Rename files

ts/util/rotatingPinoDest.node.ts

@@ -0,0 +1,99 @@
+// Copyright 2022 Signal Messenger, LLC
+// SPDX-License-Identifier: AGPL-3.0-only
+
+import fs from 'node:fs';
+import pino from 'pino';
+
+import { DAY, SECOND } from './durations/index.std.js';
+import { isMoreRecentThan } from './timestamp.std.js';
+
+export const DEFAULT_MAX_ROTATIONS = 3;
+
+const RETRY_DELAY = 5 * SECOND;
+
+// 5 seconds * 12 = 1 minute
+const MAX_RETRY_COUNT = 12;
+
+export type RotatingPinoDestOptionsType = Readonly<{
+  logFile: string;
+  maxSavedLogFiles?: number;
+  interval?: number;
+}>;
+
+export function createRotatingPinoDest({
+  logFile,
+  maxSavedLogFiles = DEFAULT_MAX_ROTATIONS,
+  interval = DAY,
+}: RotatingPinoDestOptionsType): ReturnType<typeof pino.destination> {
+  const boom = pino.destination({
+    dest: logFile,
+    sync: true,
+    mkdir: true,
+  });
+
+  let retryCount = 0;
+
+  const warn = (msg: string) => {
+    const line = JSON.stringify({
+      level: 40,
+      time: new Date(),
+      msg,
+    });
+    boom.write(`${line}\n`);
+  };
+
+  function maybeRotate(startingIndex = maxSavedLogFiles - 1) {
+    let pendingFileIndex = startingIndex;
+    try {
+      const { birthtimeMs } = fs.statSync(logFile);
+
+      if (isMoreRecentThan(birthtimeMs, interval)) {
+        return;
+      }
+
+      for (; pendingFileIndex >= 0; pendingFileIndex -= 1) {
+        const currentPath =
+          pendingFileIndex === 0 ? logFile : `${logFile}.${pendingFileIndex}`;
+        const nextPath = `${logFile}.${pendingFileIndex + 1}`;
+
+        if (fs.existsSync(nextPath)) {
+          fs.unlinkSync(nextPath);
+        }
+        if (!fs.existsSync(currentPath)) {
+          continue;
+        }
+        fs.renameSync(currentPath, nextPath);
+      }
+    } catch (error) {
+      // If we can't access the old log files - try rotating after a small
+      // delay.
+      if (
+        retryCount < MAX_RETRY_COUNT &&
+        (error.code === 'EACCES' || error.code === 'EPERM')
+      ) {
+        retryCount += 1;
+        warn(`rotatingPinoDest: retrying rotation, retryCount=${retryCount}`);
+        setTimeout(() => maybeRotate(pendingFileIndex), RETRY_DELAY);
+        return;
+      }
+
+      boom.destroy();
+      boom.emit('error', error);
+      return;
+    }
+
+    // Success, reopen
+    boom.reopen();
+
+    if (retryCount !== 0) {
+      warn(`rotatingPinoDest: rotation succeeded after ${retryCount} retries`);
+    }
+
+    retryCount = 0;
+  }
+
+  maybeRotate();
+  setInterval(maybeRotate, interval);
+
+  return boom;
+}