Create filesystem-cache.ts

src/filesystem-cache.ts

@@ -0,0 +1,57 @@
+import { join } from "node:path";
+import { tmpdir } from "node:os";
+import {
+  existsSync,
+  readFileSync,
+  writeFileSync,
+  statSync,
+  mkdirSync,
+} from "node:fs";
+import { createHash } from "node:crypto";
+import { debug } from "@actions/core";
+
+const CACHE_DIR = process.env.RUNNER_TEMP || tmpdir();
+const FS_CACHE_TIMEOUT = 1000 * 60 * 60 * 12; // hours
+
+function cacheDebug(operation: string, key: string, error: unknown): void {
+  const message = error instanceof Error ? error.message : String(error);
+  debug(`filesystem-cache: ${operation} failed for key "${key}": ${message}`);
+}
+
+function getCachePath(key: string): string {
+  const hash = createHash("sha1").update(key).digest("hex");
+  return join(CACHE_DIR, `setup-bun-${hash}.json`);
+}
+
+/**
+ * Retrieves data from the filesystem cache if it exists and is under 12 hours old.
+ */
+export function getCache(key: string): string | null {
+  const path = getCachePath(key);
+  try {
+    if (existsSync(path)) {
+      const stats = statSync(path);
+      if (FS_CACHE_TIMEOUT > Date.now() - stats.mtimeMs) {
+        return readFileSync(path, "utf8");
+      }
+    }
+  } catch (error) {
+    cacheDebug("getCache", key, error);
+  }
+  return null;
+}
+
+/**
+ * Saves data to the filesystem cache.
+ */
+export function setCache(key: string, value: string): void {
+  const path = getCachePath(key);
+  try {
+    if (!existsSync(CACHE_DIR)) {
+      mkdirSync(CACHE_DIR, { recursive: true });
+    }
+    writeFileSync(path, value, "utf8");
+  } catch (error) {
+    cacheDebug("setCache", key, error);
+  }
+}