feat: initial proposal for multithreaded execution

src/logging/Logger.ts

@@ -1,5 +1,14 @@
+import cluster from 'cluster';
+import process from 'process';
 import type { LogLevel } from './LogLevel';
 
+export interface LogMetadata {
+  /** Is the current process the Primary process */
+  isPrimary: boolean;
+  /** The process id of the current process */
+  pid: number;
+}
+
 /**
  * Logs messages on a specific level.
  *
@@ -13,7 +22,7 @@ export interface SimpleLogger {
    * @param message - The message to log.
    * @param meta - Optional metadata to include in the log message.
    */
-  log: (level: LogLevel, message: string) => SimpleLogger;
+  log: (level: LogLevel, message: string, meta?: LogMetadata) => SimpleLogger;
 }
 
 /**
@@ -79,30 +88,35 @@ export interface Logger extends SimpleLogger {
  * leaving only the implementation of {@link SimpleLogger}.
  */
 export abstract class BaseLogger implements Logger {
-  public abstract log(level: LogLevel, message: string): Logger;
+  public abstract log(level: LogLevel, message: string, meta?: LogMetadata): Logger;
+
+  private readonly getMeta = (): LogMetadata => ({
+    pid: process.pid,
+    isPrimary: cluster.isMaster,
+  });
 
   public error(message: string): Logger {
-    return this.log('error', message);
+    return this.log('error', message, this.getMeta());
   }
 
   public warn(message: string): Logger {
-    return this.log('warn', message);
+    return this.log('warn', message, this.getMeta());
   }
 
   public info(message: string): Logger {
-    return this.log('info', message);
+    return this.log('info', message, this.getMeta());
   }
 
   public verbose(message: string): Logger {
-    return this.log('verbose', message);
+    return this.log('verbose', message, this.getMeta());
   }
 
   public debug(message: string): Logger {
-    return this.log('debug', message);
+    return this.log('debug', message, this.getMeta());
   }
 
   public silly(message: string): Logger {
-    return this.log('silly', message);
+    return this.log('silly', message, this.getMeta());
   }
 }
 
@@ -118,8 +132,8 @@ export class WrappingLogger extends BaseLogger {
     this.logger = logger;
   }
 
-  public log(level: LogLevel, message: string): this {
-    this.logger.log(level, message);
+  public log(level: LogLevel, message: string, meta?: LogMetadata): this {
+    this.logger.log(level, message, meta);
     return this;
   }
 }

src/logging/WinstonLoggerFactory.ts

@@ -1,6 +1,6 @@
 import { createLogger, format, transports } from 'winston';
 import type * as Transport from 'winston-transport';
-import type { Logger } from './Logger';
+import type { Logger, LogMetadata } from './Logger';
 import type { LoggerFactory } from './LoggerFactory';
 import { WinstonLogger } from './WinstonLogger';
 
@@ -17,6 +17,13 @@ export class WinstonLoggerFactory implements LoggerFactory {
     this.level = level;
   }
 
+  private readonly clusterInfo = (meta: LogMetadata): string => {
+    if (meta.isPrimary) {
+      return 'Primary';
+    }
+    return `W-${meta.pid ?? '???'}`;
+  };
+
   public createLogger(label: string): Logger {
     return new WinstonLogger(createLogger({
       level: this.level,
@@ -24,8 +31,10 @@ export class WinstonLoggerFactory implements LoggerFactory {
         format.label({ label }),
         format.colorize(),
         format.timestamp(),
-        format.printf(({ level: levelInner, message, label: labelInner, timestamp }: Record<string, any>): string =>
-          `${timestamp} [${labelInner}] ${levelInner}: ${message}`),
+        format.metadata({ fillExcept: [ 'level', 'timestamp', 'label', 'message' ]}),
+        format.printf(({ level: levelInner, message, label: labelInner, timestamp, metadata: meta }:
+        Record<string, any>): string =>
+          `${timestamp} [${labelInner}] {${this.clusterInfo(meta)}} ${levelInner}: ${message}`),
       ),
       transports: this.createTransports(),
     }));