added Iconv-lite based parser

Author: sushantdhiman

lib/packets/packet.js

@@ -3,6 +3,7 @@ var ErrorCodeToName = require('../constants/errors.js');
 var NativeBuffer = require('buffer').Buffer;
 var Buffer = require('safe-buffer').Buffer;
 var Long = require('long');
+var StringParser = require('../parsers/string.js');
 
 function Packet (id, buffer, start, end)
 {
@@ -348,7 +349,10 @@ Packet.prototype.readLengthCodedString = function () {
     return null;
   }
   this.offset += len;
-  return this.buffer.utf8Slice(this.offset - len, this.offset);
+
+  // becuase MySQL utf8 is actually cesu8
+  // https://github.com/sidorares/node-mysql2/pull/374
+  return StringParser.decode(this.buffer.slice(this.offset - len, this.offset), 'cesu8');
 };
 
 Packet.prototype.readLengthCodedBuffer = function () {
@@ -736,9 +740,12 @@ Packet.prototype.writeString = function (s) {
     return;
   }
 
-  var bytes = Buffer.byteLength(s, 'utf8');
-  this.buffer.write(s, this.offset, bytes, 'utf8');
-  this.offset += bytes;
+  // var bytes = Buffer.byteLength(s, 'utf8');
+  // this.buffer.write(s, this.offset, bytes, 'utf8');
+  // this.offset += bytes;
+
+  var buf = StringParser.encode(s, 'cesu8');
+  this.offset += buf.copy(this.buffer, this.offset);
 };
 
 Packet.prototype.writeLengthCodedString = function (s) {

lib/packets/query.js

@@ -1,15 +1,18 @@
 var Buffer = require('safe-buffer').Buffer;
 var Packet = require('../packets/packet.js');
 var CommandCode = require('../constants/commands.js');
+var StringParser = require('../parsers/string.js');
 
-function Query (sql)
+function Query (sql, charsetNumber)
 {
   this.query = sql;
+  this.charsetNumber = charsetNumber;
 }
 
 Query.prototype.toPacket = function ()
 {
-  var length = 5 + Buffer.byteLength(this.query, 'utf8');
+  var buf = StringParser.encode(this.query, 'cesu8');
+  var length = 5 + buf.length;
   var buffer = Buffer.allocUnsafe(length);
   var packet = new Packet(0, buffer, 0, length);
   packet.offset = 4;

lib/parsers/string.js

@@ -0,0 +1,38 @@
+var Iconv = require('iconv-lite');
+var ParserCache = {};
+
+function StringParser (encoding, options) {
+  options = options || {};
+  this.encoding = encoding;
+  this.encoder = Iconv.getEncoder(encoding, options);
+  this.decoder = Iconv.getDecoder(encoding, options);
+}
+
+var prepareParser = function (encoding, options) {
+  // if available use existing parser
+  if (ParserCache[encoding]) {
+    return ParserCache[encoding];
+  }
+
+  // other wise prepare, cache and return
+  ParserCache[encoding] = new StringParser(encoding, options);
+  return ParserCache[encoding];
+};
+
+exports.decode = function (buffer, encoding) {
+  var parser = prepareParser(encoding);
+
+  var res = parser.decoder.write(buffer);
+  var trail = parser.decoder.end();
+
+  return trail ? (res + trail) : res;
+};
+
+exports.encode = function (string, encoding) {
+  var parser = prepareParser(encoding);
+
+  var res = parser.encoder.write(string);
+  var trail = parser.encoder.end();
+
+  return (trail && trail.length > 0) ? Buffer.concat([res, trail]) : res;
+};