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qwen/nodejs/node_modules/pg/lib/connection.js

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+'use strict'
+
+const EventEmitter = require('events').EventEmitter
+
+const { parse, serialize } = require('pg-protocol')
+const { getStream, getSecureStream } = require('./stream')
+
+const flushBuffer = serialize.flush()
+const syncBuffer = serialize.sync()
+const endBuffer = serialize.end()
+
+// TODO(bmc) support binary mode at some point
+class Connection extends EventEmitter {
+  constructor(config) {
+    super()
+    config = config || {}
+
+    this.stream = config.stream || getStream(config.ssl)
+    if (typeof this.stream === 'function') {
+      this.stream = this.stream(config)
+    }
+
+    this._keepAlive = config.keepAlive
+    this._keepAliveInitialDelayMillis = config.keepAliveInitialDelayMillis
+    this.lastBuffer = false
+    this.parsedStatements = {}
+    this.ssl = config.ssl || false
+    this._ending = false
+    this._emitMessage = false
+    const self = this
+    this.on('newListener', function (eventName) {
+      if (eventName === 'message') {
+        self._emitMessage = true
+      }
+    })
+  }
+
+  connect(port, host) {
+    const self = this
+
+    this._connecting = true
+    this.stream.setNoDelay(true)
+    this.stream.connect(port, host)
+
+    this.stream.once('connect', function () {
+      if (self._keepAlive) {
+        self.stream.setKeepAlive(true, self._keepAliveInitialDelayMillis)
+      }
+      self.emit('connect')
+    })
+
+    const reportStreamError = function (error) {
+      // errors about disconnections should be ignored during disconnect
+      if (self._ending && (error.code === 'ECONNRESET' || error.code === 'EPIPE')) {
+        return
+      }
+      self.emit('error', error)
+    }
+    this.stream.on('error', reportStreamError)
+
+    this.stream.on('close', function () {
+      self.emit('end')
+    })
+
+    if (!this.ssl) {
+      return this.attachListeners(this.stream)
+    }
+
+    this.stream.once('data', function (buffer) {
+      const responseCode = buffer.toString('utf8')
+      switch (responseCode) {
+        case 'S': // Server supports SSL connections, continue with a secure connection
+          break
+        case 'N': // Server does not support SSL connections
+          self.stream.end()
+          return self.emit('error', new Error('The server does not support SSL connections'))
+        default:
+          // Any other response byte, including 'E' (ErrorResponse) indicating a server error
+          self.stream.end()
+          return self.emit('error', new Error('There was an error establishing an SSL connection'))
+      }
+      const options = {
+        socket: self.stream,
+      }
+
+      if (self.ssl !== true) {
+        Object.assign(options, self.ssl)
+
+        if ('key' in self.ssl) {
+          options.key = self.ssl.key
+        }
+      }
+
+      const net = require('net')
+      if (net.isIP && net.isIP(host) === 0) {
+        options.servername = host
+      }
+      try {
+        self.stream = getSecureStream(options)
+      } catch (err) {
+        return self.emit('error', err)
+      }
+      self.attachListeners(self.stream)
+      self.stream.on('error', reportStreamError)
+
+      self.emit('sslconnect')
+    })
+  }
+
+  attachListeners(stream) {
+    parse(stream, (msg) => {
+      const eventName = msg.name === 'error' ? 'errorMessage' : msg.name
+      if (this._emitMessage) {
+        this.emit('message', msg)
+      }
+      this.emit(eventName, msg)
+    })
+  }
+
+  requestSsl() {
+    this.stream.write(serialize.requestSsl())
+  }
+
+  startup(config) {
+    this.stream.write(serialize.startup(config))
+  }
+
+  cancel(processID, secretKey) {
+    this._send(serialize.cancel(processID, secretKey))
+  }
+
+  password(password) {
+    this._send(serialize.password(password))
+  }
+
+  sendSASLInitialResponseMessage(mechanism, initialResponse) {
+    this._send(serialize.sendSASLInitialResponseMessage(mechanism, initialResponse))
+  }
+
+  sendSCRAMClientFinalMessage(additionalData) {
+    this._send(serialize.sendSCRAMClientFinalMessage(additionalData))
+  }
+
+  _send(buffer) {
+    if (!this.stream.writable) {
+      return false
+    }
+    return this.stream.write(buffer)
+  }
+
+  query(text) {
+    this._send(serialize.query(text))
+  }
+
+  // send parse message
+  parse(query) {
+    this._send(serialize.parse(query))
+  }
+
+  // send bind message
+  bind(config) {
+    this._send(serialize.bind(config))
+  }
+
+  // send execute message
+  execute(config) {
+    this._send(serialize.execute(config))
+  }
+
+  flush() {
+    if (this.stream.writable) {
+      this.stream.write(flushBuffer)
+    }
+  }
+
+  sync() {
+    this._ending = true
+    this._send(syncBuffer)
+  }
+
+  ref() {
+    this.stream.ref()
+  }
+
+  unref() {
+    this.stream.unref()
+  }
+
+  end() {
+    // 0x58 = 'X'
+    this._ending = true
+    if (!this._connecting || !this.stream.writable) {
+      this.stream.end()
+      return
+    }
+    return this.stream.write(endBuffer, () => {
+      this.stream.end()
+    })
+  }
+
+  close(msg) {
+    this._send(serialize.close(msg))
+  }
+
+  describe(msg) {
+    this._send(serialize.describe(msg))
+  }
+
+  sendCopyFromChunk(chunk) {
+    this._send(serialize.copyData(chunk))
+  }
+
+  endCopyFrom() {
+    this._send(serialize.copyDone())
+  }
+
+  sendCopyFail(msg) {
+    this._send(serialize.copyFail(msg))
+  }
+}
+
+module.exports = Connection