add hw2

node_modules/pino-abstract-transport/index.js

@@ -0,0 +1,128 @@
+'use strict'
+
+const metadata = Symbol.for('pino.metadata')
+const split = require('split2')
+const { Duplex } = require('readable-stream')
+const { parentPort, workerData } = require('worker_threads')
+
+function createDeferred () {
+  let resolve
+  let reject
+  const promise = new Promise((_resolve, _reject) => {
+    resolve = _resolve
+    reject = _reject
+  })
+  promise.resolve = resolve
+  promise.reject = reject
+  return promise
+}
+
+module.exports = function build (fn, opts = {}) {
+  const waitForConfig = opts.expectPinoConfig === true && workerData?.workerData?.pinoWillSendConfig === true
+  const parseLines = opts.parse === 'lines'
+  const parseLine = typeof opts.parseLine === 'function' ? opts.parseLine : JSON.parse
+  const close = opts.close || defaultClose
+  const stream = split(function (line) {
+    let value
+
+    try {
+      value = parseLine(line)
+    } catch (error) {
+      this.emit('unknown', line, error)
+      return
+    }
+
+    if (value === null) {
+      this.emit('unknown', line, 'Null value ignored')
+      return
+    }
+
+    if (typeof value !== 'object') {
+      value = {
+        data: value,
+        time: Date.now()
+      }
+    }
+
+    if (stream[metadata]) {
+      stream.lastTime = value.time
+      stream.lastLevel = value.level
+      stream.lastObj = value
+    }
+
+    if (parseLines) {
+      return line
+    }
+
+    return value
+  }, { autoDestroy: true })
+
+  stream._destroy = function (err, cb) {
+    const promise = close(err, cb)
+    if (promise && typeof promise.then === 'function') {
+      promise.then(cb, cb)
+    }
+  }
+
+  if (opts.expectPinoConfig === true && workerData?.workerData?.pinoWillSendConfig !== true) {
+    setImmediate(() => {
+      stream.emit('error', new Error('This transport is not compatible with the current version of pino. Please upgrade pino to the latest version.'))
+    })
+  }
+
+  if (opts.metadata !== false) {
+    stream[metadata] = true
+    stream.lastTime = 0
+    stream.lastLevel = 0
+    stream.lastObj = null
+  }
+
+  if (waitForConfig) {
+    let pinoConfig = {}
+    const configReceived = createDeferred()
+    parentPort.on('message', function handleMessage (message) {
+      if (message.code === 'PINO_CONFIG') {
+        pinoConfig = message.config
+        configReceived.resolve()
+        parentPort.off('message', handleMessage)
+      }
+    })
+
+    Object.defineProperties(stream, {
+      levels: {
+        get () { return pinoConfig.levels }
+      },
+      messageKey: {
+        get () { return pinoConfig.messageKey }
+      },
+      errorKey: {
+        get () { return pinoConfig.errorKey }
+      }
+    })
+
+    return configReceived.then(finish)
+  }
+
+  return finish()
+
+  function finish () {
+    let res = fn(stream)
+
+    if (res && typeof res.catch === 'function') {
+      res.catch((err) => {
+        stream.destroy(err)
+      })
+
+      // set it to null to not retain a reference to the promise
+      res = null
+    } else if (opts.enablePipelining && res) {
+      return Duplex.from({ writable: stream, readable: res })
+    }
+
+    return stream
+  }
+}
+
+function defaultClose (err, cb) {
+  process.nextTick(cb, err)
+}