80 lines
1.9 KiB
Markdown
80 lines
1.9 KiB
Markdown
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# CRC32 Stream
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crc32-stream is a streaming CRC32 checksumer. It uses the [crc](https://www.npmjs.org/package/crc) module behind the scenes to reliably handle binary data and fancy character sets. Data is passed through untouched.
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### Install
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```bash
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npm install crc32-stream --save
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```
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You can also use `npm install https://github.com/archiverjs/node-crc32-stream/archive/master.tar.gz` to test upcoming versions.
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### Usage
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#### CRC32Stream
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Inherits [Transform Stream](http://nodejs.org/api/stream.html#stream_class_stream_transform) options and methods.
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```js
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const {CRC32Stream} = require('crc32-stream');
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const source = fs.createReadStream('file.txt');
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const checksum = new CRC32Stream();
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checksum.on('end', function(err) {
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// do something with checksum.digest() here
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});
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// either pipe it
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source.pipe(checksum);
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// or write it
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checksum.write('string');
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checksum.end();
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```
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#### DeflateCRC32Stream
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Inherits [zlib.DeflateRaw](http://nodejs.org/api/zlib.html#zlib_class_zlib_deflateraw) options and methods.
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```js
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const {DeflateCRC32Stream} = require('crc32-stream');
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const source = fs.createReadStream('file.txt');
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const checksum = new DeflateCRC32Stream();
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checksum.on('end', function(err) {
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// do something with checksum.digest() here
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});
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// either pipe it
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source.pipe(checksum);
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// or write it
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checksum.write('string');
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checksum.end();
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```
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### Instance API
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#### digest()
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Returns the checksum digest in unsigned form.
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#### hex()
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Returns the hexadecimal representation of the checksum digest. (ie E81722F0)
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#### size(compressed)
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Returns the raw size/length of passed-through data.
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If `compressed` is `true`, it returns compressed length instead. (DeflateCRC32Stream)
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## Things of Interest
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- [Changelog](https://github.com/archiverjs/node-crc32-stream/releases)
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- [Contributing](https://github.com/archiverjs/node-crc32-stream/blob/master/CONTRIBUTING.md)
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- [MIT License](https://github.com/archiverjs/node-crc32-stream/blob/master/LICENSE-MIT)
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