First commit

node_modules/pino/lib/multistream.js

@@ -0,0 +1,203 @@
+'use strict'
+
+const metadata = Symbol.for('pino.metadata')
+const { DEFAULT_LEVELS } = require('./constants')
+
+const DEFAULT_INFO_LEVEL = DEFAULT_LEVELS.info
+
+function multistream (streamsArray, opts) {
+  streamsArray = streamsArray || []
+  opts = opts || { dedupe: false }
+
+  const streamLevels = Object.create(DEFAULT_LEVELS)
+  streamLevels.silent = Infinity
+  if (opts.levels && typeof opts.levels === 'object') {
+    Object.keys(opts.levels).forEach(i => {
+      streamLevels[i] = opts.levels[i]
+    })
+  }
+
+  const res = {
+    write,
+    add,
+    remove,
+    emit,
+    flushSync,
+    end,
+    minLevel: 0,
+    lastId: 0,
+    streams: [],
+    clone,
+    [metadata]: true,
+    streamLevels
+  }
+
+  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
+    // for handling situation when several streams has the same level
+    let recordedLevel = 0
+    let stream
+
+    // if dedupe set to true we send logs to the stream with the highest level
+    // therefore, we have to change sorting order
+    for (let i = initLoopVar(streams.length, opts.dedupe); checkLoopVar(i, streams.length, opts.dedupe); i = adjustLoopVar(i, opts.dedupe)) {
+      dest = streams[i]
+      if (dest.level <= level) {
+        if (recordedLevel !== 0 && recordedLevel !== dest.level) {
+          break
+        }
+        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
+        }
+        stream.write(data)
+        if (opts.dedupe) {
+          recordedLevel = dest.level
+        }
+      } else if (!opts.dedupe) {
+        break
+      }
+    }
+  }
+
+  function emit (...args) {
+    for (const { stream } of this.streams) {
+      if (typeof stream.emit === 'function') {
+        stream.emit(...args)
+      }
+    }
+  }
+
+  function flushSync () {
+    for (const { stream } of this.streams) {
+      if (typeof stream.flushSync === 'function') {
+        stream.flushSync()
+      }
+    }
+  }
+
+  function add (dest) {
+    if (!dest) {
+      return res
+    }
+
+    // Check that dest implements either StreamEntry or DestinationStream
+    const isStream = typeof dest.write === 'function' || dest.stream
+    const stream_ = dest.write ? dest : dest.stream
+    // This is necessary to provide a meaningful error message, otherwise it throws somewhere inside write()
+    if (!isStream) {
+      throw Error('stream object needs to implement either StreamEntry or DestinationStream interface')
+    }
+
+    const { streams, streamLevels } = this
+
+    let level
+    if (typeof dest.levelVal === 'number') {
+      level = dest.levelVal
+    } else if (typeof dest.level === 'string') {
+      level = streamLevels[dest.level]
+    } else if (typeof dest.level === 'number') {
+      level = dest.level
+    } else {
+      level = DEFAULT_INFO_LEVEL
+    }
+
+    const dest_ = {
+      stream: stream_,
+      level,
+      levelVal: undefined,
+      id: ++res.lastId
+    }
+
+    streams.unshift(dest_)
+    streams.sort(compareByLevel)
+
+    this.minLevel = streams[0].level
+
+    return res
+  }
+
+  function remove (id) {
+    const { streams } = this
+    const index = streams.findIndex(s => s.id === id)
+
+    if (index >= 0) {
+      streams.splice(index, 1)
+      streams.sort(compareByLevel)
+      this.minLevel = streams.length > 0 ? streams[0].level : -1
+    }
+
+    return res
+  }
+
+  function end () {
+    for (const { stream } of this.streams) {
+      if (typeof stream.flushSync === 'function') {
+        stream.flushSync()
+      }
+      stream.end()
+    }
+  }
+
+  function clone (level) {
+    const streams = new Array(this.streams.length)
+
+    for (let i = 0; i < streams.length; i++) {
+      streams[i] = {
+        level,
+        stream: this.streams[i].stream
+      }
+    }
+
+    return {
+      write,
+      add,
+      remove,
+      minLevel: level,
+      streams,
+      clone,
+      emit,
+      flushSync,
+      [metadata]: true
+    }
+  }
+}
+
+function compareByLevel (a, b) {
+  return a.level - b.level
+}
+
+function initLoopVar (length, dedupe) {
+  return dedupe ? length - 1 : 0
+}
+
+function adjustLoopVar (i, dedupe) {
+  return dedupe ? i - 1 : i + 1
+}
+
+function checkLoopVar (i, length, dedupe) {
+  return dedupe ? i >= 0 : i < length
+}
+
+module.exports = multistream