try windows cacheing

Author: alan-george-lk

.github/workflows/builds.yml

@@ -20,7 +20,12 @@ env:
   CARGO_INCREMENTAL: "0"
   # Pinned commit for cpp-example-collection smoke build (https://github.com/livekit-examples/cpp-example-collection)
   CPP_EXAMPLE_COLLECTION_REF: bbf0fdf72dac2239117213475449565686f8c58b
-  # vcpkg binary caching for Windows
+  # vcpkg binary caching for Windows. x-gha stores compiled vcpkg packages
+  # (protobuf, abseil, spdlog, ...) in the GitHub Actions cache, so the
+  # Windows manifest-mode dep build is skipped on a warm cache. `clear`
+  # drops the default (source-only) provider first. Requires the
+  # ACTIONS_CACHE_URL / ACTIONS_RUNTIME_TOKEN export step below.
+  VCPKG_BINARY_SOURCES: "clear;x-gha,readwrite"
   VCPKG_DEFAULT_TRIPLET: x64-windows-static-md
   VCPKG_DEFAULT_HOST_TRIPLET: x64-windows-static-md
   VCPKG_TARGET_TRIPLET: x64-windows-static-md

.github/workflows/tests.yml

@@ -18,7 +18,11 @@ env:
   # incremental dirs add nothing but bloat the cached target/ directory and
   # slow the cache upload/download.
   CARGO_INCREMENTAL: "0"
-  # vcpkg binary caching for Windows (mirrors builds.yml)
+  # vcpkg binary caching for Windows (mirrors builds.yml). x-gha stores
+  # compiled vcpkg packages in the GitHub Actions cache so the Windows
+  # manifest-mode dep build is skipped on a warm cache. Requires the
+  # ACTIONS_CACHE_URL / ACTIONS_RUNTIME_TOKEN export step below.
+  VCPKG_BINARY_SOURCES: "clear;x-gha,readwrite"
   VCPKG_DEFAULT_TRIPLET: x64-windows-static-md
   VCPKG_DEFAULT_HOST_TRIPLET: x64-windows-static-md
   VCPKG_TARGET_TRIPLET: x64-windows-static-md

build.cmd

@@ -202,6 +202,7 @@ echo   build.cmd clean-all
 goto :eof
 
 :configure_build
+call :now _T_CONFIG_START
 echo ==^> Configuring CMake (%BUILD_TYPE%)...
 if not defined VCPKG_ROOT (
     echo Warning: VCPKG_ROOT is not set. Attempting to configure without vcpkg...
@@ -213,6 +214,7 @@ if errorlevel 1 (
     echo Configuration failed!
     exit /b 1
 )
+call :elapsed "configure (%PRESET%)" %_T_CONFIG_START%
 goto build_only
 
 :build_only
@@ -225,15 +227,45 @@ if not defined BUILD_PARALLEL_JOBS (
         set "BUILD_PARALLEL_JOBS=2"
     )
 )
+call :now _T_BUILD_START
 echo ==^> Building (%BUILD_TYPE%) with %BUILD_PARALLEL_JOBS% parallel jobs...
+
+rem Optional Rust-FFI-first split: build the build_rust_ffi target on its own
+rem first so CI logs report the Rust dep/FFI compile time separately from the
+rem C++ compile time. Off by default (single build invocation).
+if "%LK_BUILD_TIMING%"=="1" (
+    call :now _T_FFI_START
+    echo ==^> [timing] Building Rust FFI target ^(build_rust_ffi^) first...
+    cmake --build "%BUILD_DIR%" --config %BUILD_TYPE% --parallel "%BUILD_PARALLEL_JOBS%" --target build_rust_ffi
+    if errorlevel 1 (
+        echo Build failed!
+        exit /b 1
+    )
+    call :elapsed "build: Rust FFI (build_rust_ffi)" %_T_FFI_START%
+)
+
 cmake --build "%BUILD_DIR%" --config %BUILD_TYPE% --parallel "%BUILD_PARALLEL_JOBS%"
 if errorlevel 1 (
     echo Build failed!
     exit /b 1
 )
+call :elapsed "build total (%PRESET%)" %_T_BUILD_START%
 echo ==^> Build complete!
 goto :eof
 
+rem ---- timing helpers ----
+rem :now <varname>  -> sets <varname> to current Unix epoch seconds.
+:now
+for /f %%s in ('powershell -NoProfile -Command "[int][double]::Parse((Get-Date -UFormat %%s))"') do set "%~1=%%s"
+goto :eof
+
+rem :elapsed "<label>" <start-epoch>  -> prints "==> [timing] <label>: <N>s".
+:elapsed
+call :now _T_ELAPSED_END
+set /a _T_ELAPSED_DIFF=%_T_ELAPSED_END% - %~2
+echo ==^> [timing] %~1: %_T_ELAPSED_DIFF%s
+goto :eof
+
 :clean
 echo ==^> Cleaning build directories...
 set "BUILD_DIR_DEBUG=%PROJECT_ROOT%\build-debug"

build.sh

@@ -133,7 +133,19 @@ parse_opts() {
   done
 }
 
+# Print "<label>: <N>s" using a start timestamp captured with `date +%s`.
+# Used for the build-phase timing breakdown surfaced in CI logs. Set
+# LK_BUILD_TIMING=1 to also split the Rust FFI build out from the C++ build.
+_lk_now() { date +%s; }
+_lk_report() {
+  local label="$1" start="$2" end
+  end="$(_lk_now)"
+  echo "==> [timing] ${label}: $((end - start))s"
+}
+
 configure() {
+  local _t_start
+  _t_start="$(_lk_now)"
   echo "==> Configuring CMake (${BUILD_TYPE}) using preset ${PRESET}..."
   local -a extra_args=()
   if [[ -n "${LIVEKIT_VERSION}" ]]; then
@@ -173,6 +185,7 @@ configure() {
     ln -sf "${BUILD_DIR}/compile_commands.json" "${PROJECT_ROOT}/compile_commands.json"
     echo "==> Symlinked compile_commands.json -> ${BUILD_DIR}/compile_commands.json"
   fi
+  _lk_report "configure (${PRESET})" "${_t_start}"
 }
 
 detect_parallel_jobs() {
@@ -201,14 +214,37 @@ build() {
   local parallel_jobs
   parallel_jobs="$(detect_parallel_jobs)"
 
+  local _t_start _t_ffi
+  _t_start="$(_lk_now)"
+
   echo "==> Building (${BUILD_TYPE}) with ${parallel_jobs} parallel jobs..."
+  local have_preset=0
   if [[ -n "${PRESET}" ]] && [[ -f "${PROJECT_ROOT}/CMakePresets.json" ]]; then
+    have_preset=1
+  fi
+
+  # Optional Rust-FFI-first split: build the build_rust_ffi target on its own
+  # first so CI logs report the Rust dep/FFI compile time separately from the
+  # C++ compile time. Off by default (single build invocation).
+  if [[ "${LK_BUILD_TIMING:-0}" == "1" ]]; then
+    _t_ffi="$(_lk_now)"
+    echo "==> [timing] Building Rust FFI target (build_rust_ffi) first..."
+    if [[ "${have_preset}" -eq 1 ]]; then
+      cmake --build --preset "${PRESET}" --parallel "${parallel_jobs}" --target build_rust_ffi
+    else
+      cmake --build "${BUILD_DIR}" --parallel "${parallel_jobs}" --target build_rust_ffi
+    fi
+    _lk_report "build: Rust FFI (build_rust_ffi)" "${_t_ffi}"
+  fi
+
+  if [[ "${have_preset}" -eq 1 ]]; then
     # Use preset build if available
     cmake --build --preset "${PRESET}" --parallel "${parallel_jobs}"
   else
     # Fallback to traditional build
     cmake --build "${BUILD_DIR}" --parallel "${parallel_jobs}"
   fi
+  _lk_report "build total (${PRESET})" "${_t_start}"
 }
 
 install_bundle() {