feat(logger): Use LRUCache to manage log history (#20325)

package-lock.json

@@ -22150,6 +22150,7 @@
       "dependencies": {
         "console-control-strings": "1.1.0",
         "lodash": "4.17.21",
+        "lru-cache": "10.3.0",
         "set-blocking": "2.0.0"
       },
       "engines": {
@@ -22157,6 +22158,14 @@
         "npm": ">=8"
       }
     },
+    "packages/logger/node_modules/lru-cache": {
+      "version": "10.3.0",
+      "resolved": "https://registry.npmjs.org/lru-cache/-/lru-cache-10.3.0.tgz",
+      "integrity": "sha512-CQl19J/g+Hbjbv4Y3mFNNXFEL/5t/KCg8POCuUqd4rMKjGG+j1ybER83hxV58zL+dFI1PTkt3GNFSHRt+d8qEQ==",
+      "engines": {
+        "node": "14 || >=16.14"
+      }
+    },
     "packages/opencv": {
       "name": "@appium/opencv",
       "version": "3.0.4",
@@ -23142,7 +23151,15 @@
       "requires": {
         "console-control-strings": "1.1.0",
         "lodash": "4.17.21",
+        "lru-cache": "10.3.0",
         "set-blocking": "2.0.0"
+      },
+      "dependencies": {
+        "lru-cache": {
+          "version": "10.3.0",
+          "resolved": "https://registry.npmjs.org/lru-cache/-/lru-cache-10.3.0.tgz",
+          "integrity": "sha512-CQl19J/g+Hbjbv4Y3mFNNXFEL/5t/KCg8POCuUqd4rMKjGG+j1ybER83hxV58zL+dFI1PTkt3GNFSHRt+d8qEQ=="
+        }
       }
     },
     "@appium/opencv": {

packages/logger/lib/log.ts

@@ -1,8 +1,8 @@
 import _ from 'lodash';
 import {EventEmitter} from 'node:events';
-// @ts-ignore This module does not provide type definitons
+// @ts-ignore This module does not provide type definitions
 import setBlocking from 'set-blocking';
-// @ts-ignore This module does not provide type definitons
+// @ts-ignore This module does not provide type definitions
 import consoleControl from 'console-control-strings';
 import * as util from 'node:util';
 import type {
@@ -17,6 +17,7 @@ import type {Writable} from 'node:stream';
 import {AsyncLocalStorage} from 'node:async_hooks';
 import { unleakString } from './utils';
 import { SecureValuesPreprocessor } from './secure-values-preprocessor';
+import { LRUCache } from 'lru-cache';
 
 const DEFAULT_LOG_LEVELS = [
   ['silly', -Infinity, {inverse: true}, 'sill'],
@@ -30,13 +31,12 @@ const DEFAULT_LOG_LEVELS = [
   ['error', 5000, {fg: 'red', bg: 'black'}, 'ERR!'],
   ['silent', Infinity],
 ] as const;
+const DEFAULT_HISTORY_SIZE = 10000;
 
 setBlocking(true);
 
 export class Log extends EventEmitter implements Logger {
   level: LogLevel | string;
-  record: MessageObject[];
-  maxRecordSize: number;
   prefixStyle: StyleObject;
   headingStyle: StyleObject;
   heading: string;
@@ -52,13 +52,16 @@ export class Log extends EventEmitter implements Logger {
   _paused: boolean;
   _secureValuesPreprocessor: SecureValuesPreprocessor;
 
+  private _history: LRUCache<number, MessageObject>;
+  private _maxRecordSize: number;
+
   constructor() {
     super();
 
     this.level = 'info';
     this._buffer = [];
-    this.record = [];
-    this.maxRecordSize = 10000;
+    this._maxRecordSize = DEFAULT_HISTORY_SIZE;
+    this._history = new LRUCache({max: this.maxRecordSize});
     this.stream = process.stderr;
     this.heading = '';
     this.prefixStyle = {fg: 'magenta'};
@@ -77,6 +80,27 @@ export class Log extends EventEmitter implements Logger {
     this.on('error', () => {});
   }
 
+  get record(): MessageObject[] {
+    return [...this._history.rvalues()] as MessageObject[];
+  }
+
+  get maxRecordSize(): number {
+    return this._maxRecordSize;
+  }
+
+  set maxRecordSize(value: number) {
+    if (value === this._maxRecordSize) {
+      return;
+    }
+
+    this._maxRecordSize = value;
+    const newHistory = new LRUCache<number, MessageObject>({max: value});
+    for (const [key, value] of this._history.rentries() as Generator<[number, MessageObject]>) {
+      newHistory.set(key, value);
+    }
+    this._history = newHistory;
+  }
+
   private useColor(): boolean {
     // by default, decide based on tty-ness.
     return (
@@ -239,12 +263,7 @@ export class Log extends EventEmitter implements Logger {
       this.emit(m.prefix, m);
     }
 
-    this.record.push(m);
-    const mrs = this.maxRecordSize;
-    if (this.record.length > mrs) {
-      this.record.shift();
-    }
-
+    this._history.set(m.id, m);
     this.emitLog(m);
   }
 

packages/logger/package.json

@@ -29,6 +29,7 @@
   "dependencies": {
     "console-control-strings": "1.1.0",
     "lodash": "4.17.21",
+    "lru-cache": "10.3.0",
     "set-blocking": "2.0.0"
   },
   "license": "ISC",

packages/logger/test/unit/basic-specs.js

@@ -363,7 +363,24 @@ describe('basic', async function () {
       log.log('verbose', 'test', 'log 2');
       log.log('verbose', 'test', 'log 3');
       log.log('verbose', 'test', 'log 4');
-      log.record.length.should.equal(3);
+      log.record.map(({message}) => message).should.eql([
+        'log 2',
+        'log 3',
+        'log 4',
+      ]);
+      log.maxRecordSize = 2;
+      log.log('verbose', 'test', 'log 5');
+      log.record.map(({message}) => message).should.eql([
+        'log 4',
+        'log 5',
+      ]);
+      log.maxRecordSize = 3;
+      log.log('verbose', 'test', 'log 6');
+      log.record.map(({message}) => message).should.eql([
+        'log 4',
+        'log 5',
+        'log 6',
+      ]);
     });
   });