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demo.js
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demo.js
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/*
* Copyright 2010, Ivan Egorov (egorich.3.04@gmail.com).
*
* Permission is hereby granted, free of charge, to any person obtaining a copy
* of this software and associated documentation files (the "Software"), to
* deal in the Software without restriction, including without limitation the
* rights to use, copy, modify, merge, publish, distribute, sublicense, and/or
* sell copies of the Software, and to permit persons to whom the Software is
* furnished to do so, subject to the following conditions:
*
* The above copyright notice and this permission notice shall be included in
* all copies or substantial portions of the Software.
*
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
* FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
* AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
* LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
* FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS
* IN THE SOFTWARE.
*/
var compress=require("../lib/compress");
var events=require('events');
var sys=require("sys");
var posix=require("fs");
var Buffer = require('buffer').Buffer;
function seq() {
var self = this;
var funs = Array.prototype.slice.call(arguments, 0);
this.start = function(initial){
process(0, initial);
}
function process(index, state) {
funs[index](state, function(err, new_state) {
if (err) throw err;
++index;
if (index == funs.length) {
self.emit('success', new_state);
return;
}
process(index, new_state);
});
}
}
sys.inherits(seq, events.EventEmitter);
function createBuffer(str, enc) {
enc = enc || 'utf8';
var len = Buffer.byteLength(str, enc);
var buf = new Buffer(len);
buf.write(str, enc, 0);
return buf;
}
// Create gzip stream
var gzip = new compress.Gzip(4);
sys.puts('gzip created');
// Pump data to be compressed
var gzdata1, gzdata2, gzdata3;
var compression = new seq(
function(state, continuation){
gzip.write(createBuffer("My data that needs "), function(err, data) {
sys.puts("Compressed size: " + data.length);
continuation(err, state + data.toString('binary'));
});
},
function(state, continuation){
gzip.write(createBuffer("to be compressed. 01234567890."), function(err, data) {
sys.puts("Compressed size: " + data.length);
continuation(err, state + data.toString('binary'));
});
},
function(state, continuation){
gzip.close(function(err, data) {
sys.puts("Last bit: " + data.length);
data = state + data.toString('binary');
sys.puts("Total compressed size: " + data.length);
continuation(err, data);
});
}
);
var gunzip = new compress.Gunzip();
var decompression = new seq(
function(state, continuation){
gunzip.write(createBuffer(state.input[0], 'binary'), function(err, data) {
state.output += data;
continuation(err, state);
});
},
function(state, continuation){
gunzip.write(createBuffer(state.input[1], 'binary'), function(err, data) {
state.output += data;
continuation(err, state);
});
},
function(state, continuation){
gunzip.close(function(err, data){
state.output += data;
continuation(err, state);
});
}
);
compression.addListener('success', doDecompress);
doCompress();
function doCompress() {
compression.start('');
}
function doDecompress(data) {
sys.puts('Decompressing');
decompression.addListener('success', function(data){
sys.puts(data.output);
});
decompression.start({input:[data.substr(0,25), data.substr(25)],output:''});
}