unichain-byte-stream

A Readable stream wrapper around Unichain that supports reading byte ranges.

When provided with optional start/end block heuristics, this module will efficiently sync only those blocks which contain the specified range.

Supports asynchronously specifying stream options, as well as the input feed, to remove the need for additional stream management modules like duplexify.

Most of the code has been extracted from Bitdrive.

Usage

The following example will return a byte stream of the entire input feed.

const ram = require('random-access-memory')
const unichain = require('@web4/unichain')
const createByteStream = require('@web4/unichain-byte-stream')

let chain = unichain(ram)
let stream = createByteStream({
  feed: chain
})

API

stream = createStream([options])

Creates a new byte stream.

If specified, options can include:

{
  feed: chain, // A unichain.
  byteOffset: 0, // Starting offset in bytes from the start of the feed.
  byteLength: 10, // The number of bytes to read.
  blockOffset: 0, // An optional starting block heuristic (optimization).
  blockLength: 10 // An optional block length that should contain the entire range (optimization).
}

stream.start([options])

Starts downloading and streaming according to the specified options.

Options are the same as in createStream. If a feed was specified in the stream constructor, then one should not provide another stream in the start options.

License

MIT