feat: add rsync-compatible max-alloc limit

tests/test_client_cli.c

@@ -247,6 +247,47 @@ static void test_parse_args_valid_compression_level() {
   config_delete(cfg);
 }
 
+static void test_parse_args_max_alloc_sizes() {
+  const char* values[] = {"1", "4K", "2m", "3G", "1T", "1P", "1E", "512B"};
+  const unsigned long long expected[] = {1,
+                                         4ULL * 1024,
+                                         2ULL * 1024 * 1024,
+                                         3ULL * 1024 * 1024 * 1024,
+                                         1ULL * 1024 * 1024 * 1024 * 1024,
+                                         1ULL * 1024 * 1024 * 1024 * 1024 * 1024,
+                                         1ULL * 1024 * 1024 * 1024 * 1024 * 1024 * 1024,
+                                         512};
+  for (size_t i = 0; i < sizeof(values) / sizeof(values[0]); i++) {
+    Config* cfg = config_create();
+    char* argv[] = {"fastsync", "--max-alloc", (char*)values[i], "/src", "/dst"};
+    int positional_args[2];
+    int positional_count = 0;
+    EXPECT_EQ_INT(parse_args(cfg, 5, argv, positional_args, &positional_count), 0);
+    EXPECT_TRUE(cfg->max_alloc == expected[i]);
+    config_delete(cfg);
+  }
+
+  Config* cfg = config_create();
+  char* argv[] = {"fastsync", "--max-alloc=8M", "/src", "/dst"};
+  int positional_args[2];
+  int positional_count = 0;
+  EXPECT_EQ_INT(parse_args(cfg, 4, argv, positional_args, &positional_count), 0);
+  EXPECT_TRUE(cfg->max_alloc == 8ULL * 1024 * 1024);
+  config_delete(cfg);
+}
+
+static void test_parse_args_rejects_invalid_max_alloc() {
+  const char* values[] = {"0", "-1", "1Z", "1K2", "18446744073709551615K"};
+  for (size_t i = 0; i < sizeof(values) / sizeof(values[0]); i++) {
+    Config* cfg = config_create();
+    char* argv[] = {"fastsync", "--max-alloc", (char*)values[i], "/src", "/dst"};
+    int positional_args[2];
+    int positional_count = 0;
+    EXPECT_EQ_INT(parse_args(cfg, 5, argv, positional_args, &positional_count), -1);
+    config_delete(cfg);
+  }
+}
+
 /* Test parse_args unknown option returns error */
 static void test_parse_args_unknown_option() {
   Config* cfg = config_create();
@@ -357,6 +398,8 @@ void test_client_cli() {
   test_parse_args_invalid_server_port();
   test_parse_args_invalid_compression_level();
   test_parse_args_valid_compression_level();
+  test_parse_args_max_alloc_sizes();
+  test_parse_args_rejects_invalid_max_alloc();
   test_parse_args_unknown_option();
   test_parse_args_rejects_unimplemented_options();
   test_parse_args_archive();

tests/test_config.c

@@ -126,6 +126,7 @@ static void test_config_send_receive() {
   send_cfg->use_metadata = true;
   send_cfg->compression_level = 5;
   send_cfg->chunk_size = 1024;
+  send_cfg->max_alloc = 8ULL * 1024 * 1024;
 
   /* Use socketpair for bidirectional communication */
   int p[2];
@@ -160,6 +161,8 @@ static void test_config_send_receive() {
         ok = false;
       if (recv_cfg->chunk_size != 1024)
         ok = false;
+      if (recv_cfg->max_alloc != 8ULL * 1024 * 1024)
+        ok = false;
     }
     config_delete(recv_cfg);
     close(p[0]);

tests/test_protocol.c

@@ -187,6 +187,21 @@ static void test_receive_str_truncated() {
   close(p[0]);
 }
 
+static void test_max_alloc_rejects_single_buffer() {
+  int p[2];
+  EXPECT_EQ_INT(pipe(p), 0);
+  ProtocolSession session;
+  protocol_session_init(&session, p[0], p[1]);
+  protocol_session_set_max_alloc(&session, 4);
+  protocol_session_bind(&session);
+  char payload[8] = {0};
+  EXPECT_TRUE(write(p[1], &(size_t){sizeof(payload)}, sizeof(size_t)) == sizeof(size_t));
+  EXPECT_NULL(protocol_receive_str(&session));
+  protocol_session_unbind();
+  close(p[0]);
+  close(p[1]);
+}
+
 void test_protocol() {
   test_send_receive_n_data();
   test_send_receive_n_data_zero();
@@ -198,4 +213,5 @@ void test_protocol() {
   test_send_receive_status();
   test_receive_n_data_truncated();
   test_receive_str_truncated();
+  test_max_alloc_rejects_single_buffer();
 }