perf: add sync benchmark workflow and optimize network apply path

.github/workflows/sync-bench.yml

@@ -0,0 +1,63 @@
+name: sync benchmark
+
+on:
+  workflow_dispatch:
+    inputs:
+      poll_delay_ms:
+        description: Polling delay between receiver checks, in milliseconds
+        required: false
+        default: '250'
+      max_polls:
+        description: Maximum number of receiver polling attempts
+        required: false
+        default: '40'
+      curl_pool:
+        description: Enable curl connection pool; use 0 to disable
+        required: false
+        default: '1'
+
+permissions:
+  contents: read
+
+jobs:
+  sync-bench-debug:
+    name: sync-bench-debug linux x86_64
+    runs-on: ubuntu-22.04
+    timeout-minutes: 20
+
+    env:
+      SYNC_BENCH_DATABASE_ID: ${{ secrets.SYNC_BENCH_DATABASE_ID }}
+      SYNC_BENCH_CLOUDSYNC_ADDRESS: ${{ secrets.SYNC_BENCH_CLOUDSYNC_ADDRESS }}
+      SYNC_BENCH_APIKEY: ${{ secrets.SYNC_BENCH_APIKEY }}
+      SYNC_BENCH_OUTPUT: json
+      SYNC_BENCH_POLL_DELAY_MS: ${{ inputs.poll_delay_ms }}
+      SYNC_BENCH_MAX_POLLS: ${{ inputs.max_polls }}
+      CLOUDSYNC_CURL_POOL: ${{ inputs.curl_pool }}
+
+    steps:
+      - uses: actions/checkout@v4.2.2
+        with:
+          submodules: true
+
+      - name: Install dependencies
+        run: |
+          sudo apt-get update
+          sudo apt-get install -y gcc make curl sqlite3 unzip
+
+      - name: Build debug benchmark
+        run: make SYNC_BENCH_DEBUG=1 extension dist/sync_bench
+
+      - name: Run sync benchmark
+        run: |
+          mkdir -p artifacts
+          ./dist/sync_bench > artifacts/sync-bench.json 2> artifacts/sync-bench.trace.log
+
+      - name: Upload benchmark artifacts
+        if: always()
+        uses: actions/upload-artifact@v4
+        with:
+          name: sync-bench-debug-${{ github.run_id }}
+          path: |
+            artifacts/sync-bench.json
+            artifacts/sync-bench.trace.log
+          if-no-files-found: warn

CHANGELOG.md

@@ -4,6 +4,19 @@ All notable changes to this project will be documented in this file.
 
 The format is based on [Keep a Changelog](https://keepachangelog.com/en/1.0.0/).
 
+## [1.0.20] - 2026-05-26
+
+### Changed
+
+- **Improved network sync performance** by reducing request overhead during `cloudsync_network_send_changes()`, especially for small payloads that can now be applied without the extra upload-URL round trip.
+- **Improved repeated sync request latency** by allowing the network layer to reuse HTTP connections across CloudSync API calls.
+
+## [1.0.19] - 2026-05-15
+
+### Added
+
+- **Mac Catalyst support**.
+
 ## [1.0.18] - 2026-04-29
 
 ### Fixed

Makefile

@@ -185,6 +185,10 @@ endif
 	T_LDFLAGS += -fprofile-arcs -ftest-coverage
 endif
 
+ifdef SYNC_BENCH_DEBUG
+	CFLAGS += -DCLOUDSYNC_NETWORK_TRACE
+endif
+
 # Native network support only for Apple platforms
 ifdef NATIVE_NETWORK
 	RELEASE_OBJ += $(patsubst %.m, $(BUILD_RELEASE)/%_m.o, $(notdir $(wildcard $(NETWORK_DIR)/*.m)))
@@ -271,6 +275,25 @@ e2e: $(TARGET) $(DIST_DIR)/integration$(EXE)
 	fi; \
 	./$(DIST_DIR)/integration$(EXE)
 
+# Run the sync performance benchmark. This is intentionally separate from e2e
+# because timings depend on network/server load and polling configuration.
+sync-bench: $(TARGET) $(DIST_DIR)/sync_bench$(EXE)
+	@if [ -f .env ]; then \
+		export $$(grep -v '^#' .env | xargs); \
+	fi; \
+	if [ -n "$(SYNC_BENCH_DATABASE_ID)" ]; then export SYNC_BENCH_DATABASE_ID="$(SYNC_BENCH_DATABASE_ID)"; fi; \
+	if [ -n "$(SYNC_BENCH_CLOUDSYNC_ADDRESS)" ]; then export SYNC_BENCH_CLOUDSYNC_ADDRESS="$(SYNC_BENCH_CLOUDSYNC_ADDRESS)"; fi; \
+	if [ -n "$(SYNC_BENCH_APIKEY)" ]; then export SYNC_BENCH_APIKEY="$(SYNC_BENCH_APIKEY)"; fi; \
+	if [ -n "$(SYNC_BENCH_POLL_DELAY_MS)" ]; then export SYNC_BENCH_POLL_DELAY_MS="$(SYNC_BENCH_POLL_DELAY_MS)"; fi; \
+	if [ -n "$(SYNC_BENCH_MAX_POLLS)" ]; then export SYNC_BENCH_MAX_POLLS="$(SYNC_BENCH_MAX_POLLS)"; fi; \
+	if [ -n "$(SYNC_BENCH_RANDOM_BLOB_SIZE_BYTES)" ]; then export SYNC_BENCH_RANDOM_BLOB_SIZE_BYTES="$(SYNC_BENCH_RANDOM_BLOB_SIZE_BYTES)"; fi; \
+	if [ -n "$(SYNC_BENCH_CLEANUP_OLDER_THAN_SECONDS)" ]; then export SYNC_BENCH_CLEANUP_OLDER_THAN_SECONDS="$(SYNC_BENCH_CLEANUP_OLDER_THAN_SECONDS)"; fi; \
+	if [ -n "$(SYNC_BENCH_OUTPUT)" ]; then export SYNC_BENCH_OUTPUT="$(SYNC_BENCH_OUTPUT)"; fi; \
+	./$(DIST_DIR)/sync_bench$(EXE)
+
+sync-bench-debug:
+	$(MAKE) SYNC_BENCH_DEBUG=1 sync-bench
+
 OPENSSL_TARBALL = $(OPENSSL_DIR)/$(OPENSSL_VERSION).tar.gz
 
 $(OPENSSL_TARBALL):

src/cloudsync.h

@@ -18,7 +18,7 @@
 extern "C" {
 #endif
 
-#define CLOUDSYNC_VERSION                       "1.0.19"
+#define CLOUDSYNC_VERSION                       "1.0.20"
 #define CLOUDSYNC_MAX_TABLENAME_LEN             512
 
 #define CLOUDSYNC_VALUE_NOTSET                  -1