--- /dev/null
+var common = require('../common.js');
+var StringDecoder = require('string_decoder').StringDecoder;
+
+var bench = common.createBenchmark(main, {
+ encoding: ['ascii', 'utf8', 'base64-utf8', 'base64-ascii'],
+ inlen: [32, 128, 1024],
+ chunk: [16, 64, 256, 1024],
+ n: [25e4]
+});
+
+var UTF_ALPHA = 'Blåbærsyltetøy';
+var ASC_ALPHA = 'Blueberry jam';
+
+function main(conf) {
+ var encoding = conf.encoding;
+ var inLen = conf.inlen | 0;
+ var chunkLen = conf.chunk | 0;
+ var n = conf.n | 0;
+
+ var alpha;
+ var chunks = [];
+ var str = '';
+ var isBase64 = (encoding === 'base64-ascii' || encoding === 'base64-utf8');
+
+ if (encoding === 'ascii' || encoding === 'base64-ascii')
+ alpha = ASC_ALPHA;
+ else if (encoding === 'utf8' || encoding === 'base64-utf8')
+ alpha = UTF_ALPHA;
+ else
+ throw new Error('Bad encoding');
+
+ var sd = new StringDecoder(isBase64 ? 'base64' : encoding);
+
+ for (var i = 0; i < inLen; ++i) {
+ if (i > 0 && (i % chunkLen) === 0 && !isBase64) {
+ chunks.push(new Buffer(str, encoding));
+ str = '';
+ }
+ str += alpha[i % alpha.length];
+ }
+ if (str.length > 0 && !isBase64)
+ chunks.push(new Buffer(str, encoding));
+ if (isBase64) {
+ str = new Buffer(str, 'utf8').toString('base64');
+ while (str.length > 0) {
+ var len = Math.min(chunkLen, str.length);
+ chunks.push(new Buffer(str.substring(0, len), 'utf8'));
+ str = str.substring(len);
+ }
+ }
+
+ var nChunks = chunks.length;
+
+ bench.start();
+ for (var i = 0; i < n; ++i) {
+ for (var j = 0; j < nChunks; ++j)
+ sd.write(chunks[j]);
+ }
+ bench.end(n);
+}
'use strict';
+const isEncoding = Buffer.isEncoding;
+
function assertEncoding(encoding) {
- if (encoding && !Buffer.isEncoding(encoding)) {
+ if (encoding && !isEncoding(encoding)) {
throw new Error('Unknown encoding: ' + encoding);
}
}
// replacement character. See https://codereview.chromium.org/121173009/ .
StringDecoder.prototype.write = function(buffer) {
var charStr = '';
+ var buflen = buffer.length;
+ var charBuffer = this.charBuffer;
+ var charLength = this.charLength;
+ var charReceived = this.charReceived;
+ var surrogateSize = this.surrogateSize;
+ var encoding = this.encoding;
// if our last write ended with an incomplete multibyte character
- while (this.charLength) {
+ while (charLength) {
// determine how many remaining bytes this buffer has to offer for this char
- var available = (buffer.length >= this.charLength - this.charReceived) ?
- this.charLength - this.charReceived :
- buffer.length;
+ var diff = charLength - charReceived;
+ var available = (buflen >= diff) ? diff : buflen;
// add the new bytes to the char buffer
- buffer.copy(this.charBuffer, this.charReceived, 0, available);
- this.charReceived += available;
+ buffer.copy(charBuffer, charReceived, 0, available);
+ charReceived += available;
- if (this.charReceived < this.charLength) {
+ if (charReceived < charLength) {
// still not enough chars in this buffer? wait for more ...
+
+ this.charLength = charLength;
+ this.charReceived = charReceived;
+
return '';
}
// remove bytes belonging to the current character from the buffer
- buffer = buffer.slice(available, buffer.length);
+ buffer = buffer.slice(available, buflen);
+ buflen = buffer.length;
// get the character that was split
- charStr = this.charBuffer.slice(0, this.charLength).toString(this.encoding);
+ charStr = charBuffer.toString(encoding, 0, charLength);
// 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;
+ charLength += surrogateSize;
charStr = '';
continue;
}
- this.charReceived = this.charLength = 0;
+ charReceived = charLength = 0;
// if there are no more bytes in this buffer, just emit our char
- if (buffer.length === 0) {
+ if (buflen === 0) {
+ this.charLength = charLength;
+ this.charReceived = charReceived;
+
return charStr;
}
- break;
}
// determine and set charLength / charReceived
- this.detectIncompleteChar(buffer);
+ if (this.detectIncompleteChar(buffer))
+ charLength = this.charLength;
+ charReceived = this.charReceived;
- var end = buffer.length;
- if (this.charLength) {
+ var end = buflen;
+ if (charLength) {
// buffer the incomplete character bytes we got
- buffer.copy(this.charBuffer, 0, buffer.length - this.charReceived, end);
- end -= this.charReceived;
+ buffer.copy(charBuffer, 0, buflen - charReceived, end);
+ end -= charReceived;
}
- charStr += buffer.toString(this.encoding, 0, end);
+ this.charLength = charLength;
+ charStr += buffer.toString(encoding, 0, end);
var end = charStr.length - 1;
var charCode = charStr.charCodeAt(end);
// 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);
- buffer.copy(this.charBuffer, 0, 0, size);
+ charLength += surrogateSize;
+ charReceived += surrogateSize;
+ charBuffer.copy(charBuffer, surrogateSize, 0, surrogateSize);
+ buffer.copy(charBuffer, 0, 0, surrogateSize);
+
+ this.charLength = charLength;
+ this.charReceived = charReceived;
+
return charStr.substring(0, end);
}
// length that character, and sets this.charReceived to the number of bytes
// that are available for this character.
StringDecoder.prototype.detectIncompleteChar = function(buffer) {
+ var buflen = buffer.length;
// determine how many bytes we have to check at the end of this buffer
- var i = (buffer.length >= 3) ? 3 : buffer.length;
+ var i = (buflen >= 3) ? 3 : buflen;
+ var newlen = false;
// Figure out if one of the last i bytes of our buffer announces an
// incomplete char.
for (; i > 0; i--) {
- var c = buffer[buffer.length - i];
+ var c = buffer[buflen - i];
// See http://en.wikipedia.org/wiki/UTF-8#Description
// 110XXXXX
- if (i == 1 && c >> 5 == 0x06) {
+ if (i === 1 && c >> 5 === 0x06) {
this.charLength = 2;
+ newlen = true;
break;
}
// 1110XXXX
- if (i <= 2 && c >> 4 == 0x0E) {
+ if (i <= 2 && c >> 4 === 0x0E) {
this.charLength = 3;
+ newlen = true;
break;
}
// 11110XXX
- if (i <= 3 && c >> 3 == 0x1E) {
+ if (i <= 3 && c >> 3 === 0x1E) {
this.charLength = 4;
+ newlen = true;
break;
}
}
+
this.charReceived = i;
+
+ return newlen;
};
StringDecoder.prototype.end = function(buffer) {
if (buffer && buffer.length)
res = this.write(buffer);
- if (this.charReceived) {
- var cr = this.charReceived;
+ var charReceived = this.charReceived;
+ if (charReceived) {
+ var cr = charReceived;
var buf = this.charBuffer;
var enc = this.encoding;
- res += buf.slice(0, cr).toString(enc);
+ res += buf.toString(enc, 0, cr);
}
return res;
}
function utf16DetectIncompleteChar(buffer) {
- this.charReceived = buffer.length % 2;
- this.charLength = this.charReceived ? 2 : 0;
+ var charReceived = this.charReceived = buffer.length % 2;
+ this.charLength = charReceived ? 2 : 0;
+ return true;
}
function base64DetectIncompleteChar(buffer) {
- this.charReceived = buffer.length % 3;
- this.charLength = this.charReceived ? 3 : 0;
+ var charReceived = this.charReceived = buffer.length % 3;
+ this.charLength = charReceived ? 3 : 0;
+ return true;
}