Add pino.multistream

benchmarks/multistream.js

@@ -0,0 +1,98 @@
+'use strict'
+
+const bench = require('fastbench')
+const bunyan = require('bunyan')
+const pino = require('../')
+const fs = require('fs')
+const dest = fs.createWriteStream('/dev/null')
+
+const tenStreams = [
+  { stream: dest },
+  { stream: dest },
+  { stream: dest },
+  { stream: dest },
+  { stream: dest },
+  { level: 'debug', stream: dest },
+  { level: 'debug', stream: dest },
+  { level: 'trace', stream: dest },
+  { level: 'warn', stream: dest },
+  { level: 'fatal', stream: dest }
+]
+const pinomsTen = pino({ level: 'debug' }, pino.multistream(tenStreams))
+
+const fourStreams = [
+  { stream: dest },
+  { stream: dest },
+  { level: 'debug', stream: dest },
+  { level: 'trace', stream: dest }
+]
+const pinomsFour = pino({ level: 'debug' }, pino.multistream(fourStreams))
+
+const pinomsOne = pino({ level: 'info' }, pino.multistream(dest))
+const blogOne = bunyan.createLogger({
+  name: 'myapp',
+  streams: [{ stream: dest }]
+})
+
+const blogTen = bunyan.createLogger({
+  name: 'myapp',
+  streams: tenStreams
+})
+const blogFour = bunyan.createLogger({
+  name: 'myapp',
+  streams: fourStreams
+})
+
+const max = 10
+const run = bench([
+  function benchBunyanTen (cb) {
+    for (let i = 0; i < max; i++) {
+      blogTen.info('hello world')
+      blogTen.debug('hello world')
+      blogTen.trace('hello world')
+      blogTen.warn('hello world')
+      blogTen.fatal('hello world')
+    }
+    setImmediate(cb)
+  },
+  function benchPinoMSTen (cb) {
+    for (let i = 0; i < max; i++) {
+      pinomsTen.info('hello world')
+      pinomsTen.debug('hello world')
+      pinomsTen.trace('hello world')
+      pinomsTen.warn('hello world')
+      pinomsTen.fatal('hello world')
+    }
+    setImmediate(cb)
+  },
+  function benchBunyanFour (cb) {
+    for (let i = 0; i < max; i++) {
+      blogFour.info('hello world')
+      blogFour.debug('hello world')
+      blogFour.trace('hello world')
+    }
+    setImmediate(cb)
+  },
+  function benchPinoMSFour (cb) {
+    for (let i = 0; i < max; i++) {
+      pinomsFour.info('hello world')
+      pinomsFour.debug('hello world')
+      pinomsFour.trace('hello world')
+    }
+    setImmediate(cb)
+  },
+  function benchBunyanOne (cb) {
+    for (let i = 0; i < max; i++) {
+      blogOne.info('hello world')
+    }
+    setImmediate(cb)
+  },
+  function benchPinoMSOne (cb) {
+    for (let i = 0; i < max; i++) {
+      pinomsOne.info('hello world')
+    }
+    setImmediate(cb)
+  }
+], 10000)
+
+run()

docs/api.md

@@ -24,6 +24,7 @@
 * [Statics](#statics)
   * [pino.destination()](#pino-destination)
   * [pino.final()](#pino-final)
+  * [pino.multistream()](#pino-multistream)
   * [pino.stdSerializers](#pino-stdserializers)
   * [pino.stdTimeFunctions](#pino-stdtimefunctions)
   * [pino.symbols](#pino-symbols)
@@ -938,6 +939,73 @@ finalLogger.info('exiting...')
 * See [Asynchronous logging ⇗](/docs/asynchronous.md)
 * See [Log loss prevention ⇗](/docs/asynchronous.md#log-loss-prevention)
 
+<a id="pino-multistream"></a>
+
+### `pino.multistream(options) => Stream`
+
+Create a stream composed by multiple destination streams:
+
+```js
+var fs = require('fs')
+var pino = require('pino')
+var streams = [
+  {stream: fs.createWriteStream('/tmp/info.stream.out')},
+  {level: 'debug', stream: fs.createWriteStream('/tmp/debug.stream.out')},
+  {level: 'fatal', stream: fs.createWriteStream('/tmp/fatal.stream.out')}
+]
+
+var log = pino({
+  level: 'debug' // this MUST be set at the lowest level of the
+                 // destinations
+}, pino.multistream(streams))
+
+log.debug('this will be written to /tmp/debug.stream.out')
+log.info('this will be written to /tmp/debug.stream.out and /tmp/info.stream.out')
+log.fatal('this will be written to /tmp/debug.stream.out, /tmp/info.stream.out and /tmp/fatal.stream.out')
+```
+
+In order for `multistream` to work, the log level _____must__ be set to the lowest level used in the streams array.
+
+#### Options
+
+* `levels`:  Pass custom log level definitions to the instance as an object.
+
++ `dedupe`: Set this to `true` to send logs only to the stream with the higher level. Default: `false`
+
+    `dedupe` flag can be useful for example when using pino-multi-stream to redirect `error` logs to `process.stderr` and others to `process.stdout`:
+
+    ```js
+    var pino = require('pino')
+    var multistream = require('pino-multi-stream').multistream
+    var streams = [
+      {stream: process.stdout},
+      {level: 'error', stream: process.stderr},
+    ]
+
+    var opts = {
+        levels: {
+            silent: Infinity,
+            fatal: 60,
+            error: 50,
+            warn: 50,
+            info: 30,
+            debug: 20,
+            trace: 10
+        },
+        dedupe: true,
+    }
+
+    var log = pino({
+      level: 'debug' // this MUST be set at the lowest level of the
+                    // destinations
+    }, multistream(streams, opts))
+
+    log.debug('this will be written ONLY to process.stdout')
+    log.info('this will be written ONLY to process.stdout')
+    log.error('this will be written ONLY to process.stderr')
+    log.fatal('this will be written ONLY to process.stderr')
+    ```
+
 <a id="pino-stdserializers"></a>
 ### `pino.stdSerializers` (Object)
 

docs/help.md

@@ -118,20 +118,7 @@ Given a similar scenario as in the [Log rotation](#rotate) section a basic
 <a id="multiple"></a>
 ## Saving to multiple files
 
-Let's assume we want to store all error messages to a separate log file.
-
-Install [pino-tee](https://npm.im/pino-tee) with:
-
-```bash
-npm i pino-tee -g
-```
-
-The following writes the log output of `app.js` to `./all-logs`, while
-writing only warnings and errors to `./warn-log:
-
-```bash
-node app.js | pino-tee warn ./warn-logs > ./all-logs
-```
+See [`pino.multistream`](/doc/api.md#pino-multistream).
 
 <a id="filter-logs"></a>
 ## Log Filtering
@@ -164,14 +151,13 @@ ExecStart=/bin/sh -c '/path/to/node app.js | pino-transport'
 
 Pino's default log destination is the singular destination of `stdout`. While
 not recommended for performance reasons, multiple destinations can be targeted
-by using [`pino-multi-stream`](https://github.com/pinojs/pino-multi-stream).
+by using [`pino.multistream`](/doc/api.md#pino-multistream).
 
 In this example we use `stderr` for `error` level logs and `stdout` as default
 for all other levels (e.g. `debug`, `info`, and `warn`).
 
 ```js
 const pino = require('pino')
-const { multistream } = require('pino-multi-stream')
 var streams = [
   {level: 'debug', stream: process.stdout},
   {level: 'error', stream: process.stderr},
@@ -180,11 +166,10 @@ var streams = [
 
 const logger = pino({
   name: 'my-app',
-  level: 'info',
-}, multistream(streams))
+  level: 'debug', // must be the lower level of all streams
+}, pino.multistream(streams))
 ```
 
-
 <a id="dupe-keys"></a>
 ## How Pino handles duplicate keys
 

lib/multistream.js

@@ -0,0 +1,138 @@
+'use strict'
+
+const metadata = Symbol.for('pino.metadata')
+
+const defaultLevels = {
+  silent: Infinity,
+  fatal: 60,
+  error: 50,
+  warn: 40,
+  info: 30,
+  debug: 20,
+  trace: 10
+}
+
+function multistream (streamsArray, opts) {
+  let counter = 0
+
+  streamsArray = streamsArray || []
+  opts = opts || { dedupe: false }
+
+  let levels = defaultLevels
+  if (opts.levels && typeof opts.levels === 'object') {
+    levels = opts.levels
+  }
+
+  const res = {
+    write,
+    add,
+    flushSync,
+    minLevel: 0,
+    streams: [],
+    clone,
+    [metadata]: true
+  }
+
+  if (Array.isArray(streamsArray)) {
+    streamsArray.forEach(add, res)
+  } else {
+    add.call(res, streamsArray)
+  }
+
+  // clean this object up
+  // or it will stay allocated forever
+  // as it is closed on the following closures
+  streamsArray = null
+
+  return res
+
+  // we can exit early because the streams are ordered by level
+  function write (data) {
+    let dest
+    const level = this.lastLevel
+    const { streams } = this
+    let stream
+    for (let i = 0; i < streams.length; i++) {
+      dest = streams[i]
+      if (dest.level <= level) {
+        stream = dest.stream
+        if (stream[metadata]) {
+          const { lastTime, lastMsg, lastObj, lastLogger } = this
+          stream.lastLevel = level
+          stream.lastTime = lastTime
+          stream.lastMsg = lastMsg
+          stream.lastObj = lastObj
+          stream.lastLogger = lastLogger
+        }
+        if (!opts.dedupe) {
+          stream.write(data)
+        }
+      } else {
+        break
+      }
+    }
+
+    if (opts.dedupe && stream) {
+      stream.write(data)
+    }
+  }
+
+  function flushSync () {
+    for (const { stream } of this.streams) {
+      if (typeof stream.flushSync === 'function') {
+        stream.flushSync()
+      }
+    }
+  }
+
+  function add (dest) {
+    const { streams } = this
+    if (typeof dest.write === 'function') {
+      return add.call(this, { stream: dest })
+    } else if (typeof dest.levelVal === 'number') {
+      return add.call(this, Object.assign({}, dest, { level: dest.levelVal, levelVal: undefined }))
+    } else if (typeof dest.level === 'string') {
+      return add.call(this, Object.assign({}, dest, { level: levels[dest.level] }))
+    } else if (typeof dest.level !== 'number') {
+      // we default level to 'info'
+      dest = Object.assign({}, dest, { level: 30 })
+    } else {
+      dest = Object.assign({}, dest)
+    }
+    dest.id = counter++
+
+    streams.unshift(dest)
+    streams.sort(compareByLevel)
+
+    this.minLevel = streams[0].level
+
+    return res
+  }
+
+  function clone (level) {
+    const streams = new Array(this.streams.length)
+
+    for (let i = 0; i < streams.length; i++) {
+      streams[i] = {
+        level: level,
+        stream: this.streams[i].stream
+      }
+    }
+
+    return {
+      write,
+      add,
+      minLevel: level,
+      streams,
+      clone,
+      flushSync,
+      [metadata]: true
+    }
+  }
+}
+
+function compareByLevel (a, b) {
+  return a.level - b.level
+}
+
+module.exports = multistream