random-access-remove

remove random chunks of a file given an offset and length

npm install random-access-remove

Why?

If you need to remove certain chunks of a file without wanting to do a full copy, this module is for you!

It is easy to use

var randomAccessFile = require('random-access-remove');

var rar = new randomAccessRemove();

//remove a single piece
rar.remove('test.txt', 0 /*offset*/, 1024 /*length*/, function(err) {
  if (err)
    console.error(err);
});

// or remove in bulk
var file = 'test2.txt';
var kb = 1024;
var size = fs.statSync(file).size;

// must be in ascending order by offset values
//[ [offset, length], ...]
var exclude = [
	[0, kb],
	[2 * kb + 1, kb],
	[4 * kb + 1, kb],
	[size - kb, kb]
];

rar.removeAll(file, exclude, function(err) {
	if (err)
		console.error(err);
});

Inspiration

The format of this module is a copy of the awesome module random-access-file by mafintosh. This module is not affiliated with that module and was written to follow the format outlined in random-access because it makes sense.

Implementation

Under the hood, this module does the following:

• creates a readstream of the file arg
• creates a tmp output file (file + '.tmp')
• intercepts the piped data and excludes the data within the range/ranges passed to it
• deletes the original file arg
• renames the .tmp file to the original file name

License

MIT