40 lines
1.1 KiB
JavaScript
40 lines
1.1 KiB
JavaScript
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var spawn = require('child_process').spawn,
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util = require('util'),
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ResponseStream = require('../../lib').ResponseStream;
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/**
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* Accepts a writable stream, i.e. fs.WriteStream, and returns a StreamStack
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* whose 'write()' calls are transparently sent to a 'gzip' process before
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* being written to the target stream.
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*/
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var GzipEncode = module.exports = function GzipEncode(options) {
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ResponseStream.call(this, options);
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if (compression) {
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process.assert(compression >= 1 && compression <= 9);
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this.compression = compression;
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}
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this.on('pipe', this.encode);
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}
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util.inherits(GzipEncode, ResponseStream);
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GzipEncode.prototype.encode = function (source) {
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this.source = source;
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};
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GzipEncode.prototype.pipe = function (dest) {
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if (!this.source) {
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throw new Error('GzipEncode is only pipeable once it has been piped to');
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}
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this.encoder = spawn('gzip', ['-'+this.compression]);
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this.encoder.stdout.pipe(dest);
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this.encoder.stdin.pipe(this.source);
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};
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inherits(GzipEncoderStack, StreamStack);
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exports.GzipEncoderStack = GzipEncoderStack;
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GzipEncoderStack.prototype.compression = 6;
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