# bsdiff-rs

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Bsdiff is a method of diffing files. This crate is a port of a [bsdiff library](https://github.com/mendsley/bsdiff).
High performance patching. All written in safe
Rust.

It is usually a good idea to use bsdiff alongside a compression algorithm like bzip2.

## Usage

```rust
fn main() {
    let one = vec![1, 2, 3, 4, 5];
    let two = vec![1, 2, 4, 6];
    let mut patch = Vec::new();

    bsdiff::diff(&one, &two, &mut patch).unwrap();

    let mut patched = Vec::with_capacity(two.len());
    bsdiff::patch(&one, &mut patch.as_slice(), &mut patched).unwrap();
    assert_eq!(patched, two);
}
```

## Diffing Files

```rust
fn diff_files(file_a: &str, file_b: &str, patch_file: &str) -> std::io::Result<()> {
    let old = std::fs::read(file_a)?;
    let new = std::fs::read(file_b)?;
    let mut patch = Vec::new();

    bsdiff::diff(&old, &new, &mut patch)?;
    // TODO: compress `patch` here
    std::fs::write(patch_file, &patch)
}
```

## Patching Files

```rust
fn patch_file(file_a: &str, patch_file: &str, file_b: &str) -> std::io::Result<()> {
    let old = std::fs::read(file_a)?;
    let patch = std::fs::read(patch_file)?;
    // TODO: decompress `patch` here
    let mut new = Vec::new();

    bsdiff::patch(&old, &mut patch.as_slice(), &mut new)?;
    std::fs::write(file_b, &new)
}
```