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http: pack response body buffer in first tcp packet

Apply the same optimization to res.end(buf) that is applied to res.end(str).

Speeds up `node benchmark/http_simple_auto -k -c 1 -n 25000 buffer/1`
(non-chunked response body) by about 750x. That's not a typo.

Chunked responses:

  $ cat tmp/http-chunked-client.js
  // Run `node benchmark/http_simple` in another terminal.
  var http = require('http'), url = require('url');
  var options = url.parse('http://127.0.0.1:8000/buffer/1/1');
  options.agent = new http.Agent({ maxSockets: 1 });
  for (var i = 0; i < 25000; ++i) http.get(options);

Before:

  $ time out/Release/node tmp/http-chunked-client.js
  real    16m40.411s
  user    0m9.184s
  sys     0m0.604s

After:

  $ time out/Release/node tmp/http-chunked-client.js
  real    0m5.386s
  user    0m2.768s
  sys     0m0.728s

That's still a 185x speed-up.

Fixes #4415.
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1 parent ba407ce commit 5a19c07c087c5749e31737cb4fb5a113643f35d6 @bnoordhuis bnoordhuis committed Dec 19, 2012
Showing with 71 additions and 8 deletions.
  1. +71 −8 lib/http.js
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@@ -759,6 +759,10 @@ OutgoingMessage.prototype.addTrailers = function(headers) {
};
+var zero_chunk_buf = new Buffer('\r\n0\r\n');
+var crlf_buf = new Buffer('\r\n');
+
+
OutgoingMessage.prototype.end = function(data, encoding) {
if (this.finished) {
return false;
@@ -776,8 +780,7 @@ OutgoingMessage.prototype.end = function(data, encoding) {
var ret;
var hot = this._headerSent === false &&
- typeof(data) === 'string' &&
- data.length > 0 &&
+ (data && data.length > 0) &&
this.output.length === 0 &&
this.connection &&
this.connection.writable &&
@@ -789,13 +792,73 @@ OutgoingMessage.prototype.end = function(data, encoding) {
// res.end(blah);
// HACKY.
- if (this.chunkedEncoding) {
- var l = Buffer.byteLength(data, encoding).toString(16);
- ret = this.connection.write(this._header + l + CRLF +
- data + '\r\n0\r\n' +
- this._trailer + '\r\n', encoding);
+ if (typeof data === 'string') {
+ if (this.chunkedEncoding) {
+ var l = Buffer.byteLength(data, encoding).toString(16);
+ ret = this.connection.write(this._header + l + CRLF +
+ data + '\r\n0\r\n' +
+ this._trailer + '\r\n', encoding);
+ } else {
+ ret = this.connection.write(this._header + data, encoding);
+ }
+ } else if (Buffer.isBuffer(data)) {
+ if (this.chunkedEncoding) {
+ var chunk_size = data.length.toString(16);
+
+ // Skip expensive Buffer.byteLength() calls; only ISO-8859-1 characters
+ // are allowed in HTTP headers. Therefore:
+ //
+ // this._header.length == Buffer.byteLength(this._header.length)
+ // this._trailer.length == Buffer.byteLength(this._trailer.length)
+ //
+ var header_len = this._header.length;
+ var chunk_size_len = chunk_size.length;
+ var data_len = data.length;
+ var trailer_len = this._trailer.length;
+
+ var len = header_len
+ + chunk_size_len
+ + 2 // '\r\n'.length
+ + data_len
+ + 5 // '\r\n0\r\n'.length
+ + trailer_len
+ + 2; // '\r\n'.length
+
+ var buf = new Buffer(len);
+ var off = 0;
+
+ buf.write(this._header, off, header_len, 'ascii');
+ off += header_len;
+
+ buf.write(chunk_size, off, chunk_size_len, 'ascii');
+ off += chunk_size_len;
+
+ crlf_buf.copy(buf, off);
+ off += 2;
+
+ data.copy(buf, off);
+ off += data_len;
+
+ zero_chunk_buf.copy(buf, off);
+ off += 5;
+
+ if (trailer_len > 0) {
+ buf.write(this._trailer, off, trailer_len, 'ascii');
+ off += trailer_len;
+ }
+
+ crlf_buf.copy(buf, off);
+
+ ret = this.connection.write(buf);
+ } else {
+ var header_len = this._header.length;
+ var buf = new Buffer(header_len + data.length);
+ buf.write(this._header, 0, header_len, 'ascii');
+ data.copy(buf, header_len);
+ ret = this.connection.write(buf);
+ }
} else {
- ret = this.connection.write(this._header + data, encoding);
+ throw new TypeError('first argument must be a string or Buffer');
}
this._headerSent = true;

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