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