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"]
18 #![unstable(feature = "rustc_private")]
20 #![crate_type = "rlib"]
21 #![crate_type = "dylib"]
22 #![doc(html_logo_url = "http://www.rust-lang.org/logos/rust-logo-128x128-blk-v2.png",
23 html_favicon_url = "http://www.rust-lang.org/favicon.ico",
24 html_root_url = "http://doc.rust-lang.org/nightly/")]
29 #![feature(staged_api)]
31 #[cfg(test)] #[macro_use] extern crate log;
35 use libc::{c_void, size_t, c_int};
45 impl Deref for Bytes {
47 fn deref(&self) -> &[u8] {
48 unsafe { slice::from_raw_parts(*self.ptr, self.len) }
54 unsafe { libc::free(*self.ptr as *mut _); }
58 #[link(name = "miniz", kind = "static")]
60 /// Raw miniz compression function.
61 fn tdefl_compress_mem_to_heap(psrc_buf: *const c_void,
63 pout_len: *mut size_t,
67 /// Raw miniz decompression function.
68 fn tinfl_decompress_mem_to_heap(psrc_buf: *const c_void,
70 pout_len: *mut size_t,
75 static LZ_NORM : c_int = 0x80; // LZ with 128 probes, "normal"
76 static TINFL_FLAG_PARSE_ZLIB_HEADER : c_int = 0x1; // parse zlib header and adler32 checksum
77 static TDEFL_WRITE_ZLIB_HEADER : c_int = 0x01000; // write zlib header and adler32 checksum
79 fn deflate_bytes_internal(bytes: &[u8], flags: c_int) -> Option<Bytes> {
81 let mut outsz : size_t = 0;
82 let res = tdefl_compress_mem_to_heap(bytes.as_ptr() as *const _,
83 bytes.len() as size_t,
87 let res = Unique::new(res as *mut u8);
88 Some(Bytes { ptr: res, len: outsz as uint })
95 /// Compress a buffer, without writing any sort of header on the output.
96 pub fn deflate_bytes(bytes: &[u8]) -> Option<Bytes> {
97 deflate_bytes_internal(bytes, LZ_NORM)
100 /// Compress a buffer, using a header that zlib can understand.
101 pub fn deflate_bytes_zlib(bytes: &[u8]) -> Option<Bytes> {
102 deflate_bytes_internal(bytes, LZ_NORM | TDEFL_WRITE_ZLIB_HEADER)
105 fn inflate_bytes_internal(bytes: &[u8], flags: c_int) -> Option<Bytes> {
107 let mut outsz : size_t = 0;
108 let res = tinfl_decompress_mem_to_heap(bytes.as_ptr() as *const _,
109 bytes.len() as size_t,
113 let res = Unique::new(res as *mut u8);
114 Some(Bytes { ptr: res, len: outsz as uint })
121 /// Decompress a buffer, without parsing any sort of header on the input.
122 pub fn inflate_bytes(bytes: &[u8]) -> Option<Bytes> {
123 inflate_bytes_internal(bytes, 0)
126 /// Decompress a buffer that starts with a zlib header.
127 pub fn inflate_bytes_zlib(bytes: &[u8]) -> Option<Bytes> {
128 inflate_bytes_internal(bytes, TINFL_FLAG_PARSE_ZLIB_HEADER)
133 #![allow(deprecated)]
134 use super::{inflate_bytes, deflate_bytes};
139 fn test_flate_round_trip() {
140 let mut r = rand::thread_rng();
141 let mut words = vec!();
143 let range = r.gen_range(1, 10);
144 let v = r.gen_iter::<u8>().take(range).collect::<Vec<u8>>();
148 let mut input = vec![];
150 input.push_all(r.choose(&words).unwrap());
152 debug!("de/inflate of {} bytes of random word-sequences",
154 let cmp = deflate_bytes(&input).expect("deflation failed");
155 let out = inflate_bytes(&cmp).expect("inflation failed");
156 debug!("{} bytes deflated to {} ({:.1}% size)",
157 input.len(), cmp.len(),
158 100.0 * ((cmp.len() as f64) / (input.len() as f64)));
159 assert_eq!(&*input, &*out);
164 fn test_zlib_flate() {
165 let bytes = vec!(1, 2, 3, 4, 5);
166 let deflated = deflate_bytes(&bytes).expect("deflation failed");
167 let inflated = inflate_bytes(&deflated).expect("inflation failed");
168 assert_eq!(&*inflated, &*bytes);