1 // Copyright 2012 The Rust Project Developers. See the COPYRIGHT
2 // file at the top-level directory of this distribution and at
3 // http://rust-lang.org/COPYRIGHT.
5 // Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
6 // http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
7 // <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
8 // option. This file may not be copied, modified, or distributed
9 // except according to those terms.
11 //! Simple [DEFLATE][def]-based compression. This is a wrapper around the
12 //! [`miniz`][mz] library, which is a one-file pure-C implementation of zlib.
14 //! [def]: https://en.wikipedia.org/wiki/DEFLATE
15 //! [mz]: https://code.google.com/p/miniz/
17 #![crate_name = "flate"]
19 #![crate_type = "rlib"]
20 #![crate_type = "dylib"]
21 #![doc(html_logo_url = "http://www.rust-lang.org/logos/rust-logo-128x128-blk-v2.png",
22 html_favicon_url = "http://www.rust-lang.org/favicon.ico",
23 html_root_url = "http://doc.rust-lang.org/nightly/")]
26 #[cfg(test)] #[phase(plugin, link)] extern crate log;
31 use libc::{c_void, size_t, c_int};
33 #[link(name = "miniz", kind = "static")]
35 /// Raw miniz compression function.
36 fn tdefl_compress_mem_to_heap(psrc_buf: *const c_void,
38 pout_len: *mut size_t,
42 /// Raw miniz decompression function.
43 fn tinfl_decompress_mem_to_heap(psrc_buf: *const c_void,
45 pout_len: *mut size_t,
50 static LZ_NORM : c_int = 0x80; // LZ with 128 probes, "normal"
51 static TINFL_FLAG_PARSE_ZLIB_HEADER : c_int = 0x1; // parse zlib header and adler32 checksum
52 static TDEFL_WRITE_ZLIB_HEADER : c_int = 0x01000; // write zlib header and adler32 checksum
54 fn deflate_bytes_internal(bytes: &[u8], flags: c_int) -> Option<CVec<u8>> {
56 let mut outsz : size_t = 0;
57 let res = tdefl_compress_mem_to_heap(bytes.as_ptr() as *const _,
58 bytes.len() as size_t,
62 Some(CVec::new_with_dtor(res as *mut u8, outsz as uint, proc() libc::free(res)))
69 /// Compress a buffer, without writing any sort of header on the output.
70 pub fn deflate_bytes(bytes: &[u8]) -> Option<CVec<u8>> {
71 deflate_bytes_internal(bytes, LZ_NORM)
74 /// Compress a buffer, using a header that zlib can understand.
75 pub fn deflate_bytes_zlib(bytes: &[u8]) -> Option<CVec<u8>> {
76 deflate_bytes_internal(bytes, LZ_NORM | TDEFL_WRITE_ZLIB_HEADER)
79 fn inflate_bytes_internal(bytes: &[u8], flags: c_int) -> Option<CVec<u8>> {
81 let mut outsz : size_t = 0;
82 let res = tinfl_decompress_mem_to_heap(bytes.as_ptr() as *const _,
83 bytes.len() as size_t,
87 Some(CVec::new_with_dtor(res as *mut u8, outsz as uint, proc() libc::free(res)))
94 /// Decompress a buffer, without parsing any sort of header on the input.
95 pub fn inflate_bytes(bytes: &[u8]) -> Option<CVec<u8>> {
96 inflate_bytes_internal(bytes, 0)
99 /// Decompress a buffer that starts with a zlib header.
100 pub fn inflate_bytes_zlib(bytes: &[u8]) -> Option<CVec<u8>> {
101 inflate_bytes_internal(bytes, TINFL_FLAG_PARSE_ZLIB_HEADER)
106 use super::{inflate_bytes, deflate_bytes};
111 fn test_flate_round_trip() {
112 let mut r = rand::task_rng();
113 let mut words = vec!();
114 for _ in range(0u, 20) {
115 let range = r.gen_range(1u, 10);
116 let v = r.gen_iter::<u8>().take(range).collect::<Vec<u8>>();
119 for _ in range(0u, 20) {
120 let mut input = vec![];
121 for _ in range(0u, 2000) {
122 input.push_all(r.choose(words.as_slice()).unwrap().as_slice());
124 debug!("de/inflate of {} bytes of random word-sequences",
126 let cmp = deflate_bytes(input.as_slice()).expect("deflation failed");
127 let out = inflate_bytes(cmp.as_slice()).expect("inflation failed");
128 debug!("{} bytes deflated to {} ({:.1}% size)",
129 input.len(), cmp.len(),
130 100.0 * ((cmp.len() as f64) / (input.len() as f64)));
131 assert_eq!(input.as_slice(), out.as_slice());
136 fn test_zlib_flate() {
137 let bytes = vec!(1, 2, 3, 4, 5);
138 let deflated = deflate_bytes(bytes.as_slice()).expect("deflation failed");
139 let inflated = inflate_bytes(deflated.as_slice()).expect("inflation failed");
140 assert_eq!(inflated.as_slice(), bytes.as_slice());