Welcome to OGeek Q&A Community for programmer and developer-Open, Learning and Share
Welcome To Ask or Share your Answers For Others

Categories

0 votes
722 views
in Technique[技术] by (71.8m points)

node.js - HTTP - how to send multiple pre-cached gzipped chunks?

Lets say I have 2 individually gziped html chunks in memory. Can I send chunk1+chunk2 to HTTP client? Does any browser supports this? Or there is no way to do this and I have to gzip the whole stream not individual chunks?

I want to serve to clients for example chunk1+chunk2 and chunk2+chunk1 etc (different order) but I don't want to compress the whole page every time and I dont want to cache the whole page. I want to use precompressed cached chunks and send them.

nodejs code (node v0.10.7):

// creating pre cached data buffers
var zlib = require('zlib');
var chunk1, chunk2;
zlib.gzip(new Buffer('test1'), function(err, data){
  chunk1 = data;
});
zlib.gzip(new Buffer('test2'), function(err, data){
  chunk2 = data;
});


var http = require('http');
http.createServer(function (req, res) {
      res.writeHead(200, {'Content-Type': 'text/plain', 'Content-Encoding': 'gzip'});
      // writing two pre gziped buffers
      res.write(chunk1); // if I send only this one everything is OK
      res.write(chunk2); // if I send two chunks Chrome trying to download file
      res.end();
}).listen(8080);

When my example server returns this kind of response Chrome browser display download window (it doesnt understand it :/

See Question&Answers more detail:os

与恶龙缠斗过久,自身亦成为恶龙;凝视深渊过久,深渊将回以凝视…
Welcome To Ask or Share your Answers For Others

1 Reply

0 votes
by (71.8m points)

I haven't tried it, but if the http clients are compliant with RFC 1952, then they should accept concatenated gzip streams, and decompress them with the same result as if the data were all compressed into one stream. The HTTP 1.1 standard in RFC 2616 does in fact refer to RFC 1952.

If by "chunks" you are referring to chunked transfer encoding, then that is independent of the compression. If the clients do accept concatenated streams, then there is no reason for chunked transfer encoded boundaries to have to align with the gzip streams within.

As to how to do it, simply gzip your pieces and directly concatenate them. No other formatting or preparation is required.


与恶龙缠斗过久,自身亦成为恶龙;凝视深渊过久,深渊将回以凝视…
OGeek|极客中国-欢迎来到极客的世界,一个免费开放的程序员编程交流平台!开放,进步,分享!让技术改变生活,让极客改变未来! Welcome to OGeek Q&A Community for programmer and developer-Open, Learning and Share
Click Here to Ask a Question

1.4m articles

1.4m replys

5 comments

57.0k users

...