LDJSONStream

Parse a binary stream of stringified new line separated JSON objects and write to output. Implements a Transform stream.

Features:

• LDJSON support
• NDJSON support
• simple and dependency free
• easy to audit

Example

A simple filter that logs all objects that have the name baz:

const Writable = require('stream').Writable;
const LDJSONStream = require('ld-jsonstream');

var ls = new LDJSONStream({ objectMode: true });

ls.pipe(new Writable({
  objectMode: true,
  write: function(obj, encoding, cb) {
    if (obj.name === 'baz') {
      console.log(obj);
    }
    cb();
  }
}));

ls.write('{ "name" : "bar" }\n{ "name" : "baz" }\n');

A more practical use case would be to read from stdin with something like: process.stdin.pipe(ls).

Installation

$ npm install ld-jsonstream

API

LDJSONStream([opts])

• [opts] {Object} object containing optional parameters

opts:

• maxDocLength {Number, default 16777216} maximum JSON document size in bytes
• maxDocs {Number, default infinite} maximum number of documents to receive
• maxBytes {Number, default infinite} maximum number of bytes to receive
• flush {Boolean, default true} whether to flush any remaining data on writer end
• debug {Boolean, default false} whether to do extra console logging or not
• hide {Boolean, default false} whether to suppress errors or not (used in tests)
• readableObjectMode {Boolean, default false} Sets objectMode for the readable side of the stream. Note: the writable side of the stream can never be in object mode. If you have such a case, you don't need this module.
• objectMode {Boolean, default false} alias for readableObjectMode

events:

• "data" {Object} emits one object at a time
• "end" stream end

this.buffer

• {Buffer} buffer, can be used to manually flush any remaining bytes

this.bytesRead

• {Number} total number of bytes read

Tests

$ npm test

License

ISC

Copyright (c) 2014, 2015, 2016, 2019 Tim Kuijsten

Permission to use, copy, modify, and/or distribute this software for any purpose with or without fee is hereby granted, provided that the above copyright notice and this permission notice appear in all copies.

THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.