Hole-Punch

Crates.io License Unsafe Maintenance

A (wip) dead simple, cross platform crate for finding the locations of holes in sparse files.

Currently supports Unix-like platforms that support the SEEK_HOLE and SEEK_DATA commands on lseek, as well as windows.

The operating systems that currently support filesystem-level sparsity information are:

  1. Linux
  2. Android
  3. FreeBSD
  4. Windows

These are currently implemented with a compile time switch, and SparseFile::scan_chunks will always immediately return with a ScanError::UnsupportedPlatform error on platforms not on this list.

Usage

```rust use std::fs::File; use hole_punch::*;

let mut file = File::open("a big sparse file"); let segments = file.scanchunks().expect("Unable to scan chunks"); for segment in segment { if let SegmentType::Data = segment.segmenttype { let start = segment.start; let end = segment.end;

    let length = end - start;
    do_something_with_data(&mut file, start, length);
}

} ```

License

Hole-Punch is distributed under your choice of the MIT license, or Apache 2.0.

TO-DOs

The following features are on my "to implement" list, in order of importance:

  1. Windows support
  2. Fallback mode (reading the entire file manually looking for chunks of 0s)