67 lines
1.6 KiB
JavaScript
67 lines
1.6 KiB
JavaScript
/**
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* node-crc32-stream
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*
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* Copyright (c) 2014 Chris Talkington, contributors.
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* Licensed under the MIT license.
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* https://github.com/archiverjs/node-crc32-stream/blob/master/LICENSE-MIT
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*/
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var zlib = require('zlib');
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var inherits = require('util').inherits;
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var crc32 = require('buffer-crc32');
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var DeflateCRC32Stream = module.exports = function (options) {
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zlib.DeflateRaw.call(this, options);
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this.checksum = new Buffer(4);
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this.checksum.writeInt32BE(0, 0);
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this.rawSize = 0;
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this.compressedSize = 0;
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// BC v0.8
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if (typeof zlib.DeflateRaw.prototype.push !== 'function') {
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this.on('data', function(chunk) {
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if (chunk) {
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this.compressedSize += chunk.length;
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}
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});
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}
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};
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inherits(DeflateCRC32Stream, zlib.DeflateRaw);
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DeflateCRC32Stream.prototype.push = function(chunk, encoding) {
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if (chunk) {
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this.compressedSize += chunk.length;
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}
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return zlib.DeflateRaw.prototype.push.call(this, chunk, encoding);
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};
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DeflateCRC32Stream.prototype.write = function(chunk, enc, cb) {
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if (chunk) {
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this.checksum = crc32(chunk, this.checksum);
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this.rawSize += chunk.length;
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}
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return zlib.DeflateRaw.prototype.write.call(this, chunk, enc, cb);
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};
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DeflateCRC32Stream.prototype.digest = function() {
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return crc32.unsigned(0, this.checksum);
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};
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DeflateCRC32Stream.prototype.hex = function() {
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return this.digest().toString(16).toUpperCase();
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};
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DeflateCRC32Stream.prototype.size = function(compressed) {
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compressed = compressed || false;
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if (compressed) {
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return this.compressedSize;
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} else {
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return this.rawSize;
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}
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}; |