diff options
Diffstat (limited to 'lib/string_decoder.js')
-rw-r--r-- | lib/string_decoder.js | 46 |
1 files changed, 21 insertions, 25 deletions
diff --git a/lib/string_decoder.js b/lib/string_decoder.js index 6b1e30895a..fe4c9fc170 100644 --- a/lib/string_decoder.js +++ b/lib/string_decoder.js @@ -57,29 +57,29 @@ var StringDecoder = exports.StringDecoder = function(encoding) { StringDecoder.prototype.write = function(buffer) { var charStr = ''; - var offset = 0; - // if our last write ended with an incomplete multibyte character while (this.charLength) { // determine how many remaining bytes this buffer has to offer for this char - var i = (buffer.length >= this.charLength - this.charReceived) ? + var available = (buffer.length >= this.charLength - this.charReceived) ? this.charLength - this.charReceived : buffer.length; // add the new bytes to the char buffer - buffer.copy(this.charBuffer, this.charReceived, offset, i); - this.charReceived += (i - offset); - offset = i; + buffer.copy(this.charBuffer, this.charReceived, 0, available); + this.charReceived += available; if (this.charReceived < this.charLength) { // still not enough chars in this buffer? wait for more ... return ''; } + // remove bytes belonging to the current character from the buffer + buffer = buffer.slice(available, buffer.length); + // get the character that was split charStr = this.charBuffer.slice(0, this.charLength).toString(this.encoding); - // lead surrogate (D800-DBFF) is also the incomplete character + // CESU-8: lead surrogate (D800-DBFF) is also the incomplete character var charCode = charStr.charCodeAt(charStr.length - 1); if (charCode >= 0xD800 && charCode <= 0xDBFF) { this.charLength += this.surrogateSize; @@ -89,34 +89,33 @@ StringDecoder.prototype.write = function(buffer) { this.charReceived = this.charLength = 0; // if there are no more bytes in this buffer, just emit our char - if (i == buffer.length) return charStr; - - // otherwise cut off the characters end from the beginning of this buffer - buffer = buffer.slice(i, buffer.length); + if (buffer.length === 0) { + return charStr; + } break; } - var lenIncomplete = this.detectIncompleteChar(buffer); + // determine and set charLength / charReceived + this.detectIncompleteChar(buffer); var end = buffer.length; if (this.charLength) { // buffer the incomplete character bytes we got - buffer.copy(this.charBuffer, 0, buffer.length - lenIncomplete, end); - this.charReceived = lenIncomplete; - end -= lenIncomplete; + buffer.copy(this.charBuffer, 0, buffer.length - this.charReceived, end); + end -= this.charReceived; } charStr += buffer.toString(this.encoding, 0, end); var end = charStr.length - 1; var charCode = charStr.charCodeAt(end); - // lead surrogate (D800-DBFF) is also the incomplete character + // CESU-8: lead surrogate (D800-DBFF) is also the incomplete character if (charCode >= 0xD800 && charCode <= 0xDBFF) { var size = this.surrogateSize; this.charLength += size; this.charReceived += size; this.charBuffer.copy(this.charBuffer, size, 0, size); - this.charBuffer.write(charStr.charAt(charStr.length - 1), this.encoding); + buffer.copy(this.charBuffer, 0, 0, size); return charStr.substring(0, end); } @@ -153,8 +152,7 @@ StringDecoder.prototype.detectIncompleteChar = function(buffer) { break; } } - - return i; + this.charReceived = i; }; StringDecoder.prototype.end = function(buffer) { @@ -177,13 +175,11 @@ function passThroughWrite(buffer) { } function utf16DetectIncompleteChar(buffer) { - var incomplete = this.charReceived = buffer.length % 2; - this.charLength = incomplete ? 2 : 0; - return incomplete; + this.charReceived = buffer.length % 2; + this.charLength = this.charReceived ? 2 : 0; } function base64DetectIncompleteChar(buffer) { - var incomplete = this.charReceived = buffer.length % 3; - this.charLength = incomplete ? 3 : 0; - return incomplete; + this.charReceived = buffer.length % 3; + this.charLength = this.charReceived ? 3 : 0; } |