node-query/node_modules/mysql2/lib/pool.js

178 lines
4.1 KiB
JavaScript

var mysql = require('../index.js');
var Connection = mysql.Connection;
var EventEmitter = require('events').EventEmitter;
var Util = require('util');
var PoolConnection = require('./pool_connection.js');
module.exports = Pool;
Util.inherits(Pool, EventEmitter);
function Pool(options) {
EventEmitter.call(this);
this.config = options.config;
this.config.connectionConfig.pool = this;
this._allConnections = [];
this._freeConnections = [];
this._connectionQueue = [];
this._closed = false;
}
Pool.prototype.getConnection = function (cb) {
if (this._closed) {
return process.nextTick(function(){
return cb(new Error('Pool is closed.'));
});
}
var connection;
if (this._freeConnections.length > 0) {
connection = this._freeConnections.shift();
return process.nextTick(function(){
return cb(null, connection);
});
}
if (this.config.connectionLimit === 0 || this._allConnections.length < this.config.connectionLimit) {
connection = new PoolConnection(this, { config: this.config.connectionConfig });
this._allConnections.push(connection);
return connection.connect(function(err) {
if (this._closed) {
return cb(new Error('Pool is closed.'));
}
if (err) {
return cb(err);
}
this.emit('connection', connection);
return cb(null, connection);
}.bind(this));
}
if (!this.config.waitForConnections) {
return process.nextTick(function(){
return cb(new Error('No connections available.'));
});
}
if (this.config.queueLimit && this._connectionQueue.length >= this.config.queueLimit) {
return cb(new Error('Queue limit reached.'));
}
this._connectionQueue.push(cb);
};
Pool.prototype.releaseConnection = function (connection) {
var cb;
if (!connection._pool) {
// The connection has been removed from the pool and is no longer good.
if (this._connectionQueue.length) {
cb = this._connectionQueue.shift();
process.nextTick(this.getConnection.bind(this, cb));
}
} else if (this._connectionQueue.length) {
cb = this._connectionQueue.shift();
process.nextTick(cb.bind(null, null, connection));
} else {
this._freeConnections.push(connection);
}
};
Pool.prototype.end = function (cb) {
this._closed = true;
if (typeof cb != "function") {
cb = function (err) {
if (err) throw err;
};
}
var calledBack = false;
var closedConnections = 0;
var connection;
var endCB = function(err) {
if (calledBack) {
return;
}
if (err || ++closedConnections >= this._allConnections.length) {
calledBack = true;
return cb(err);
}
}.bind(this);
if (this._allConnections.length === 0) {
return endCB();
}
for (var i = 0; i < this._allConnections.length; i++) {
connection = this._allConnections[i];
connection._realEnd(endCB);
}
};
Pool.prototype.query = function (sql, values, cb) {
if (typeof values === 'function') {
cb = values;
values = null;
}
this.getConnection(function (err, conn) {
if (err) return cb(err);
conn.query(sql, values, function () {
conn.release();
cb.apply(this, arguments);
});
});
};
Pool.prototype.execute = function (sql, values, cb) {
if (typeof values === 'function') {
cb = values;
values = null;
}
this.getConnection(function (err, conn) {
if (err) return cb(err);
conn.execute(sql, values, function () {
conn.release();
cb.apply(this, arguments);
});
});
};
Pool.prototype._removeConnection = function(connection) {
var i;
for (i = 0; i < this._allConnections.length; i++) {
if (this._allConnections[i] === connection) {
this._allConnections.splice(i, 1);
break;
}
}
for (i = 0; i < this._freeConnections.length; i++) {
if (this._freeConnections[i] === connection) {
this._freeConnections.splice(i, 1);
break;
}
}
this.releaseConnection(connection);
};
Pool.prototype.escape = function(value) {
return mysql.escape(value, this.config.connectionConfig.stringifyObjects, this.config.connectionConfig.timezone);
};