node-postgres/lib/query.js
Alexander Sulfrian 37e958f779 added arrayParser
2011-01-28 18:06:05 +01:00

419 lines
11 KiB
JavaScript

var EventEmitter = require('events').EventEmitter;
var sys = require('sys');var sys = require('sys');
var Query = function(config) {
this.text = config.text;
this.values = config.values;
this.rows = config.rows;
this.types = config.types;
this.name = config.name;
//for code clarity purposes we'll declare this here though it's not
//set or used until a rowDescription message comes in
this.rowDescription = null;
this.callback = config.callback;
EventEmitter.call(this);
};
sys.inherits(Query, EventEmitter);
var p = Query.prototype;
p.requiresPreparation = function() {
return (this.values || 0).length > 0 || this.name || this.rows;
};
var noParse = function(val) {
return val;
};
p.submit = function(connection) {
var self = this;
if(this.requiresPreparation()) {
this.prepare(connection);
} else {
connection.query(this.text);
}
var converters = [];
var names = [];
var rows = [];
var handleRowDescription = function(msg) {
console.log(JSON.stringify(msg));
for(var i = 0; i < msg.fields.length; i++) {
converters[i] = dataTypeParsers[msg.fields[i].dataTypeID] || noParse;
names[i] = msg.fields[i].name;
};
};
var handleDatarow = function(msg) {
var result = {};
for(var i = 0; i < msg.fields.length; i++) {
var rawValue = msg.fields[i];
result[names[i]] = rawValue === null ? null : converters[i](rawValue);
console.log(names[i] + ": " + result[names[i]]);
}
self.emit('row', result);
//if no reciever, buffer rows
if(self.callback) {
rows.push(result);
}
};
var onCommandComplete = function() {
self.callback(null, {rows: rows});
rows = [];
}
if(self.callback) {
connection.on('commandComplete', onCommandComplete)
}
var onError = function(err) {
//remove all listeners
connection.removeListener('rowDescription', handleDatarow);
connection.removeListener('dataRow', handleDatarow);
connection.removeListener('error', onError);
connection.removeListener('readyForQuery', onReadyForQuery);
if(self.callback) {
self.callback(err);
connection.removeListener('commandComplete', onCommandComplete);
} else {
self.emit('error', err);
}
self.emit('end');
};
var onReadyForQuery = function() {
//remove all listeners
connection.removeListener('rowDescription', handleRowDescription);
connection.removeListener('dataRow', handleDatarow);
connection.removeListener('readyForQuery', onReadyForQuery);
connection.removeListener('error', onError);
if(self.callback) {
connection.removeListener('commandComplete', onCommandComplete);
}
self.emit('end');
};
connection.on('rowDescription', handleRowDescription);
connection.on('dataRow', handleDatarow);
connection.on('readyForQuery', onReadyForQuery);
connection.on('error', onError);
};
p.hasBeenParsed = function(connection) {
return this.name && connection.parsedStatements[this.name];
};
p.prepare = function(connection) {
var self = this;
if(!this.hasBeenParsed(connection)) {
connection.parsedStatements[this.name] = true;
connection.parse({
text: self.text,
name: self.name,
types: self.types
});
}
//TODO is there some btter way to prepare values for the database?
if(self.values) {
self.values = self.values.map(function(val) {
return (val instanceof Date) ? JSON.stringify(val) : val;
});
}
//http://developer.postgresql.org/pgdocs/postgres/protocol-flow.html#PROTOCOL-FLOW-EXT-QUERY
connection.bind({
portal: self.name,
statement: self.name,
values: self.values
});
connection.describe({
type: 'P',
name: self.name || ""
});
var getRows = function() {
connection.execute({
portal: self.name,
rows: self.rows
});
connection.flush();
};
getRows();
//TODO support EmptyQueryResponse, ErrorResponse, and PortalSuspended
var onCommandComplete = function() {
connection.removeListener('error', onCommandComplete);
connection.removeListener('commandComplete', onCommandComplete);
connection.removeListener('portalSuspended', getRows);
connection.sync();
};
connection.on('portalSuspended', getRows);
connection.on('commandComplete', onCommandComplete);
connection.on('error', onCommandComplete);
};
var dateParser = function(isoDate) {
//TODO find some regexp help
//this method works but it's ooglay
//if you wanna contribute...... ;)
var split = isoDate.split(' ');
var dateMatcher = /(\d{4})-(\d{2})-(\d{2})/;
var date = split[0];
var time = split[1];
var match = dateMatcher.exec(date);
var splitDate = date.split('-');
var year = match[1];
var month = parseInt(match[2],10)-1;
var day = match[3];
var splitTime = time.split(':');
var hour = parseInt(splitTime[0],10);
var min = parseInt(splitTime[1],10);
var end = splitTime[2];
var seconds = /(\d{2})/.exec(end);
seconds = (seconds ? seconds[1] : 0);
seconds = parseInt(seconds,10);
var mili = /\.(\d{1,})/.exec(end+"000");
mili = mili ? mili[1].slice(0,3) : 0;
var tZone = /([Z|+\-])(\d{2})?(\d{2})?/.exec(end);
//minutes to adjust for timezone
var tzAdjust = 0;
if(tZone) {
var type = tZone[1];
switch(type) {
case 'Z': break;
case '-':
tzAdjust = -(((parseInt(tZone[2],10)*60)+(parseInt(tZone[3]||0,10))));
break;
case '+':
tzAdjust = (((parseInt(tZone[2],10)*60)+(parseInt(tZone[3]||0,10))));
break;
default:
throw new Error("Unidentifed tZone part " + type);
}
}
var utcOffset = Date.UTC(year, month, day, hour, min, seconds, mili);
var date = new Date(utcOffset - (tzAdjust * 60* 1000));
return date;
};
function shl(a,b) {
// Copyright (c) 1996 Henri Torgemane. All Rights Reserved.
// fix for crappy <<
for (var i=0;i<b;i++) {
a=a%0x80000000;
if (a&0x40000000==0x40000000)
{
a-=0x40000000;
a*=2;
a+=0x80000000;
} else
a*=2;
};
return a;
}
var parseFloat = function(data, precisionBits, exponentBits) {
var bias = Math.pow(2, exponentBits - 1) - 1;
var sign = parseBits(data, 1);
var exponent = parseBits(data, exponentBits, 1);
if (exponent == 0)
return 0;
// parse mantissa
var precisionBitsCounter = 1;
var parsePrecisionBits = function(lastValue, newValue, bits) {
if (lastValue == 0) {
lastValue = 1;
}
for (var i = 1; i <= bits; i++) {
precisionBitsCounter /= 2;
if ((newValue & (0x1 << (bits - i))) > 0) {
lastValue += precisionBitsCounter;
}
}
return lastValue;
};
var mantissa = parseBits(data, precisionBits, exponentBits + 1, parsePrecisionBits);
// special cases
if (exponent == (Math.pow(2, exponentBits + 1) - 1)) {
if (mantissa == 0) {
return (sign == 0) ? Infinity : -Infinity;
}
return NaN;
}
// normale number
return ((sign == 0) ? 1 : -1) * Math.pow(2, exponent - bias) * mantissa;
};
var parseBits = function(data, bits, offset, callback) {
offset = offset || 0;
callback = callback || function(lastValue, newValue, bits) { return (lastValue * Math.pow(2, bits)) + newValue; };
var offsetBytes = offset >> 3;
// read first (maybe partial) byte
var mask = 0xff;
var firstBits = 8 - (offset % 8);
if (bits < firstBits) {
mask = (0xff << (8 - bits)) & 0xff;
firstBits = bits;
}
if (offset) {
mask = mask >> (offset % 8);
}
var result = callback(0, data[offsetBytes] & mask, firstBits);
// read bytes
var bytes = (bits + offset) >> 3;
for (var i = offsetBytes + 1; i < bytes; i++) {
result = callback(result, data[i], 8);
}
// bits to read, that are not a complete byte
var lastBits = (bits + offset) % 8;
if (lastBits > 0) {
result = callback(result, data[bytes] >> (8 - lastBits), lastBits);
}
return result;
}
var parseBinaryInt64 = function(value) {
return parseBits(value, 64);
}
var parseBinaryInt32 = function(value) {
return parseBits(value, 32);
}
var parseBinaryInt16 = function(value) {
return parseBits(value, 16);
}
var parseBinaryFloat32 = function(value) {
return parseFloat(value, 23, 8);
}
var parseBinaryFloat64 = function(value) {
return parseFloat(value, 52, 11);
}
var parseDate = function(value) {
var sign = parseBits(value, 1);
var rawValue = parseBits(value, 63, 1);
// discard usecs and shift from 2000 to 1970
return new Date((((sign == 0) ? 1 : -1) * rawValue / 1000) + 946684800000);
}
var arrayParser = function(value) {
var dim = parseBits(value, 32);
var flags = parseBits(value, 32, 32);
var elementType = parseBits(value, 32, 64);
var offset = 96;
var dims = new Array();
for (var i = 0; i < dim; i++) {
// parse dimension
dims[i] = parseBits(value, 32, offset);
offset += 32;
// ignore lower bounds
offset += 32;
};
var parseElement = function(elementType) {
// parse content length
var length = parseBits(value, 32, offset);
offset += 32;
// parse null values
if (length == 0xffffffff) {
return null;
}
if (elementType == 0x17) {
// int
var result = parseBits(value, length * 8, offset);
offset += length * 8;
return result;
}
else if (elementType == 0x19) {
// string
var result = value.toString('utf8', offset >> 3, (offset += (length << 3)) >> 3);
return result;
}
else {
console.log("ERROR: ElementType not implemented: " + elementType);
}
};
var parseArray = function(dimension, elementType) {
var array = new Array();
if (dimension.length > 1) {
var count = dimension.shift();
for (var i = 0; i < count; i++) {
array[i] = parseArray(dimension, elementType);
}
dimension.unshift(count);
}
else {
for (var i = 0; i < dimension[0]; i++) {
array[i] = parseElement(elementType);
}
}
return array;
}
return parseArray(dims, elementType);
};
// To help we test dateParser
Query.dateParser = dateParser;
var dataTypeParsers = {
16: function(dbVal) { //boolean
console.log(JSON.stringify(dbVal));
return value[0] == 1;
},
20: parseBinaryInt64,
21: parseBinaryInt16,
23: parseBinaryInt32,
26: parseBinaryInt64,
700: parseBinaryFloat32,
701: parseBinaryFloat64,
1007: arrayParser,
1009: arrayParser,
1114: parseDate,
//1184: parseBinaryInt64
// 1700: parseFloat,
};
module.exports = Query;