DziennikOcen/node_modules/mysql/lib/protocol/sequences/Sequence.js
User Kill3rs4 84150f8404 Initial D
2022-01-11 20:18:26 +01:00

126 lines
3.2 KiB
JavaScript

var Util = require('util');
var EventEmitter = require('events').EventEmitter;
var Packets = require('../packets');
var ErrorConstants = require('../constants/errors');
var Timer = require('../Timer');
// istanbul ignore next: Node.js < 0.10 not covered
var listenerCount = EventEmitter.listenerCount
|| function(emitter, type){ return emitter.listeners(type).length; };
var LONG_STACK_DELIMITER = '\n --------------------\n';
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;
this._timer = new Timer(this);
}
Sequence.determinePacket = function(byte) {
switch (byte) {
case 0x00: return Packets.OkPacket;
case 0xfe: return Packets.EofPacket;
case 0xff: return Packets.ErrorPacket;
default: return undefined;
}
};
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.sqlMessage = packet.message;
err.sqlState = packet.sqlState;
return err;
};
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._addLongStackTrace = function _addLongStackTrace(err) {
var callSiteStack = this._callSite && this._callSite.stack;
if (!callSiteStack || typeof callSiteStack !== 'string') {
// No recorded call site
return;
}
if (err.stack.indexOf(LONG_STACK_DELIMITER) !== -1) {
// Error stack already looks long
return;
}
var index = callSiteStack.indexOf('\n');
if (index !== -1) {
// Append recorded call site
err.stack += LONG_STACK_DELIMITER + callSiteStack.substr(index + 1);
}
};
Sequence.prototype._onTimeout = function _onTimeout() {
this.emit('timeout');
};