masker

A library for masking patterns in input data. Create a Masker with a set of input patterns - e.g. strings or slices - and your desired mask pattern, then use it to replace those input patterns in data you feed to it. Conceptually, this isn't much more than find and replace with multiple patterns and a common replacement, however it handles two awkward things:

• It allows you to stream data in chunks and still apply the replacements, with some small buffering as needed.
• It handles overlapping matches where replacing either one might leave part of the other exposed.

For the latter point, imagine our targets to mask were "captcha" and "hat"; what happens for "capchat"? If we replace "captcha" first with our mask, say "XXXX", we'll get "XXXXt" as our output. If we replace "hat" first, we'll get "captcXXXX". This library will produce "XXXX" only - no part of any masked string that appears in the text will be revealed, even when it overlaps with other masked strings.

Example:

use masker::Masker;

let m = Masker::new(&["frog", "cat"], "XXXX");
let mut cm = m.mask_chunks();
let mut v = Vec::new();
v.extend(cm.mask_chunk("the ba"));
v.extend(cm.mask_chunk("d f"));
v.extend(cm.mask_chunk("rog sat on the c"));
v.extend(cm.mask_chunk("at"));
v.extend(cm.finish());

License

This code is made available under either an Apache-2.0 or an MIT license.