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node-task/node_modules/mysql2/lib/compile_binary_parser.js

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2014-09-24 17:56:53 -04:00
var FieldFlags = require('./constants/field_flags');
var Charsets = require('./constants/charsets');
var Types = require('./constants/types');
var vm = require('vm');
var srcEscape = require('./helpers').srcEscape;
var typeNames = [];
for (var t in Types) {
typeNames[Types[t]] = t;
}
function compile(fields, options, config) {
var result = [];
var i=0;
var nullBitmapLength = Math.floor((fields.length + 7 + 2) / 8);
result.push('(function(){ return function BinaryRow(packet) {');
if (options.rowsAsArray)
result.push(' var result = new Array(' + fields.length + ')');
var resultTables = {};
var resultTablesArray = [];
if (options.nestTables === true) {
for (i = 0; i < fields.length; i++) {
resultTables[fields[i].table] = 1;
}
resultTablesArray = Object.keys(resultTables);
for (i = 0; i < resultTablesArray.length; i++) {
result.push(' this[' + srcEscape(resultTablesArray[i]) + '] = {};');
}
}
result.push(' var statusByte = packet.readInt8();');
for (i=0; i < nullBitmapLength; ++i)
result.push(' var nullBitmaskByte' + i + ' = packet.readInt8();');
var lvalue = '';
var currentFieldNullBit = 4;
var nullByteIndex = 0;
var fieldName = '';
var tableName = '';
for (i = 0; i < fields.length; i++) {
fieldName = srcEscape(fields[i].name);
result.push(' // ' + fieldName + ': '+ typeNames[fields[i].columnType]);
if (typeof options.nestTables == 'string') {
tableName = srcEscape(fields[i].table);
lvalue = [' this[', srcEscape(fields[i].table + options.nestTables + fields[i].name), ']'].join('');
} else if (options.nestTables === true) {
tableName = srcEscape(fields[i].table);
lvalue = [' this[', tableName, '][', fieldName, ']'].join('');
} else if (options.rowsAsArray) {
lvalue = ' result[' + i.toString(10) + ']';
} else
lvalue = ' this[' + srcEscape(fields[i].name) + ']';
if (fields[i].flags & FieldFlags.NOT_NULL) { // don't need to check null bitmap if field can't be null.
result.push(lvalue + ' = ' + readCodeFor(fields[i], config));
} else if (fields[i].columnType == Types.NULL) {
result.push(lvalue + ' = null;');
} else {
result.push(' if (nullBitmaskByte' + nullByteIndex + ' & ' + currentFieldNullBit + ')');
result.push(' ' + lvalue + ' = null;');
result.push(' else');
result.push(' ' + lvalue + ' = ' + readCodeFor(fields[i], config));
}
currentFieldNullBit *= 2;
if (currentFieldNullBit == 0x100)
{
currentFieldNullBit = 1;
nullByteIndex++;
}
}
if (options.rowsAsArray)
result.push(' return result;');
result.push('}; })()');
var src = result.join('\n');
if (config.debug) {
console.log('Compiled text protocol row parser:');
var cardinal = require('cardinal');
console.log(cardinal.highlight(src));
}
return vm.runInThisContext(src);
}
function readCodeFor(field, config) {
var unsigned = field.flags & FieldFlags.UNSIGNED;
switch(field.columnType) {
case Types.TINY:
return unsigned ? "packet.readInt8();" : "packet.readSInt8();";
case Types.SHORT:
return unsigned ? "packet.readInt16();" : "packet.readSInt16();";
case Types.LONG:
case Types.INT24: // in binary protocol int24 is encoded in 4 bytes int32
return unsigned ? "packet.readInt32();" : "packet.readSInt32();";
case Types.YEAR:
return "packet.readInt16()";
case Types.FLOAT:
return "packet.readFloat();";
case Types.DOUBLE:
return "packet.readDouble();";
case Types.NULL:
return "null;";
case Types.DATE:
case Types.DATETIME:
case Types.TIMESTAMP:
case Types.NEWDATE:
if (config.dateStrings)
return "packet.readDateTimeString();";
return "packet.readDateTime();";
case Types.TIME:
return "packet.readTimeString()";
case Types.DECIMAL:
case Types.NEWDECIMAL:
return "packet.readLengthCodedString();";
case Types.GEOMETRY:
return "packet.parseGeometryValue();";
case Types.LONGLONG: // TODO: 8 bytes. Implement as two 4 bytes read for now (it's out of JavaScript int precision!)
return unsigned ? "packet.readInt64();" : "packet.readSInt64();";
default:
if (field.characterSet == Charsets.BINARY)
return "packet.readLengthCodedBuffer();";
else
return "packet.readLengthCodedString();";
}
}
module.exports = compile;