From 0abdec72d0e4c3e9d9b61acf658c75ba1d8858ee Mon Sep 17 00:00:00 2001
From: Stefan Dirix <sdirix@eclipsesource.com>
Date: Thu, 25 May 2023 23:37:07 +0200
Subject: [PATCH] fix: propagate log-config changes

If Theia is started with the "--log-config" option the 'LogLevelCliContribution' watches
for file changes and fires a 'logConfigChangedEvent'. This event was not listened to.
Therefore already existing 'ILogger' levels were not updated. This is now fixed by
notifying loggers about log config changes to update their log level.

Signed-off-by: Stefan Dirix <sdirix@eclipsesource.com>

Contributed on behalf of STMicroelectronics
---
 CHANGELOG.md                                    |  4 ++++
 packages/core/src/common/logger-protocol.ts     |  4 ++++
 packages/core/src/common/logger-watcher.ts      | 16 +++++++++++++---
 packages/core/src/common/logger.ts              |  5 +++++
 packages/core/src/node/console-logger-server.ts |  6 +++++-
 5 files changed, 31 insertions(+), 4 deletions(-)

diff --git a/CHANGELOG.md b/CHANGELOG.md
index a4bb0c145048b..2f209ed86e132 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -4,6 +4,10 @@
 
 - [Previous Changelogs](https://github.com/eclipse-theia/theia/tree/master/doc/changelogs/)
 
+## v1.42.0 - 09/28/2023
+
+- [core] fixed logger level propagation when log config file changes at runtime [#12566](https://github.com/eclipse-theia/theia/pull/12566) - Contributed on behalf of STMicroelectronics.
+
 ## v1.41.0 - 08/31/2023
 
 - [application-package] added handling to quit the electron app when the backend fails to start [#12778](https://github.com/eclipse-theia/theia/pull/12778) - Contributed on behalf of STMicroelectronics.
diff --git a/packages/core/src/common/logger-protocol.ts b/packages/core/src/common/logger-protocol.ts
index 57327924c901c..8079711d25ee3 100644
--- a/packages/core/src/common/logger-protocol.ts
+++ b/packages/core/src/common/logger-protocol.ts
@@ -38,6 +38,7 @@ export interface ILogLevelChangedEvent {
 
 export interface ILoggerClient {
     onLogLevelChanged(event: ILogLevelChangedEvent): void;
+    onLogConfigChanged(): void;
 }
 
 @injectable()
@@ -49,6 +50,9 @@ export class DispatchingLoggerClient implements ILoggerClient {
         this.clients.forEach(client => client.onLogLevelChanged(event));
     }
 
+    onLogConfigChanged(): void {
+        this.clients.forEach(client => client.onLogConfigChanged());
+    }
 }
 
 export const rootLoggerName = 'root';
diff --git a/packages/core/src/common/logger-watcher.ts b/packages/core/src/common/logger-watcher.ts
index 945c68d6cee54..8e72e5757983f 100644
--- a/packages/core/src/common/logger-watcher.ts
+++ b/packages/core/src/common/logger-watcher.ts
@@ -22,11 +22,15 @@ import { ILoggerClient, ILogLevelChangedEvent } from './logger-protocol';
 export class LoggerWatcher {
 
     getLoggerClient(): ILoggerClient {
-        const emitter = this.onLogLevelChangedEmitter;
+        const logLevelEmitter = this.onLogLevelChangedEmitter;
+        const logConfigEmitter = this.onLogConfigChangedEmitter;
         return {
             onLogLevelChanged(event: ILogLevelChangedEvent): void {
-                emitter.fire(event);
-            }
+                logLevelEmitter.fire(event);
+            },
+            onLogConfigChanged(): void {
+                logConfigEmitter.fire();
+            },
         };
     }
 
@@ -36,6 +40,12 @@ export class LoggerWatcher {
         return this.onLogLevelChangedEmitter.event;
     }
 
+    private onLogConfigChangedEmitter = new Emitter<void>();
+
+    get onLogConfigChanged(): Event<void> {
+        return this.onLogConfigChangedEmitter.event;
+    }
+
     // FIXME: get rid of it, backend services should as well set a client on the server
     fireLogLevelChanged(event: ILogLevelChangedEvent): void {
         this.onLogLevelChangedEmitter.fire(event);
diff --git a/packages/core/src/common/logger.ts b/packages/core/src/common/logger.ts
index 54900d53ac773..bd4a9b2379e8a 100644
--- a/packages/core/src/common/logger.ts
+++ b/packages/core/src/common/logger.ts
@@ -261,6 +261,11 @@ export class Logger implements ILogger {
                 }
             });
         });
+
+        /* Refetch log level if overall config in backend changed. */
+        this.loggerWatcher.onLogConfigChanged(() => {
+            this._logLevel = this.created.then(_ => this.server.getLogLevel(this.name));
+        });
     }
 
     setLogLevel(logLevel: number): Promise<void> {
diff --git a/packages/core/src/node/console-logger-server.ts b/packages/core/src/node/console-logger-server.ts
index a8068c29c6f69..850939d84a684 100644
--- a/packages/core/src/node/console-logger-server.ts
+++ b/packages/core/src/node/console-logger-server.ts
@@ -17,7 +17,7 @@
 import { inject, injectable, postConstruct } from 'inversify';
 import { LoggerWatcher } from '../common/logger-watcher';
 import { LogLevelCliContribution } from './logger-cli-contribution';
-import { ILoggerServer, ILoggerClient, ConsoleLogger } from '../common/logger-protocol';
+import { ILoggerServer, ILoggerClient, ConsoleLogger, rootLoggerName } from '../common/logger-protocol';
 
 @injectable()
 export class ConsoleLoggerServer implements ILoggerServer {
@@ -32,9 +32,13 @@ export class ConsoleLoggerServer implements ILoggerServer {
 
     @postConstruct()
     protected init(): void {
+        this.setLogLevel(rootLoggerName, this.cli.defaultLogLevel);
         for (const name of Object.keys(this.cli.logLevels)) {
             this.setLogLevel(name, this.cli.logLevels[name]);
         }
+        this.cli.onLogConfigChanged(() => {
+            this.client?.onLogConfigChanged();
+        });
     }
 
     async setLogLevel(name: string, newLogLevel: number): Promise<void> {