oxipng/src/deflate/libz_stream.rs
2016-07-30 23:14:36 -04:00

136 lines
4.3 KiB
Rust

// Raw un-exported bindings to libz for encoding/decoding
// Copyright (c) 2014 Alex Crichton, MIT & Apache licenses
// Originally from flate2 crate for miniz
// Modified for use in oxipng
use std::marker;
use std::mem;
use libc::{c_int, c_uint};
use libz_sys;
pub struct Stream<D: Direction> {
raw: libz_sys::z_stream,
_marker: marker::PhantomData<D>,
}
pub enum Compress {}
pub enum Decompress {}
#[doc(hidden)]
pub trait Direction {
unsafe fn destroy(stream: *mut libz_sys::z_stream) -> c_int;
}
impl Stream<Compress> {
pub fn new_compress(lvl: c_int,
window_bits: c_int,
mem_size: c_int,
strategy: c_int)
-> Stream<Compress> {
unsafe {
let mut state: libz_sys::z_stream = mem::zeroed();
let ret = libz_sys::deflateInit2_(&mut state,
lvl,
libz_sys::Z_DEFLATED,
window_bits,
mem_size,
strategy,
libz_sys::zlibVersion(),
mem::size_of::<libz_sys::z_stream>() as i32);
debug_assert_eq!(ret, 0);
Stream {
raw: state,
_marker: marker::PhantomData,
}
}
}
pub fn new_decompress() -> Stream<Decompress> {
unsafe {
let mut state: libz_sys::z_stream = mem::zeroed();
let ret = libz_sys::inflateInit2_(&mut state,
15,
libz_sys::zlibVersion(),
mem::size_of::<libz_sys::z_stream>() as i32);
debug_assert_eq!(ret, 0);
Stream {
raw: state,
_marker: marker::PhantomData,
}
}
}
}
impl<T: Direction> Stream<T> {
#[inline]
pub fn total_in(&self) -> usize {
self.raw.total_in as usize
}
#[inline]
pub fn total_out(&self) -> usize {
self.raw.total_out as usize
}
}
impl Stream<Decompress> {
pub fn decompress_vec(&mut self, input: &mut [u8], output: &mut Vec<u8>) -> c_int {
self.raw.avail_in = (input.len() - self.total_in()) as c_uint;
self.raw.avail_out = (output.capacity() - self.total_out()) as c_uint;
unsafe {
self.raw.next_in = input.as_mut_ptr().offset(self.total_in() as isize);
self.raw.next_out = output.as_mut_ptr().offset(self.total_out() as isize);
let rc = libz_sys::inflate(&mut self.raw, libz_sys::Z_NO_FLUSH);
output.set_len(self.total_out() as usize);
rc
}
}
}
impl Stream<Compress> {
pub fn compress_vec(&mut self, input: &mut [u8], output: &mut Vec<u8>) -> c_int {
self.raw.avail_in = (input.len() - self.total_in() as usize) as c_uint;
self.raw.avail_out = (output.capacity() - self.total_out() as usize) as c_uint;
unsafe {
self.raw.next_in = input.as_mut_ptr().offset(self.total_in() as isize);
self.raw.next_out = output.as_mut_ptr().offset(self.total_out() as isize);
let rc = libz_sys::deflate(&mut self.raw,
if self.raw.avail_in > 0 {
libz_sys::Z_NO_FLUSH
} else {
libz_sys::Z_FINISH
});
output.set_len(self.total_out() as usize);
rc
}
}
#[inline]
pub fn reset(&mut self) -> c_int {
unsafe { libz_sys::deflateReset(&mut self.raw) }
}
}
impl Direction for Compress {
#[inline]
unsafe fn destroy(stream: *mut libz_sys::z_stream) -> c_int {
libz_sys::deflateEnd(stream)
}
}
impl Direction for Decompress {
#[inline]
unsafe fn destroy(stream: *mut libz_sys::z_stream) -> c_int {
libz_sys::inflateEnd(stream)
}
}
impl<D: Direction> Drop for Stream<D> {
#[inline]
fn drop(&mut self) {
unsafe {
let _ = <D as Direction>::destroy(&mut self.raw);
}
}
}