Prefetch optional macOS extension caches alongside PHP installation

src/extensions.ts

@@ -1,5 +1,18 @@
 import * as utils from './utils';
 
+/** Select only unversioned, requested macOS extension caches. */
+export async function extensionPacks(
+  extension_csv: string,
+  version: string,
+  os: string
+): Promise<string[]> {
+  if (os !== 'darwin' || !/^8\.[2-5]$/.test(version)) return [];
+  const requested = await utils.extensionArray(extension_csv);
+  return ['imagick', 'mongodb', 'memcached'].filter(
+    name => requested.includes(name) && !requested.includes(':' + name)
+  );
+}
+
 /**
  * Install and enable extensions for darwin
  *

src/install.ts

@@ -31,6 +31,13 @@ export async function getScript(os: string): Promise<string> {
   const ini_file: string = await utils.parseIniFile(
     await utils.getInput('ini-file', false)
   );
+  const packs = await extensions.extensionPacks(extension_csv, version, os);
+  if (packs.length) {
+    process.env['SETUP_PHP_EXTENSION_PACKS'] = packs.join(' ');
+    process.env['SETUP_PHP_NODE'] = process.execPath;
+  } else {
+    delete process.env['SETUP_PHP_EXTENSION_PACKS'];
+  }
   let script = await utils.joins('.', script_path, `'${version}'`, ini_file);
   if (extension_csv) {
     script += await extensions.addExtension(extension_csv, version, os);

src/scripts/darwin.sh

@@ -77,6 +77,9 @@ add_brew_extension() {
   prefix=$2
   expected_version=${3:-}
   extension="$(get_extension_from_formula "$formula")"
+  if [ "$extension" = memcached ] && [ -n "${extension_cache_memcached_dependencies:-}" ]; then
+    enable_extension_cache_dependencies "$extension"
+  fi
   enable_extension "$extension" "$prefix"
   if check_extension "$extension" && { [ -z "$expected_version" ] || check_extension_version "$extension" "$expected_version"; }; then
     add_log "${tick:?}" "$extension" "Enabled"
@@ -337,4 +340,10 @@ export HOMEBREW_NO_INSTALL_FROM_API=1
 configure_brew
 read_env
 self_hosted_setup
+if [ -n "${SETUP_PHP_EXTENSION_PACKS:-}" ]; then
+  # shellcheck source=.
+  . "$scripts/extensions/darwin_cache.sh"
+  start_extension_cache_downloads
+fi
 setup_php
+if [ -n "${SETUP_PHP_EXTENSION_PACKS:-}" ]; then finish_extension_cache_downloads; fi

src/scripts/extensions/darwin_cache.sh

@@ -0,0 +1,59 @@
+# Optional macOS extension archives. Downloads overlap PHP installation; the
+# PHP-only path never sources this file or contacts the extension cache.
+start_extension_cache_downloads() {
+  extension_cache_dir=$(mktemp -d "${RUNNER_TEMP:-/tmp}/setup-php-extensions.XXXXXX") || return 0
+  (
+    cache_installer="$extension_cache_dir/install-extensions.cjs"
+    cache_primary="https://github.com/shivammathur/php-darwin/releases/download/extensions"
+    cache_mirror="https://artifacts.php-darwin.setup-php.com/extensions"
+    curl -fsSL --retry 0 --connect-timeout 3 --max-time 3 --max-filesize 2000000 \
+      "$cache_primary/install-extensions.cjs" -o "$cache_installer" ||
+      curl -fsSL --retry 0 --connect-timeout 3 --max-time 10 --max-filesize 2000000 \
+        "$cache_mirror/install-extensions.cjs" -o "$cache_installer" || exit 0
+    IFS=' ' read -r -a cache_extensions <<< "$SETUP_PHP_EXTENSION_PACKS"
+    "$SETUP_PHP_NODE" "$cache_installer" prefetch "$extension_cache_dir" \
+      "$version" "$debug" "$ts" "$(uname -m)" "${cache_extensions[@]}"
+  ) > "$extension_cache_dir/download.log" 2>&1 &
+  extension_cache_pid=$!
+}
+
+finish_extension_cache_downloads() {
+  [ -n "${extension_cache_pid:-}" ] || return 0
+  wait "$extension_cache_pid" || true
+  extension_cache_pid=
+  if [[ "${verbose:-${VERBOSE:-}}" =~ ^(true|v{1,3})$ ]]; then
+    cat "$extension_cache_dir/download.log"
+  fi
+  [ -s "$extension_cache_dir/install-extensions.cjs" ] || return 0
+  local extension variable value
+  for extension in $SETUP_PHP_EXTENSION_PACKS; do
+    [ -s "$extension_cache_dir/$extension.json" ] || continue
+    if "$SETUP_PHP_NODE" "$extension_cache_dir/install-extensions.cjs" install "$extension_cache_dir" "$extension"; then
+      while IFS='=' read -r variable value; do
+        case "$variable" in
+          MAGICK_CONFIGURE_PATH|MAGICK_CODER_MODULE_PATH|MAGICK_FILTER_MODULE_PATH)
+            add_env "$variable" "$value"
+            ;;
+        esac
+      done < "$extension_cache_dir/$extension.env"
+      # Store the dependency names in shell variables; the download directory
+      # can be removed before the action enables its requested extensions.
+      if [ "$extension" = memcached ]; then
+        extension_cache_memcached_dependencies='igbinary msgpack'
+      fi
+    else
+      printf 'setup-php: %s cache unavailable for this PHP; using the existing installer\n' "$extension"
+    fi
+  done
+  rm -rf "$extension_cache_dir"
+  extension_cache_dir=
+}
+
+enable_extension_cache_dependencies() {
+  if [ "$1" = memcached ] && [ -n "${extension_cache_memcached_dependencies:-}" ]; then
+    local dependency
+    for dependency in $extension_cache_memcached_dependencies; do
+      enable_extension "$dependency" extension
+    done
+  fi
+}