103 lines
3.4 KiB
Rust
103 lines
3.4 KiB
Rust
// 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 compression
|
|
|
|
*/
|
|
|
|
// NB: transitionary, de-mode-ing.
|
|
#[forbid(deprecated_mode)];
|
|
#[forbid(deprecated_pattern)];
|
|
|
|
use libc;
|
|
use libc::{c_void, size_t, c_int};
|
|
use ptr;
|
|
use rand;
|
|
use vec;
|
|
|
|
extern mod rustrt {
|
|
unsafe fn tdefl_compress_mem_to_heap(psrc_buf: *const c_void,
|
|
src_buf_len: size_t,
|
|
pout_len: *size_t,
|
|
flags: c_int) -> *c_void;
|
|
|
|
unsafe fn tinfl_decompress_mem_to_heap(psrc_buf: *const c_void,
|
|
src_buf_len: size_t,
|
|
pout_len: *size_t,
|
|
flags: c_int) -> *c_void;
|
|
}
|
|
|
|
const lz_none : c_int = 0x0; // Huffman-coding only.
|
|
const lz_fast : c_int = 0x1; // LZ with only one probe
|
|
const lz_norm : c_int = 0x80; // LZ with 128 probes, "normal"
|
|
const lz_best : c_int = 0xfff; // LZ with 4095 probes, "best"
|
|
|
|
pub fn deflate_bytes(bytes: &[const u8]) -> ~[u8] {
|
|
do vec::as_const_buf(bytes) |b, len| {
|
|
unsafe {
|
|
let mut outsz : size_t = 0;
|
|
let res =
|
|
rustrt::tdefl_compress_mem_to_heap(b as *c_void,
|
|
len as size_t,
|
|
ptr::addr_of(&outsz),
|
|
lz_norm);
|
|
assert res as int != 0;
|
|
let out = vec::raw::from_buf_raw(res as *u8,
|
|
outsz as uint);
|
|
libc::free(res);
|
|
move out
|
|
}
|
|
}
|
|
}
|
|
|
|
pub fn inflate_bytes(bytes: &[const u8]) -> ~[u8] {
|
|
do vec::as_const_buf(bytes) |b, len| {
|
|
unsafe {
|
|
let mut outsz : size_t = 0;
|
|
let res =
|
|
rustrt::tinfl_decompress_mem_to_heap(b as *c_void,
|
|
len as size_t,
|
|
ptr::addr_of(&outsz),
|
|
0);
|
|
assert res as int != 0;
|
|
let out = vec::raw::from_buf_raw(res as *u8,
|
|
outsz as uint);
|
|
libc::free(res);
|
|
move out
|
|
}
|
|
}
|
|
}
|
|
|
|
#[test]
|
|
#[allow(non_implicitly_copyable_typarams)]
|
|
fn test_flate_round_trip() {
|
|
let r = rand::Rng();
|
|
let mut words = ~[];
|
|
for 20.times {
|
|
words.push(r.gen_bytes(r.gen_uint_range(1, 10)));
|
|
}
|
|
for 20.times {
|
|
let mut in = ~[];
|
|
for 2000.times {
|
|
in.push_all(r.choose(words));
|
|
}
|
|
debug!("de/inflate of %u bytes of random word-sequences",
|
|
in.len());
|
|
let cmp = deflate_bytes(in);
|
|
let out = inflate_bytes(cmp);
|
|
debug!("%u bytes deflated to %u (%.1f%% size)",
|
|
in.len(), cmp.len(),
|
|
100.0 * ((cmp.len() as float) / (in.len() as float)));
|
|
assert(in == out);
|
|
}
|
|
}
|