Streaming Boyer-Moore-Horspool searching for node.js
npm install streamsearchDescription
===========
streamsearch is a module for node.js that allows searching a stream using the Boyer-Moore-Horspool algorithm.
This module is based heavily on the Streaming Boyer-Moore-Horspool C++ implementation by Hongli Lai here.
Requirements
============
* node.js -- v10.0.0 or newer
Installation
============
npm install streamsearch
Example
=======
``js
const { inspect } = require('util');
const StreamSearch = require('streamsearch');
const needle = Buffer.from('\r\n');
const ss = new StreamSearch(needle, (isMatch, data, start, end) => {
if (data)
console.log('data: ' + inspect(data.toString('latin1', start, end)));
if (isMatch)
console.log('match!');
});
const chunks = [
'foo',
' bar',
'\r',
'\n',
'baz, hello\r',
'\n world.',
'\r\n Node.JS rules!!\r\n\r\n',
];
for (const chunk of chunks)
ss.push(Buffer.from(chunk));
// output:
//
// data: 'foo'
// data: ' bar'
// match!
// data: 'baz, hello'
// match!
// data: ' world.'
// match!
// data: ' Node.JS rules!!'
// match!
// data: ''
// match!
`
API
===
Properties
----------
* maxMatches - < _integer_ > - The maximum number of matches. Defaults to Infinity.
* matches - < _integer_ > - The current match count.
Functions
---------
* (constructor)(< _mixed_ >needle, < _function_ >callback) - Creates and returns a new instance for searching for a _Buffer_ or _string_ needle. callback is called any time there is non-matching data and/or there is a needle match. callback will be called with the following arguments:
1. isMatch - _boolean_ - Indicates whether a match has been found
2. data - _mixed_ - If set, this contains data that did not match the needle.
3. start - _integer_ - The index in data where the non-matching data begins (inclusive).
4. end - _integer_ - The index in data where the non-matching data ends (exclusive).
5. isSafeData - _boolean_ - Indicates if it is safe to store a reference to data (e.g. as-is or via data.slice()) or not, as in some cases data may point to a Buffer whose contents change over time.
* destroy() - _(void)_ - Emits any last remaining unmatched data that may still be buffered and then resets internal state.
* push(< _Buffer_ >chunk) - _integer_ - Processes chunk, searching for a match. The return value is the last processed index in chunk` + 1.
* reset() - _(void)_ - Resets internal state. Useful for when you wish to start searching a new/different stream for example.