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"]
20 #![allow(unknown_features)] #![feature(int_uint)]
22 #![crate_type = "rlib"]
23 #![crate_type = "dylib"]
24 #![doc(html_logo_url = "http://www.rust-lang.org/logos/rust-logo-128x128-blk-v2.png",
25 html_favicon_url = "http://www.rust-lang.org/favicon.ico",
26 html_root_url = "http://doc.rust-lang.org/nightly/")]
28 #[cfg(test)] #[macro_use] extern crate log;
32 use libc::{c_void, size_t, c_int};
42 impl Deref for Bytes {
44 fn deref(&self) -> &[u8] {
45 unsafe { slice::from_raw_mut_buf(&self.ptr.0, self.len) }
51 unsafe { libc::free(self.ptr.0 as *mut _); }
55 #[link(name = "miniz", kind = "static")]
57 /// Raw miniz compression function.
58 fn tdefl_compress_mem_to_heap(psrc_buf: *const c_void,
60 pout_len: *mut size_t,
64 /// Raw miniz decompression function.
65 fn tinfl_decompress_mem_to_heap(psrc_buf: *const c_void,
67 pout_len: *mut size_t,
72 static LZ_NORM : c_int = 0x80; // LZ with 128 probes, "normal"
73 static TINFL_FLAG_PARSE_ZLIB_HEADER : c_int = 0x1; // parse zlib header and adler32 checksum
74 static TDEFL_WRITE_ZLIB_HEADER : c_int = 0x01000; // write zlib header and adler32 checksum
76 fn deflate_bytes_internal(bytes: &[u8], flags: c_int) -> Option<Bytes> {
78 let mut outsz : size_t = 0;
79 let res = tdefl_compress_mem_to_heap(bytes.as_ptr() as *const _,
80 bytes.len() as size_t,
84 let res = Unique(res as *mut u8);
85 Some(Bytes { ptr: res, len: outsz as uint })
92 /// Compress a buffer, without writing any sort of header on the output.
93 pub fn deflate_bytes(bytes: &[u8]) -> Option<Bytes> {
94 deflate_bytes_internal(bytes, LZ_NORM)
97 /// Compress a buffer, using a header that zlib can understand.
98 pub fn deflate_bytes_zlib(bytes: &[u8]) -> Option<Bytes> {
99 deflate_bytes_internal(bytes, LZ_NORM | TDEFL_WRITE_ZLIB_HEADER)
102 fn inflate_bytes_internal(bytes: &[u8], flags: c_int) -> Option<Bytes> {
104 let mut outsz : size_t = 0;
105 let res = tinfl_decompress_mem_to_heap(bytes.as_ptr() as *const _,
106 bytes.len() as size_t,
110 let res = Unique(res as *mut u8);
111 Some(Bytes { ptr: res, len: outsz as uint })
118 /// Decompress a buffer, without parsing any sort of header on the input.
119 pub fn inflate_bytes(bytes: &[u8]) -> Option<Bytes> {
120 inflate_bytes_internal(bytes, 0)
123 /// Decompress a buffer that starts with a zlib header.
124 pub fn inflate_bytes_zlib(bytes: &[u8]) -> Option<Bytes> {
125 inflate_bytes_internal(bytes, TINFL_FLAG_PARSE_ZLIB_HEADER)
130 use super::{inflate_bytes, deflate_bytes};
135 fn test_flate_round_trip() {
136 let mut r = rand::thread_rng();
137 let mut words = vec!();
138 for _ in range(0u, 20) {
139 let range = r.gen_range(1u, 10);
140 let v = r.gen_iter::<u8>().take(range).collect::<Vec<u8>>();
143 for _ in range(0u, 20) {
144 let mut input = vec![];
145 for _ in range(0u, 2000) {
146 input.push_all(r.choose(words.as_slice()).unwrap().as_slice());
148 debug!("de/inflate of {} bytes of random word-sequences",
150 let cmp = deflate_bytes(input.as_slice()).expect("deflation failed");
151 let out = inflate_bytes(cmp.as_slice()).expect("inflation failed");
152 debug!("{} bytes deflated to {} ({:.1}% size)",
153 input.len(), cmp.len(),
154 100.0 * ((cmp.len() as f64) / (input.len() as f64)));
155 assert_eq!(input, out.as_slice());
160 fn test_zlib_flate() {
161 let bytes = vec!(1, 2, 3, 4, 5);
162 let deflated = deflate_bytes(bytes.as_slice()).expect("deflation failed");
163 let inflated = inflate_bytes(deflated.as_slice()).expect("inflation failed");
164 assert_eq!(inflated.as_slice(), bytes);