1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
#![cfg_attr(stage0, feature(custom_attribute))]
#![crate_name = "flate"]
#![unstable(feature = "rustc_private")]
#![staged_api]
#![crate_type = "rlib"]
#![crate_type = "dylib"]
#![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/nightly/")]
#![feature(libc)]
#![feature(staged_api)]
#![feature(unique)]
#![cfg_attr(test, feature(rustc_private, rand, collections))]
#[cfg(test)] #[macro_use] extern crate log;
extern crate libc;
use libc::{c_void, size_t, c_int};
use std::fmt;
use std::ops::Deref;
use std::ptr::Unique;
use std::slice;
#[derive(Clone, Eq, Hash, Ord, PartialEq, PartialOrd)]
pub struct Error {
_unused: (),
}
impl Error {
fn new() -> Error {
Error {
_unused: (),
}
}
}
impl fmt::Debug for Error {
fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
"decompression error".fmt(f)
}
}
pub struct Bytes {
ptr: Unique<u8>,
len: usize,
}
impl Deref for Bytes {
type Target = [u8];
fn deref(&self) -> &[u8] {
unsafe { slice::from_raw_parts(*self.ptr, self.len) }
}
}
impl Drop for Bytes {
fn drop(&mut self) {
unsafe { libc::free(*self.ptr as *mut _); }
}
}
#[link(name = "miniz", kind = "static")]
extern {
fn tdefl_compress_mem_to_heap(psrc_buf: *const c_void,
src_buf_len: size_t,
pout_len: *mut size_t,
flags: c_int)
-> *mut c_void;
fn tinfl_decompress_mem_to_heap(psrc_buf: *const c_void,
src_buf_len: size_t,
pout_len: *mut size_t,
flags: c_int)
-> *mut c_void;
}
const LZ_NORM: c_int = 0x80;
const TINFL_FLAG_PARSE_ZLIB_HEADER: c_int = 0x1;
const TDEFL_WRITE_ZLIB_HEADER: c_int = 0x01000;
fn deflate_bytes_internal(bytes: &[u8], flags: c_int) -> Bytes {
unsafe {
let mut outsz: size_t = 0;
let res = tdefl_compress_mem_to_heap(bytes.as_ptr() as *const _,
bytes.len() as size_t,
&mut outsz,
flags);
assert!(!res.is_null());
Bytes {
ptr: Unique::new(res as *mut u8),
len: outsz as usize,
}
}
}
pub fn deflate_bytes(bytes: &[u8]) -> Bytes {
deflate_bytes_internal(bytes, LZ_NORM)
}
pub fn deflate_bytes_zlib(bytes: &[u8]) -> Bytes {
deflate_bytes_internal(bytes, LZ_NORM | TDEFL_WRITE_ZLIB_HEADER)
}
fn inflate_bytes_internal(bytes: &[u8], flags: c_int) -> Result<Bytes,Error> {
unsafe {
let mut outsz: size_t = 0;
let res = tinfl_decompress_mem_to_heap(bytes.as_ptr() as *const _,
bytes.len() as size_t,
&mut outsz,
flags);
if !res.is_null() {
Ok(Bytes {
ptr: Unique::new(res as *mut u8),
len: outsz as usize,
})
} else {
Err(Error::new())
}
}
}
pub fn inflate_bytes(bytes: &[u8]) -> Result<Bytes,Error> {
inflate_bytes_internal(bytes, 0)
}
pub fn inflate_bytes_zlib(bytes: &[u8]) -> Result<Bytes,Error> {
inflate_bytes_internal(bytes, TINFL_FLAG_PARSE_ZLIB_HEADER)
}
#[cfg(test)]
mod tests {
#![allow(deprecated)]
use super::{inflate_bytes, deflate_bytes};
use std::__rand::{thread_rng, Rng};
#[test]
fn test_flate_round_trip() {
let mut r = thread_rng();
let mut words = vec![];
for _ in 0..20 {
let range = r.gen_range(1, 10);
let v = r.gen_iter::<u8>().take(range).collect::<Vec<u8>>();
words.push(v);
}
for _ in 0..20 {
let mut input = vec![];
for _ in 0..2000 {
input.push_all(r.choose(&words).unwrap());
}
debug!("de/inflate of {} bytes of random word-sequences",
input.len());
let cmp = deflate_bytes(&input);
let out = inflate_bytes(&cmp).unwrap();
debug!("{} bytes deflated to {} ({:.1}% size)",
input.len(), cmp.len(),
100.0 * ((cmp.len() as f64) / (input.len() as f64)));
assert_eq!(&*input, &*out);
}
}
#[test]
fn test_zlib_flate() {
let bytes = vec![1, 2, 3, 4, 5];
let deflated = deflate_bytes(&bytes);
let inflated = inflate_bytes(&deflated).unwrap();
assert_eq!(&*inflated, &*bytes);
}
}