2 files changed, 120 insertions, 0 deletions
diff --git a/std b/std
deleted file mode 160000
-Subproject 43aafbf33285753e7b42230f0eb7969b300f71c
diff --git a/std/log/handlers.ts b/std/log/handlers.ts
new file mode 100644
index 000000000..5dfd0caa4
--- /dev/null
+++ b/std/log/handlers.ts
@@ -0,0 +1,120 @@
+// Copyright 2018-2019 the Deno authors. All rights reserved. MIT license.
+const { open } = Deno;
+type File = Deno.File;
+type Writer = Deno.Writer;
+import { getLevelByName, LogLevel } from "./levels.ts";
+import { LogRecord } from "./logger.ts";
+import { red, yellow, blue, bold } from "../fmt/colors.ts";
+
+const DEFAULT_FORMATTER = "{levelName} {msg}";
+type FormatterFunction = (logRecord: LogRecord) => string;
+
+interface HandlerOptions {
+  formatter?: string | FormatterFunction;
+}
+
+export class BaseHandler {
+  level: number;
+  levelName: string;
+  formatter: string | FormatterFunction;
+
+  constructor(levelName: string, options: HandlerOptions = {}) {
+    this.level = getLevelByName(levelName);
+    this.levelName = levelName;
+
+    this.formatter = options.formatter || DEFAULT_FORMATTER;
+  }
+
+  handle(logRecord: LogRecord): void {
+    if (this.level > logRecord.level) return;
+
+    const msg = this.format(logRecord);
+    return this.log(msg);
+  }
+
+  format(logRecord: LogRecord): string {
+    if (this.formatter instanceof Function) {
+      return this.formatter(logRecord);
+    }
+
+    return this.formatter.replace(
+      /{(\S+)}/g,
+      (match, p1): string => {
+        const value = logRecord[p1 as keyof LogRecord];
+
+        // do not interpolate missing values
+        if (!value) {
+          return match;
+        }
+
+        return String(value);
+      }
+    );
+  }
+
+  log(_msg: string): void {}
+  async setup(): Promise<void> {}
+  async destroy(): Promise<void> {}
+}
+
+export class ConsoleHandler extends BaseHandler {
+  format(logRecord: LogRecord): string {
+    let msg = super.format(logRecord);
+
+    switch (logRecord.level) {
+      case LogLevel.INFO:
+        msg = blue(msg);
+        break;
+      case LogLevel.WARNING:
+        msg = yellow(msg);
+        break;
+      case LogLevel.ERROR:
+        msg = red(msg);
+        break;
+      case LogLevel.CRITICAL:
+        msg = bold(red(msg));
+        break;
+      default:
+        break;
+    }
+
+    return msg;
+  }
+
+  log(msg: string): void {
+    console.log(msg);
+  }
+}
+
+export abstract class WriterHandler extends BaseHandler {
+  protected _writer!: Writer;
+  private _encoder = new TextEncoder();
+
+  log(msg: string): void {
+    this._writer.write(this._encoder.encode(msg + "\n"));
+  }
+}
+
+interface FileHandlerOptions extends HandlerOptions {
+  filename: string;
+}
+
+export class FileHandler extends WriterHandler {
+  private _file!: File;
+  private _filename: string;
+
+  constructor(levelName: string, options: FileHandlerOptions) {
+    super(levelName, options);
+    this._filename = options.filename;
+  }
+
+  async setup(): Promise<void> {
+    // open file in append mode - write only
+    this._file = await open(this._filename, "a");
+    this._writer = this._file;
+  }
+
+  async destroy(): Promise<void> {
+    await this._file.close();
+  }
+}