Description

This module is a port of streamsearch for es modules using Web APIs, namely ReadableStream and Uint8Array.

Node's stream.Readable can be used with IterableStreamSearch class starting from v11.14.0.

Installation

npm install @ssttevee/streamsearch

Example

import { ReadableStreamSearch, iterateStrings } from '@ssttevee/streamsearch';

const res = await fetch('https://httpbin.org/stream/10');
const search = new ReadableStreamSearch('\n', res.body);

for await (const str of iterateStrings(search)) {
    console.log(str);
}

Each function can also be imported individually for bundling efficiency.

import { iterateStrings } from '@ssttevee/streamsearch/iterate-strings';
import { IteratorStreamSearch } from '@ssttevee/streamsearch/iterator';

API

Classes

StreamSearch

Constructor: new StreamSearch(needle: Uint8Array | string)

Base class that implements the Boyer-Moore-Horspool algorithm. Use feed(chunk: Uint8Array) to push data and end() to get remaining data. Returns an array of Token (either Uint8Array chunks or MATCH symbols).

IteratorStreamSearch

Constructor: new IteratorStreamSearch(needle: Uint8Array | string, iter: AsyncIterable<Uint8Array>)

Wraps an async iterable (e.g., Node.js streams with Symbol.asyncIterator). Implements AsyncIterable<Token>.

QueueableStreamSearch

Constructor: new QueueableStreamSearch(needle: Uint8Array | string)

Manual push-based interface. Use push(...chunks: Uint8Array[]) to add data and close() when done. Implements AsyncIterable<Token>.

ReadableStreamSearch

Constructor: new ReadableStreamSearch(needle: Uint8Array | string, stream: ReadableStream<Uint8Array>)

Wraps a Web ReadableStream. Implements AsyncIterable<Token>.

Helper functions

iterateChunks(iter: AsyncIterable<Token>): AsyncIterableIterator<Uint8Array[]>

Yields arrays of Uint8Array chunks between matches. Each match produces a separate array.

iterateChunksConcatted(iter: AsyncIterable<Token>): AsyncIterableIterator<Uint8Array>

Like iterateChunks but concatenates each chunk array into a single Uint8Array.

iterateStrings(iter: AsyncIterable<Token>): AsyncIterableIterator<string>

Yields UTF-8 decoded strings between matches.

split(chunks: Uint8Array | Uint8Array[], needle: Uint8Array | string): Uint8Array[]

Synchronous split function. Returns an array of Uint8Array chunks split by the needle.