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

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var EventEmitter = require('events').EventEmitter;
var defaults = require(__dirname + '/defaults');
var genericPool = require('generic-pool');
var pools = {
//dictionary of all key:pool pairs
all: {},
//reference to the client constructor - can override in tests or for require('pg').native
Client: require(__dirname + '/client'),
getOrCreate: function(clientConfig) {
clientConfig = clientConfig || {};
var name = JSON.stringify(clientConfig);
var pool = pools.all[name];
if(pool) {
return pool;
}
pool = genericPool.Pool({
name: name,
max: clientConfig.poolSize || defaults.poolSize,
idleTimeoutMillis: clientConfig.poolIdleTimeout || defaults.poolIdleTimeout,
reapIntervalMillis: clientConfig.reapIntervalMillis || defaults.reapIntervalMillis,
log: clientConfig.poolLog || defaults.poolLog,
create: function(cb) {
var client = new pools.Client(clientConfig);
client.connect(function(err) {
if(err) return cb(err, null);
//handle connected client background errors by emitting event
//via the pg object and then removing errored client from the pool
client.on('error', function(e) {
pool.emit('error', e, client);
// If the client is already being destroyed, the error
// occurred during stream ending. Do not attempt to destroy
// the client again.
if (!client._destroying) {
pool.destroy(client);
}
});
// Remove connection from pool on disconnect
client.on('end', function(e) {
// Do not enter infinite loop between pool.destroy
// and client 'end' event...
if ( ! client._destroying ) {
pool.destroy(client);
}
});
client.poolCount = 0;
return cb(null, client);
});
},
destroy: function(client) {
client._destroying = true;
client.poolCount = undefined;
client.end();
}
});
pools.all[name] = pool;
//mixin EventEmitter to pool
EventEmitter.call(pool);
for(var key in EventEmitter.prototype) {
if(EventEmitter.prototype.hasOwnProperty(key)) {
pool[key] = EventEmitter.prototype[key];
}
}
//monkey-patch with connect method
pool.connect = function(cb) {
var domain = process.domain;
pool.acquire(function(err, client) {
if(domain) {
cb = domain.bind(cb);
}
if(err) return cb(err, null, function() {/*NOOP*/});
client.poolCount++;
cb(null, client, function(err) {
if(err) {
pool.destroy(client);
} else {
pool.release(client);
}
});
});
};
return pool;
}
};
module.exports = pools;