| // Copyright 2012 The Rust Project Developers. See the COPYRIGHT |
| // file at the top-level directory of this distribution and at |
| // http://rust-lang.org/COPYRIGHT. |
| // |
| // Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or |
| // http://www.apache.org/licenses/LICENSE-2.0> or the MIT license |
| // <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your |
| // option. This file may not be copied, modified, or distributed |
| // except according to those terms. |
| |
| /*! |
| |
| Simple [DEFLATE][def]-based compression. This is a wrapper around the |
| [`miniz`][mz] library, which is a one-file pure-C implementation of zlib. |
| |
| [def]: https://en.wikipedia.org/wiki/DEFLATE |
| [mz]: https://code.google.com/p/miniz/ |
| |
| */ |
| |
| #![crate_id = "flate#0.11.0"] |
| #![experimental] |
| #![crate_type = "rlib"] |
| #![crate_type = "dylib"] |
| #![license = "MIT/ASL2"] |
| #![doc(html_logo_url = "http://www.rust-lang.org/logos/rust-logo-128x128-blk-v2.png", |
| html_favicon_url = "http://www.rust-lang.org/favicon.ico", |
| html_root_url = "http://doc.rust-lang.org/0.11.0/")] |
| #![feature(phase)] |
| |
| #[cfg(test)] #[phase(plugin, link)] extern crate log; |
| |
| extern crate libc; |
| |
| use std::c_vec::CVec; |
| use libc::{c_void, size_t, c_int}; |
| |
| #[link(name = "miniz", kind = "static")] |
| extern { |
| /// Raw miniz compression function. |
| fn tdefl_compress_mem_to_heap(psrc_buf: *c_void, |
| src_buf_len: size_t, |
| pout_len: *mut size_t, |
| flags: c_int) |
| -> *mut c_void; |
| |
| /// Raw miniz decompression function. |
| fn tinfl_decompress_mem_to_heap(psrc_buf: *c_void, |
| src_buf_len: size_t, |
| pout_len: *mut size_t, |
| flags: c_int) |
| -> *mut c_void; |
| } |
| |
| static LZ_NORM : c_int = 0x80; // LZ with 128 probes, "normal" |
| static TINFL_FLAG_PARSE_ZLIB_HEADER : c_int = 0x1; // parse zlib header and adler32 checksum |
| static TDEFL_WRITE_ZLIB_HEADER : c_int = 0x01000; // write zlib header and adler32 checksum |
| |
| fn deflate_bytes_internal(bytes: &[u8], flags: c_int) -> Option<CVec<u8>> { |
| unsafe { |
| let mut outsz : size_t = 0; |
| let res = tdefl_compress_mem_to_heap(bytes.as_ptr() as *c_void, |
| bytes.len() as size_t, |
| &mut outsz, |
| flags); |
| if !res.is_null() { |
| Some(CVec::new_with_dtor(res as *mut u8, outsz as uint, proc() libc::free(res))) |
| } else { |
| None |
| } |
| } |
| } |
| |
| /// Compress a buffer, without writing any sort of header on the output. |
| pub fn deflate_bytes(bytes: &[u8]) -> Option<CVec<u8>> { |
| deflate_bytes_internal(bytes, LZ_NORM) |
| } |
| |
| /// Compress a buffer, using a header that zlib can understand. |
| pub fn deflate_bytes_zlib(bytes: &[u8]) -> Option<CVec<u8>> { |
| deflate_bytes_internal(bytes, LZ_NORM | TDEFL_WRITE_ZLIB_HEADER) |
| } |
| |
| fn inflate_bytes_internal(bytes: &[u8], flags: c_int) -> Option<CVec<u8>> { |
| unsafe { |
| let mut outsz : size_t = 0; |
| let res = tinfl_decompress_mem_to_heap(bytes.as_ptr() as *c_void, |
| bytes.len() as size_t, |
| &mut outsz, |
| flags); |
| if !res.is_null() { |
| Some(CVec::new_with_dtor(res as *mut u8, outsz as uint, proc() libc::free(res))) |
| } else { |
| None |
| } |
| } |
| } |
| |
| /// Decompress a buffer, without parsing any sort of header on the input. |
| pub fn inflate_bytes(bytes: &[u8]) -> Option<CVec<u8>> { |
| inflate_bytes_internal(bytes, 0) |
| } |
| |
| /// Decompress a buffer that starts with a zlib header. |
| pub fn inflate_bytes_zlib(bytes: &[u8]) -> Option<CVec<u8>> { |
| inflate_bytes_internal(bytes, TINFL_FLAG_PARSE_ZLIB_HEADER) |
| } |
| |
| #[cfg(test)] |
| mod tests { |
| use super::{inflate_bytes, deflate_bytes}; |
| use std::rand; |
| use std::rand::Rng; |
| |
| #[test] |
| fn test_flate_round_trip() { |
| let mut r = rand::task_rng(); |
| let mut words = vec!(); |
| for _ in range(0u, 20) { |
| let range = r.gen_range(1u, 10); |
| let v = r.gen_iter::<u8>().take(range).collect::<Vec<u8>>(); |
| words.push(v); |
| } |
| for _ in range(0u, 20) { |
| let mut input = vec![]; |
| for _ in range(0u, 2000) { |
| input.push_all(r.choose(words.as_slice()).unwrap().as_slice()); |
| } |
| debug!("de/inflate of {} bytes of random word-sequences", |
| input.len()); |
| let cmp = deflate_bytes(input.as_slice()).expect("deflation failed"); |
| let out = inflate_bytes(cmp.as_slice()).expect("inflation failed"); |
| debug!("{} bytes deflated to {} ({:.1f}% size)", |
| input.len(), cmp.len(), |
| 100.0 * ((cmp.len() as f64) / (input.len() as f64))); |
| assert_eq!(input.as_slice(), out.as_slice()); |
| } |
| } |
| |
| #[test] |
| fn test_zlib_flate() { |
| let bytes = vec!(1, 2, 3, 4, 5); |
| let deflated = deflate_bytes(bytes.as_slice()).expect("deflation failed"); |
| let inflated = inflate_bytes(deflated.as_slice()).expect("inflation failed"); |
| assert_eq!(inflated.as_slice(), bytes.as_slice()); |
| } |
| } |