var Util = require('util'); var EventEmitter = require('events').EventEmitter; var Packets = require('../packets'); var ErrorConstants = require('../constants/errors'); var listenerCount = EventEmitter.listenerCount || function(emitter, type){ return emitter.listeners(type).length; }; module.exports = Sequence; Util.inherits(Sequence, EventEmitter); function Sequence(options, callback) { if (typeof options === 'function') { callback = options; options = {}; } EventEmitter.call(this); options = options || {}; this._callback = callback; this._callSite = null; this._ended = false; this._timeout = options.timeout; // For Timers this._idleNext = null; this._idlePrev = null; this._idleStart = null; this._idleTimeout = undefined; this._repeat = null; } Sequence.determinePacket = function(byte) { switch (byte) { case 0x00: return Packets.OkPacket; case 0xfe: return Packets.EofPacket; case 0xff: return Packets.ErrorPacket; } }; Sequence.prototype.hasErrorHandler = function() { return Boolean(this._callback) || listenerCount(this, 'error') > 1; }; Sequence.prototype._packetToError = function(packet) { var code = ErrorConstants[packet.errno] || 'UNKNOWN_CODE_PLEASE_REPORT'; var err = new Error(code + ': ' + packet.message); err.code = code; err.errno = packet.errno; err.sqlState = packet.sqlState; return err; }; Sequence.prototype._addLongStackTrace = function _addLongStackTrace(err) { if (!this._callSite || !this._callSite.stack) { return; } var delimiter = '\n --------------------\n'; if (err.stack.indexOf(delimiter) > -1) { return; } err.stack += delimiter + this._callSite.stack.replace(/.+\n/, ''); }; Sequence.prototype.end = function(err) { if (this._ended) { return; } this._ended = true; if (err) { this._addLongStackTrace(err); } // Without this we are leaking memory. This problem was introduced in // 8189925374e7ce3819bbe88b64c7b15abac96b16. I suspect that the error object // causes a cyclic reference that the GC does not detect properly, but I was // unable to produce a standalone version of this leak. This would be a great // challenge for somebody interested in difficult problems : )! this._callSite = null; // try...finally for exception safety try { if (err) { this.emit('error', err); } } finally { try { if (this._callback) { this._callback.apply(this, arguments); } } finally { this.emit('end'); } } }; Sequence.prototype['OkPacket'] = function(packet) { this.end(null, packet); }; Sequence.prototype['ErrorPacket'] = function(packet) { this.end(this._packetToError(packet)); }; // Implemented by child classes Sequence.prototype.start = function() {}; Sequence.prototype._onTimeout = function _onTimeout() { this.emit('timeout'); };