refactor: split transfer and protocol responsibilities

src/server/receiver.c

@@ -0,0 +1,126 @@
+#include "receiver.h"
+
+#include "chunk.h"
+#include "log.h"
+#include "protocol.h"
+#include "utils.h"
+#include <stdlib.h>
+#include <sys/stat.h>
+
+static bool receiver_process_chunk(Chunk* chunk, const ReceiverSink* sink) {
+  for (int i = 0; i < chunk->element_count; i++) {
+    File* file = chunk->items[i];
+    chunk->items[i] = NULL;
+    if (!sink->store_file(file, sink->context)) {
+      chunk_destroy(chunk);
+      return false;
+    }
+  }
+  chunk_destroy(chunk);
+  return true;
+}
+
+static bool receiver_process_batch(Config* config, int file_descriptor) {
+  int count;
+  if (config->checksum || !receive_int(file_descriptor, &count) || count < 0 ||
+      count > MAX_MANIFEST_ENTRIES)
+    return false;
+  for (int i = 0; i < count; i++) {
+    char* check_path = receive_str(file_descriptor);
+    if (!check_path)
+      return false;
+    unsigned long long check_size;
+    long long check_mtime;
+    if (!receive_n_data(file_descriptor, &check_size, sizeof(check_size)) ||
+        !receive_n_data(file_descriptor, &check_mtime, sizeof(check_mtime))) {
+      free(check_path);
+      return false;
+    }
+    if (!utils_valid_batch_path(check_path)) {
+      free(check_path);
+      send_status(file_descriptor, STATUS_ERROR);
+      return false;
+    }
+    char* full_path = path_cat(config->receive_root_directory, check_path);
+    struct stat st;
+    bool has_old = full_path && lstat(full_path, &st) == 0;
+    bool match = has_old && (unsigned long long)st.st_size == check_size &&
+                 (long long)st.st_mtime == check_mtime;
+    bool sent = send_status(file_descriptor, match ? STATUS_OK : STATUS_NEXT);
+    free(full_path);
+    free(check_path);
+    if (!sent)
+      return false;
+  }
+  return true;
+}
+
+int receiver_process(Config* config, int file_descriptor, const ReceiverSink* sink) {
+  Status status;
+  if (!receive_status(file_descriptor, &status))
+    return -1;
+  while (status == STATUS_NEXT || status == STATUS_CHUNK || status == STATUS_CHECK ||
+         status == STATUS_KEEPALIVE || status == STATUS_ABORT || status == STATUS_CHECK_BATCH) {
+    if (status == STATUS_KEEPALIVE) {
+      if (!send_status(file_descriptor, STATUS_KEEPALIVE))
+        return -1;
+      goto next;
+    }
+    if (status == STATUS_ABORT) {
+      log_message(LOG_LEVEL_INFO, "Received abort from client, cleaning up");
+      return -1;
+    }
+    if (status == STATUS_CHECK) {
+      bool skipped;
+      File* file = receive_incremental_check(file_descriptor, config, &skipped);
+      if (!skipped && (!file || !sink->store_file(file, sink->context)))
+        goto receive_error;
+    } else if (status == STATUS_CHUNK) {
+      Chunk* chunk = receive_chunk_data(file_descriptor, config);
+      if (!chunk || !receiver_process_chunk(chunk, sink))
+        goto receive_error;
+    } else if (status == STATUS_CHECK_BATCH) {
+      if (!receiver_process_batch(config, file_descriptor))
+        return -1;
+      goto next;
+    } else {
+      File* file = file_receive(config, file_descriptor);
+      if (!file) {
+        log_message(LOG_LEVEL_ERROR, "Failed to receive file");
+        goto receive_error;
+      }
+      if (!sink->store_file(file, sink->context))
+        goto receive_error;
+    }
+  next:
+    if (!receive_status(file_descriptor, &status))
+      goto receive_error;
+  }
+  if (status == STATUS_MANIFEST && receive_manifest(file_descriptor, config, &status) != 0)
+    return -1;
+  if (status != STATUS_FINISHED) {
+    log_message(LOG_LEVEL_ERROR, "Did not receive FINISHED Status");
+    goto receive_error;
+  }
+  if (sink->send_success && !send_status(file_descriptor, STATUS_OK))
+    return -1;
+  return 0;
+
+receive_error:
+  if (sink->send_error)
+    send_status(file_descriptor, STATUS_ERROR);
+  return -1;
+}
+
+static bool receiver_save_file(File* file, void* context) {
+  Config* config = context;
+  bool success =
+      !config->save_to_disk || file_save_to_disk(config->receive_root_directory, file, config);
+  file_destroy(file);
+  return success;
+}
+
+int receiver_receive_files(Config* config, int file_descriptor) {
+  ReceiverSink sink = {receiver_save_file, config, true, true};
+  return receiver_process(config, file_descriptor, &sink);
+}