digest-stream - Simple pass-through stream (RW) which calculates the a crypto digest (sha/md5 hash) of a stream and also the length. Pipe your stream through this to get digest and length. (streams2)
Simple node.js pass-through stream (RW) which calculates the a crypto digest (sha/md5 hash) of a stream and also the length. Pipe your stream through this to get digest and length. (streams2)
npm install digest-stream
Provide a the digest algorithm, optional input encoding, digest encoding, and a listener function when you construct the stream. The listener will be called with the resultant digest and length of the stream just prior to end being emitted.
Since this uses the node.js crypto package, refer to http://nodejs.org/api/crypto.html for the specific options available.
digestStream(algorithm, [inputEncoding,] digestEncoding, [options], listenerFn)- constructs a new stream instance, the listenerFn will be called prior to the
endevent being emitted.
inputEncodingis optional and defaults to
binaryif not provided.
options- optional streams options
listenerFnfunction signature is
digestis the digest for the stream data in the digest encoding format specified when instance was created.
dataLengthis the length of the data in the stream (provided for convenience). If listenerFn returns an object that is an instance of Error, then the error will be signaled in the stream.
var digestStream = require'digest-stream';var digest;var dataLength;digest = resultDigest;dataLength = length;var dstream = digestStream'sha1' 'hex' listenerFn; // create instancereadstreampipedstream // digest and length calculated as it passes throughpipe
By making this simple pass-through stream which calculates the digest and length of a stream, it becomes really easy to add this functionality to a streaming workflow, just by piping it through this stream, the digest and length will be available prior to
end being fired.
If you have input or ideas or would like to get involved, you may: