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44 lines
1.1 KiB
44 lines
1.1 KiB
/**
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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 inherits = require('util').inherits;
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var Transform = require('readable-stream').Transform;
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var crc32 = require('crc').crc32;
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var CRC32Stream = module.exports = function CRC32Stream(options) {
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Transform.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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};
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inherits(CRC32Stream, Transform);
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CRC32Stream.prototype._transform = function(chunk, encoding, callback) {
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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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callback(null, chunk);
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};
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CRC32Stream.prototype.digest = function(encoding) {
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var checksum = new Buffer(4);
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checksum.writeUInt32BE(this.checksum >>> 0, 0);
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return encoding ? checksum.toString(encoding) : checksum;
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};
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CRC32Stream.prototype.hex = function() {
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return this.digest('hex').toUpperCase();
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};
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CRC32Stream.prototype.size = function() {
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return this.rawSize;
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};
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