@ int send_files_multithreaded(Config* config) {
  if (config->show_progress) {
    progress_created = (thrd_create(&progress, progress_thread_fn, context) == thrd_success);
    if (!progress_created) {
-      log_perror("Error creating progress thread");
+      perror("Error creating progress thread.\n");
      /* Non-fatal; continue without progress reporting */
    }
  }
@@ -1,38 +1,37 @@
 #include "client_validation.h"
-#include "log.h"
 #include "usage.h"
 #include <stdio.h>

 /* Validate config after parsing. Returns true if valid. */
 bool validate_config(const Config* config) {
  if (!config->send_directory || !config->receive_root_directory) {
-    log_message(LOG_LEVEL_ERROR, "source and destination directories are required");
+    fprintf(stderr, "Error: source and destination directories are required\n");
    print_usage();
    return false;
  }
  if (config->use_sendfile && (config->use_chunk_serialization || config->use_compression)) {
-    log_message(LOG_LEVEL_ERROR, "-f/--sendfile cannot be combined with -c (compression) or -s "
-                                 "(chunk serialization)");
+    fprintf(stderr, "Error: -f/--sendfile cannot be combined with -c (compression) or -s (chunk "
+                    "serialization)\n");
    return false;
  }
  if (config->transport == TRANSPORT_SSH && config->use_sendfile) {
-    log_message(LOG_LEVEL_ERROR, "-f/--sendfile is not supported with SSH transport");
+    fprintf(stderr, "Error: -f/--sendfile is not supported with SSH transport\n");
    return false;
  }
  if (config->use_incremental && config->use_chunk_serialization) {
-    log_message(LOG_LEVEL_ERROR, "--incremental is not supported with -s (chunk serialization)");
+    fprintf(stderr, "Error: --incremental is not supported with -s (chunk serialization)\n");
    return false;
  }
  if (config->use_delta && !config->use_incremental) {
-    log_message(LOG_LEVEL_ERROR, "--delta requires --incremental");
+    fprintf(stderr, "Error: --delta requires --incremental\n");
    return false;
  }
  if (config->use_delta && config->use_chunk_serialization) {
-    log_message(LOG_LEVEL_ERROR, "--delta cannot be combined with -s (chunk serialization)");
+    fprintf(stderr, "Error: --delta cannot be combined with -s (chunk serialization)\n");
    return false;
  }
  if (config->use_delta && config->use_sendfile) {
-    log_message(LOG_LEVEL_ERROR, "--delta cannot be combined with -f (sendfile)");
+    fprintf(stderr, "Error: --delta cannot be combined with -f (sendfile)\n");
    return false;
  }
  if (config->append || config->append_verify) {
@@ -43,7 +42,7 @@ bool validate_config(const Config* config) {
  }
  if (config->use_tls) {
    if (!config->tls_cert || !config->tls_key) {
-      log_message(LOG_LEVEL_ERROR, "--tls requires --cert and --key");
+      fprintf(stderr, "Error: --tls requires --cert and --key\n");
      return false;
    }
  }
@@ -1,4 +1,3 @@
-#include "log.h"
 #include "scanner.h"
 #include "array_list.h"
 #include "chunk.h"
@@ -227,7 +226,7 @@ static int open_next_directory(DirectoryScanner* scanner) {
  free(de);
  scanner->current_dir = opendir(scanner->current_path);
  if (scanner->current_dir == NULL) {
-    log_perror("Could not open directory");
+    perror("Could not open directory");
    free(scanner->current_path);
    scanner->current_path = NULL;
    scanner->failed = true;
@@ -364,8 +363,6 @@ static int parallel_worker_thread(void* arg) {
      cnd_broadcast(&wa->ps->result_not_empty);
      cnd_broadcast(&wa->ps->result_not_full);
      mtx_unlock(&wa->ps->result_mutex);
-      for (int j = i; j < wa->dir_count; j++)
-        free(wa->dirs[j]);
      break;
    }
    Chunk* chunk;
@@ -401,23 +398,18 @@ static int parallel_worker_thread(void* arg) {
  return thrd_success;
 }

-static void parallel_scanner_creation_failed(ParallelScanner* ps) {
-  mtx_lock(&ps->result_mutex);
-  ps->failed = true;
-  atomic_store(&ps->cancelled, true);
-  ps->expected_threads = ps->created_threads;
-  if (ps->completed >= ps->expected_threads)
-    ps->done = true;
-  cnd_broadcast(&ps->result_not_empty);
-  cnd_broadcast(&ps->result_not_full);
-  mtx_unlock(&ps->result_mutex);
-}
-
-/* Initialize result queue and synchronization primitives. Returns true on success. */
-static bool parallel_scanner_init(ParallelScanner* ps) {
+ParallelScanner* parallel_scanner_create_with_options(const char* root_directory,
+                                                      const ScannerOptions* options) {
+  if (!root_directory || !options)
+    return NULL;
+  ParallelScanner* ps = calloc(1, sizeof(ParallelScanner));
+  if (!ps)
+    return NULL;
  ps->result_queue = queue_create(100, chunk_destroy);
-  if (!ps->result_queue)
-    return false;
+  if (!ps->result_queue) {
+    free(ps);
+    return NULL;
+  }
  atomic_init(&ps->cancelled, false);
  int init = 0;
  bool ok = true;
@@ -442,220 +434,14 @@ static bool parallel_scanner_init(ParallelScanner* ps) {
    if (init >= 1)
      mtx_destroy(&ps->result_mutex);
    queue_destroy(ps->result_queue);
-    ps->result_queue = NULL;
-    return false;
-  }
-  return true;
-}
-
-/* Split files into chunks of roughly chunk_size bytes. Returns the first chunk (also stored
- * chunks beyond the first are enqueued on `queue`). Nulls out consumed entries in `files`.
- * Sets *failed on allocation/enqueue errors. */
-static Chunk* batch_files(ArrayList* files, unsigned long long chunk_size, Queue* queue,
-                          bool* failed) {
-  Chunk* first = NULL;
-  if (files->size <= 0)
-    return NULL;
-  ArrayList* batch = array_list_create(NULL);
-  if (!batch) {
-    *failed = true;
+    free(ps);
    return NULL;
  }
-  unsigned long long batch_size = 0;
-  for (int i = 0; i < files->size; i++) {
-    File* f = (File*)files->items[i];
-    if (!array_list_add(batch, f)) {
-      *failed = true;
-      break;
-    }
-    batch_size += f->data->size;
-    if (batch_size >= chunk_size || i == files->size - 1) {
-      void** items = array_list_to_array(batch);
-      if (!items) {
-        *failed = true;
-        array_list_delete(batch);
-        batch = NULL;
-        break;
-      }
-      Chunk* c = chunk_create((File**)items, batch->size);
-      free(items);
-      if (!c) {
-        *failed = true;
-        array_list_delete(batch);
-        batch = NULL;
-        break;
-      }
-      int batch_start = i - batch->size + 1;
-      for (int j = batch_start; j <= i; j++)
-        files->items[j] = NULL;
-      batch->item_destroyer = NULL;
-      array_list_delete(batch);
-      batch = NULL;
-      if (!first) {
-        first = c;
-      } else {
-        if (!queue_enqueue(queue, c)) {
-          chunk_destroy(c);
-          *failed = true;
-        }
-      }
-      if (i < files->size - 1) {
-        batch = array_list_create(NULL);
-        if (!batch) {
-          *failed = true;
-          break;
-        }
-        batch_size = 0;
-      }
-    }
-  }
-  if (batch) {
-    batch->item_destroyer = NULL;
-    array_list_delete(batch);
-  }
-  return first;
-}

-/* Scan one root-directory entry into either the subdirs or files list. */
-static void scan_root_entry(const ScannerOptions* options, const char* root_directory,
-                            const struct dirent* entry, ArrayList* root_files, ArrayList* subdirs,
-                            ParallelScanner* ps) {
-  ScannerEntry inspected;
-  int inspection =
-      scanner_inspect_entry(options, root_directory, root_directory, entry->d_name, &inspected);
-  if (inspection < 0) {
-    ps->failed = true;
-    return;
-  }
-  if (inspection == 0)
-    return;
-  char* cur_path = inspected.path;
-  struct stat st = inspected.stats;
-  if (inspected.is_directory) {
-    if (!array_list_add(subdirs, cur_path)) {
-      free(cur_path);
-      ps->failed = true;
-    }
-    return;
-  }
-  File* file = file_create(cur_path);
-  free(cur_path);
-  if (!file) {
-    ps->failed = true;
-    return;
-  }
-  file->data->size = st.st_size;
-  if (options->use_metadata)
-    file->metadata = file_metadata_create(&st);
-  if (options->use_metadata && !file->metadata) {
-    file_destroy(file);
-    ps->failed = true;
-    return;
-  }
-  if (!array_list_add(root_files, file)) {
-    file_destroy(file);
-    ps->failed = true;
-  }
-}
-
-/* Scan the root directory itself, collecting root files and subdirectories.
- * Returns false if the root directory could not be opened. */
-static bool scan_root_directory(ParallelScanner* ps, const char* root_directory,
-                                const ScannerOptions* options, ArrayList* root_files,
-                                ArrayList* subdirs) {
  DIR* dir = opendir(root_directory);
  if (!dir) {
-    log_perror("Could not open root directory for parallel scan");
-    return false;
-  }
-  const struct dirent* entry;
-  while ((entry = readdir(dir)) != NULL) {
-    if (strcmp(entry->d_name, ".") == 0 || strcmp(entry->d_name, "..") == 0)
-      continue;
-    scan_root_entry(options, root_directory, entry, root_files, subdirs, ps);
-  }
-  closedir(dir);
-  return true;
-}
-
-/* Spawn worker threads, one per group of subdirectories. */
-static void spawn_parallel_workers(ParallelScanner* ps, ArrayList* subdirs,
-                                   const ScannerOptions* options, unsigned long long cs) {
-  if (subdirs->size <= 0)
-    return;
-  int n = options->num_threads > 0 ? options->num_threads : 4;
-  if (n > subdirs->size)
-    n = subdirs->size;
-
-  ps->num_threads = n;
-  ps->expected_threads = n;
-  ps->threads = calloc(n, sizeof(thrd_t));
-  if (!ps->threads) {
-    ps->num_threads = 0;
-    ps->expected_threads = 0;
-    ps->failed = true;
-    return;
-  }
-  int dirs_per_thread = subdirs->size / n;
-  int remainder = subdirs->size % n;
-  int start = 0;
-  ps->num_threads = 0;
-  for (int t = 0; t < n; t++) {
-    int count = dirs_per_thread + (t < remainder ? 1 : 0);
-    if (count == 0)
-      break;
-    ParallelWorkerArg* wa = calloc(1, sizeof(ParallelWorkerArg));
-    if (!wa) {
-      parallel_scanner_creation_failed(ps);
-      break;
-    }
-    wa->ps = ps;
-    wa->dirs = calloc(count, sizeof(char*));
-    if (!wa->dirs) {
-      free(wa);
-      parallel_scanner_creation_failed(ps);
-      break;
-    }
-    bool dup_ok = true;
-    for (int j = 0; j < count; j++) {
-      wa->dirs[j] = str_dup((char*)subdirs->items[start + j]);
-      if (!wa->dirs[j])
-        dup_ok = false;
-    }
-    if (!dup_ok) {
-      for (int j = 0; j < count; j++)
-        free(wa->dirs[j]);
-      free(wa->dirs);
-      free(wa);
-      parallel_scanner_creation_failed(ps);
-      break;
-    }
-    wa->dir_count = count;
-    wa->options = *options;
-    wa->options.chunk_size = cs;
-    start += count;
-    if (thrd_create(&ps->threads[t], parallel_worker_thread, wa) != thrd_success) {
-      for (int j = 0; j < count; j++)
-        free(wa->dirs[j]);
-      free(wa->dirs);
-      free(wa);
-      parallel_scanner_creation_failed(ps);
-      break;
-    }
-    ps->num_threads++;
-    ps->created_threads++;
-  }
-}
-
-ParallelScanner* parallel_scanner_create_with_options(const char* root_directory,
-                                                      const ScannerOptions* options) {
-  if (!root_directory || !options)
-    return NULL;
-  ParallelScanner* ps = calloc(1, sizeof(ParallelScanner));
-  if (!ps)
-    return NULL;
-  if (!parallel_scanner_init(ps)) {
-    free(ps);
+    perror("Could not open root directory for parallel scan");
+    parallel_scanner_destroy(ps);
    return NULL;
  }

@@ -664,26 +450,207 @@ ParallelScanner* parallel_scanner_create_with_options(const char* root_directory
  if (!root_files || !subdirs) {
    array_list_delete(root_files);
    array_list_delete(subdirs);
+    closedir(dir);
    parallel_scanner_destroy(ps);
    return NULL;
  }
-
-  if (!scan_root_directory(ps, root_directory, options, root_files, subdirs)) {
-    array_list_delete(root_files);
-    array_list_delete(subdirs);
-    parallel_scanner_destroy(ps);
-    return NULL;
+  const struct dirent* entry;
+  while ((entry = readdir(dir)) != NULL) {
+    if (strcmp(entry->d_name, ".") == 0 || strcmp(entry->d_name, "..") == 0)
+      continue;
+    ScannerEntry inspected;
+    int inspection =
+        scanner_inspect_entry(options, root_directory, root_directory, entry->d_name, &inspected);
+    if (inspection < 0) {
+      ps->failed = true;
+      continue;
+    }
+    if (inspection == 0)
+      continue;
+    char* cur_path = inspected.path;
+    struct stat st = inspected.stats;
+    if (inspected.is_directory) {
+      if (!array_list_add(subdirs, cur_path)) {
+        free(cur_path);
+        ps->failed = true;
+      }
+    } else {
+      File* file = file_create(cur_path);
+      free(cur_path);
+      if (!file) {
+        ps->failed = true;
+        continue;
+      }
+      file->data->size = st.st_size;
+      if (options->use_metadata)
+        file->metadata = file_metadata_create(&st);
+      if (options->use_metadata && !file->metadata) {
+        file_destroy(file);
+        ps->failed = true;
+        continue;
+      }
+      if (!array_list_add(root_files, file)) {
+        file_destroy(file);
+        ps->failed = true;
+      }
+    }
  }
+  closedir(dir);

  unsigned long long cs = options->chunk_size > 0 ? options->chunk_size : DESIRED_CHUNK_SIZE;
-  ps->initial_chunk = batch_files(root_files, cs, ps->result_queue, &ps->failed);
+  if (root_files->size > 0) {
+    ArrayList* batch = array_list_create(NULL);
+    if (!batch) {
+      ps->failed = true;
+      array_list_delete(root_files);
+      array_list_delete(subdirs);
+      parallel_scanner_destroy(ps);
+      return NULL;
+    }
+    unsigned long long batch_size = 0;
+    Chunk* first = NULL;
+    for (int i = 0; i < root_files->size; i++) {
+      File* f = (File*)root_files->items[i];
+      if (!array_list_add(batch, f)) {
+        ps->failed = true;
+        break;
+      }
+      batch_size += f->data->size;
+      if (batch_size >= cs || i == root_files->size - 1) {
+        void** items = array_list_to_array(batch);
+        if (!items) {
+          ps->failed = true;
+          batch->item_destroyer = file_destroy;
+          array_list_delete(batch);
+          batch = NULL;
+          break;
+        }
+        Chunk* c = chunk_create((File**)items, batch->size);
+        free(items);
+        if (!c) {
+          ps->failed = true;
+          batch->item_destroyer = file_destroy;
+          array_list_delete(batch);
+          batch = NULL;
+          break;
+        }
+        batch->item_destroyer = NULL;
+        array_list_delete(batch);
+        batch = NULL;
+        if (!first) {
+          first = c;
+        } else {
+          if (!queue_enqueue(ps->result_queue, c)) {
+            chunk_destroy(c);
+            ps->failed = true;
+          }
+        }
+        if (i < root_files->size - 1) {
+          batch = array_list_create(NULL);
+          if (!batch) {
+            ps->failed = true;
+            break;
+          }
+          batch_size = 0;
+        }
+      }
+    }
+    if (batch) {
+      batch->item_destroyer = NULL;
+      array_list_delete(batch);
+    }
+    ps->initial_chunk = first;
+    root_files->item_destroyer = NULL;
+  }
  array_list_delete(root_files);

-  spawn_parallel_workers(ps, subdirs, options, cs);
+  int n = options->num_threads > 0 ? options->num_threads : 4;
+  if (n > subdirs->size)
+    n = subdirs->size > 0 ? subdirs->size : 1;
+
+  if (subdirs->size > 0) {
+    ps->num_threads = n;
+    ps->expected_threads = n;
+    ps->threads = calloc(n, sizeof(thrd_t));
+    if (!ps->threads) {
+      array_list_delete(subdirs);
+      parallel_scanner_destroy(ps);
+      return NULL;
+    }
+    int dirs_per_thread = subdirs->size / n;
+    int remainder = subdirs->size % n;
+    int start = 0;
+    ps->num_threads = 0;
+    for (int t = 0; t < n; t++) {
+      int count = dirs_per_thread + (t < remainder ? 1 : 0);
+      if (count == 0)
+        break;
+      ParallelWorkerArg* wa = calloc(1, sizeof(ParallelWorkerArg));
+      if (!wa) {
+        ps->failed = true;
+        break;
+      }
+      wa->ps = ps;
+      wa->dirs = calloc(count, sizeof(char*));
+      if (!wa->dirs) {
+        free(wa);
+        ps->failed = true;
+        break;
+      }
+      bool dup_ok = true;
+      for (int j = 0; j < count; j++) {
+        wa->dirs[j] = str_dup((char*)subdirs->items[start + j]);
+        if (!wa->dirs[j])
+          dup_ok = false;
+      }
+      if (!dup_ok) {
+        for (int j = 0; j < count; j++)
+          free(wa->dirs[j]);
+        free(wa->dirs);
+        free(wa);
+        ps->failed = true;
+        break;
+      }
+      wa->dir_count = count;
+      wa->options = *options;
+      wa->options.chunk_size = cs;
+      start += count;
+      if (thrd_create(&ps->threads[t], parallel_worker_thread, wa) != thrd_success) {
+        for (int j = 0; j < count; j++)
+          free(wa->dirs[j]);
+        free(wa->dirs);
+        free(wa);
+        ps->failed = true;
+        atomic_store(&ps->cancelled, true);
+        ps->expected_threads = ps->created_threads;
+        mtx_lock(&ps->result_mutex);
+        cnd_broadcast(&ps->result_not_empty);
+        cnd_broadcast(&ps->result_not_full);
+        mtx_unlock(&ps->result_mutex);
+        break;
+      }
+      ps->num_threads++;
+      ps->created_threads++;
+    }
+  }
  array_list_delete(subdirs);
  return ps;
 }

+ParallelScanner* parallel_scanner_create(const char* root_directory, bool use_metadata,
+                                         unsigned long long chunk_size, char** exclude_patterns,
+                                         int exclude_count, char** include_patterns,
+                                         int include_count, unsigned long long max_size,
+                                         unsigned long long min_size, int max_depth,
+                                         int num_threads, bool follow_symlinks, bool copy_links,
+                                         bool safe_links, bool copy_unsafe_links, bool checksum) {
+  ScannerOptions options = {use_metadata,     chunk_size,        exclude_patterns, exclude_count,
+                            include_patterns, include_count,     max_size,         min_size,
+                            max_depth,        num_threads,       follow_symlinks,  copy_links,
+                            safe_links,       copy_unsafe_links, checksum};
+  return parallel_scanner_create_with_options(root_directory, &options);
+}
+
 Chunk* parallel_scanner_next(ParallelScanner* ps) {
  if (ps->initial_chunk) {
    Chunk* c = ps->initial_chunk;
@@ -692,11 +659,6 @@ Chunk* parallel_scanner_next(ParallelScanner* ps) {
  }
  if (ps->num_threads == 0) {
    mtx_lock(&ps->result_mutex);
-    if (!queue_is_empty(ps->result_queue)) {
-      Chunk* chunk = queue_dequeue(ps->result_queue);
-      mtx_unlock(&ps->result_mutex);
-      return chunk;
-    }
    ps->done = true;
    mtx_unlock(&ps->result_mutex);
    return NULL;
@@ -77,6 +77,13 @@ Chunk* directory_scanner_next(DirectoryScanner* scanner);
 bool directory_scanner_failed(const DirectoryScanner* scanner);
 void directory_scanner_destroy(DirectoryScanner* scanner);

+ParallelScanner* parallel_scanner_create(const char* root_directory, bool use_metadata,
+                                         unsigned long long chunk_size, char** exclude_patterns,
+                                         int exclude_count, char** include_patterns,
+                                         int include_count, unsigned long long max_size,
+                                         unsigned long long min_size, int max_depth,
+                                         int num_threads, bool follow_symlinks, bool copy_links,
+                                         bool safe_links, bool copy_unsafe_links, bool checksum);
 ParallelScanner* parallel_scanner_create_with_options(const char* root_directory,
                                                      const ScannerOptions* options);
 Chunk* parallel_scanner_next(ParallelScanner* scanner);
@@ -20,16 +20,6 @@ static char* authorized_root;
 static int authorized_root_fd = -1;
 static bool allow_delete;

-static void release_authorization(void) {
-  file_set_authorized_root(-1, NULL);
-  utils_set_authorized_root_fd(-1);
-  if (authorized_root_fd >= 0)
-    close(authorized_root_fd);
-  authorized_root_fd = -1;
-  free(authorized_root);
-  authorized_root = NULL;
-}
-
 static bool path_is_within(const char* root, const char* path) {
  size_t n = strlen(root);
  return strncmp(root, path, n) == 0 && (path[n] == '\0' || path[n] == '/');
@@ -48,13 +38,7 @@ static bool __attribute__((unused)) configure_authorization(const char* root) {
    authorized_root = NULL;
    return false;
  }
-  if (!file_set_authorized_root(authorized_root_fd, authorized_root)) {
-    close(authorized_root_fd);
-    authorized_root_fd = -1;
-    free(authorized_root);
-    authorized_root = NULL;
-    return false;
-  }
+  file_set_authorized_root(authorized_root_fd, authorized_root);
  utils_set_authorized_root_fd(authorized_root_fd);
  return true;
 }
@@ -122,14 +106,13 @@ void handler(int file_descriptor) {
      protocol_session_unbind();
      return;
    }
-    context->session.total_allocated_bytes = session.total_allocated_bytes;
    thrd_t receiver, writer;
    bool receiver_created = thrd_create(&receiver, receive_thread, context) == thrd_success;
    bool writer_created = false;
    if (receiver_created)
      writer_created = thrd_create(&writer, write_thread, context) == thrd_success;
    if (!receiver_created || !writer_created) {
-      log_perror("Error creating Threads");
+      perror("Error creating Threads");
      if (receiver_created) {
        mtx_lock(&context->mutex);
        atomic_store(&context->cancelled, true);
@@ -243,35 +226,33 @@ int main(int argc, char* argv[]) {
  if (stdio_mode) {
    io_set_fds(STDIN_FILENO, STDOUT_FILENO);
    handler(STDIN_FILENO);
-    release_authorization();
+    file_set_authorized_root(-1, NULL);
+    utils_set_authorized_root_fd(-1);
+    close(authorized_root_fd);
+    free(authorized_root);
    return 0;
  }
  g_server = server_create(port);
  if (!g_server) {
    log_message(LOG_LEVEL_ERROR, "Failed to create server");
-    release_authorization();
    return 1;
  }
  if (use_tls) {
    if (!tls_cert || !tls_key) {
      fprintf(stderr, "Error: --tls requires --cert and --key\n");
      server_delete(&g_server);
-      release_authorization();
      return 1;
    }
    tls_global_init();
    if (!server_create_tls(g_server, tls_cert, tls_key, tls_ca)) {
      log_message(LOG_LEVEL_ERROR, "Failed to set up TLS");
      server_delete(&g_server);
-      release_authorization();
      return 1;
    }
    server_listen_tls(g_server, handler);
  } else {
    server_listen(g_server, handler);
  }
-  server_delete(&g_server);
-  release_authorization();
  return 0;
 }
 #endif
@@ -1,4 +1,3 @@
-#include "log.h"
 #include "array_list.h"
 #include <stdio.h>
 #include <stdlib.h>
@@ -7,7 +6,7 @@
 ArrayList* array_list_create(void (*item_destroyer)(void* item)) {
  ArrayList* list = (ArrayList*)malloc(sizeof(ArrayList));
  if (list == NULL) {
-    log_perror("ERROR: Could not allocate memory for array list struct");
+    perror("ERROR: Could not allocate memory for array list struct");
    return NULL;
  }

@@ -35,7 +34,7 @@ void array_list_delete(ArrayList* array_list) {
  free(array_list);
 }

-static bool array_list_extend(ArrayList* array_list) {
+bool array_list_extend(ArrayList* array_list) {
  if (array_list == NULL)
    return false;
  int new_capacity = array_list->capacity * 2;
@@ -43,7 +42,7 @@ static bool array_list_extend(ArrayList* array_list) {
    new_capacity = INITIAL_ARRAY_SIZE;
  void* new_items = realloc(array_list->items, new_capacity * sizeof(void*));
  if (new_items == NULL) {
-    log_perror("ERROR: Could not reallocate memory for array list items");
+    perror("ERROR: Could not reallocate memory for array list items");
    return false;
  }
  array_list->items = new_items;
@@ -69,7 +68,7 @@ void** array_list_to_array(const ArrayList* array_list) {
  }
  void** array = malloc(array_list->size * sizeof(void*));
  if (array == NULL) {
-    log_perror("Could not malloc space for array from array list!");
+    perror("Could not malloc space for array from array list!");
    return NULL;
  }
  memcpy(array, array_list->items, array_list->size * sizeof(void*));
@@ -14,6 +14,7 @@ typedef struct ArrayList {

 ArrayList* array_list_create(void (*item_destroyer)(void* item));
 void array_list_delete(ArrayList* array_list);
+bool array_list_extend(ArrayList* array_list);
 bool array_list_add(ArrayList* array_list, void* item);
 void** array_list_to_array(const ArrayList* array_list);

@@ -1,5 +1,4 @@
 #include <stddef.h>
-#include <stdint.h>
 #include <stdio.h>
 #include <stdlib.h>
 #include <string.h>
@@ -15,12 +14,11 @@

 /* Maximum individual file data size within a chunk (64 MB) */
 #define MAX_FILE_DATA_SIZE (64ULL * 1024 * 1024)
-#define MAX_CHUNK_FILES (1024 * 1024)

 Chunk* chunk_create(File** items, int element_count) {
  Chunk* chunk = (Chunk*)malloc(sizeof(Chunk));
  if (chunk == NULL) {
-    log_perror("ERROR: Could not allocate memory for chunk structure");
+    perror("ERROR: Could not allocate memory for chunk structure");
    return NULL;
  }

@@ -94,11 +92,6 @@ Chunk* chunk_deserialize(Data* data, bool use_metadata) {
  size_t remaining_size = data->size;

  while (remaining_size > 0) {
-    if (files->size >= MAX_CHUNK_FILES) {
-      log_message(LOG_LEVEL_ERROR, "Chunk contains too many files");
-      array_list_delete(files);
-      return NULL;
-    }
    if (remaining_size < sizeof(size_t)) {
      log_message(LOG_LEVEL_ERROR, "Invalid chunk format: not enough data for path length");
      array_list_delete(files);
@@ -110,7 +103,7 @@ Chunk* chunk_deserialize(Data* data, bool use_metadata) {
    data_pointer += sizeof(size_t);
    remaining_size -= sizeof(size_t);

-    if (path_len > SIZE_MAX - 1 || remaining_size < path_len) {
+    if (remaining_size < path_len) {
      log_message(LOG_LEVEL_ERROR, "Invalid chunk format: not enough data for path");
      array_list_delete(files);
      return NULL;
@@ -118,7 +111,7 @@ Chunk* chunk_deserialize(Data* data, bool use_metadata) {

    char* path = malloc(path_len + 1);
    if (path == NULL) {
-      log_perror("Could not allocate memory for file path");
+      perror("Could not allocate memory for file path");
      array_list_delete(files);
      return NULL;
    }
@@ -129,15 +122,10 @@ Chunk* chunk_deserialize(Data* data, bool use_metadata) {

    File* file = file_create(path);
    free(path);
-    if (file == NULL) {
-      array_list_delete(files);
-      return NULL;
-    }

    if (use_metadata) {
      if (remaining_size < sizeof(int)) {
        log_message(LOG_LEVEL_ERROR, "Invalid chunk format: not enough data for metadata");
-        file_destroy(file);
        array_list_delete(files);
        return NULL;
      }
@@ -146,7 +134,6 @@ Chunk* chunk_deserialize(Data* data, bool use_metadata) {
      memcpy(&present_flag, data_pointer, sizeof(int));
      if (present_flag && remaining_size < sizeof(int) + FILE_METADATA_WIRE_SIZE) {
        log_message(LOG_LEVEL_ERROR, "Invalid chunk format: not enough data for metadata body");
-        file_destroy(file);
        array_list_delete(files);
        return NULL;
      }
@@ -154,16 +141,10 @@ Chunk* chunk_deserialize(Data* data, bool use_metadata) {
      remaining_size -= sizeof(int);
      if (file->metadata)
        remaining_size -= FILE_METADATA_WIRE_SIZE;
-      else if (present_flag) {
-        file_destroy(file);
-        array_list_delete(files);
-        return NULL;
-      }
    }

    if (remaining_size < sizeof(size_t)) {
      log_message(LOG_LEVEL_ERROR, "Invalid chunk format: not enough data for data size");
-      file_destroy(file);
      array_list_delete(files);
      return NULL;
    }
@@ -175,7 +156,6 @@ Chunk* chunk_deserialize(Data* data, bool use_metadata) {

    if (remaining_size < file_data_size) {
      log_message(LOG_LEVEL_ERROR, "Invalid chunk format: not enough data for file content");
-      file_destroy(file);
      array_list_delete(files);
      return NULL;
    }
@@ -184,48 +164,29 @@ Chunk* chunk_deserialize(Data* data, bool use_metadata) {
    if (file_data_size > MAX_FILE_DATA_SIZE) {
      log_message(LOG_LEVEL_ERROR, "File data size %zu exceeds maximum %llu", file_data_size,
                  (unsigned long long)MAX_FILE_DATA_SIZE);
-      file_destroy(file);
      array_list_delete(files);
      return NULL;
    }

-    void* file_data = malloc(file_data_size > 0 ? file_data_size : 1);
+    void* file_data = malloc(file_data_size);
    if (file_data == NULL) {
-      log_perror("Could not allocate memory for file data");
-      file_destroy(file);
+      perror("Could not allocate memory for file data");
      array_list_delete(files);
      return NULL;
    }
    memcpy(file_data, data_pointer, file_data_size);
    data_destroy(file->data);
    file->data = data_create(file_data, file_data_size);
-    if (file->data == NULL) {
-      file_destroy(file);
-      array_list_delete(files);
-      return NULL;
-    }
    data_pointer += file_data_size;
    remaining_size -= file_data_size;

-    if (!array_list_add(files, file)) {
-      file_destroy(file);
-      array_list_delete(files);
-      return NULL;
-    }
+    array_list_add(files, file);
  }

  File** file_array = (File**)array_list_to_array(files);
-  if (file_array == NULL) {
-    array_list_delete(files);
-    return NULL;
-  }
  Chunk* chunk = chunk_create(file_array, files->size);

  free(file_array);
-  if (chunk == NULL) {
-    array_list_delete(files);
-    return NULL;
-  }
  files->item_destroyer = NULL;
  array_list_delete(files);

@@ -108,7 +108,7 @@ Config* config_create(void) {
  return config;
 }

-bool config_is_remote_dest(const char* s) {
+bool is_remote_dest(const char* s) {
  if (s == NULL)
    return false;
  const char* colon = strchr(s, ':');
@@ -124,7 +124,7 @@ bool config_is_remote_dest(const char* s) {
 }

 void config_parse_ssh_dest(Config* config) {
-  if (!config_is_remote_dest(config->receive_root_directory))
+  if (!is_remote_dest(config->receive_root_directory))
    return;
  config->transport = TRANSPORT_SSH;
  config->ssh_destination = str_dup(config->receive_root_directory);
@@ -135,7 +135,7 @@ Config* config_create(void);
 void config_delete(Config* config);
 bool config_send(int file_descriptor, const Config* config);
 Config* config_receive(int file_descriptor);
-bool config_is_remote_dest(const char* s);
+bool is_remote_dest(const char* s);
 void config_parse_ssh_dest(Config* config);

 #endif
@@ -1,14 +1,27 @@
+#include <dirent.h>
+#include <errno.h>
+#include <fcntl.h>
+#include <libgen.h>
+#include <limits.h>
+#include <poll.h>
+#include <stddef.h>
 #include <stdio.h>
 #include <stdlib.h>
 #include <string.h>
+#include <sys/sendfile.h>
 #include <sys/stat.h>
 #include <unistd.h>
+#include <time.h>

-#include "data.h"
+#include "compression.h"
 #include "delta.h"
+#include "log.h"
+#include "config.h"
+#include "data.h"
 #include "file.h"
 #include "file_store.h"
-#include "log.h"
+#include "metadata.h"
+#include "protocol.h"
 #include "utils.h"

 bool file_checksum(File* file, uint64_t* checksum) {
@@ -29,7 +42,7 @@ File* file_create(const char* path) {
    return NULL;
  File* file = (File*)malloc(sizeof(File));
  if (file == NULL) {
-    log_perror("ERROR: Could not allocate memory for file struct");
+    perror("ERROR: Could not allocate memory for file struct");
    return NULL;
  }

@@ -69,7 +82,7 @@ void file_destroy(void* item) {
 FileMetadata* file_metadata_create(const struct stat* stats) {
  FileMetadata* m = malloc(sizeof(FileMetadata));
  if (m == NULL) {
-    log_perror("ERROR: Could not allocate memory for file metadata");
+    perror("ERROR: Could not allocate memory for file metadata");
    return NULL;
  }
  m->mode = stats->st_mode;
@@ -96,7 +109,7 @@ bool file_load_data(File* file) {
      return true;
    file->data->data = malloc(file->data->size);
    if (file->data->data == NULL) {
-      log_perror("Could not allocate memory for file data");
+      perror("Could not allocate memory for file data");
      return false;
    }
  }
@@ -111,29 +124,711 @@ bool file_load_data(File* file) {
  return true;
 }

-bool file_set_authorized_root(int fd, const char* canonical_path) {
-  return file_store_set_authorized_root(fd, canonical_path);
+bool file_send_single_calls(File* file, int file_descriptor, bool use_metadata,
+                            int compression_level, bool send_path) {
+  if (!file || !file->path || !file->data)
+    return false;
+  const Data* data_to_send = file->data;
+  Data* compressed_data = NULL;
+  if (compression_level > 0 && !compression_should_skip(file->path)) {
+    compressed_data = data_compress(file->data, compression_level);
+    if (compressed_data == NULL) {
+      log_message(LOG_LEVEL_ERROR, "Failed to compress file data");
+      return false;
+    }
+    data_to_send = compressed_data;
+  }
+  if (send_path && !send_str(file_descriptor, file->path)) {
+    data_destroy(compressed_data);
+    return false;
+  }
+  if (use_metadata && !metadata_send(file_descriptor, file->metadata)) {
+    data_destroy(compressed_data);
+    return false;
+  }
+  if (!send_data(file_descriptor, data_to_send)) {
+    data_destroy(compressed_data);
+    return false;
+  }
+  data_destroy(compressed_data);
+  return true;
 }

-bool file_write_to_disk(const char* path, const void* data, unsigned long long data_size,
-                        bool inplace, bool sparse) {
+void file_set_authorized_root(int fd, const char* canonical_path) {
+  file_store_set_authorized_root(fd, canonical_path);
+}
+
+static bool path_is_within_root(const char* root, const char* path) {
+  size_t n = strlen(root);
+  return strncmp(root, path, n) == 0 && (path[n] == '\0' || path[n] == '/');
+}
+
+bool file_save_to_disk(const char* root_directory, const File* file, const Config* config) {
+  bool backup_enabled = config && config->backup;
+  bool inplace = config && config->inplace;
+  bool sparse = config && config->preserve_sparse;
+  const char* backup_suffix = (config && config->suffix) ? config->suffix : "~";
+  const char* backup_dir = (config && config->backup_dir) ? config->backup_dir : NULL;
+  const char* partial_dir = (config && config->partial_dir) ? config->partial_dir : NULL;
+  char *confined_backup = NULL, *confined_partial = NULL;
+
+  if (!file || !file->path || !file->data || has_path_traversal(file->path) ||
+      (backup_enabled &&
+       (!backup_suffix || backup_suffix[0] == '\0' || strchr(backup_suffix, '/') != NULL ||
+        strcmp(backup_suffix, ".") == 0 || strcmp(backup_suffix, "..") == 0))) {
+    log_message(LOG_LEVEL_ERROR, "Invalid file or path received");
+    return false;
+  }
+
+  /* These options arrive from the client.  They are names below the server
+     root, never independent filesystem roots. */
+  if ((backup_dir && (backup_dir[0] == '/' || has_path_traversal(backup_dir))) ||
+      (partial_dir && (partial_dir[0] == '/' || has_path_traversal(partial_dir))))
+    return false;
+  if (backup_dir && !(confined_backup = path_cat(root_directory, backup_dir)))
+    return false;
+  if (partial_dir && !(confined_partial = path_cat(root_directory, partial_dir))) {
+    free(confined_backup);
+    return false;
+  }
+
+  char* resolved_root = NULL;
+  const char* actual_root =
+      (partial_dir && config && config->partial) ? confined_partial : root_directory;
+  resolved_root = realpath(actual_root, NULL);
+  if (resolved_root == NULL) {
+    if (mkdir_r(actual_root)) {
+      resolved_root = realpath(actual_root, NULL);
+    }
+  }
+  if (resolved_root == NULL) {
+    log_message(LOG_LEVEL_ERROR, "Failed to resolve destination root: %s", actual_root);
+    free(confined_backup);
+    free(confined_partial);
+    return false;
+  }
+  char* resolved_base = realpath(root_directory, NULL);
+  if (resolved_base == NULL || !path_is_within_root(resolved_base, resolved_root)) {
+    free(resolved_base);
+    free(confined_backup);
+    free(confined_partial);
+    free(resolved_root);
+    return false;
+  }
+  free(resolved_base);
+
+  char* disk_path = path_cat(resolved_root, file->path);
+  if (disk_path == NULL) {
+    free(confined_backup);
+    free(confined_partial);
+    free(resolved_root);
+    return false;
+  }
+
+  /* --update is receiver-side policy: never replace a newer destination. */
+  if (config && config->update) {
+    struct stat destination_stat;
+    if (stat(disk_path, &destination_stat) == 0 && file->metadata &&
+        destination_stat.st_mtime > file->metadata->mtime_sec) {
+      free(resolved_root);
+      free(confined_backup);
+      free(confined_partial);
+      free(disk_path);
+      return true;
+    }
+  }
+
+  if (backup_enabled) {
+    struct stat backup_stat;
+    if (stat(disk_path, &backup_stat) == 0) {
+      char* backup_path = NULL;
+      if (backup_dir) {
+        char* resolved_backup_dir = realpath(confined_backup, NULL);
+        if (!resolved_backup_dir) {
+          mkdir_r(confined_backup);
+          resolved_backup_dir = realpath(confined_backup, NULL);
+        }
+        if (resolved_backup_dir) {
+          char* backup_base = realpath(root_directory, NULL);
+          if (backup_base && path_is_within_root(backup_base, resolved_backup_dir))
+            backup_path = path_cat(resolved_backup_dir, file->path);
+          free(backup_base);
+          free(resolved_backup_dir);
+        }
+      }
+      if (!backup_path) {
+        size_t path_len = strlen(disk_path);
+        size_t suffix_len = strlen(backup_suffix);
+        backup_path = malloc(path_len + suffix_len + 1);
+        if (backup_path) {
+          memcpy(backup_path, disk_path, path_len);
+          memcpy(backup_path + path_len, backup_suffix, suffix_len + 1);
+        }
+      }
+      if (backup_path) {
+        char* backup_dir_path = str_dup(backup_path);
+        if (backup_dir_path) {
+          const char* bdir = dirname(backup_dir_path);
+          mkdir_r(bdir);
+          free(backup_dir_path);
+        }
+        if (!file_store_rename_secure(disk_path, backup_path)) {
+          free(backup_path);
+          free(resolved_root);
+          free(confined_backup);
+          free(confined_partial);
+          free(disk_path);
+          return false;
+        }
+        free(backup_path);
+      }
+    }
+  }
+
+  char* dir_dup = str_dup(disk_path);
+  if (!dir_dup) {
+    free(confined_backup);
+    free(confined_partial);
+    free(resolved_root);
+    free(disk_path);
+    return false;
+  }
+  char* dir_str = dirname(dir_dup);
+  if (!mkdir_r(dir_str)) {
+    free(dir_dup);
+    free(confined_backup);
+    free(confined_partial);
+    free(resolved_root);
+    free(disk_path);
+    return false;
+  }
+  char* resolved_dir = realpath(dir_str, NULL);
+  free(dir_dup);
+  if (resolved_dir == NULL) {
+    log_message(LOG_LEVEL_ERROR, "Failed to resolve directory for: %s", disk_path);
+    free(confined_backup);
+    free(confined_partial);
+    free(resolved_root);
+    free(disk_path);
+    return false;
+  }
+
+  size_t root_len = strlen(resolved_root);
+  if (strncmp(resolved_dir, resolved_root, root_len) != 0 ||
+      (resolved_dir[root_len] != '\0' && resolved_dir[root_len] != '/')) {
+    log_message(LOG_LEVEL_ERROR, "Path escape detected: %s is outside %s", disk_path, actual_root);
+    free(resolved_dir);
+    free(confined_backup);
+    free(confined_partial);
+    free(resolved_root);
+    free(disk_path);
+    return false;
+  }
+  free(resolved_dir);
+  free(resolved_root);
+
+  bool ok = file_store_write_secure(disk_path, file->data->data, file->data->size, inplace, sparse,
+                                    file->metadata);
+  free(confined_backup);
+  free(confined_partial);
+  free(disk_path);
+  return ok;
+}
+
+static File* receive_delta_file(int fd, const Config* config, const char* check_path,
+                                void* old_data, unsigned long long old_size) {
+  if (!old_data)
+    return NULL;
+
+  DeltaSignature* sig = delta_signature_create(old_data, old_size, config->delta_block_size);
+  if (!sig) {
+    free(old_data);
+    return NULL;
+  }
+
+  Data* sig_data = delta_signature_serialize(sig);
+  if (!sig_data) {
+    delta_signature_destroy(sig);
+    free(old_data);
+    return NULL;
+  }
+
+  bool sig_sent = send_status(fd, STATUS_DELTA_SIGNATURE) && send_data(fd, sig_data);
+  data_destroy(sig_data);
+
+  if (!sig_sent) {
+    delta_signature_destroy(sig);
+    free(old_data);
+    return NULL;
+  }
+
+  Status resp;
+  if (!receive_status(fd, &resp)) {
+    delta_signature_destroy(sig);
+    free(old_data);
+    return NULL;
+  }
+
+  if (resp == STATUS_DELTA_DATA) {
+    Data* delta_data = receive_data(fd);
+    if (!delta_data) {
+      delta_signature_destroy(sig);
+      free(old_data);
+      send_status(fd, STATUS_ERROR);
+      return NULL;
+    }
+
+    Data* raw_delta = delta_data;
+    if (config->use_compression) {
+      raw_delta = data_decompress(delta_data);
+      data_destroy(delta_data);
+      if (!raw_delta) {
+        free(old_data);
+        delta_signature_destroy(sig);
+        send_status(fd, STATUS_ERROR);
+        return NULL;
+      }
+    }
+
+    Delta* delta = delta_deserialize(raw_delta);
+    data_destroy(raw_delta);
+    if (!delta) {
+      free(old_data);
+      delta_signature_destroy(sig);
+      send_status(fd, STATUS_ERROR);
+      return NULL;
+    }
+
+    void* new_data = delta_apply(old_data, old_size, delta, config->delta_block_size);
+    uint64_t new_size = delta->new_file_size;
+    delta_destroy(delta);
+
+    if (!new_data) {
+      free(old_data);
+      delta_signature_destroy(sig);
+      send_status(fd, STATUS_ERROR);
+      return NULL;
+    }
+
+    File* file = file_create(check_path);
+    if (!file) {
+      free(new_data);
+      free(old_data);
+      delta_signature_destroy(sig);
+      send_status(fd, STATUS_ERROR);
+      return NULL;
+    }
+
+    if (config->use_metadata) {
+      int meta_ok = 1;
+      file->metadata = metadata_receive(fd, &meta_ok);
+      if (!meta_ok) {
+        file_destroy(file);
+        free(new_data);
+        free(old_data);
+        delta_signature_destroy(sig);
+        send_status(fd, STATUS_ERROR);
+        return NULL;
+      }
+    }
+
+    data_destroy(file->data);
+    file->data = data_create(new_data, (size_t)new_size);
+
+    free(old_data);
+    delta_signature_destroy(sig);
+    return file;
+  }
+
+  if (resp == STATUS_NEXT) {
+    delta_signature_destroy(sig);
+    free(old_data);
+
+    File* file = file_create(check_path);
+    if (!file) {
+      send_status(fd, STATUS_ERROR);
+      return NULL;
+    }
+
+    if (config->use_metadata) {
+      int meta_ok = 1;
+      file->metadata = metadata_receive(fd, &meta_ok);
+      if (!meta_ok) {
+        file_destroy(file);
+        send_status(fd, STATUS_ERROR);
+        return NULL;
+      }
+    }
+
+    Data* file_data = receive_data(fd);
+    if (file_data == NULL) {
+      file_destroy(file);
+      send_status(fd, STATUS_ERROR);
+      return NULL;
+    }
+
+    if (config->use_compression) {
+      Data* uncompressed = data_decompress(file_data);
+      data_destroy(file_data);
+      if (uncompressed == NULL) {
+        file_destroy(file);
+        send_status(fd, STATUS_ERROR);
+        return NULL;
+      }
+      file_data = uncompressed;
+    }
+
+    data_destroy(file->data);
+    file->data = file_data;
+    return file;
+  }
+
+  delta_signature_destroy(sig);
+  free(old_data);
+  return NULL;
+}
+
+File* receive_incremental_check(int fd, const Config* config, bool* skipped) {
+  *skipped = false;
+  char* check_path = receive_str(fd);
+  if (check_path == NULL) {
+    send_status(fd, STATUS_ERROR);
+    return NULL;
+  }
+
+  unsigned long long check_size;
+  long long check_mtime;
+  uint64_t check_checksum = 0;
+  if (!receive_n_data(fd, &check_size, sizeof(check_size)) ||
+      !receive_n_data(fd, &check_mtime, sizeof(check_mtime))) {
+    free(check_path);
+    send_status(fd, STATUS_ERROR);
+    return NULL;
+  }
+  if (config->checksum && !receive_n_data(fd, &check_checksum, sizeof(check_checksum))) {
+    free(check_path);
+    send_status(fd, STATUS_ERROR);
+    return NULL;
+  }
+
+  if (has_path_traversal(check_path)) {
+    log_message(LOG_LEVEL_ERROR, "Path traversal detected: %s", check_path);
+    free(check_path);
+    send_status(fd, STATUS_ERROR);
+    return NULL;
+  }
+
+  char* full_path = path_cat(config->receive_root_directory, check_path);
+  struct stat st;
+  bool has_old_file = false;
+  int old_fd = -1;
+  if (full_path) {
+    char* leaf = NULL;
+    int parent_fd = file_store_open_secure_parent(full_path, &leaf);
+    if (parent_fd >= 0) {
+      old_fd = openat(parent_fd, leaf, O_RDONLY | O_CLOEXEC | O_NOFOLLOW);
+      free(leaf);
+      close(parent_fd);
+      has_old_file = old_fd >= 0 && fstat(old_fd, &st) == 0 && S_ISREG(st.st_mode);
+    }
+  }
+  unsigned long long old_size = has_old_file ? (unsigned long long)st.st_size : 0;
+  void* old_data = NULL;
+  if (has_old_file && old_size > 0) {
+    old_data = malloc((size_t)old_size);
+    if (old_data) {
+      size_t got = 0;
+      while (got < (size_t)old_size) {
+        ssize_t n = read(old_fd, (char*)old_data + got, (size_t)old_size - got);
+        if (n <= 0) {
+          free(old_data);
+          old_data = NULL;
+          break;
+        }
+        got += (size_t)n;
+      }
+    }
+  }
+  if (old_fd >= 0) {
+    close(old_fd);
+  }
+
+  bool match = has_old_file && (unsigned long long)st.st_size == check_size;
+  if (match && config->checksum) {
+    uint64_t old_checksum = old_size == 0 ? delta_xxhash64("", 0) : 0;
+    if (old_data)
+      old_checksum = delta_xxhash64(old_data, (size_t)old_size);
+    match = (old_size == 0 || old_data) && old_checksum == check_checksum;
+    free(old_data);
+    old_data = NULL;
+  } else if (match) {
+    match = (long long)st.st_mtime == check_mtime;
+  }
+
+  if (match) {
+    free(old_data);
+    if (!send_status(fd, STATUS_OK)) {
+      free(full_path);
+      free(check_path);
+      return NULL;
+    }
+    free(full_path);
+    free(check_path);
+    *skipped = true;
+    return NULL;
+  }
+
+  bool try_delta = config->use_delta && has_old_file &&
+                   delta_should_attempt(old_size, check_size, config->delta_max_file_size);
+
+  if (try_delta) {
+    File* delta_file = receive_delta_file(fd, config, check_path, old_data, old_size);
+    old_data = NULL; /* receive_delta_file consumes the snapshot on every path */
+    if (delta_file) {
+      free(full_path);
+      free(check_path);
+      return delta_file;
+    }
+    free(old_data);
+    old_data = NULL;
+    try_delta = false;
+  }
+
+  if (!try_delta) {
+    if (!send_status(fd, STATUS_NEXT)) {
+      free(full_path);
+      free(check_path);
+      return NULL;
+    }
+  }
+
+  File* file = file_create(check_path);
+  free(check_path);
+  free(full_path);
+  if (file == NULL) {
+    send_status(fd, STATUS_ERROR);
+    return NULL;
+  }
+
+  if (config->use_metadata) {
+    int meta_ok = 1;
+    file->metadata = metadata_receive(fd, &meta_ok);
+    if (!meta_ok) {
+      file_destroy(file);
+      send_status(fd, STATUS_ERROR);
+      return NULL;
+    }
+  }
+
+  Data* file_data = receive_data(fd);
+  if (file_data == NULL) {
+    file_destroy(file);
+    send_status(fd, STATUS_ERROR);
+    return NULL;
+  }
+
+  if (config->use_compression) {
+    Data* uncompressed = data_decompress(file_data);
+    data_destroy(file_data);
+    if (uncompressed == NULL) {
+      file_destroy(file);
+      send_status(fd, STATUS_ERROR);
+      return NULL;
+    }
+    file_data = uncompressed;
+  }
+
+  data_destroy(file->data);
+  file->data = file_data;
+  return file;
+}
+
+bool to_disk(const char* path, const void* data, unsigned long long data_size, bool inplace,
+             bool sparse) {
  if (!path || (!data && data_size != 0) || has_path_traversal(path))
    return false;
  return file_store_write_secure(path, data, data_size, inplace, sparse, NULL);
 }

+bool file_send_sendfile(File* file, int file_descriptor, bool use_metadata, int compression_level,
+                        bool send_path) {
+  if (!file || !file->path || !file->data)
+    return false;
+  if (compression_level > 0)
+    return file_send_single_calls(file, file_descriptor, use_metadata, compression_level,
+                                  send_path);
+
+  if (send_path && !send_str(file_descriptor, file->path))
+    return false;
+  if (use_metadata && !metadata_send(file_descriptor, file->metadata))
+    return false;
+
+  int fd = open(file->path, O_RDONLY);
+  if (fd == -1) {
+    perror("Could not open file for sendfile");
+    return false;
+  }
+
+  unsigned long long file_size = file->data->size;
+  struct stat source_stat;
+  if (fstat(fd, &source_stat) != 0 || !S_ISREG(source_stat.st_mode) ||
+      (unsigned long long)source_stat.st_size < file_size) {
+    close(fd);
+    return false;
+  }
+  if (!send_n_data(file_descriptor, &file_size, sizeof(unsigned long long))) {
+    close(fd);
+    return false;
+  }
+
+  /* sendfile cannot encrypt TLS records.  Keep the framing identical but
+     route encrypted transfers through the deadline-aware IO layer. */
+  if (io_get_ssl() != NULL) {
+    unsigned char buffer[64 * 1024];
+    unsigned long long remaining = file_size;
+    bool ok = true;
+    while (remaining > 0) {
+      size_t want = remaining > sizeof(buffer) ? sizeof(buffer) : (size_t)remaining;
+      ssize_t got = read(fd, buffer, want);
+      if (got <= 0 || !send_n_data(file_descriptor, buffer, (size_t)got)) {
+        ok = false;
+        break;
+      }
+      remaining -= (unsigned long long)got;
+    }
+    close(fd);
+    return ok;
+  }
+
+  off_t offset = 0;
+  struct timespec deadline;
+  clock_gettime(CLOCK_MONOTONIC, &deadline);
+  deadline.tv_sec += 60;
+  while ((unsigned long long)offset < file_size) {
+    struct timespec now;
+    clock_gettime(CLOCK_MONOTONIC, &now);
+    long long remaining = (long long)(deadline.tv_sec - now.tv_sec) * 1000LL +
+                          (deadline.tv_nsec - now.tv_nsec) / 1000000LL;
+    if (remaining <= 0) {
+      close(fd);
+      return false;
+    }
+    struct pollfd pfd = {.fd = file_descriptor, .events = POLLOUT};
+    int timeout = remaining > INT_MAX ? INT_MAX : (int)remaining;
+    int polled = poll(&pfd, 1, timeout);
+    if (polled <= 0 || (pfd.revents & (POLLERR | POLLHUP | POLLNVAL))) {
+      close(fd);
+      return false;
+    }
+    ssize_t sent = sendfile(file_descriptor, fd, &offset, file_size - offset);
+    if (sent == -1) {
+      if (errno == EAGAIN || errno == EINTR)
+        continue;
+      perror("sendfile failed");
+      close(fd);
+      return false;
+    }
+    if (sent == 0) {
+      close(fd);
+      return false;
+    }
+  }
+
+  close(fd);
+  return true;
+}
+
+File* file_receive(const Config* config, int file_descriptor) {
+  char* path = receive_str(file_descriptor);
+  if (path == NULL)
+    return NULL;
+  if (path[0] == '\0' || has_path_traversal(path)) {
+    log_message(LOG_LEVEL_ERROR, "Invalid received file path: %s", path);
+    free(path);
+    return NULL;
+  }
+  File* file = file_create(path);
+  free(path);
+  if (file == NULL)
+    return NULL;
+  if (config->use_metadata) {
+    int meta_ok = 1;
+    file->metadata = metadata_receive(file_descriptor, &meta_ok);
+    if (!meta_ok) {
+      file_destroy(file);
+      return NULL;
+    }
+  }
+  Data* file_data = receive_data(file_descriptor);
+  if (file_data == NULL) {
+    file_destroy(file);
+    return NULL;
+  }
+  if (config->use_compression) {
+    Data* file_data_uncompressed = data_decompress(file_data);
+    data_destroy(file_data);
+    if (file_data_uncompressed == NULL) {
+      file_destroy(file);
+      return NULL;
+    }
+    file_data = file_data_uncompressed;
+  }
+  data_destroy(file->data);
+  file->data = file_data;
+  return file;
+}
+
 size_t file_content_to_buffer(File* file) {
  FILE* file_pointer = fopen(file->path, "rb");
  if (file_pointer == NULL) {
-    log_perror("Could not open the file!");
+    perror("Could not open the file!");
    return 0;
  }
  size_t bytes_read = fread(file->data->data, 1, file->data->size, file_pointer);
  if (bytes_read != (size_t)file->data->size) {
    fclose(file_pointer);
-    log_perror("Read unexpected number of bytes from File!");
+    perror("Read unexpected number of bytes from File!");
    return 0;
  }
  fclose(file_pointer);
  return bytes_read;
 }
+
+int receive_manifest(int fd, const Config* config, int* next_status) {
+  int received_status = STATUS_ERROR;
+  int* status_out = next_status ? next_status : &received_status;
+  int count;
+  if (!receive_int(fd, &count))
+    return -1;
+  if (count < 0 || count > MAX_MANIFEST_ENTRIES)
+    return -1;
+  ArrayList* manifest = array_list_create(free);
+  if (!manifest)
+    return -1;
+  size_t manifest_bytes = 0;
+  for (int i = 0; i < count; i++) {
+    char* s = receive_str(fd);
+    size_t entry_size = s ? strlen(s) : 0;
+    if (!s || s[0] == '\0' || s[0] == '/' || has_path_traversal(s) ||
+        entry_size > MAX_MANIFEST_BYTES - manifest_bytes ||
+        (manifest_bytes += entry_size) > MAX_MANIFEST_BYTES || !array_list_add(manifest, s)) {
+      free(s);
+      array_list_delete(manifest);
+      return -1;
+    }
+  }
+  if (!receive_status(fd, status_out)) {
+    array_list_delete(manifest);
+    return -1;
+  }
+  /* Deletion is a commit operation: never perform it until the sender has
+     completed the manifest frame successfully. */
+  if (*status_out != STATUS_FINISHED || !config->use_delete) {
+    array_list_delete(manifest);
+    return *status_out == STATUS_FINISHED ? 0 : -1;
+  }
+  fprintf(stderr, "Deleting files not in manifest...\n");
+  bool deletion_ok = delete_extras(config->receive_root_directory, manifest);
+  array_list_delete(manifest);
+  return deletion_ok ? 0 : -1;
+}
@@ -1,23 +1,45 @@
 #ifndef FILE_H
 #define FILE_H

-#include "file_send.h"
-#include "file_receive.h"
-#include "file_types.h"
+#include "config.h"
+#include "data.h"
 #include <stdbool.h>
-#include <stdint.h>
+#include <sys/stat.h>

-/* File/FileMetadata lifecycle and local disk helpers. */
+typedef enum { FILE_TYPE_REGULAR, FILE_TYPE_SYMLINK, FILE_TYPE_DIR } FileType;
+
+typedef struct {
+  mode_t mode;
+  uid_t uid;
+  gid_t gid;
+  time_t mtime_sec;
+  long mtime_nsec;
+} FileMetadata;
+
+typedef struct {
+  char* path;
+  Data* data;
+  FileMetadata* metadata;
+  bool skip;
+} File;

 File* file_create(const char* path);
 void file_destroy(void* item);
 bool file_load_data(File* file);
 bool file_checksum(File* file, uint64_t* checksum);
+File* file_receive(const Config* config, int file_descriptor);
+bool file_send_single_calls(File* file, int file_descriptor, bool use_metadata,
+                            int compression_level, bool send_path);
+bool file_send_sendfile(File* file, int file_descriptor, bool use_metadata, int compression_level,
+                        bool send_path);
 size_t file_content_to_buffer(File* file);
 FileMetadata* file_metadata_create(const struct stat* stats);
 void file_metadata_destroy(void* metadata);
-bool file_write_to_disk(const char* path, const void* data, unsigned long long data_size,
-                        bool inplace, bool sparse);
-bool file_set_authorized_root(int fd, const char* canonical_path);
+bool to_disk(const char* path, const void* data, unsigned long long data_size, bool inplace,
+             bool sparse);
+bool file_save_to_disk(const char* root_directory, const File* file, const Config* config);
+void file_set_authorized_root(int fd, const char* canonical_path);
+File* receive_incremental_check(int fd, const Config* config, bool* skipped);
+int receive_manifest(int fd, const Config* config, int* next_status);

 #endif
@@ -1,588 +0,0 @@
-#include <errno.h>
-#include <fcntl.h>
-#include <libgen.h>
-#include <stdio.h>
-#include <stdlib.h>
-#include <string.h>
-#include <sys/stat.h>
-#include <unistd.h>
-
-#include "array_list.h"
-#include "compression.h"
-#include "config.h"
-#include "data.h"
-#include "delta.h"
-#include "file.h"
-#include "file_store.h"
-#include "log.h"
-#include "metadata.h"
-#include "protocol.h"
-#include "utils.h"
-
-static bool path_is_within_root(const char* root, const char* path) {
-  size_t n = strlen(root);
-  return strncmp(root, path, n) == 0 && (path[n] == '\0' || path[n] == '/');
-}
-
-bool file_save_to_disk(const char* root_directory, const File* file, const Config* config) {
-  bool backup_enabled = config && config->backup;
-  bool inplace = config && config->inplace;
-  bool sparse = config && config->preserve_sparse;
-  const char* backup_suffix = (config && config->suffix) ? config->suffix : "~";
-  const char* backup_dir = (config && config->backup_dir) ? config->backup_dir : NULL;
-  const char* partial_dir = (config && config->partial_dir) ? config->partial_dir : NULL;
-  char *confined_backup = NULL, *confined_partial = NULL;
-
-  if (!file || !file->path || !file->data || has_path_traversal(file->path) ||
-      (backup_enabled &&
-       (!backup_suffix || backup_suffix[0] == '\0' || strchr(backup_suffix, '/') != NULL ||
-        strcmp(backup_suffix, ".") == 0 || strcmp(backup_suffix, "..") == 0))) {
-    log_message(LOG_LEVEL_ERROR, "Invalid file or path received");
-    return false;
-  }
-
-  /* These options arrive from the client.  They are names below the server
-     root, never independent filesystem roots. */
-  if ((backup_dir && (backup_dir[0] == '/' || has_path_traversal(backup_dir))) ||
-      (partial_dir && (partial_dir[0] == '/' || has_path_traversal(partial_dir))))
-    return false;
-  if (backup_dir && !(confined_backup = path_cat(root_directory, backup_dir)))
-    return false;
-  if (partial_dir && !(confined_partial = path_cat(root_directory, partial_dir))) {
-    free(confined_backup);
-    return false;
-  }
-
-  char* resolved_root = NULL;
-  const char* actual_root =
-      (partial_dir && config && config->partial) ? confined_partial : root_directory;
-  resolved_root = realpath(actual_root, NULL);
-  if (resolved_root == NULL) {
-    if (mkdir_r(actual_root)) {
-      resolved_root = realpath(actual_root, NULL);
-    }
-  }
-  if (resolved_root == NULL) {
-    log_message(LOG_LEVEL_ERROR, "Failed to resolve destination root: %s", actual_root);
-    free(confined_backup);
-    free(confined_partial);
-    return false;
-  }
-  char* resolved_base = realpath(root_directory, NULL);
-  if (resolved_base == NULL || !path_is_within_root(resolved_base, resolved_root)) {
-    free(resolved_base);
-    free(confined_backup);
-    free(confined_partial);
-    free(resolved_root);
-    return false;
-  }
-  free(resolved_base);
-
-  char* disk_path = path_cat(resolved_root, file->path);
-  if (disk_path == NULL) {
-    free(confined_backup);
-    free(confined_partial);
-    free(resolved_root);
-    return false;
-  }
-
-  /* --update is receiver-side policy: never replace a newer destination. */
-  if (config && config->update) {
-    struct stat destination_stat;
-    if (stat(disk_path, &destination_stat) == 0 && file->metadata &&
-        destination_stat.st_mtime > file->metadata->mtime_sec) {
-      free(resolved_root);
-      free(confined_backup);
-      free(confined_partial);
-      free(disk_path);
-      return true;
-    }
-  }
-
-  if (backup_enabled) {
-    struct stat backup_stat;
-    if (stat(disk_path, &backup_stat) == 0) {
-      char* backup_path = NULL;
-      if (backup_dir) {
-        char* resolved_backup_dir = realpath(confined_backup, NULL);
-        if (!resolved_backup_dir) {
-          mkdir_r(confined_backup);
-          resolved_backup_dir = realpath(confined_backup, NULL);
-        }
-        if (resolved_backup_dir) {
-          char* backup_base = realpath(root_directory, NULL);
-          if (backup_base && path_is_within_root(backup_base, resolved_backup_dir))
-            backup_path = path_cat(resolved_backup_dir, file->path);
-          free(backup_base);
-          free(resolved_backup_dir);
-        }
-      }
-      if (!backup_path) {
-        size_t path_len = strlen(disk_path);
-        size_t suffix_len = strlen(backup_suffix);
-        backup_path = malloc(path_len + suffix_len + 1);
-        if (backup_path) {
-          memcpy(backup_path, disk_path, path_len);
-          memcpy(backup_path + path_len, backup_suffix, suffix_len + 1);
-        }
-      }
-      if (backup_path) {
-        char* backup_dir_path = str_dup(backup_path);
-        if (backup_dir_path) {
-          const char* bdir = dirname(backup_dir_path);
-          mkdir_r(bdir);
-          free(backup_dir_path);
-        }
-        if (!file_store_rename_secure(disk_path, backup_path)) {
-          free(backup_path);
-          free(resolved_root);
-          free(confined_backup);
-          free(confined_partial);
-          free(disk_path);
-          return false;
-        }
-        free(backup_path);
-      }
-    }
-  }
-
-  char* dir_dup = str_dup(disk_path);
-  if (!dir_dup) {
-    free(confined_backup);
-    free(confined_partial);
-    free(resolved_root);
-    free(disk_path);
-    return false;
-  }
-  char* dir_str = dirname(dir_dup);
-  if (!mkdir_r(dir_str)) {
-    free(dir_dup);
-    free(confined_backup);
-    free(confined_partial);
-    free(resolved_root);
-    free(disk_path);
-    return false;
-  }
-  char* resolved_dir = realpath(dir_str, NULL);
-  free(dir_dup);
-  if (resolved_dir == NULL) {
-    log_message(LOG_LEVEL_ERROR, "Failed to resolve directory for: %s", disk_path);
-    free(confined_backup);
-    free(confined_partial);
-    free(resolved_root);
-    free(disk_path);
-    return false;
-  }
-
-  size_t root_len = strlen(resolved_root);
-  if (strncmp(resolved_dir, resolved_root, root_len) != 0 ||
-      (resolved_dir[root_len] != '\0' && resolved_dir[root_len] != '/')) {
-    log_message(LOG_LEVEL_ERROR, "Path escape detected: %s is outside %s", disk_path, actual_root);
-    free(resolved_dir);
-    free(confined_backup);
-    free(confined_partial);
-    free(resolved_root);
-    free(disk_path);
-    return false;
-  }
-  free(resolved_dir);
-  free(resolved_root);
-
-  bool ok = file_store_write_secure(disk_path, file->data->data, file->data->size, inplace, sparse,
-                                    file->metadata);
-  free(confined_backup);
-  free(confined_partial);
-  free(disk_path);
-  return ok;
-}
-
-static File* receive_delta_file(int fd, const Config* config, const char* check_path,
-                                void* old_data, unsigned long long old_size, bool* failed) {
-  if (!old_data)
-    return NULL;
-
-  DeltaSignature* sig = delta_signature_create(old_data, old_size, config->delta_block_size);
-  if (!sig) {
-    free(old_data);
-    *failed = true;
-    return NULL;
-  }
-
-  Data* sig_data = delta_signature_serialize(sig);
-  if (!sig_data) {
-    delta_signature_destroy(sig);
-    free(old_data);
-    *failed = true;
-    return NULL;
-  }
-
-  bool sig_sent = send_status(fd, STATUS_DELTA_SIGNATURE) && send_data(fd, sig_data);
-  data_destroy(sig_data);
-
-  if (!sig_sent) {
-    delta_signature_destroy(sig);
-    free(old_data);
-    *failed = true;
-    return NULL;
-  }
-
-  Status resp;
-  if (!receive_status(fd, &resp)) {
-    delta_signature_destroy(sig);
-    free(old_data);
-    *failed = true;
-    return NULL;
-  }
-
-  if (resp == STATUS_DELTA_DATA) {
-    Data* delta_data = receive_data(fd);
-    if (!delta_data) {
-      delta_signature_destroy(sig);
-      free(old_data);
-      *failed = true;
-      return NULL;
-    }
-
-    Data* raw_delta = delta_data;
-    if (config->use_compression) {
-      raw_delta = data_decompress(delta_data);
-      data_destroy(delta_data);
-      if (!raw_delta) {
-        free(old_data);
-        delta_signature_destroy(sig);
-        *failed = true;
-        return NULL;
-      }
-    }
-
-    Delta* delta = delta_deserialize(raw_delta);
-    data_destroy(raw_delta);
-    if (!delta) {
-      free(old_data);
-      delta_signature_destroy(sig);
-      *failed = true;
-      return NULL;
-    }
-
-    void* new_data = delta_apply(old_data, old_size, delta, config->delta_block_size);
-    uint64_t new_size = delta->new_file_size;
-    delta_destroy(delta);
-
-    if (!new_data) {
-      free(old_data);
-      delta_signature_destroy(sig);
-      *failed = true;
-      return NULL;
-    }
-
-    File* file = file_create(check_path);
-    if (!file) {
-      free(new_data);
-      free(old_data);
-      delta_signature_destroy(sig);
-      *failed = true;
-      return NULL;
-    }
-
-    if (config->use_metadata) {
-      int meta_ok = 1;
-      file->metadata = metadata_receive(fd, &meta_ok);
-      if (!meta_ok) {
-        file_destroy(file);
-        free(new_data);
-        free(old_data);
-        delta_signature_destroy(sig);
-        *failed = true;
-        return NULL;
-      }
-    }
-
-    data_destroy(file->data);
-    file->data = data_create(new_data, (size_t)new_size);
-
-    free(old_data);
-    delta_signature_destroy(sig);
-    return file;
-  }
-
-  if (resp == STATUS_NEXT) {
-    delta_signature_destroy(sig);
-    free(old_data);
-
-    File* file = file_create(check_path);
-    if (!file) {
-      *failed = true;
-      return NULL;
-    }
-
-    if (config->use_metadata) {
-      int meta_ok = 1;
-      file->metadata = metadata_receive(fd, &meta_ok);
-      if (!meta_ok) {
-        file_destroy(file);
-        *failed = true;
-        return NULL;
-      }
-    }
-
-    Data* file_data = receive_data(fd);
-    if (file_data == NULL) {
-      file_destroy(file);
-      *failed = true;
-      return NULL;
-    }
-
-    if (config->use_compression) {
-      Data* uncompressed = data_decompress(file_data);
-      data_destroy(file_data);
-      if (uncompressed == NULL) {
-        file_destroy(file);
-        *failed = true;
-        return NULL;
-      }
-      file_data = uncompressed;
-    }
-
-    data_destroy(file->data);
-    file->data = file_data;
-    return file;
-  }
-
-  delta_signature_destroy(sig);
-  free(old_data);
-  *failed = true;
-  return NULL;
-}
-
-File* receive_incremental_check(int fd, const Config* config, bool* skipped) {
-  *skipped = false;
-  char* check_path = receive_str(fd);
-  if (check_path == NULL) {
-    return NULL;
-  }
-
-  unsigned long long check_size;
-  long long check_mtime;
-  uint64_t check_checksum = 0;
-  if (!receive_n_data(fd, &check_size, sizeof(check_size)) ||
-      !receive_n_data(fd, &check_mtime, sizeof(check_mtime))) {
-    free(check_path);
-    return NULL;
-  }
-  if (config->checksum && !receive_n_data(fd, &check_checksum, sizeof(check_checksum))) {
-    free(check_path);
-    return NULL;
-  }
-
-  if (has_path_traversal(check_path)) {
-    log_message(LOG_LEVEL_ERROR, "Path traversal detected: %s", check_path);
-    free(check_path);
-    return NULL;
-  }
-
-  char* full_path = path_cat(config->receive_root_directory, check_path);
-  struct stat st;
-  bool has_old_file = false;
-  int old_fd = -1;
-  if (full_path) {
-    char* leaf = NULL;
-    int parent_fd = file_store_open_secure_parent(full_path, &leaf);
-    if (parent_fd >= 0) {
-      old_fd = openat(parent_fd, leaf, O_RDONLY | O_CLOEXEC | O_NOFOLLOW);
-      free(leaf);
-      close(parent_fd);
-      has_old_file = old_fd >= 0 && fstat(old_fd, &st) == 0 && S_ISREG(st.st_mode);
-    }
-  }
-  unsigned long long old_size = has_old_file ? (unsigned long long)st.st_size : 0;
-  void* old_data = NULL;
-  if (has_old_file && old_size > 0) {
-    old_data = malloc((size_t)old_size);
-    if (old_data) {
-      size_t got = 0;
-      while (got < (size_t)old_size) {
-        ssize_t n = read(old_fd, (char*)old_data + got, (size_t)old_size - got);
-        if (n <= 0) {
-          free(old_data);
-          old_data = NULL;
-          break;
-        }
-        got += (size_t)n;
-      }
-    }
-  }
-  if (old_fd >= 0) {
-    close(old_fd);
-  }
-
-  bool match = has_old_file && (unsigned long long)st.st_size == check_size;
-  if (match && config->checksum) {
-    uint64_t old_checksum = old_size == 0 ? delta_xxhash64("", 0) : 0;
-    if (old_data)
-      old_checksum = delta_xxhash64(old_data, (size_t)old_size);
-    match = (old_size == 0 || old_data) && old_checksum == check_checksum;
-    free(old_data);
-    old_data = NULL;
-  } else if (match) {
-    match = (long long)st.st_mtime == check_mtime;
-  }
-
-  if (match) {
-    free(old_data);
-    if (!send_status(fd, STATUS_OK)) {
-      free(full_path);
-      free(check_path);
-      return NULL;
-    }
-    free(full_path);
-    free(check_path);
-    *skipped = true;
-    return NULL;
-  }
-
-  bool try_delta = config->use_delta && has_old_file &&
-                   delta_should_attempt(old_size, check_size, config->delta_max_file_size);
-
-  if (try_delta) {
-    bool delta_failed = false;
-    File* delta_file =
-        receive_delta_file(fd, config, check_path, old_data, old_size, &delta_failed);
-    old_data = NULL; /* receive_delta_file consumes the snapshot on every path */
-    if (delta_file) {
-      free(full_path);
-      free(check_path);
-      return delta_file;
-    }
-    if (delta_failed) {
-      free(full_path);
-      free(check_path);
-      return NULL;
-    }
-    free(old_data);
-    old_data = NULL;
-    try_delta = false;
-  }
-
-  if (!try_delta) {
-    if (!send_status(fd, STATUS_NEXT)) {
-      free(full_path);
-      free(check_path);
-      return NULL;
-    }
-  }
-
-  File* file = file_create(check_path);
-  free(check_path);
-  free(full_path);
-  if (file == NULL) {
-    return NULL;
-  }
-
-  if (config->use_metadata) {
-    int meta_ok = 1;
-    file->metadata = metadata_receive(fd, &meta_ok);
-    if (!meta_ok) {
-      file_destroy(file);
-      return NULL;
-    }
-  }
-
-  Data* file_data = receive_data(fd);
-  if (file_data == NULL) {
-    file_destroy(file);
-    return NULL;
-  }
-
-  if (config->use_compression) {
-    Data* uncompressed = data_decompress(file_data);
-    data_destroy(file_data);
-    if (uncompressed == NULL) {
-      file_destroy(file);
-      return NULL;
-    }
-    file_data = uncompressed;
-  }
-
-  data_destroy(file->data);
-  file->data = file_data;
-  return file;
-}
-
-File* file_receive(const Config* config, int file_descriptor) {
-  char* path = receive_str(file_descriptor);
-  if (path == NULL)
-    return NULL;
-  if (path[0] == '\0' || has_path_traversal(path)) {
-    log_message(LOG_LEVEL_ERROR, "Invalid received file path: %s", path);
-    free(path);
-    return NULL;
-  }
-  File* file = file_create(path);
-  free(path);
-  if (file == NULL)
-    return NULL;
-  if (config->use_metadata) {
-    int meta_ok = 1;
-    file->metadata = metadata_receive(file_descriptor, &meta_ok);
-    if (!meta_ok) {
-      file_destroy(file);
-      return NULL;
-    }
-  }
-  Data* file_data = receive_data(file_descriptor);
-  if (file_data == NULL) {
-    file_destroy(file);
-    return NULL;
-  }
-  if (config->use_compression) {
-    Data* file_data_uncompressed = data_decompress(file_data);
-    data_destroy(file_data);
-    if (file_data_uncompressed == NULL) {
-      file_destroy(file);
-      return NULL;
-    }
-    file_data = file_data_uncompressed;
-  }
-  data_destroy(file->data);
-  file->data = file_data;
-  return file;
-}
-
-int receive_manifest(int fd, const Config* config, int* next_status) {
-  int received_status = STATUS_ERROR;
-  int* status_out = next_status ? next_status : &received_status;
-  int count;
-  if (!receive_int(fd, &count))
-    return -1;
-  if (count < 0 || count > MAX_MANIFEST_ENTRIES)
-    return -1;
-  ArrayList* manifest = array_list_create(free);
-  if (!manifest)
-    return -1;
-  size_t manifest_bytes = 0;
-  for (int i = 0; i < count; i++) {
-    char* s = receive_str(fd);
-    size_t entry_size = s ? strlen(s) : 0;
-    if (!s || s[0] == '\0' || s[0] == '/' || has_path_traversal(s) ||
-        entry_size > MAX_MANIFEST_BYTES - manifest_bytes ||
-        (manifest_bytes += entry_size) > MAX_MANIFEST_BYTES || !array_list_add(manifest, s)) {
-      free(s);
-      array_list_delete(manifest);
-      return -1;
-    }
-  }
-  if (!receive_status(fd, status_out)) {
-    array_list_delete(manifest);
-    return -1;
-  }
-  /* Deletion is a commit operation: never perform it until the sender has
-     completed the manifest frame successfully. */
-  if (*status_out != STATUS_FINISHED || !config->use_delete) {
-    array_list_delete(manifest);
-    return *status_out == STATUS_FINISHED ? 0 : -1;
-  }
-  fprintf(stderr, "Deleting files not in manifest...\n");
-  bool deletion_ok = delete_extras(config->receive_root_directory, manifest);
-  array_list_delete(manifest);
-  return deletion_ok ? 0 : -1;
-}
@@ -1,15 +0,0 @@
-#ifndef FILE_RECEIVE_H
-#define FILE_RECEIVE_H
-
-#include "config.h"
-#include "file_types.h"
-#include <stdbool.h>
-
-/* Server-side file receive/save path. */
-
-File* file_receive(const Config* config, int file_descriptor);
-File* receive_incremental_check(int fd, const Config* config, bool* skipped);
-int receive_manifest(int fd, const Config* config, int* next_status);
-bool file_save_to_disk(const char* root_directory, const File* file, const Config* config);
-
-#endif
@@ -1,136 +0,0 @@
-#include <errno.h>
-#include <fcntl.h>
-#include <limits.h>
-#include <poll.h>
-#include <stdio.h>
-#include <stdlib.h>
-#include <string.h>
-#include <sys/sendfile.h>
-#include <sys/stat.h>
-#include <time.h>
-#include <unistd.h>
-
-#include "compression.h"
-#include "data.h"
-#include "file.h"
-#include "log.h"
-#include "metadata.h"
-#include "protocol.h"
-
-bool file_send_single_calls(File* file, int file_descriptor, bool use_metadata,
-                            int compression_level, bool send_path) {
-  if (!file || !file->path || !file->data)
-    return false;
-  const Data* data_to_send = file->data;
-  Data* compressed_data = NULL;
-  if (compression_level > 0 && !compression_should_skip(file->path)) {
-    compressed_data = data_compress(file->data, compression_level);
-    if (compressed_data == NULL) {
-      log_message(LOG_LEVEL_ERROR, "Failed to compress file data");
-      return false;
-    }
-    data_to_send = compressed_data;
-  }
-  if (send_path && !send_str(file_descriptor, file->path)) {
-    data_destroy(compressed_data);
-    return false;
-  }
-  if (use_metadata && !metadata_send(file_descriptor, file->metadata)) {
-    data_destroy(compressed_data);
-    return false;
-  }
-  if (!send_data(file_descriptor, data_to_send)) {
-    data_destroy(compressed_data);
-    return false;
-  }
-  data_destroy(compressed_data);
-  return true;
-}
-
-bool file_send_sendfile(File* file, int file_descriptor, bool use_metadata, int compression_level,
-                        bool send_path) {
-  if (!file || !file->path || !file->data)
-    return false;
-  if (compression_level > 0)
-    return file_send_single_calls(file, file_descriptor, use_metadata, compression_level,
-                                  send_path);
-
-  if (send_path && !send_str(file_descriptor, file->path))
-    return false;
-  if (use_metadata && !metadata_send(file_descriptor, file->metadata))
-    return false;
-
-  int fd = open(file->path, O_RDONLY);
-  if (fd == -1) {
-    log_perror("Could not open file for sendfile");
-    return false;
-  }
-
-  unsigned long long file_size = file->data->size;
-  struct stat source_stat;
-  if (fstat(fd, &source_stat) != 0 || !S_ISREG(source_stat.st_mode) ||
-      (unsigned long long)source_stat.st_size < file_size) {
-    close(fd);
-    return false;
-  }
-  if (!send_n_data(file_descriptor, &file_size, sizeof(unsigned long long))) {
-    close(fd);
-    return false;
-  }
-
-  /* sendfile cannot encrypt TLS records.  Keep the framing identical but
-     route encrypted transfers through the deadline-aware IO layer. */
-  if (io_get_ssl() != NULL) {
-    unsigned char buffer[64 * 1024];
-    unsigned long long remaining = file_size;
-    bool ok = true;
-    while (remaining > 0) {
-      size_t want = remaining > sizeof(buffer) ? sizeof(buffer) : (size_t)remaining;
-      ssize_t got = read(fd, buffer, want);
-      if (got <= 0 || !send_n_data(file_descriptor, buffer, (size_t)got)) {
-        ok = false;
-        break;
-      }
-      remaining -= (unsigned long long)got;
-    }
-    close(fd);
-    return ok;
-  }
-
-  off_t offset = 0;
-  struct timespec deadline;
-  clock_gettime(CLOCK_MONOTONIC, &deadline);
-  deadline.tv_sec += 60;
-  while ((unsigned long long)offset < file_size) {
-    struct timespec now;
-    clock_gettime(CLOCK_MONOTONIC, &now);
-    long long remaining = (long long)(deadline.tv_sec - now.tv_sec) * 1000LL +
-                          (deadline.tv_nsec - now.tv_nsec) / 1000000LL;
-    if (remaining <= 0) {
-      close(fd);
-      return false;
-    }
-    struct pollfd pfd = {.fd = file_descriptor, .events = POLLOUT};
-    int timeout = remaining > INT_MAX ? INT_MAX : (int)remaining;
-    int polled = poll(&pfd, 1, timeout);
-    if (polled <= 0 || (pfd.revents & (POLLERR | POLLHUP | POLLNVAL))) {
-      close(fd);
-      return false;
-    }
-    ssize_t sent = sendfile(file_descriptor, fd, &offset, file_size - offset);
-    if (sent == -1) {
-      if (errno == EAGAIN || errno == EINTR)
-        continue;
-      log_perror("sendfile failed");
-      close(fd);
-      return false;
-    }
-    if (sent == 0) {
-      close(fd);
-      return false;
-    }
-  }
-
-  close(fd);
-  return true;
-}
@@ -1,14 +0,0 @@
-#ifndef FILE_SEND_H
-#define FILE_SEND_H
-
-#include "file_types.h"
-#include <stdbool.h>
-
-/* Client-side file send path. */
-
-bool file_send_single_calls(File* file, int file_descriptor, bool use_metadata,
-                            int compression_level, bool send_path);
-bool file_send_sendfile(File* file, int file_descriptor, bool use_metadata, int compression_level,
-                        bool send_path);
-
-#endif
@@ -20,14 +20,10 @@ static bool path_is_within_root(const char* root, const char* path) {
         (path[root_length] == '\0' || path[root_length] == '/');
 }

-bool file_store_set_authorized_root(int fd, const char* canonical_path) {
-  char* new_path = canonical_path ? str_dup(canonical_path) : NULL;
-  if (canonical_path && !new_path)
-    return false;
-  free(authorized_root_path);
-  authorized_root_path = new_path;
+void file_store_set_authorized_root(int fd, const char* canonical_path) {
  authorized_root_fd = fd;
-  return true;
+  free(authorized_root_path);
+  authorized_root_path = canonical_path ? str_dup(canonical_path) : NULL;
 }

 int file_store_open_secure_parent(const char* path, char** leaf_out) {
@@ -134,20 +130,9 @@ bool file_store_write_secure(const char* path, const void* data, unsigned long l
        ok = file_restore_metadata_fd(fd, metadata);
    }
  } else {
-    int tmp_size = snprintf(NULL, 0, ".%s.tmp.%ld.%u", leaf, (long)getpid(), 99U);
-    if (tmp_size < 0) {
-      close(dirfd);
-      free(leaf);
-      return false;
-    }
-    char* tmp = malloc((size_t)tmp_size + 1);
-    if (!tmp) {
-      close(dirfd);
-      free(leaf);
-      return false;
-    }
+    char tmp[NAME_MAX];
    for (unsigned int i = 0; i < 100 && !ok; ++i) {
-      snprintf(tmp, (size_t)tmp_size + 1, ".%s.tmp.%ld.%u", leaf, (long)getpid(), i);
+      snprintf(tmp, sizeof(tmp), ".%s.tmp.%ld.%u", leaf, (long)getpid(), i);
      fd = openat(dirfd, tmp, O_WRONLY | O_CREAT | O_EXCL | O_CLOEXEC | O_NOFOLLOW, 0600);
      if (fd < 0)
        continue;
@@ -165,7 +150,6 @@ bool file_store_write_secure(const char* path, const void* data, unsigned long l
      if (!ok)
        unlinkat(dirfd, tmp, 0);
    }
-    free(tmp);
  }
  if (fd >= 0)
    close(fd);
@@ -4,7 +4,7 @@
 #include "file.h"
 #include <stdbool.h>

-bool file_store_set_authorized_root(int fd, const char* canonical_path);
+void file_store_set_authorized_root(int fd, const char* canonical_path);
 int file_store_open_secure_parent(const char* path, char** leaf_out);
 bool file_store_rename_secure(const char* old_path, const char* new_path);
 bool file_store_write_secure(const char* path, const void* data, unsigned long long data_size,
@@ -1,25 +0,0 @@
-#ifndef FILE_TYPES_H
-#define FILE_TYPES_H
-
-#include "data.h"
-#include <stdbool.h>
-#include <sys/stat.h>
-
-typedef enum { FILE_TYPE_REGULAR, FILE_TYPE_SYMLINK, FILE_TYPE_DIR } FileType;
-
-typedef struct {
-  mode_t mode;
-  uid_t uid;
-  gid_t gid;
-  time_t mtime_sec;
-  long mtime_nsec;
-} FileMetadata;
-
-typedef struct {
-  char* path;
-  Data* data;
-  FileMetadata* metadata;
-  bool skip;
-} File;
-
-#endif
@@ -1,8 +1,6 @@
 #include "log.h"
-#include <errno.h>
 #include <stdarg.h>
 #include <stdio.h>
-#include <string.h>
 #include <time.h>

 static const char* log_level_strings[] = {"DEBUG", "INFO", "WARN", "ERROR"};
@@ -52,7 +50,3 @@ void log_message(LogLevel log_level, const char* format, ...) {
    va_end(args);
  }
 }
-
-void log_perror(const char* context) {
-  log_message(LOG_LEVEL_ERROR, "%s: %s", context, strerror(errno));
-}
@@ -6,7 +6,6 @@
 typedef enum { LOG_LEVEL_DEBUG, LOG_LEVEL_INFO, LOG_LEVEL_WARNING, LOG_LEVEL_ERROR } LogLevel;

 void log_message(LogLevel log_level, const char* message, ...);
-void log_perror(const char* context);
 void set_log_level(LogLevel level);
 void log_set_file(FILE* fp);

@@ -55,7 +55,7 @@ PipelineContextSender* pipeline_context_sender_create(Config* config, Queue* que
  return context;

 fail:
-  log_perror("Error initializing synchronization objects");
+  perror("Error initializing synchronization objects");
  if (init >= 6)
    cnd_destroy(&context->condition_not_empty_loader);
  if (init >= 5)
@@ -116,7 +116,7 @@ PipelineContextReceiver* pipeline_context_receiver_create(Config* config, Queue*
  return context;

 fail:
-  log_perror("Error initializing synchronization objects");
+  perror("Error initializing synchronization objects");
  if (init >= 3)
    cnd_destroy(&context->condition_not_empty);
  if (init >= 2)
@@ -183,15 +183,6 @@ int write_thread(void* pipeline_context) {
  bool save_to_disk = context->config->save_to_disk;
  char* root_directory = str_dup(context->config->receive_root_directory);
  mtx_unlock(&context->mutex);
-  if (save_to_disk && !root_directory) {
-    mtx_lock(&context->mutex);
-    atomic_store(&context->cancelled, true);
-    context->receiver_done = true;
-    cnd_broadcast(&context->condition_not_full);
-    cnd_broadcast(&context->condition_not_empty);
-    mtx_unlock(&context->mutex);
-    return thrd_error;
-  }

  while (true) {
    File* file =
@@ -19,7 +19,6 @@ static __thread int io_read_fd = -1;
 static __thread int io_write_fd = -1;
 static __thread SSL* io_ssl;
 static __thread ProtocolSession* bound_session;
-static __thread ProtocolSession legacy_io_session = {.read_fd = -1, .write_fd = -1};

 static unsigned long long io_bwlimit = 0;
 static long long bw_tokens = 0;
@@ -27,6 +26,8 @@ static struct timespec bw_last_refill = {0, 0};
 static mtx_t bw_mutex;
 static once_flag bw_mutex_once = ONCE_FLAG_INIT;

+static __thread unsigned long long total_allocated_bytes = 0;
+
 void io_set_fds(int read_fd, int write_fd) {
  bound_session = NULL;
  io_read_fd = read_fd;
@@ -34,11 +35,7 @@ void io_set_fds(int read_fd, int write_fd) {
  /* A descriptor switch starts a new transport; never reuse a TLS object
     belonging to a previous connection or test pipe. */
  io_ssl = NULL;
-  legacy_io_session.read_fd = read_fd;
-  legacy_io_session.write_fd = write_fd;
-  legacy_io_session.ssl = NULL;
-  legacy_io_session.total_allocated_bytes = 0;
-  protocol_session_set_bwlimit(&legacy_io_session, io_bwlimit);
+  total_allocated_bytes = 0;
 }

 void protocol_session_init(ProtocolSession* session, int read_fd, int write_fd) {
@@ -129,30 +126,32 @@ SSL* io_get_ssl(void) {
  return io_ssl;
 }

-static ProtocolSession* legacy_session(int read_fd, int write_fd) {
+static ProtocolSession* legacy_session(void) {
+  static __thread ProtocolSession session;
  if (bound_session)
    return bound_session;
-  int target_read_fd = io_read_fd != -1 ? io_read_fd : read_fd;
-  int target_write_fd = io_write_fd != -1 ? io_write_fd : write_fd;
-  if (legacy_io_session.read_fd != target_read_fd ||
-      legacy_io_session.write_fd != target_write_fd) {
-    legacy_io_session.read_fd = target_read_fd;
-    legacy_io_session.write_fd = target_write_fd;
-    legacy_io_session.total_allocated_bytes = 0;
-    protocol_session_set_bwlimit(&legacy_io_session, io_bwlimit);
-  } else if (legacy_io_session.bwlimit != io_bwlimit) {
-    protocol_session_set_bwlimit(&legacy_io_session, io_bwlimit);
-  }
-  legacy_io_session.ssl = io_ssl;
-  return &legacy_io_session;
+  session.read_fd = io_read_fd;
+  session.write_fd = io_write_fd;
+  session.ssl = io_ssl;
+  session.bwlimit = io_bwlimit;
+  session.bw_tokens = (unsigned long long)(bw_tokens < 0 ? 0 : bw_tokens);
+  session.bw_last_refill_sec = bw_last_refill.tv_sec;
+  session.bw_last_refill_nsec = bw_last_refill.tv_nsec;
+  return &session;
 }

 bool send_n_data(int file_descriptor, const void* data, size_t data_size) {
-  return protocol_send_n_data(legacy_session(-1, file_descriptor), data, data_size);
+  ProtocolSession* session = legacy_session();
+  if (session->write_fd == -1)
+    session->write_fd = file_descriptor;
+  return protocol_send_n_data(session, data, data_size);
 }

 bool receive_n_data(int file_descriptor, void* data, size_t data_size) {
-  return protocol_receive_n_data(legacy_session(file_descriptor, -1), data, data_size);
+  ProtocolSession* session = legacy_session();
+  if (session->read_fd == -1)
+    session->read_fd = file_descriptor;
+  return protocol_receive_n_data(session, data, data_size);
 }

 static int deadline_remaining_ms(const struct timespec* deadline) {
@@ -404,26 +403,34 @@ bool protocol_receive_status(ProtocolSession* session, Status* status) {
 }

 bool send_str(int fd, const char* data) {
-  return protocol_send_str(legacy_session(-1, fd), data);
+  (void)fd;
+  return protocol_send_str(legacy_session(), data);
 }
 char* receive_str(int fd) {
-  return protocol_receive_str(legacy_session(fd, -1));
+  (void)fd;
+  return protocol_receive_str(legacy_session());
 }
 bool send_data(int fd, const Data* data) {
-  return protocol_send_data(legacy_session(-1, fd), data);
+  (void)fd;
+  return protocol_send_data(legacy_session(), data);
 }
 Data* receive_data(int fd) {
-  return protocol_receive_data(legacy_session(fd, -1));
+  (void)fd;
+  return protocol_receive_data(legacy_session());
 }
 bool send_int(int fd, int data) {
-  return protocol_send_int(legacy_session(-1, fd), data);
+  (void)fd;
+  return protocol_send_int(legacy_session(), data);
 }
 bool receive_int(int fd, int* data) {
-  return protocol_receive_int(legacy_session(fd, -1), data);
+  (void)fd;
+  return protocol_receive_int(legacy_session(), data);
 }
 bool send_status(int fd, Status status) {
-  return protocol_send_status(legacy_session(-1, fd), status);
+  (void)fd;
+  return protocol_send_status(legacy_session(), status);
 }
 bool receive_status(int fd, Status* status) {
-  return protocol_receive_status(legacy_session(fd, -1), status);
+  (void)fd;
+  return protocol_receive_status(legacy_session(), status);
 }
@@ -1,4 +1,3 @@
-#include "log.h"
 #include <stdbool.h>
 #include <limits.h>
 #include <stdio.h>
@@ -14,7 +13,7 @@ Queue* queue_create(int capacity, void (*destroyer)(void* item)) {

  Queue* queue = (Queue*)malloc(sizeof(Queue));
  if (queue == NULL) {
-    log_perror("ERROR: Could not allocate memory for queue structure");
+    perror("ERROR: Could not allocate memory for queue structure");
    return NULL;
  }

@@ -73,7 +72,7 @@ static bool queue_double_capacity(Queue* queue) {
    new_capacity = 100;
  void** new_items = malloc(new_capacity * sizeof(void*));
  if (new_items == NULL) {
-    log_perror("ERROR: Could not allocate memory for doubling capacity of queue.");
+    perror("ERROR: Could not allocate memory for doubling capacity of queue.");
    return false;
  }
  for (int i = 0; i < queue->size; i++)
@@ -128,7 +127,7 @@ bool queue_enqueue_multithreaded_cancel(Queue* queue, void* item, mtx_t* mutex,

 void* queue_dequeue(Queue* queue) {
  if (queue == NULL || queue_is_empty(queue)) {
-    log_perror("ERROR: Could not dequeue from null or empty queue.");
+    perror("ERROR: Could not dequeue from null or empty queue.");
    return NULL;
  }

@@ -1,4 +1,3 @@
-#include "log.h"
 #include "transport_ssh.h"
 #include "utils.h"
 #include <fcntl.h>
@@ -77,7 +76,7 @@ Client* client_connect_ssh(const char* destination, int port, const char* server

  int sv[2];
  if (socketpair(AF_UNIX, SOCK_STREAM, 0, sv) < 0) {
-    log_perror("socketpair failed");
+    perror("socketpair failed");
    remote_dest_destroy(&r);
    return NULL;
  }
@@ -90,7 +89,7 @@ Client* client_connect_ssh(const char* destination, int port, const char* server

  int exec_pipe[2];
  if (pipe(exec_pipe) < 0) {
-    log_perror("pipe failed");
+    perror("pipe failed");
    close(sv[0]);
    close(sv[1]);
    remote_dest_destroy(&r);
@@ -99,7 +98,7 @@ Client* client_connect_ssh(const char* destination, int port, const char* server

  pid_t pid = fork();
  if (pid < 0) {
-    log_perror("fork failed");
+    perror("fork failed");
    close(sv[0]);
    close(sv[1]);
    close(exec_pipe[0]);
@@ -152,7 +151,7 @@ Client* client_connect_ssh(const char* destination, int port, const char* server
    ssh_argv[ac++] = "--stdio";
    ssh_argv[ac] = NULL;
    execvp("ssh", ssh_argv);
-    log_perror("exec of ssh failed");
+    perror("exec of ssh failed");
    ssize_t wret = write(exec_pipe[1], "x", 1);
    (void)wret;
    _exit(1);
@@ -30,20 +30,20 @@ static void sigchld_handler(int sig) {
 Server* server_create(int port) {
  Server* server = (Server*)malloc(sizeof(Server));
  if (server == NULL) {
-    log_perror("Could not allocate space for Server");
+    perror("Could not allocate space for Server");
    return NULL;
  }

  int file_descriptor = socket(AF_INET, SOCK_STREAM, 0);
  if (file_descriptor < 0) {
-    log_perror("Could not create Socket!");
+    perror("Could not create Socket!");
    free(server);
    return NULL;
  }
  server->file_descriptor = file_descriptor;
  int opt = 1;
  if (setsockopt(server->file_descriptor, SOL_SOCKET, SO_REUSEADDR, &opt, sizeof(opt))) {
-    log_perror("Error setting a socket option!");
+    perror("Error setting a socket option!");
    close(server->file_descriptor);
    free(server);
    return NULL;
@@ -59,7 +59,7 @@ Server* server_create(int port) {

  if (bind(server->file_descriptor, (struct sockaddr*)&server->address, server->address_length) <
      0) {
-    log_perror("Could not bind server");
+    perror("Could not bind server");
    close(server->file_descriptor);
    free(server);
    return NULL;
@@ -83,7 +83,7 @@ void server_delete(Server** server) {
 static void accept_loop(Server* server, void (*child_fn)(int, void*), void* child_ctx,
                        const char* log_fmt) {
  if (listen(server->file_descriptor, SOMAXCONN) < 0) {
-    log_perror("Could not listen on port!");
+    perror("Could not listen on port!");
    return;
  }
  signal(SIGCHLD, sigchld_handler);
@@ -92,7 +92,7 @@ static void accept_loop(Server* server, void (*child_fn)(int, void*), void* chil
    socklen_t client_len = sizeof(client_addr);
    int fd = accept(server->file_descriptor, (struct sockaddr*)&client_addr, &client_len);
    if (fd < 0) {
-      log_perror("Could not accept the connection");
+      perror("Could not accept the connection");
      continue;
    }
    tcp_apply_socket_timeout(fd);
@@ -151,10 +151,6 @@ int tcp_get_contimeout_sec(void) {
  return g_contimeout_sec;
 }

-int tcp_get_timeout_sec(void) {
-  return g_timeout_sec;
-}
-
 static void tcp_apply_socket_timeout(int fd) {
  struct timeval tv;
  tv.tv_sec = g_timeout_sec;
@@ -222,7 +218,7 @@ bool tcp_connect_socket(Client* client, char* host, int port) {
  freeaddrinfo(result);

  if (!connected) {
-    log_perror("Could not connect to Server!");
+    perror("Could not connect to Server!");
    return false;
  }

@@ -35,6 +35,5 @@ void client_disconnect(Client* client);
 void client_delete(Client* client);
 void tcp_set_timeouts(int timeout_sec, int contimeout_sec);
 int tcp_get_contimeout_sec(void);
-int tcp_get_timeout_sec(void);

 #endif
@@ -9,7 +9,6 @@
 #include <stdio.h>
 #include <stdlib.h>
 #include <string.h>
-#include <time.h>
 #include <unistd.h>

 bool tls_global_init(void) {
@@ -93,7 +92,6 @@ static SSL* wrap_fd_with_ssl(int fd, SSL_CTX* ctx, bool is_server, const char* h
  }

  // Retry SSL_accept/SSL_connect on WANT_READ/WANT_WRITE (non-blocking handshake)
-  time_t deadline = time(NULL) + (is_server ? tcp_get_timeout_sec() : tcp_get_contimeout_sec());
  int ret;
  do {
    if (is_server)
@@ -103,8 +101,7 @@ static SSL* wrap_fd_with_ssl(int fd, SSL_CTX* ctx, bool is_server, const char* h

    if (ret <= 0) {
      int ssl_err = SSL_get_error(ssl, ret);
-      if ((ssl_err == SSL_ERROR_WANT_READ || ssl_err == SSL_ERROR_WANT_WRITE) &&
-          time(NULL) < deadline)
+      if (ssl_err == SSL_ERROR_WANT_READ || ssl_err == SSL_ERROR_WANT_WRITE)
        continue;
      log_message(LOG_LEVEL_ERROR, "SSL %s failed", is_server ? "accept" : "connect");
      log_ssl_errors();
@@ -1,4 +1,3 @@
-#include "log.h"
 #include "utils.h"
 #include "array_list.h"
 #include "libgen.h"
@@ -55,7 +54,7 @@ bool mkdir_r(const char* path) {
    struct stat st;
    if (stat(path_current, &st) != 0) {
      if (mkdir(path_current, 0755) != 0) {
-        log_perror("Could not create directory");
+        perror("Could not create directory");
        ok = false;
        break;
      }
@@ -11,7 +11,7 @@ static void test_file_operations() {
  char* test_content = "Hello, Chunk System!";
  unsigned long long test_len = strlen(test_content);

-  file_write_to_disk(test_path, test_content, test_len, false, false);
+  to_disk(test_path, test_content, test_len, false, false);

  File* f = file_create(test_path);
  EXPECT_NOT_NULL(f);
@@ -43,8 +43,8 @@ static void test_chunk_operations() {
  char* content2 = "chunk item number 2";
  unsigned long long len2 = strlen(content2);

-  file_write_to_disk(path1, content1, len1, false, false);
-  file_write_to_disk(path2, content2, len2, false, false);
+  to_disk(path1, content1, len1, false, false);
+  to_disk(path2, content2, len2, false, false);

  struct stat st1, st2;
  stat(path1, &st1);
@@ -62,8 +62,8 @@ static void test_chunk_compress_decompress_roundtrip() {
  char* content2 = "chunk compression test file 2 with more data";
  unsigned long long len2 = strlen(content2);

-  file_write_to_disk(path1, content1, len1, false, false);
-  file_write_to_disk(path2, content2, len2, false, false);
+  to_disk(path1, content1, len1, false, false);
+  to_disk(path2, content2, len2, false, false);

  struct stat st1, st2;
  EXPECT_EQ_INT(stat(path1, &st1), 0);
@@ -244,26 +244,26 @@ static void test_config_receive_truncated() {
  close(p[1]);
 }

-static void test_config_is_remote_dest() {
+static void test_is_remote_dest() {
  /* Valid SSH-style destinations */
-  EXPECT_TRUE(config_is_remote_dest("user@host:/path"));
-  EXPECT_TRUE(config_is_remote_dest("host:/path"));
-  EXPECT_TRUE(config_is_remote_dest("user@192.168.1.1:/remote/path"));
+  EXPECT_TRUE(is_remote_dest("user@host:/path"));
+  EXPECT_TRUE(is_remote_dest("host:/path"));
+  EXPECT_TRUE(is_remote_dest("user@192.168.1.1:/remote/path"));

  /* Invalid destinations */
-  EXPECT_FALSE(config_is_remote_dest(NULL));
-  EXPECT_FALSE(config_is_remote_dest(""));
-  EXPECT_FALSE(config_is_remote_dest(":"));
-  EXPECT_FALSE(config_is_remote_dest("/local/path"));
-  EXPECT_FALSE(config_is_remote_dest("relative/path"));
+  EXPECT_FALSE(is_remote_dest(NULL));
+  EXPECT_FALSE(is_remote_dest(""));
+  EXPECT_FALSE(is_remote_dest(":"));
+  EXPECT_FALSE(is_remote_dest("/local/path"));
+  EXPECT_FALSE(is_remote_dest("relative/path"));
  /* C:/windows/path is treated as remote (colon with no preceding slash) */
-  EXPECT_TRUE(config_is_remote_dest("C:/windows/path"));
+  EXPECT_TRUE(is_remote_dest("C:/windows/path"));

  /* Edge cases */
-  EXPECT_FALSE(config_is_remote_dest("noslash"));
-  EXPECT_FALSE(config_is_remote_dest("/"));
-  EXPECT_TRUE(config_is_remote_dest("host:"));
-  EXPECT_TRUE(config_is_remote_dest("user@host:"));
+  EXPECT_FALSE(is_remote_dest("noslash"));
+  EXPECT_FALSE(is_remote_dest("/"));
+  EXPECT_TRUE(is_remote_dest("host:"));
+  EXPECT_TRUE(is_remote_dest("user@host:"));
 }

 void test_config() {
@@ -278,5 +278,5 @@ void test_config() {
    test_config_send_receive_version_mismatch();
    test_config_receive_truncated();
  }
-  test_config_is_remote_dest();
+  test_is_remote_dest();
 }
@@ -34,8 +34,7 @@ static void test_file_destroy_normal() {

 static void test_file_load_data() {
  const char* content = "Hello Load Test";
-  EXPECT_TRUE(
-      file_write_to_disk("test_file_load_data.txt", content, strlen(content), false, false));
+  EXPECT_TRUE(to_disk("test_file_load_data.txt", content, strlen(content), false, false));

  struct stat st;
  EXPECT_EQ_INT(stat("test_file_load_data.txt", &st), 0);
@@ -88,16 +87,15 @@ static void test_file_save_to_disk() {
  rmdir("test_save_tmp");
 }

-static void test_file_write_to_disk_basic() {
-  const char* content = "Basic file_write_to_disk test";
-  EXPECT_TRUE(file_write_to_disk("test_file_write_to_disk_basic.txt", content, strlen(content),
-                                 false, false));
+static void test_to_disk_basic() {
+  const char* content = "Basic to_disk test";
+  EXPECT_TRUE(to_disk("test_to_disk_basic.txt", content, strlen(content), false, false));

  struct stat st;
-  EXPECT_EQ_INT(stat("test_file_write_to_disk_basic.txt", &st), 0);
+  EXPECT_EQ_INT(stat("test_to_disk_basic.txt", &st), 0);
  EXPECT_EQ_INT((int)st.st_size, (int)strlen(content));

-  FILE* fp = fopen("test_file_write_to_disk_basic.txt", "rb");
+  FILE* fp = fopen("test_to_disk_basic.txt", "rb");
  EXPECT_NOT_NULL(fp);
  char buf[100];
  size_t nread = fread(buf, 1, sizeof(buf), fp);
@@ -105,13 +103,12 @@ static void test_file_write_to_disk_basic() {
  EXPECT_EQ_INT((int)nread, (int)strlen(content));
  EXPECT_EQ_INT(memcmp(buf, content, strlen(content)), 0);

-  unlink("test_file_write_to_disk_basic.txt");
+  unlink("test_to_disk_basic.txt");
 }

-static void test_file_write_to_disk_creates_dirs() {
+static void test_to_disk_creates_dirs() {
  const char* content = "Nested dir test";
-  EXPECT_TRUE(file_write_to_disk("test_nested_tmp/nested/file.txt", content, strlen(content), false,
-                                 false));
+  EXPECT_TRUE(to_disk("test_nested_tmp/nested/file.txt", content, strlen(content), false, false));

  struct stat st;
  EXPECT_EQ_INT(stat("test_nested_tmp/nested/file.txt", &st), 0);
@@ -129,15 +126,15 @@ static void test_file_write_to_disk_creates_dirs() {
  rmdir("test_nested_tmp");
 }

-static void test_file_write_to_disk_does_not_follow_symlink() {
-  const char* outside = "test_file_write_to_disk_outside.txt";
-  const char* link = "test_file_write_to_disk_link.txt";
+static void test_to_disk_does_not_follow_symlink() {
+  const char* outside = "test_to_disk_outside.txt";
+  const char* link = "test_to_disk_link.txt";
  const char* content = "confined";
  unlink(outside);
  unlink(link);
-  EXPECT_TRUE(file_write_to_disk(outside, "outside", 7, false, false));
+  EXPECT_TRUE(to_disk(outside, "outside", 7, false, false));
  EXPECT_EQ_INT(symlink(outside, link), 0);
-  EXPECT_TRUE(file_write_to_disk(link, content, strlen(content), false, false));
+  EXPECT_TRUE(to_disk(link, content, strlen(content), false, false));
  FILE* fp = fopen(outside, "rb");
  char buf[16] = {0};
  EXPECT_NOT_NULL(fp);
@@ -154,7 +151,7 @@ static void test_file_write_to_disk_does_not_follow_symlink() {

 static void test_file_content_to_buffer() {
  const char* content = "Buffer content test";
-  EXPECT_TRUE(file_write_to_disk("test_buffer_file.txt", content, strlen(content), false, false));
+  EXPECT_TRUE(to_disk("test_buffer_file.txt", content, strlen(content), false, false));

  File* f = file_create("test_buffer_file.txt");
  EXPECT_NOT_NULL(f);
@@ -276,7 +273,7 @@ static void test_file_send_no_path() {
 }

 static void test_file_metadata_create() {
-  EXPECT_TRUE(file_write_to_disk("test_meta_file.txt", "metadata test", 13, false, false));
+  EXPECT_TRUE(to_disk("test_meta_file.txt", "metadata test", 13, false, false));
  struct stat st;
  EXPECT_EQ_INT(stat("test_meta_file.txt", &st), 0);

@@ -385,7 +382,7 @@ static void test_file_send_single_calls_metadata_and_path() {
  /* Create a real file on disk so we can have metadata */
  const char* content = "File with metadata";
  size_t len = strlen(content);
-  EXPECT_TRUE(file_write_to_disk("test_meta_send.txt", content, len, false, false));
+  EXPECT_TRUE(to_disk("test_meta_send.txt", content, len, false, false));

  struct stat st;
  EXPECT_EQ_INT(stat("test_meta_send.txt", &st), 0);
@@ -458,9 +455,9 @@ void test_file() {
  test_file_load_data();
  test_file_load_data_missing_file();
  test_file_save_to_disk();
-  test_file_write_to_disk_basic();
-  test_file_write_to_disk_creates_dirs();
-  test_file_write_to_disk_does_not_follow_symlink();
+  test_to_disk_basic();
+  test_to_disk_creates_dirs();
+  test_to_disk_does_not_follow_symlink();
  test_file_content_to_buffer();
  test_file_save_to_disk_path_traversal();
  test_file_save_to_disk_deep_traversal();
@@ -15,7 +15,7 @@
 static void test_sendfile_basic() {
  const char* content = "Hello from sendfile test!";
  size_t len = strlen(content);
-  EXPECT_TRUE(file_write_to_disk("test_sendfile_basic.txt", content, len, false, false));
+  EXPECT_TRUE(to_disk("test_sendfile_basic.txt", content, len, false, false));

  File* file = file_create("test_sendfile_basic.txt");
  EXPECT_NOT_NULL(file);
@@ -77,7 +77,7 @@ static void test_sendfile_basic() {
 static void test_sendfile_empty_file() {
  const char* content = "";
  size_t len = 0;
-  EXPECT_TRUE(file_write_to_disk("test_sendfile_empty.txt", content, len, false, false));
+  EXPECT_TRUE(to_disk("test_sendfile_empty.txt", content, len, false, false));

  File* file = file_create("test_sendfile_empty.txt");
  EXPECT_NOT_NULL(file);
@@ -156,7 +156,7 @@ static void test_sendfile_missing_file() {
 static void test_sendfile_compression_fallback() {
  const char* content = "Compression fallback content";
  size_t len = strlen(content);
-  EXPECT_TRUE(file_write_to_disk("test_sendfile_comp.txt", content, len, false, false));
+  EXPECT_TRUE(to_disk("test_sendfile_comp.txt", content, len, false, false));

  struct stat st;
  EXPECT_EQ_INT(stat("test_sendfile_comp.txt", &st), 0);
@@ -222,7 +222,7 @@ static void test_sendfile_compression_fallback() {
 static void test_sendfile_no_path() {
  const char* content = "No path sendfile test";
  size_t len = strlen(content);
-  EXPECT_TRUE(file_write_to_disk("test_sendfile_nopath.txt", content, len, false, false));
+  EXPECT_TRUE(to_disk("test_sendfile_nopath.txt", content, len, false, false));

  File* file = file_create("test_sendfile_nopath.txt");
  EXPECT_NOT_NULL(file);
@@ -101,7 +101,7 @@ static void test_fuzz_delta_deserialize() {
 /* Smoke test for metadata_from_buf fuzz target */
 static void test_fuzz_metadata_from_buf() {
  /* Create a real file to get metadata from */
-  EXPECT_TRUE(file_write_to_disk("fuzz_meta_test.txt", "metadata test", 13, false, false));
+  EXPECT_TRUE(to_disk("fuzz_meta_test.txt", "metadata test", 13, false, false));

  struct stat st;
  EXPECT_EQ_INT(stat("fuzz_meta_test.txt", &st), 0);
@@ -125,7 +125,7 @@ static void test_metadata_rejects_invalid_values() {
 static void test_file_restore_metadata() {
  const char* path = "temp_meta_restore_test.txt";
  const char* content = "test content";
-  EXPECT_TRUE(file_write_to_disk(path, content, strlen(content), false, false));
+  EXPECT_TRUE(to_disk(path, content, strlen(content), false, false));

  FileMetadata m;
  m.mode = 0644;
@@ -84,7 +84,7 @@ static void test_property_chunk_roundtrip() {
    for (int i = 0; i < content_len; i++)
      content[i] = (char)(rand() % 256);

-    file_write_to_disk(path, content, content_len, false, false);
+    to_disk(path, content, content_len, false, false);

    struct stat st;
    stat(path, &st);
@@ -13,7 +13,7 @@
 static void test_chunk_deserialize_truncated() {
  char* path = "test_rob_trunc.txt";
  char* content = "hello";
-  file_write_to_disk(path, content, strlen(content), false, false);
+  to_disk(path, content, strlen(content), false, false);

  struct stat st;
  stat(path, &st);
@@ -7,7 +7,7 @@
 #include <unistd.h>

 static void create_test_file(const char* path, const char* content) {
-  (void)file_write_to_disk(path, content, strlen(content), false, false);
+  (void)to_disk(path, content, strlen(content), false, false);
 }

 static void test_scanner_single_file() {
@@ -385,35 +385,6 @@ static void test_scanner_no_patterns() {
  rmdir(dir);
 }

-static void test_parallel_scanner_root_chunks_without_workers() {
-  const char* dir = "test_parallel_scan_root";
-  const char* file1 = "test_parallel_scan_root/a.txt";
-  const char* file2 = "test_parallel_scan_root/b.txt";
-
-  EXPECT_EQ_INT(mkdir(dir, 0755), 0);
-  create_test_file(file1, "a");
-  create_test_file(file2, "b");
-
-  ScannerOptions options = {false, 1, NULL,  0,     NULL,  0,     0,    0,
-                            0,     0, false, false, false, false, false};
-  ParallelScanner* scanner = parallel_scanner_create_with_options(dir, &options);
-  EXPECT_NOT_NULL(scanner);
-
-  int total_files = 0;
-  Chunk* chunk;
-  while ((chunk = parallel_scanner_next(scanner)) != NULL) {
-    total_files += chunk->element_count;
-    chunk_destroy(chunk);
-  }
-  EXPECT_EQ_INT(total_files, 2);
-  EXPECT_FALSE(parallel_scanner_failed(scanner));
-
-  parallel_scanner_destroy(scanner);
-  unlink(file1);
-  unlink(file2);
-  rmdir(dir);
-}
-
 void test_scanner() {
  test_scanner_single_file();
  test_scanner_multiple_files();
@@ -428,5 +399,4 @@ void test_scanner() {
  test_scanner_size_range();
  test_scanner_mixed_patterns();
  test_scanner_no_patterns();
-  test_parallel_scanner_root_chunks_without_workers();
 }