Add read-only dependency cache mode (#1169)

Co-authored-by: Copilot App <223556219+Copilot@users.noreply.github.com>

Copilot-Session: b3f6f152-8ac4-4c29-b04a-acac8e100777

src/cleanup-java.ts

@@ -1,7 +1,7 @@
 import * as core from '@actions/core';
 import * as gpg from './gpg.js';
 import * as constants from './constants.js';
-import {isJobStatusSuccess} from './util.js';
+import {getBooleanInput, isJobStatusSuccess} from './util.js';
 import {save} from './cache.js';
 import {fileURLToPath} from 'url';
 
@@ -28,7 +28,16 @@ async function removePrivateKeyFromKeychain() {
 async function saveCache() {
   const jobStatus = isJobStatusSuccess();
   const cache = core.getInput(constants.INPUT_CACHE);
-  return jobStatus && cache ? save(cache) : Promise.resolve();
+  if (!jobStatus || !cache) {
+    return;
+  }
+
+  if (getBooleanInput(constants.INPUT_CACHE_READ_ONLY, false)) {
+    core.info('Cache saving is skipped because cache-read-only is enabled.');
+    return;
+  }
+
+  await save(cache);
 }
 
 /**

src/constants.ts

@@ -38,6 +38,7 @@ export const GPG_PASSPHRASE_PROFILE_ID = 'setup-java-gpg';
 
 export const INPUT_CACHE = 'cache';
 export const INPUT_CACHE_DEPENDENCY_PATH = 'cache-dependency-path';
+export const INPUT_CACHE_READ_ONLY = 'cache-read-only';
 export const INPUT_JOB_STATUS = 'job-status';
 
 export const STATE_GPG_PRIVATE_KEY_FINGERPRINT = 'gpg-private-key-fingerprint';