Quelle deflate.rs
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Spracherkennung für: .rs vermutete Sprache: Unknown {[0] [0] [0]} [Methode: Schwerpunktbildung, einfache Gewichte, sechs Dimensionen]
use core::{ffi::CStr, marker::PhantomData, mem::MaybeUninit, ops::ControlFlow};
use crate::{
adler32::adler32,
allocate::Allocator,
c_api::{gz_header, internal_state, z_checksum, z_stream},
crc32::{crc32, Crc32Fold},
read_buf::ReadBuf,
trace, DeflateFlush, ReturnCode, ADLER32_INITIAL_VALUE, CRC32_INITIAL_VALUE, MAX_WBIT S,
MIN_WBITS,
};
use self::{
algorithm::CONFIGURATION_TABLE,
hash_calc::{Crc32HashCalc, HashCalcVariant, RollHashCalc, StandardHashCalc},
pending::Pending,
trees_tbl::STATIC_LTREE,
window::Window,
};
mod algorithm;
mod compare256;
mod hash_calc;
mod longest_match;
mod pending;
mod slide_hash;
mod trees_tbl;
mod window;
#[repr(C)]
pub struct DeflateStream<'a> {
pub(crate) next_in: *mut crate::c_api::Bytef,
pub(crate) avail_in: crate::c_api::uInt,
pub(crate) total_in: crate::c_api::z_size,
pub(crate) next_out: *mut crate::c_api::Bytef,
pub(crate) avail_out: crate::c_api::uInt,
pub(crate) total_out: crate::c_api::z_size,
pub(crate) msg: *const core::ffi::c_char,
pub(crate) state: &'a mut State<'a>,
pub(crate) alloc: Allocator<'a>,
pub(crate) data_type: core::ffi::c_int,
pub(crate) adler: crate::c_api::z_checksum,
pub(crate) reserved: crate::c_api::uLong,
}
impl<'a> DeflateStream<'a> {
const _S: () = assert!(core::mem::size_of::<z_stream>() == core::mem::size_of::<Self>());
const _A: () = assert!(core::mem::align_of::<z_stream>() == core::mem::align_of::<Self>());
/// # Safety
///
/// Behavior is undefined if any of the following conditions are violated:
///
/// - `strm` satisfies the conditions of [`pointer::as_mut`]
/// - if not `NULL`, `strm` as initialized using [`init`] or similar
///
/// [`pointer::as_mut`]: https://doc.rust-lang.org/core/primitive.pointer.html#method.as_mut
#[inline(always)]
pub unsafe fn from_stream_mut(strm: *mut z_stream) -> Option<&'a mut Self> {
{
// Safety: ptr points to a valid value of type z_stream (if non-null)
let stream = unsafe { strm.as_ref() }?;
if stream.zalloc.is_none() || stream.zfree.is_none() {
return None;
}
if stream.state.is_null() {
return None;
}
}
// Safety: DeflateStream has an equivalent layout as z_stream
unsafe { strm.cast::<DeflateStream>().as_mut() }
}
fn as_z_stream_mut(&mut self) -> &mut z_stream {
// safety: a valid &mut DeflateStream is also a valid &mut z_stream
unsafe { &mut *(self as *mut DeflateStream as *mut z_stream) }
}
pub fn pending(&self) -> (usize, u8) {
(
self.state.bit_writer.pending.pending,
self.state.bit_writer.bits_used,
)
}
}
/// number of elements in hash table
pub(crate) const HASH_SIZE: usize = 65536;
/// log2(HASH_SIZE)
const HASH_BITS: usize = 16;
/// Maximum value for memLevel in deflateInit2
const MAX_MEM_LEVEL: i32 = 9;
const DEF_MEM_LEVEL: i32 = if MAX_MEM_LEVEL > 8 { 8 } else { MAX_MEM_LEVEL };
#[repr(i32)]
#[derive(Debug, Clone, Copy, PartialEq, Eq, Hash, Default)]
#[cfg_attr(feature = "__internal-fuzz", derive(arbitrary::Arbitrary))]
pub enum Method {
#[default]
Deflated = 8,
}
impl TryFrom<i32> for Method {
type Error = ();
fn try_from(value: i32) -> Result<Self, Self::Error> {
match value {
8 => Ok(Self::Deflated),
_ => Err(()),
}
}
}
#[derive(Debug, Clone, Copy, PartialEq, Eq, Hash)]
#[cfg_attr(feature = "__internal-fuzz", derive(arbitrary::Arbitrary))]
pub struct DeflateConfig {
pub level: i32,
pub method: Method,
pub window_bits: i32,
pub mem_level: i32,
pub strategy: Strategy,
}
#[cfg(any(test, feature = "__internal-test"))]
impl quickcheck::Arbitrary for DeflateConfig {
fn arbitrary(g: &mut quickcheck::Gen) -> Self {
let mem_levels: Vec<_> = (1..=9).collect();
let levels: Vec<_> = (0..=9).collect();
let mut window_bits = Vec::new();
window_bits.extend(9..=15); // zlib
window_bits.extend(9 + 16..=15 + 16); // gzip
window_bits.extend(-15..=-9); // raw
Self {
level: *g.choose(&levels).unwrap(),
method: Method::Deflated,
window_bits: *g.choose(&window_bits).unwrap(),
mem_level: *g.choose(&mem_levels).unwrap(),
strategy: *g
.choose(&[
Strategy::Default,
Strategy::Filtered,
Strategy::HuffmanOnly,
Strategy::Rle,
Strategy::Fixed,
])
.unwrap(),
}
}
}
impl DeflateConfig {
pub fn new(level: i32) -> Self {
Self {
level,
..Self::default()
}
}
}
impl Default for DeflateConfig {
fn default() -> Self {
Self {
level: crate::c_api::Z_DEFAULT_COMPRESSION,
method: Method::Deflated,
window_bits: MAX_WBITS,
mem_level: DEF_MEM_LEVEL,
strategy: Strategy::Default,
}
}
}
// TODO: This could use `MaybeUninit::slice_assume_init` when it is stable.
unsafe fn slice_assume_init_mut<T>(slice: &mut [MaybeUninit<T>]) -> &mut [T] {
&mut *(slice as *mut [MaybeUninit<T>] as *mut [T])
}
// when stable, use MaybeUninit::write_slice
fn slice_to_uninit<T>(slice: &[T]) -> &[MaybeUninit<T>] {
// safety: &[T] and &[MaybeUninit<T>] have the same layout
unsafe { &*(slice as *const [T] as *const [MaybeUninit<T>]) }
}
pub fn init(stream: &mut z_stream, config: DeflateConfig) -> ReturnCode {
let DeflateConfig {
mut level,
method: _,
mut window_bits,
mem_level,
strategy,
} = config;
/* Todo: ignore strm->next_in if we use it as window */
stream.msg = core::ptr::null_mut();
// for safety we must really make sure that alloc and free are consistent
// this is a (slight) deviation from stock zlib. In this crate we pick the rust
// allocator as the default, but `libz-rs-sys` always explicitly sets an allocator,
// and can configure the C allocator
#[cfg(feature = "rust-allocator")]
if stream.zalloc.is_none() || stream.zfree.is_none() {
stream.configure_default_rust_allocator()
}
#[cfg(feature = "c-allocator")]
if stream.zalloc.is_none() || stream.zfree.is_none() {
stream.configure_default_c_allocator()
}
if stream.zalloc.is_none() || stream.zfree.is_none() {
return ReturnCode::StreamError;
}
if level == crate::c_api::Z_DEFAULT_COMPRESSION {
level = 6;
}
let wrap = if window_bits < 0 {
if window_bits < -MAX_WBITS {
return ReturnCode::StreamError;
}
window_bits = -window_bits;
0
} else if window_bits > MAX_WBITS {
window_bits -= 16;
2
} else {
1
};
if (!(1..=MAX_MEM_LEVEL).contains(&mem_level))
|| !(MIN_WBITS..=MAX_WBITS).contains(&window_bits)
|| !(0..=9).contains(&level)
|| (window_bits == 8 && wrap != 1)
{
return ReturnCode::StreamError;
}
let window_bits = if window_bits == 8 {
9 /* until 256-byte window bug fixed */
} else {
window_bits as usize
};
let alloc = Allocator {
zalloc: stream.zalloc.unwrap(),
zfree: stream.zfree.unwrap(),
opaque: stream.opaque,
_marker: PhantomData,
};
// allocated here to have the same order as zlib
let Some(state_allocation) = alloc.allocate::<State>() else {
return ReturnCode::MemError;
};
let w_size = 1 << window_bits;
let window = Window::new_in(&alloc, window_bits);
let prev = alloc.allocate_slice::<u16>(w_size);
let head = alloc.allocate::<[u16; HASH_SIZE]>();
let lit_bufsize = 1 << (mem_level + 6); // 16K elements by default
let pending = Pending::new_in(&alloc, 4 * lit_bufsize);
// zlib-ng overlays the pending_buf and sym_buf. We cannot really do that safely
let sym_buf = ReadBuf::new_in(&alloc, 3 * lit_bufsize);
// if any allocation failed, clean up allocations that did succeed
let (window, prev, head, pending, sym_buf) = match (window, prev, head, pending, sym_buf) {
(Some(window), Some(prev), Some(head), Some(pending), Some(sym_buf)) => {
(window, prev, head, pending, sym_buf)
}
(window, prev, head, pending, sym_buf) => {
unsafe {
if let Some(mut sym_buf) = sym_buf {
alloc.deallocate(sym_buf.as_mut_ptr(), sym_buf.capacity())
}
if let Some(pending) = pending {
pending.drop_in(&alloc);
}
if let Some(head) = head {
alloc.deallocate(head.as_mut_ptr(), 1)
}
if let Some(prev) = prev {
alloc.deallocate(prev.as_mut_ptr(), prev.len())
}
if let Some(mut window) = window {
window.drop_in(&alloc);
}
alloc.deallocate(state_allocation.as_mut_ptr(), 1);
}
return ReturnCode::MemError;
}
};
prev.fill(MaybeUninit::zeroed());
let prev = unsafe { slice_assume_init_mut(prev) };
*head = MaybeUninit::zeroed();
let head = unsafe { head.assume_init_mut() };
let state = State {
status: Status::Init,
// window
w_bits: window_bits,
w_size,
w_mask: w_size - 1,
// allocated values
window,
prev,
head,
bit_writer: BitWriter::from_pending(pending),
//
lit_bufsize,
//
sym_buf,
//
level: level as i8, // set to zero again for testing?
strategy,
// these fields are not set explicitly at this point
last_flush: 0,
wrap,
strstart: 0,
block_start: 0,
block_open: 0,
window_size: 0,
insert: 0,
matches: 0,
opt_len: 0,
static_len: 0,
lookahead: 0,
ins_h: 0,
max_chain_length: 0,
max_lazy_match: 0,
good_match: 0,
nice_match: 0,
//
l_desc: TreeDesc::EMPTY,
d_desc: TreeDesc::EMPTY,
bl_desc: TreeDesc::EMPTY,
bl_count: [0u16; MAX_BITS + 1],
//
heap: Heap::new(),
//
crc_fold: Crc32Fold::new(),
gzhead: None,
gzindex: 0,
//
match_start: 0,
match_length: 0,
prev_match: 0,
match_available: false,
prev_length: 0,
// just provide a valid default; gets set properly later
hash_calc_variant: HashCalcVariant::Standard,
};
let state = state_allocation.write(state);
stream.state = state as *mut _ as *mut internal_state;
let Some(stream) = (unsafe { DeflateStream::from_stream_mut(stream) }) else {
if cfg!(debug_assertions) {
unreachable!("we should have initialized the stream properly");
}
return ReturnCode::StreamError;
};
reset(stream)
}
pub fn params(stream: &mut DeflateStream, level: i32, strategy: Strategy) -> ReturnCode {
let level = if level == crate::c_api::Z_DEFAULT_COMPRESSION {
6
} else {
level
};
if !(0..=9).contains(&level) {
return ReturnCode::StreamError;
}
let level = level as i8;
let func = CONFIGURATION_TABLE[stream.state.level as usize].func;
let state = &mut stream.state;
if (strategy != state.strategy || func != CONFIGURATION_TABLE[level as usize].func)
&& state.last_flush != -2
{
// Flush the last buffer.
let err = deflate(stream, DeflateFlush::Block);
if err == ReturnCode::StreamError {
return err;
}
let state = &mut stream.state;
if stream.avail_in != 0
|| ((state.strstart as isize - state.block_start) + state.lookahead as isize) != 0
{
return ReturnCode::BufError;
}
}
let state = &mut stream.state;
if state.level != level {
if state.level == 0 && state.matches != 0 {
if state.matches == 1 {
self::slide_hash::slide_hash(state);
} else {
state.head.fill(0);
}
state.matches = 0;
}
lm_set_level(state, level);
}
state.strategy = strategy;
ReturnCode::Ok
}
pub fn set_dictionary(stream: &mut DeflateStream, mut dictionary: &[u8]) -> ReturnCode {
let state = &mut stream.state;
let wrap = state.wrap;
if wrap == 2 || (wrap == 1 && state.status != Status::Init) || state.lookahead != 0 {
return ReturnCode::StreamError;
}
// when using zlib wrappers, compute Adler-32 for provided dictionary
if wrap == 1 {
stream.adler = adler32(stream.adler as u32, dictionary) as z_checksum;
}
// avoid computing Adler-32 in read_buf
state.wrap = 0;
// if dictionary would fill window, just replace the history
if dictionary.len() >= state.window.capacity() {
if wrap == 0 {
// clear the hash table
state.head.fill(0);
state.strstart = 0;
state.block_start = 0;
state.insert = 0;
} else {
/* already empty otherwise */
}
// use the tail
dictionary = &dictionary[dictionary.len() - state.w_size..];
}
// insert dictionary into window and hash
let avail = stream.avail_in;
let next = stream.next_in;
stream.avail_in = dictionary.len() as _;
stream.next_in = dictionary.as_ptr() as *mut u8;
fill_window(stream);
while stream.state.lookahead >= STD_MIN_MATCH {
let str = stream.state.strstart;
let n = stream.state.lookahead - (STD_MIN_MATCH - 1);
stream.state.insert_string(str, n);
stream.state.strstart = str + n;
stream.state.lookahead = STD_MIN_MATCH - 1;
fill_window(stream);
}
let state = &mut stream.state;
state.strstart += state.lookahead;
state.block_start = state.strstart as _;
state.insert = state.lookahead;
state.lookahead = 0;
state.prev_length = 0;
state.match_available = false;
// restore the state
stream.next_in = next;
stream.avail_in = avail;
state.wrap = wrap;
ReturnCode::Ok
}
pub fn prime(stream: &mut DeflateStream, mut bits: i32, value: i32) -> ReturnCode {
// our logic actually supports up to 32 bits.
debug_assert!(bits <= 16, "zlib only supports up to 16 bits here");
let mut value64 = value as u64;
let state = &mut stream.state;
if bits < 0
|| bits > BitWriter::BIT_BUF_SIZE as i32
|| bits > (core::mem::size_of_val(&value) << 3) as i32
{
return ReturnCode::BufError;
}
let mut put;
loop {
put = BitWriter::BIT_BUF_SIZE - state.bit_writer.bits_used;
let put = Ord::min(put as i32, bits);
if state.bit_writer.bits_used == 0 {
state.bit_writer.bit_buffer = value64;
} else {
state.bit_writer.bit_buffer |=
(value64 & ((1 << put) - 1)) << state.bit_writer.bits_used;
}
state.bit_writer.bits_used += put as u8;
state.bit_writer.flush_bits();
value64 >>= put;
bits -= put;
if bits == 0 {
break;
}
}
ReturnCode::Ok
}
pub fn copy<'a>(
dest: &mut MaybeUninit<DeflateStream<'a>>,
source: &mut DeflateStream<'a>,
) -> ReturnCode {
// Safety: source and dest are both mutable references, so guaranteed not to overlap.
// dest being a reference to maybe uninitialized memory makes a copy of 1 DeflateStream valid.
unsafe {
core::ptr::copy_nonoverlapping(source, dest.as_mut_ptr(), 1);
}
let alloc = &source.alloc;
// allocated here to have the same order as zlib
let Some(state_allocation) = alloc.allocate::<State>() else {
return ReturnCode::MemError;
};
let source_state = &source.state;
let window = source_state.window.clone_in(alloc);
let prev = alloc.allocate_slice::<u16>(source_state.w_size);
let head = alloc.allocate::<[u16; HASH_SIZE]>();
let pending = source_state.bit_writer.pending.clone_in(alloc);
let sym_buf = source_state.sym_buf.clone_in(alloc);
// if any allocation failed, clean up allocations that did succeed
let (window, prev, head, pending, sym_buf) = match (window, prev, head, pending, sym_buf) {
(Some(window), Some(prev), Some(head), Some(pending), Some(sym_buf)) => {
(window, prev, head, pending, sym_buf)
}
(window, prev, head, pending, sym_buf) => {
// Safety: this access is in-bounds
let field_ptr = unsafe { core::ptr::addr_of_mut!((*dest.as_mut_ptr()).state) };
unsafe { core::ptr::write(field_ptr as *mut *mut State, core::ptr::null_mut()) };
// Safety: it is an assumpion on DeflateStream that (de)allocation does not cause UB.
unsafe {
if let Some(mut sym_buf) = sym_buf {
alloc.deallocate(sym_buf.as_mut_ptr(), sym_buf.capacity())
}
if let Some(pending) = pending {
pending.drop_in(alloc);
}
if let Some(head) = head {
alloc.deallocate(head.as_mut_ptr(), HASH_SIZE)
}
if let Some(prev) = prev {
alloc.deallocate(prev.as_mut_ptr(), prev.len())
}
if let Some(mut window) = window {
window.drop_in(alloc);
}
alloc.deallocate(state_allocation.as_mut_ptr(), 1);
}
return ReturnCode::MemError;
}
};
prev.copy_from_slice(slice_to_uninit(source_state.prev));
let prev = unsafe { core::slice::from_raw_parts_mut(prev.as_mut_ptr().cast(), prev.len()) };
let head = head.write(*source_state.head);
let mut bit_writer = BitWriter::from_pending(pending);
bit_writer.bits_used = source_state.bit_writer.bits_used;
bit_writer.bit_buffer = source_state.bit_writer.bit_buffer;
let dest_state = State {
status: source_state.status,
bit_writer,
last_flush: source_state.last_flush,
wrap: source_state.wrap,
strategy: source_state.strategy,
level: source_state.level,
good_match: source_state.good_match,
nice_match: source_state.nice_match,
l_desc: source_state.l_desc.clone(),
d_desc: source_state.d_desc.clone(),
bl_desc: source_state.bl_desc.clone(),
bl_count: source_state.bl_count,
match_length: source_state.match_length,
prev_match: source_state.prev_match,
match_available: source_state.match_available,
strstart: source_state.strstart,
match_start: source_state.match_start,
prev_length: source_state.prev_length,
max_chain_length: source_state.max_chain_length,
max_lazy_match: source_state.max_lazy_match,
block_start: source_state.block_start,
block_open: source_state.block_open,
window,
sym_buf,
lit_bufsize: source_state.lit_bufsize,
window_size: source_state.window_size,
matches: source_state.matches,
opt_len: source_state.opt_len,
static_len: source_state.static_len,
insert: source_state.insert,
w_size: source_state.w_size,
w_bits: source_state.w_bits,
w_mask: source_state.w_mask,
lookahead: source_state.lookahead,
prev,
head,
ins_h: source_state.ins_h,
heap: source_state.heap.clone(),
hash_calc_variant: source_state.hash_calc_variant,
crc_fold: source_state.crc_fold,
gzhead: None,
gzindex: source_state.gzindex,
};
// write the cloned state into state_ptr
let state_ptr = state_allocation.write(dest_state);
// insert the state_ptr into `dest`
let field_ptr = unsafe { core::ptr::addr_of_mut!((*dest.as_mut_ptr()).state) };
unsafe { core::ptr::write(field_ptr as *mut *mut State, state_ptr) };
// update the gzhead field (it contains a mutable reference so we need to be careful
let field_ptr = unsafe { core::ptr::addr_of_mut!((*dest.as_mut_ptr()).state.gzhead) };
unsafe { core::ptr::copy(&source_state.gzhead, field_ptr, 1) };
ReturnCode::Ok
}
/// # Returns
///
/// - Err when deflate is not done. A common cause is insufficient output space
/// - Ok otherwise
pub fn end<'a>(stream: &'a mut DeflateStream) -> Result<&'a mut z_stream, &'a mut z_stream> {
let status = stream.state.status;
let alloc = stream.alloc;
// deallocate in reverse order of allocations
unsafe {
// safety: we make sure that these fields are not used (by invalidating the state pointer)
stream.state.sym_buf.drop_in(&alloc);
stream.state.bit_writer.pending.drop_in(&alloc);
alloc.deallocate(stream.state.head, 1);
if !stream.state.prev.is_empty() {
alloc.deallocate(stream.state.prev.as_mut_ptr(), stream.state.prev.len());
}
stream.state.window.drop_in(&alloc);
}
let state = stream.state as *mut State;
let stream = stream.as_z_stream_mut();
stream.state = core::ptr::null_mut();
// safety: `state` is not used later
unsafe {
alloc.deallocate(state, 1);
}
match status {
Status::Busy => Err(stream),
_ => Ok(stream),
}
}
pub fn reset(stream: &mut DeflateStream) -> ReturnCode {
let ret = reset_keep(stream);
if ret == ReturnCode::Ok {
lm_init(stream.state);
}
ret
}
fn reset_keep(stream: &mut DeflateStream) -> ReturnCode {
stream.total_in = 0;
stream.total_out = 0;
stream.msg = core::ptr::null_mut();
stream.data_type = crate::c_api::Z_UNKNOWN;
let state = &mut stream.state;
state.bit_writer.pending.reset_keep();
// can be made negative by deflate(..., Z_FINISH);
state.wrap = state.wrap.abs();
state.status = match state.wrap {
2 => Status::GZip,
_ => Status::Init,
};
stream.adler = match state.wrap {
2 => {
state.crc_fold = Crc32Fold::new();
CRC32_INITIAL_VALUE as _
}
_ => ADLER32_INITIAL_VALUE as _,
};
state.last_flush = -2;
state.zng_tr_init();
ReturnCode::Ok
}
fn lm_init(state: &mut State) {
state.window_size = 2 * state.w_size;
// zlib uses CLEAR_HASH here
state.head.fill(0);
// Set the default configuration parameters:
lm_set_level(state, state.level);
state.strstart = 0;
state.block_start = 0;
state.lookahead = 0;
state.insert = 0;
state.prev_length = 0;
state.match_available = false;
state.match_start = 0;
state.ins_h = 0;
}
fn lm_set_level(state: &mut State, level: i8) {
state.max_lazy_match = CONFIGURATION_TABLE[level as usize].max_lazy as usize;
state.good_match = CONFIGURATION_TABLE[level as usize].good_length as usize;
state.nice_match = CONFIGURATION_TABLE[level as usize].nice_length as usize;
state.max_chain_length = CONFIGURATION_TABLE[level as usize].max_chain as usize;
state.hash_calc_variant = HashCalcVariant::for_max_chain_length(state.max_chain_length);
state.level = level;
}
pub fn tune(
stream: &mut DeflateStream,
good_length: usize,
max_lazy: usize,
nice_length: usize,
max_chain: usize,
) -> ReturnCode {
stream.state.good_match = good_length;
stream.state.max_lazy_match = max_lazy;
stream.state.nice_match = nice_length;
stream.state.max_chain_length = max_chain;
ReturnCode::Ok
}
#[repr(C)]
#[derive(Debug, Clone, Copy, PartialEq, Eq)]
pub(crate) struct Value {
a: u16,
b: u16,
}
impl Value {
pub(crate) const fn new(a: u16, b: u16) -> Self {
Self { a, b }
}
pub(crate) fn freq_mut(&mut self) -> &mut u16 {
&mut self.a
}
pub(crate) fn code_mut(&mut self) -> &mut u16 {
&mut self.a
}
pub(crate) fn dad_mut(&mut self) -> &mut u16 {
&mut self.b
}
pub(crate) fn len_mut(&mut self) -> &mut u16 {
&mut self.b
}
#[inline(always)]
pub(crate) const fn freq(self) -> u16 {
self.a
}
pub(crate) fn code(self) -> u16 {
self.a
}
pub(crate) fn dad(self) -> u16 {
self.b
}
pub(crate) fn len(self) -> u16 {
self.b
}
}
/// number of length codes, not counting the special END_BLOCK code
pub(crate) const LENGTH_CODES: usize = 29;
/// number of literal bytes 0..255
const LITERALS: usize = 256;
/// number of Literal or Length codes, including the END_BLOCK code
pub(crate) const L_CODES: usize = LITERALS + 1 + LENGTH_CODES;
/// number of distance codes
pub(crate) const D_CODES: usize = 30;
/// number of codes used to transfer the bit lengths
const BL_CODES: usize = 19;
/// maximum heap size
const HEAP_SIZE: usize = 2 * L_CODES + 1;
/// all codes must not exceed MAX_BITS bits
const MAX_BITS: usize = 15;
/// Bit length codes must not exceed MAX_BL_BITS bits
const MAX_BL_BITS: usize = 7;
pub(crate) const DIST_CODE_LEN: usize = 512;
struct BitWriter<'a> {
pub(crate) pending: Pending<'a>, // output still pending
pub(crate) bit_buffer: u64,
pub(crate) bits_used: u8,
/// total bit length of compressed file (NOTE: zlib-ng uses a 32-bit integer here)
#[cfg(feature = "ZLIB_DEBUG")]
compressed_len: usize,
/// bit length of compressed data sent (NOTE: zlib-ng uses a 32-bit integer here)
#[cfg(feature = "ZLIB_DEBUG")]
bits_sent: usize,
}
impl<'a> BitWriter<'a> {
pub(crate) const BIT_BUF_SIZE: u8 = 64;
fn from_pending(pending: Pending<'a>) -> Self {
Self {
pending,
bit_buffer: 0,
bits_used: 0,
#[cfg(feature = "ZLIB_DEBUG")]
compressed_len: 0,
#[cfg(feature = "ZLIB_DEBUG")]
bits_sent: 0,
}
}
fn flush_bits(&mut self) {
debug_assert!(self.bits_used <= 64);
let removed = self.bits_used.saturating_sub(7).next_multiple_of(8);
let keep_bytes = self.bits_used / 8; // can never divide by zero
let src = &self.bit_buffer.to_le_bytes();
self.pending.extend(&src[..keep_bytes as usize]);
self.bits_used -= removed;
self.bit_buffer = self.bit_buffer.checked_shr(removed as u32).unwrap_or(0);
}
fn emit_align(&mut self) {
debug_assert!(self.bits_used <= 64);
let keep_bytes = self.bits_used.div_ceil(8);
let src = &self.bit_buffer.to_le_bytes();
self.pending.extend(&src[..keep_bytes as usize]);
self.bits_used = 0;
self.bit_buffer = 0;
self.sent_bits_align();
}
fn send_bits_trace(&self, _value: u64, _len: u8) {
trace!(" l {:>2} v {:>4x} ", _len, _value);
}
fn cmpr_bits_add(&mut self, _len: usize) {
#[cfg(feature = "ZLIB_DEBUG")]
{
self.compressed_len += _len;
}
}
fn cmpr_bits_align(&mut self) {
#[cfg(feature = "ZLIB_DEBUG")]
{
self.compressed_len = self.compressed_len.next_multiple_of(8);
}
}
fn sent_bits_add(&mut self, _len: usize) {
#[cfg(feature = "ZLIB_DEBUG")]
{
self.bits_sent += _len;
}
}
fn sent_bits_align(&mut self) {
#[cfg(feature = "ZLIB_DEBUG")]
{
self.bits_sent = self.bits_sent.next_multiple_of(8);
}
}
fn send_bits(&mut self, val: u64, len: u8) {
debug_assert!(len <= 64);
debug_assert!(self.bits_used <= 64);
let total_bits = len + self.bits_used;
self.send_bits_trace(val, len);
self.sent_bits_add(len as usize);
if total_bits < Self::BIT_BUF_SIZE {
self.bit_buffer |= val << self.bits_used;
self.bits_used = total_bits;
} else if self.bits_used == Self::BIT_BUF_SIZE {
// with how send_bits is called, this is unreachable in practice
self.pending.extend(&self.bit_buffer.to_le_bytes());
self.bit_buffer = val;
self.bits_used = len;
} else {
self.bit_buffer |= val << self.bits_used;
self.pending.extend(&self.bit_buffer.to_le_bytes());
self.bit_buffer = val >> (Self::BIT_BUF_SIZE - self.bits_used);
self.bits_used = total_bits - Self::BIT_BUF_SIZE;
}
}
fn send_code(&mut self, code: usize, tree: &[Value]) {
let node = tree[code];
self.send_bits(node.code() as u64, node.len() as u8)
}
/// Send one empty static block to give enough lookahead for inflate.
/// This takes 10 bits, of which 7 may remain in the bit buffer.
pub fn align(&mut self) {
self.emit_tree(BlockType::StaticTrees, false);
self.emit_end_block(&STATIC_LTREE, false);
self.flush_bits();
}
pub(crate) fn emit_tree(&mut self, block_type: BlockType, is_last_block: bool) {
let header_bits = (block_type as u64) << 1 | (is_last_block as u64);
self.send_bits(header_bits, 3);
trace!("\n--- Emit Tree: Last: {}\n", is_last_block as u8);
}
pub(crate) fn emit_end_block_and_align(&mut self, ltree: &[Value], is_last_block: bool) {
self.emit_end_block(ltree, is_last_block);
if is_last_block {
self.emit_align();
}
}
fn emit_end_block(&mut self, ltree: &[Value], _is_last_block: bool) {
const END_BLOCK: usize = 256;
self.send_code(END_BLOCK, ltree);
trace!(
"\n+++ Emit End Block: Last: {} Pending: {} Total Out: {}\n",
_is_last_block as u8,
self.pending.pending().len(),
"<unknown>"
);
}
pub(crate) fn emit_lit(&mut self, ltree: &[Value], c: u8) -> u16 {
self.send_code(c as usize, ltree);
#[cfg(feature = "ZLIB_DEBUG")]
if let Some(c) = char::from_u32(c as u32) {
if isgraph(c as u8) {
trace!(" '{}' ", c);
}
}
ltree[c as usize].len()
}
pub(crate) fn emit_dist(
&mut self,
ltree: &[Value],
dtree: &[Value],
lc: u8,
mut dist: usize,
) -> usize {
let mut lc = lc as usize;
/* Send the length code, len is the match length - STD_MIN_MATCH */
let mut code = self::trees_tbl::LENGTH_CODE[lc] as usize;
let c = code + LITERALS + 1;
assert!(c < L_CODES, "bad l_code");
// send_code_trace(s, c);
let lnode = ltree[c];
let mut match_bits: u64 = lnode.code() as u64;
let mut match_bits_len = lnode.len() as usize;
let mut extra = StaticTreeDesc::EXTRA_LBITS[code] as usize;
if extra != 0 {
lc -= self::trees_tbl::BASE_LENGTH[code] as usize;
match_bits |= (lc as u64) << match_bits_len;
match_bits_len += extra;
}
dist -= 1; /* dist is now the match distance - 1 */
code = State::d_code(dist) as usize;
assert!(code < D_CODES, "bad d_code");
// send_code_trace(s, code);
/* Send the distance code */
let dnode = dtree[code];
match_bits |= (dnode.code() as u64) << match_bits_len;
match_bits_len += dnode.len() as usize;
extra = StaticTreeDesc::EXTRA_DBITS[code] as usize;
if extra != 0 {
dist -= self::trees_tbl::BASE_DIST[code] as usize;
match_bits |= (dist as u64) << match_bits_len;
match_bits_len += extra;
}
self.send_bits(match_bits, match_bits_len as u8);
match_bits_len
}
fn compress_block_help(&mut self, sym_buf: &[u8], ltree: &[Value], dtree: &[Value]) {
for chunk in sym_buf.chunks_exact(3) {
let [dist_low, dist_high, lc] = *chunk else {
unreachable!("out of bound access on the symbol buffer");
};
match u16::from_be_bytes([dist_high, dist_low]) as usize {
0 => self.emit_lit(ltree, lc) as usize,
dist => self.emit_dist(ltree, dtree, lc, dist),
};
}
self.emit_end_block(ltree, false)
}
fn send_tree(&mut self, tree: &[Value], bl_tree: &[Value], max_code: usize) {
/* tree: the tree to be scanned */
/* max_code and its largest code of non zero frequency */
let mut prevlen: isize = -1; /* last emitted length */
let mut curlen; /* length of current code */
let mut nextlen = tree[0].len(); /* length of next code */
let mut count = 0; /* repeat count of the current code */
let mut max_count = 7; /* max repeat count */
let mut min_count = 4; /* min repeat count */
/* tree[max_code+1].Len = -1; */
/* guard already set */
if nextlen == 0 {
max_count = 138;
min_count = 3;
}
for n in 0..=max_code {
curlen = nextlen;
nextlen = tree[n + 1].len();
count += 1;
if count < max_count && curlen == nextlen {
continue;
} else if count < min_count {
loop {
self.send_code(curlen as usize, bl_tree);
count -= 1;
if count == 0 {
break;
}
}
} else if curlen != 0 {
if curlen as isize != prevlen {
self.send_code(curlen as usize, bl_tree);
count -= 1;
}
assert!((3..=6).contains(&count), " 3_6?");
self.send_code(REP_3_6, bl_tree);
self.send_bits(count - 3, 2);
} else if count <= 10 {
self.send_code(REPZ_3_10, bl_tree);
self.send_bits(count - 3, 3);
} else {
self.send_code(REPZ_11_138, bl_tree);
self.send_bits(count - 11, 7);
}
count = 0;
prevlen = curlen as isize;
if nextlen == 0 {
max_count = 138;
min_count = 3;
} else if curlen == nextlen {
max_count = 6;
min_count = 3;
} else {
max_count = 7;
min_count = 4;
}
}
}
}
#[repr(C)]
pub(crate) struct State<'a> {
status: Status,
last_flush: i32, /* value of flush param for previous deflate call */
bit_writer: BitWriter<'a>,
pub(crate) wrap: i8, /* bit 0 true for zlib, bit 1 true for gzip */
pub(crate) strategy: Strategy,
pub(crate) level: i8,
/// Use a faster search when the previous match is longer than this
pub(crate) good_match: usize,
/// Stop searching when current match exceeds this
pub(crate) nice_match: usize,
// part of the fields below
// dyn_ltree: [Value; ],
// dyn_dtree: [Value; ],
// bl_tree: [Value; ],
l_desc: TreeDesc<HEAP_SIZE>, /* literal and length tree */
d_desc: TreeDesc<{ 2 * D_CODES + 1 }>, /* distance tree */
bl_desc: TreeDesc<{ 2 * BL_CODES + 1 }>, /* Huffman tree for bit lengths */
pub(crate) bl_count: [u16; MAX_BITS + 1],
pub(crate) match_length: usize, /* length of best match */
pub(crate) prev_match: u16, /* previous match */
pub(crate) match_available: bool, /* set if previous match exists */
pub(crate) strstart: usize, /* start of string to insert */
pub(crate) match_start: usize, /* start of matching string */
/// Length of the best match at previous step. Matches not greater than this
/// are discarded. This is used in the lazy match evaluation.
pub(crate) prev_length: usize,
/// To speed up deflation, hash chains are never searched beyond this length.
/// A higher limit improves compression ratio but degrades the speed.
pub(crate) max_chain_length: usize,
// TODO untangle this mess! zlib uses the same field differently based on compression level
// we should just have 2 fields for clarity!
//
// Insert new strings in the hash table only if the match length is not
// greater than this length. This saves time but degrades compression.
// max_insert_length is used only for compression levels <= 3.
// define max_insert_length max_lazy_match
/// Attempt to find a better match only when the current match is strictly smaller
/// than this value. This mechanism is used only for compression levels >= 4.
pub(crate) max_lazy_match: usize,
/// Window position at the beginning of the current output block. Gets
/// negative when the window is moved backwards.
pub(crate) block_start: isize,
/// Whether or not a block is currently open for the QUICK deflation scheme.
/// true if there is an active block, or false if the block was just closed
pub(crate) block_open: u8,
pub(crate) window: Window<'a>,
pub(crate) sym_buf: ReadBuf<'a>,
/// Size of match buffer for literals/lengths. There are 4 reasons for
/// limiting lit_bufsize to 64K:
/// - frequencies can be kept in 16 bit counters
/// - if compression is not successful for the first block, all input
/// data is still in the window so we can still emit a stored block even
/// when input comes from standard input. (This can also be done for
/// all blocks if lit_bufsize is not greater than 32K.)
/// - if compression is not successful for a file smaller than 64K, we can
/// even emit a stored file instead of a stored block (saving 5 bytes).
/// This is applicable only for zip (not gzip or zlib).
/// - creating new Huffman trees less frequently may not provide fast
/// adaptation to changes in the input data statistics. (Take for
/// example a binary file with poorly compressible code followed by
/// a highly compressible string table.) Smaller buffer sizes give
/// fast adaptation but have of course the overhead of transmitting
/// trees more frequently.
/// - I can't count above 4
lit_bufsize: usize,
/// Actual size of window: 2*wSize, except when the user input buffer is directly used as sliding window.
pub(crate) window_size: usize,
/// number of string matches in current block
pub(crate) matches: usize,
/// bit length of current block with optimal trees
opt_len: usize,
/// bit length of current block with static trees
static_len: usize,
/// bytes at end of window left to insert
pub(crate) insert: usize,
pub(crate) w_size: usize, /* LZ77 window size (32K by default) */
pub(crate) w_bits: usize, /* log2(w_size) (8..16) */
pub(crate) w_mask: usize, /* w_size - 1 */
pub(crate) lookahead: usize, /* number of valid bytes ahead in window */
pub(crate) prev: &'a mut [u16],
pub(crate) head: &'a mut [u16; HASH_SIZE],
/// hash index of string to be inserted
pub(crate) ins_h: usize,
heap: Heap,
pub(crate) hash_calc_variant: HashCalcVariant,
crc_fold: crate::crc32::Crc32Fold,
gzhead: Option<&'a mut gz_header>,
gzindex: usize,
}
#[derive(Debug, Clone, Copy, PartialEq, Eq, Hash, PartialOrd, Ord, Default)]
#[cfg_attr(feature = "__internal-fuzz", derive(arbitrary::Arbitrary))]
pub enum Strategy {
#[default]
Default = 0,
Filtered = 1,
HuffmanOnly = 2,
Rle = 3,
Fixed = 4,
}
impl TryFrom<i32> for Strategy {
type Error = ();
fn try_from(value: i32) -> Result<Self, Self::Error> {
match value {
0 => Ok(Strategy::Default),
1 => Ok(Strategy::Filtered),
2 => Ok(Strategy::HuffmanOnly),
3 => Ok(Strategy::Rle),
4 => Ok(Strategy::Fixed),
_ => Err(()),
}
}
}
#[derive(Debug, PartialEq, Eq)]
enum DataType {
Binary = 0,
Text = 1,
Unknown = 2,
}
impl<'a> State<'a> {
pub const BIT_BUF_SIZE: u8 = BitWriter::BIT_BUF_SIZE;
pub(crate) fn max_dist(&self) -> usize {
self.w_size - MIN_LOOKAHEAD
}
// TODO untangle this mess! zlib uses the same field differently based on compression level
// we should just have 2 fields for clarity!
pub(crate) fn max_insert_length(&self) -> usize {
self.max_lazy_match
}
/// Total size of the pending buf. But because `pending` shares memory with `sym_buf`, this is
/// not the number of bytes that are actually in `pending`!
pub(crate) fn pending_buf_size(&self) -> usize {
self.lit_bufsize * 4
}
pub(crate) fn update_hash(&self, h: u32, val: u32) -> u32 {
match self.hash_calc_variant {
HashCalcVariant::Standard => StandardHashCalc::update_hash(h, val),
HashCalcVariant::Crc32 => unsafe { Crc32HashCalc::update_hash(h, val) },
HashCalcVariant::Roll => RollHashCalc::update_hash(h, val),
}
}
pub(crate) fn quick_insert_string(&mut self, string: usize) -> u16 {
match self.hash_calc_variant {
HashCalcVariant::Standard => StandardHashCalc::quick_insert_string(self, string),
HashCalcVariant::Crc32 => unsafe { Crc32HashCalc::quick_insert_string(self, string) },
HashCalcVariant::Roll => RollHashCalc::quick_insert_string(self, string),
}
}
pub(crate) fn insert_string(&mut self, string: usize, count: usize) {
match self.hash_calc_variant {
HashCalcVariant::Standard => StandardHashCalc::insert_string(self, string, count),
HashCalcVariant::Crc32 => unsafe { Crc32HashCalc::insert_string(self, string, count) },
HashCalcVariant::Roll => RollHashCalc::insert_string(self, string, count),
}
}
pub(crate) fn tally_lit(&mut self, unmatched: u8) -> bool {
self.sym_buf.push(0);
self.sym_buf.push(0);
self.sym_buf.push(unmatched);
*self.l_desc.dyn_tree[unmatched as usize].freq_mut() += 1;
assert!(
unmatched as usize <= STD_MAX_MATCH - STD_MIN_MATCH,
"zng_tr_tally: bad literal"
);
// signal that the current block should be flushed
self.sym_buf.len() == self.sym_buf.capacity() - 3
}
const fn d_code(dist: usize) -> u8 {
let index = if dist < 256 { dist } else { 256 + (dist >> 7) };
self::trees_tbl::DIST_CODE[index]
}
pub(crate) fn tally_dist(&mut self, mut dist: usize, len: usize) -> bool {
let symbols = [dist as u8, (dist >> 8) as u8, len as u8];
self.sym_buf.extend(&symbols);
self.matches += 1;
dist -= 1;
assert!(
dist < self.max_dist() && Self::d_code(dist) < D_CODES as u8,
"tally_dist: bad match"
);
let index = self::trees_tbl::LENGTH_CODE[len] as usize + LITERALS + 1;
*self.l_desc.dyn_tree[index].freq_mut() += 1;
*self.d_desc.dyn_tree[Self::d_code(dist) as usize].freq_mut() += 1;
// signal that the current block should be flushed
self.sym_buf.len() == self.sym_buf.capacity() - 3
}
fn detect_data_type(dyn_tree: &[Value]) -> DataType {
// set bits 0..6, 14..25, and 28..31
// 0xf3ffc07f = binary 11110011111111111100000001111111
const NON_TEXT: u64 = 0xf3ffc07f;
let mut mask = NON_TEXT;
/* Check for non-textual bytes. */
for value in &dyn_tree[0..32] {
if (mask & 1) != 0 && value.freq() != 0 {
return DataType::Binary;
}
mask >>= 1;
}
/* Check for textual bytes. */
if dyn_tree[9].freq() != 0 || dyn_tree[10].freq() != 0 || dyn_tree[13].freq() != 0 {
return DataType::Text;
}
if dyn_tree[32..LITERALS].iter().any(|v| v.freq() != 0) {
return DataType::Text;
}
// there are no explicit text or non-text bytes. The stream is either empty or has only
// tolerated bytes
DataType::Binary
}
fn compress_block_static_trees(&mut self) {
self.bit_writer.compress_block_help(
self.sym_buf.filled(),
self::trees_tbl::STATIC_LTREE.as_slice(),
self::trees_tbl::STATIC_DTREE.as_slice(),
)
}
fn compress_block_dynamic_trees(&mut self) {
self.bit_writer.compress_block_help(
self.sym_buf.filled(),
&self.l_desc.dyn_tree,
&self.d_desc.dyn_tree,
);
}
fn header(&self) -> u16 {
// preset dictionary flag in zlib header
const PRESET_DICT: u16 = 0x20;
// The deflate compression method (the only one supported in this version)
const Z_DEFLATED: u16 = 8;
let dict = match self.strstart {
0 => 0,
_ => PRESET_DICT,
};
let h =
(Z_DEFLATED + ((self.w_bits as u16 - 8) << 4)) << 8 | (self.level_flags() << 6) | dict;
h + 31 - (h % 31)
}
fn level_flags(&self) -> u16 {
if self.strategy >= Strategy::HuffmanOnly || self.level < 2 {
0
} else if self.level < 6 {
1
} else if self.level == 6 {
2
} else {
3
}
}
fn zng_tr_init(&mut self) {
self.l_desc.stat_desc = &StaticTreeDesc::L;
self.d_desc.stat_desc = &StaticTreeDesc::D;
self.bl_desc.stat_desc = &StaticTreeDesc::BL;
self.bit_writer.bit_buffer = 0;
self.bit_writer.bits_used = 0;
#[cfg(feature = "ZLIB_DEBUG")]
{
self.bit_writer.compressed_len = 0;
self.bit_writer.bits_sent = 0;
}
// Initialize the first block of the first file:
self.init_block();
}
/// initializes a new block
fn init_block(&mut self) {
// Initialize the trees.
// TODO would a memset also work here?
for value in &mut self.l_desc.dyn_tree[..L_CODES] {
*value.freq_mut() = 0;
}
for value in &mut self.d_desc.dyn_tree[..D_CODES] {
*value.freq_mut() = 0;
}
for value in &mut self.bl_desc.dyn_tree[..BL_CODES] {
*value.freq_mut() = 0;
}
// end of block literal code
const END_BLOCK: usize = 256;
*self.l_desc.dyn_tree[END_BLOCK].freq_mut() = 1;
self.opt_len = 0;
self.static_len = 0;
self.sym_buf.clear();
self.matches = 0;
}
}
#[repr(u8)]
#[derive(Debug, Clone, Copy, PartialEq, Eq)]
enum Status {
Init = 1,
GZip = 4,
Extra = 5,
Name = 6,
Comment = 7,
Hcrc = 8,
Busy = 2,
Finish = 3,
}
const fn rank_flush(f: i32) -> i32 {
// rank Z_BLOCK between Z_NO_FLUSH and Z_PARTIAL_FLUSH
((f) * 2) - (if (f) > 4 { 9 } else { 0 })
}
#[derive(Debug)]
pub(crate) enum BlockState {
/// block not completed, need more input or more output
NeedMore = 0,
/// block flush performed
BlockDone = 1,
/// finish started, need only more output at next deflate
FinishStarted = 2,
/// finish done, accept no more input or output
FinishDone = 3,
}
// Maximum stored block length in deflate format (not including header).
pub(crate) const MAX_STORED: usize = 65535; // so u16::max
pub(crate) fn read_buf_window(stream: &mut DeflateStream, offset: usize, size: usize) -> usize {
let len = Ord::min(stream.avail_in as usize, size);
if len == 0 {
return 0;
}
stream.avail_in -= len as u32;
if stream.state.wrap == 2 {
// we likely cannot fuse the crc32 and the copy here because the input can be changed by
// a concurrent thread. Therefore it cannot be converted into a slice!
let window = &mut stream.state.window;
window.initialize_at_least(offset + len);
unsafe { window.copy_and_initialize(offset..offset + len, stream.next_in) };
let data = &stream.state.window.filled()[offset..][..len];
stream.state.crc_fold.fold(data, CRC32_INITIAL_VALUE);
} else if stream.state.wrap == 1 {
// we likely cannot fuse the adler32 and the copy here because the input can be changed by
// a concurrent thread. Therefore it cannot be converted into a slice!
let window = &mut stream.state.window;
window.initialize_at_least(offset + len);
unsafe { window.copy_and_initialize(offset..offset + len, stream.next_in) };
let data = &stream.state.window.filled()[offset..][..len];
stream.adler = adler32(stream.adler as u32, data) as _;
} else {
let window = &mut stream.state.window;
window.initialize_at_least(offset + len);
unsafe { window.copy_and_initialize(offset..offset + len, stream.next_in) };
}
stream.next_in = stream.next_in.wrapping_add(len);
stream.total_in += len as crate::c_api::z_size;
len
}
pub(crate) enum BlockType {
StoredBlock = 0,
StaticTrees = 1,
DynamicTrees = 2,
}
pub(crate) fn zng_tr_stored_block(
state: &mut State,
window_range: core::ops::Range<usize>,
is_last: bool,
) {
// send block type
state.bit_writer.emit_tree(BlockType::StoredBlock, is_last);
// align on byte boundary
state.bit_writer.emit_align();
state.bit_writer.cmpr_bits_align();
let input_block: &[u8] = &state.window.filled()[window_range];
let stored_len = input_block.len() as u16;
state.bit_writer.pending.extend(&stored_len.to_le_bytes());
state
.bit_writer
.pending
.extend(&(!stored_len).to_le_bytes());
state.bit_writer.cmpr_bits_add(32);
state.bit_writer.sent_bits_add(32);
if stored_len > 0 {
state.bit_writer.pending.extend(input_block);
state.bit_writer.cmpr_bits_add((stored_len << 3) as usize);
state.bit_writer.sent_bits_add((stored_len << 3) as usize);
}
}
/// The minimum match length mandated by the deflate standard
pub(crate) const STD_MIN_MATCH: usize = 3;
/// The maximum match length mandated by the deflate standard
pub(crate) const STD_MAX_MATCH: usize = 258;
/// The minimum wanted match length, affects deflate_quick, deflate_fast, deflate_medium and deflate_slow
pub(crate) const WANT_MIN_MATCH: usize = 4;
pub(crate) const MIN_LOOKAHEAD: usize = STD_MAX_MATCH + STD_MIN_MATCH + 1;
pub(crate) fn fill_window(stream: &mut DeflateStream) {
debug_assert!(stream.state.lookahead < MIN_LOOKAHEAD);
let wsize = stream.state.w_size;
loop {
let state = &mut stream.state;
let mut more = state.window_size - state.lookahead - state.strstart;
// If the window is almost full and there is insufficient lookahead,
// move the upper half to the lower one to make room in the upper half.
if state.strstart >= wsize + state.max_dist() {
// in some cases zlib-ng copies uninitialized bytes here. We cannot have that, so
// explicitly initialize them with zeros.
//
// see also the "fill_window_out_of_bounds" test.
state.window.initialize_at_least(2 * wsize);
state.window.filled_mut().copy_within(wsize..2 * wsize, 0);
if state.match_start >= wsize {
state.match_start -= wsize;
} else {
state.match_start = 0;
state.prev_length = 0;
}
state.strstart -= wsize; /* we now have strstart >= MAX_DIST */
state.block_start -= wsize as isize;
if state.insert > state.strstart {
state.insert = state.strstart;
}
self::slide_hash::slide_hash(state);
more += wsize;
}
if stream.avail_in == 0 {
break;
}
// If there was no sliding:
// strstart <= WSIZE+MAX_DIST-1 && lookahead <= MIN_LOOKAHEAD - 1 &&
// more == window_size - lookahead - strstart
// => more >= window_size - (MIN_LOOKAHEAD-1 + WSIZE + MAX_DIST-1)
// => more >= window_size - 2*WSIZE + 2
// In the BIG_MEM or MMAP case (not yet supported),
// window_size == input_size + MIN_LOOKAHEAD &&
// strstart + s->lookahead <= input_size => more >= MIN_LOOKAHEAD.
// Otherwise, window_size == 2*WSIZE so more >= 2.
// If there was sliding, more >= WSIZE. So in all cases, more >= 2.
assert!(more >= 2, "more < 2");
let n = read_buf_window(stream, stream.state.strstart + stream.state.lookahead, more);
let state = &mut stream.state;
state.lookahead += n;
// Initialize the hash value now that we have some input:
if state.lookahead + state.insert >= STD_MIN_MATCH {
let string = state.strstart - state.insert;
if state.max_chain_length > 1024 {
let v0 = state.window.filled()[string] as u32;
let v1 = state.window.filled()[string + 1] as u32;
state.ins_h = state.update_hash(v0, v1) as usize;
} else if string >= 1 {
state.quick_insert_string(string + 2 - STD_MIN_MATCH);
}
let mut count = state.insert;
if state.lookahead == 1 {
count -= 1;
}
if count > 0 {
state.insert_string(string, count);
state.insert -= count;
}
}
// If the whole input has less than STD_MIN_MATCH bytes, ins_h is garbage,
// but this is not important since only literal bytes will be emitted.
if !(stream.state.lookahead < MIN_LOOKAHEAD && stream.avail_in != 0) {
break;
}
}
// initialize some memory at the end of the (filled) window, so SIMD operations can go "out of
// bounds" without violating any requirements. The window allocation is already slightly bigger
// to allow for this.
stream.state.window.initialize_out_of_bounds();
assert!(
stream.state.strstart <= stream.state.window_size - MIN_LOOKAHEAD,
"not enough room for search"
);
}
pub(crate) struct StaticTreeDesc {
/// static tree or NULL
pub(crate) static_tree: &'static [Value],
/// extra bits for each code or NULL
extra_bits: &'static [u8],
/// base index for extra_bits
extra_base: usize,
/// max number of elements in the tree
elems: usize,
/// max bit length for the codes
max_length: u16,
}
impl StaticTreeDesc {
const EMPTY: Self = Self {
static_tree: &[],
extra_bits: &[],
extra_base: 0,
elems: 0,
max_length: 0,
};
/// extra bits for each length code
const EXTRA_LBITS: [u8; LENGTH_CODES] = [
0, 0, 0, 0, 0, 0, 0, 0, 1, 1, 1, 1, 2, 2, 2, 2, 3, 3, 3, 3, 4, 4, 4, 4, 5, 5, 5, 5, 0,
];
/// extra bits for each distance code
const EXTRA_DBITS: [u8; D_CODES] = [
0, 0, 0, 0, 1, 1, 2, 2, 3, 3, 4, 4, 5, 5, 6, 6, 7, 7, 8, 8, 9, 9, 10, 10, 11, 11, 12, 12,
13, 13,
];
/// extra bits for each bit length code
const EXTRA_BLBITS: [u8; BL_CODES] = [0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 2, 3, 7];
/// The lengths of the bit length codes are sent in order of decreasing
/// probability, to avoid transmitting the lengths for unused bit length codes.
const BL_ORDER: [u8; BL_CODES] = [
16, 17, 18, 0, 8, 7, 9, 6, 10, 5, 11, 4, 12, 3, 13, 2, 14, 1, 15,
];
pub(crate) const L: Self = Self {
static_tree: &self::trees_tbl::STATIC_LTREE,
extra_bits: &Self::EXTRA_LBITS,
extra_base: LITERALS + 1,
elems: L_CODES,
max_length: MAX_BITS as u16,
};
pub(crate) const D: Self = Self {
static_tree: &self::trees_tbl::STATIC_DTREE,
extra_bits: &Self::EXTRA_DBITS,
extra_base: 0,
elems: D_CODES,
max_length: MAX_BITS as u16,
};
pub(crate) const BL: Self = Self {
static_tree: &[],
extra_bits: &Self::EXTRA_BLBITS,
extra_base: 0,
elems: BL_CODES,
max_length: MAX_BL_BITS as u16,
};
}
#[derive(Clone)]
struct TreeDesc<const N: usize> {
dyn_tree: [Value; N],
max_code: usize,
stat_desc: &'static StaticTreeDesc,
}
impl<const N: usize> TreeDesc<N> {
const EMPTY: Self = Self {
dyn_tree: [Value::new(0, 0); N],
max_code: 0,
stat_desc: &StaticTreeDesc::EMPTY,
};
}
fn build_tree<const N: usize>(state: &mut State, desc: &mut TreeDesc<N>) {
let tree = &mut desc.dyn_tree;
let stree = desc.stat_desc.static_tree;
let elements = desc.stat_desc.elems;
let mut max_code = state.heap.initialize(&mut tree[..elements]);
// The pkzip format requires that at least one distance code exists,
// and that at least one bit should be sent even if there is only one
// possible code. So to avoid special checks later on we force at least
// two codes of non zero frequency.
while state.heap.heap_len < 2 {
state.heap.heap_len += 1;
let node = if max_code < 2 {
max_code += 1;
max_code
} else {
0
};
debug_assert!(node >= 0);
let node = node as usize;
state.heap.heap[state.heap.heap_len] = node as u32;
*tree[node].freq_mut() = 1;
state.heap.depth[node] = 0;
state.opt_len -= 1;
if !stree.is_empty() {
state.static_len -= stree[node].len() as usize;
}
/* node is 0 or 1 so it does not have extra bits */
}
debug_assert!(max_code >= 0);
let max_code = max_code as usize;
desc.max_code = max_code;
// The elements heap[heap_len/2+1 .. heap_len] are leaves of the tree,
// establish sub-heaps of increasing lengths:
let mut n = state.heap.heap_len / 2;
while n >= 1 {
state.heap.pqdownheap(tree, n);
n -= 1;
}
state.heap.construct_huffman_tree(tree, elements);
// At this point, the fields freq and dad are set. We can now
// generate the bit lengths.
gen_bitlen(state, desc);
// The field len is now set, we can generate the bit codes
gen_codes(&mut desc.dyn_tree, max_code, &state.bl_count);
}
fn gen_bitlen<const N: usize>(state: &mut State, desc: &mut TreeDesc<N>) {
let heap = &mut state.heap;
let tree = &mut desc.dyn_tree;
let max_code = desc.max_code;
let stree = desc.stat_desc.static_tree;
let extra = desc.stat_desc.extra_bits;
let base = desc.stat_desc.extra_base;
let max_length = desc.stat_desc.max_length;
state.bl_count.fill(0);
// In a first pass, compute the optimal bit lengths (which may
// overflow in the case of the bit length tree).
*tree[heap.heap[heap.heap_max] as usize].len_mut() = 0; /* root of the heap */
// number of elements with bit length too large
let mut overflow: i32 = 0;
for h in heap.heap_max + 1..HEAP_SIZE {
let n = heap.heap[h] as usize;
let mut bits = tree[tree[n].dad() as usize].len() + 1;
if bits > max_length {
bits = max_length;
overflow += 1;
}
// We overwrite tree[n].Dad which is no longer needed
*tree[n].len_mut() = bits;
// not a leaf node
if n > max_code {
continue;
}
state.bl_count[bits as usize] += 1;
let mut xbits = 0;
if n >= base {
xbits = extra[n - base] as usize;
}
let f = tree[n].freq() as usize;
state.opt_len += f * (bits as usize + xbits);
if !stree.is_empty() {
state.static_len += f * (stree[n].len() as usize + xbits);
}
}
if overflow == 0 {
return;
}
/* Find the first bit length which could increase: */
loop {
let mut bits = max_length as usize - 1;
while state.bl_count[bits] == 0 {
bits -= 1;
}
state.bl_count[bits] -= 1; /* move one leaf down the tree */
state.bl_count[bits + 1] += 2; /* move one overflow item as its brother */
state.bl_count[max_length as usize] -= 1;
/* The brother of the overflow item also moves one step up,
* but this does not affect bl_count[max_length]
*/
overflow -= 2;
if overflow <= 0 {
break;
}
}
// Now recompute all bit lengths, scanning in increasing frequency.
// h is still equal to HEAP_SIZE. (It is simpler to reconstruct all
// lengths instead of fixing only the wrong ones. This idea is taken
// from 'ar' written by Haruhiko Okumura.)
let mut h = HEAP_SIZE;
for bits in (1..=max_length).rev() {
let mut n = state.bl_count[bits as usize];
while n != 0 {
h -= 1;
let m = heap.heap[h] as usize;
if m > max_code {
continue;
}
if tree[m].len() != bits {
// Tracev((stderr, "code %d bits %d->%u\n", m, tree[m].Len, bits));
state.opt_len += (bits * tree[m].freq()) as usize;
state.opt_len -= (tree[m].len() * tree[m].freq()) as usize;
*tree[m].len_mut() = bits;
}
n -= 1;
}
}
}
/// Checks that symbol is a printing character (excluding space)
#[allow(unused)]
fn isgraph(c: u8) -> bool {
(c > 0x20) && (c <= 0x7E)
}
fn gen_codes(tree: &mut [Value], max_code: usize, bl_count: &[u16]) {
/* tree: the tree to decorate */
/* max_code: largest code with non zero frequency */
/* bl_count: number of codes at each bit length */
let mut next_code = [0; MAX_BITS + 1]; /* next code value for each bit length */
let mut code = 0; /* running code value */
/* The distribution counts are first used to generate the code values
* without bit reversal.
*/
for bits in 1..=MAX_BITS {
code = (code + bl_count[bits - 1]) << 1;
next_code[bits] = code;
}
/* Check that the bit counts in bl_count are consistent. The last code
* must be all ones.
*/
assert!(
code + bl_count[MAX_BITS] - 1 == (1 << MAX_BITS) - 1,
"inconsistent bit counts"
);
trace!("\ngen_codes: max_code {max_code} ");
for n in 0..=max_code {
let len = tree[n].len();
if len == 0 {
continue;
}
/* Now reverse the bits */
assert!((1..=15).contains(&len), "code length must be 1-15");
*tree[n].code_mut() = next_code[len as usize].reverse_bits() >> (16 - len);
next_code[len as usize] += 1;
if tree != self::trees_tbl::STATIC_LTREE.as_slice() {
trace!(
"\nn {:>3} {} l {:>2} c {:>4x} ({:x}) ",
n,
if isgraph(n as u8) {
char::from_u32(n as u32).unwrap()
} else {
' '
},
len,
tree[n].code(),
next_code[len as usize] - 1
);
}
}
}
/// repeat previous bit length 3-6 times (2 bits of repeat count)
const REP_3_6: usize = 16;
/// repeat a zero length 3-10 times (3 bits of repeat count)
const REPZ_3_10: usize = 17;
/// repeat a zero length 11-138 times (7 bits of repeat count)
const REPZ_11_138: usize = 18;
fn scan_tree(bl_desc: &mut TreeDesc<{ 2 * BL_CODES + 1 }>, tree: &mut [Value], max_code: usize) {
/* tree: the tree to be scanned */
/* max_code: and its largest code of non zero frequency */
let mut prevlen = -1isize; /* last emitted length */
let mut curlen: isize; /* length of current code */
let mut nextlen = tree[0].len(); /* length of next code */
let mut count = 0; /* repeat count of the current code */
let mut max_count = 7; /* max repeat count */
let mut min_count = 4; /* min repeat count */
if nextlen == 0 {
max_count = 138;
min_count = 3;
}
*tree[max_code + 1].len_mut() = 0xffff; /* guard */
let bl_tree = &mut bl_desc.dyn_tree;
for n in 0..=max_code {
curlen = nextlen as isize;
nextlen = tree[n + 1].len();
count += 1;
if count < max_count && curlen == nextlen as isize {
continue;
} else if count < min_count {
*bl_tree[curlen as usize].freq_mut() += count;
} else if curlen != 0 {
if curlen != prevlen {
*bl_tree[curlen as usize].freq_mut() += 1;
}
*bl_tree[REP_3_6].freq_mut() += 1;
} else if count <= 10 {
*bl_tree[REPZ_3_10].freq_mut() += 1;
} else {
*bl_tree[REPZ_11_138].freq_mut() += 1;
}
count = 0;
prevlen = curlen;
if nextlen == 0 {
max_count = 138;
min_count = 3;
} else if curlen == nextlen as isize {
max_count = 6;
min_count = 3;
} else {
max_count = 7;
min_count = 4;
}
}
}
fn send_all_trees(state: &mut State, lcodes: usize, dcodes: usize, blcodes: usize) {
assert!(
lcodes >= 257 && dcodes >= 1 && blcodes >= 4,
"not enough codes"
);
assert!(
lcodes <= L_CODES && dcodes <= D_CODES && blcodes <= BL_CODES,
"too many codes"
);
trace!("\nbl counts: ");
state.bit_writer.send_bits(lcodes as u64 - 257, 5); /* not +255 as stated in appnote.txt */
state.bit_writer.send_bits(dcodes as u64 - 1, 5);
state.bit_writer.send_bits(blcodes as u64 - 4, 4); /* not -3 as stated in appnote.txt */
for rank in 0..blcodes {
trace!("\nbl code {:>2} ", StaticTreeDesc::BL_ORDER[rank]);
state.bit_writer.send_bits(
state.bl_desc.dyn_tree[StaticTreeDesc::BL_ORDER[rank] as usize].len() as u64,
3,
);
}
trace!("\nbl tree: sent {}", state.bit_writer.bits_sent);
// literal tree
state
.bit_writer
.send_tree(&state.l_desc.dyn_tree, &state.bl_desc.dyn_tree, lcodes - 1);
trace!("\nlit tree: sent {}", state.bit_writer.bits_sent);
// distance tree
state
.bit_writer
.send_tree(&state.d_desc.dyn_tree, &state.bl_desc.dyn_tree, dcodes - 1);
trace!("\ndist tree: sent {}", state.bit_writer.bits_sent);
}
/// Construct the Huffman tree for the bit lengths and return the index in
/// bl_order of the last bit length code to send.
fn build_bl_tree(state: &mut State) -> usize {
/* Determine the bit length frequencies for literal and distance trees */
scan_tree(
&mut state.bl_desc,
&mut state.l_desc.dyn_tree,
state.l_desc.max_code,
);
scan_tree(
&mut state.bl_desc,
&mut state.d_desc.dyn_tree,
state.d_desc.max_code,
);
/* Build the bit length tree: */
{
let mut tmp = TreeDesc::EMPTY;
core::mem::swap(&mut tmp, &mut state.bl_desc);
build_tree(state, &mut tmp);
core::mem::swap(&mut tmp, &mut state.bl_desc);
}
/* opt_len now includes the length of the tree representations, except
* the lengths of the bit lengths codes and the 5+5+4 bits for the counts.
*/
/* Determine the number of bit length codes to send. The pkzip format
* requires that at least 4 bit length codes be sent. (appnote.txt says
* 3 but the actual value used is 4.)
*/
let mut max_blindex = BL_CODES - 1;
while max_blindex >= 3 {
let index = StaticTreeDesc::BL_ORDER[max_blindex] as usize;
if state.bl_desc.dyn_tree[index].len() != 0 {
break;
}
max_blindex -= 1;
}
/* Update opt_len to include the bit length tree and counts */
state.opt_len += 3 * (max_blindex + 1) + 5 + 5 + 4;
trace!(
"\ndyn trees: dyn {}, stat {}",
state.opt_len,
state.static_len
);
max_blindex
}
fn zng_tr_flush_block(
stream: &mut DeflateStream,
window_offset: Option<usize>,
stored_len: u32,
last: bool,
) {
/* window_offset: offset of the input block into the window */
/* stored_len: length of input block */
/* last: one if this is the last block for a file */
let mut opt_lenb;
let static_lenb;
let mut max_blindex = 0;
let state = &mut stream.state;
if state.sym_buf.is_empty() {
opt_lenb = 0;
static_lenb = 0;
state.static_len = 7;
} else if state.level > 0 {
if stream.data_type == DataType::Unknown as i32 {
stream.data_type = State::detect_data_type(&state.l_desc.dyn_tree) as i32;
}
{
let mut tmp = TreeDesc::EMPTY;
core::mem::swap(&mut tmp, &mut state.l_desc);
build_tree(state, &mut tmp);
core::mem::swap(&mut tmp, &mut state.l_desc);
trace!(
"\nlit data: dyn {}, stat {}",
state.opt_len,
state.static_len
);
}
{
let mut tmp = TreeDesc::EMPTY;
core::mem::swap(&mut tmp, &mut state.d_desc);
build_tree(state, &mut tmp);
core::mem::swap(&mut tmp, &mut state.d_desc);
trace!(
"\ndist data: dyn {}, stat {}",
state.opt_len,
state.static_len
);
}
// Build the bit length tree for the above two trees, and get the index
// in bl_order of the last bit length code to send.
max_blindex = build_bl_tree(state);
// Determine the best encoding. Compute the block lengths in bytes.
opt_lenb = (state.opt_len + 3 + 7) >> 3;
static_lenb = (state.static_len + 3 + 7) >> 3;
trace!(
"\nopt {}({}) stat {}({}) stored {} lit {} ",
opt_lenb,
state.opt_len,
static_lenb,
state.static_len,
stored_len,
state.sym_buf.len() / 3
);
if static_lenb <= opt_lenb || state.strategy == Strategy::Fixed {
opt_lenb = static_lenb;
}
} else {
assert!(window_offset.is_some(), "lost buf");
/* force a stored block */
opt_lenb = stored_len as usize + 5;
static_lenb = stored_len as usize + 5;
}
if stored_len as usize + 4 <= opt_lenb && window_offset.is_some() {
/* 4: two words for the lengths
* The test buf != NULL is only necessary if LIT_BUFSIZE > WSIZE.
* Otherwise we can't have processed more than WSIZE input bytes since
* the last block flush, because compression would have been
* successful. If LIT_BUFSIZE <= WSIZE, it is never too late to
* transform a block into a stored block.
*/
let window_offset = window_offset.unwrap();
let range = window_offset..window_offset + stored_len as usize;
zng_tr_stored_block(state, range, last);
} else if static_lenb == opt_lenb {
state.bit_writer.emit_tree(BlockType::StaticTrees, last);
state.compress_block_static_trees();
// cmpr_bits_add(s, s.static_len);
} else {
state.bit_writer.emit_tree(BlockType::DynamicTrees, last);
send_all_trees(
state,
state.l_desc.max_code + 1,
state.d_desc.max_code + 1,
max_blindex + 1,
);
state.compress_block_dynamic_trees();
}
// TODO
// This check is made mod 2^32, for files larger than 512 MB and unsigned long implemented on 32 bits.
// assert_eq!(state.compressed_len, state.bits_sent, "bad compressed size");
state.init_block();
if last {
state.bit_writer.emit_align();
}
// Tracev((stderr, "\ncomprlen {}(%lu) ", s->compressed_len>>3, s->compressed_len-7*last));
}
pub(crate) fn flush_block_only(stream: &mut DeflateStream, is_last: bool) {
zng_tr_flush_block(
stream,
(stream.state.block_start >= 0).then_some(stream.state.block_start as usize),
(stream.state.strstart as isize - stream.state.block_start) as u32,
is_last,
);
stream.state.block_start = stream.state.strstart as isize;
flush_pending(stream)
}
#[must_use]
fn flush_bytes(stream: &mut DeflateStream, mut bytes: &[u8]) -> ControlFlow<ReturnCode> {
let mut state = &mut stream.state;
// we'll be using the pending buffer as temporary storage
let mut beg = state.bit_writer.pending.pending().len(); /* start of bytes to update crc */
while state.bit_writer.pending.remaining() < bytes.len() {
let copy = state.bit_writer.pending.remaining();
state.bit_writer.pending.extend(&bytes[..copy]);
stream.adler = crc32(
stream.adler as u32,
&state.bit_writer.pending.pending()[beg..],
) as z_checksum;
state.gzindex += copy;
flush_pending(stream);
state = &mut stream.state;
// could not flush all the pending output
if !state.bit_writer.pending.pending().is_empty() {
state.last_flush = -1;
return ControlFlow::Break(ReturnCode::Ok);
}
beg = 0;
bytes = &bytes[copy..];
}
state.bit_writer.pending.extend(bytes);
stream.adler = crc32(
stream.adler as u32,
&state.bit_writer.pending.pending()[beg..],
) as z_checksum;
state.gzindex = 0;
ControlFlow::Continue(())
}
pub fn deflate(stream: &mut DeflateStream, flush: DeflateFlush) -> ReturnCode {
if stream.next_out.is_null()
|| (stream.avail_in != 0 && stream.next_in.is_null())
|| (stream.state.status == Status::Finish && flush != DeflateFlush::Finish)
{
let err = ReturnCode::StreamError;
stream.msg = err.error_message();
return err;
}
if stream.avail_out == 0 {
let err = ReturnCode::BufError;
stream.msg = err.error_message();
return err;
}
let old_flush = stream.state.last_flush;
stream.state.last_flush = flush as i32;
/* Flush as much pending output as possible */
if !stream.state.bit_writer.pending.pending().is_empty() {
flush_pending(stream);
if stream.avail_out == 0 {
/* Since avail_out is 0, deflate will be called again with
* more output space, but possibly with both pending and
* avail_in equal to zero. There won't be anything to do,
* but this is not an error situation so make sure we
* return OK instead of BUF_ERROR at next call of deflate:
*/
stream.state.last_flush = -1;
return ReturnCode::Ok;
}
/* Make sure there is something to do and avoid duplicate consecutive
* flushes. For repeated and useless calls with Z_FINISH, we keep
* returning Z_STREAM_END instead of Z_BUF_ERROR.
*/
} else if stream.avail_in == 0
&& rank_flush(flush as i32) <= rank_flush(old_flush)
&& flush != DeflateFlush::Finish
{
let err = ReturnCode::BufError;
stream.msg = err.error_message();
return err;
}
/* User must not provide more input after the first FINISH: */
if stream.state.status == Status::Finish && stream.avail_in != 0 {
let err = ReturnCode::BufError;
stream.msg = err.error_message();
return err;
}
/* Write the header */
if stream.state.status == Status::Init && stream.state.wrap == 0 {
stream.state.status = Status::Busy;
}
if stream.state.status == Status::Init {
let header = stream.state.header();
stream
.state
.bit_writer
.pending
.extend(&header.to_be_bytes());
/* Save the adler32 of the preset dictionary: */
if stream.state.strstart != 0 {
let adler = stream.adler as u32;
stream.state.bit_writer.pending.extend(&adler.to_be_bytes());
}
stream.adler = ADLER32_INITIAL_VALUE as _;
stream.state.status = Status::Busy;
// compression must start with an empty pending buffer
flush_pending(stream);
if !stream.state.bit_writer.pending.pending().is_empty() {
stream.state.last_flush = -1;
return ReturnCode::Ok;
}
}
if stream.state.status == Status::GZip {
/* gzip header */
stream.state.crc_fold = Crc32Fold::new();
stream.state.bit_writer.pending.extend(&[31, 139, 8]);
let extra_flags = if stream.state.level == 9 {
2
} else if stream.state.strategy >= Strategy::HuffmanOnly || stream.state.level < 2 {
4
} else {
0
};
match &stream.state.gzhead {
None => {
let bytes = [0, 0, 0, 0, 0, extra_flags, gz_header::OS_CODE];
stream.state.bit_writer.pending.extend(&bytes);
stream.state.status = Status::Busy;
/* Compression must start with an empty pending buffer */
flush_pending(stream);
if !stream.state.bit_writer.pending.pending().is_empty() {
stream.state.last_flush = -1;
return ReturnCode::Ok;
}
}
Some(gzhead) => {
stream.state.bit_writer.pending.extend(&[gzhead.flags()]);
let bytes = (gzhead.time as u32).to_le_bytes();
stream.state.bit_writer.pending.extend(&bytes);
stream
.state
.bit_writer
.pending
.extend(&[extra_flags, gzhead.os as u8]);
if !gzhead.extra.is_null() {
let bytes = (gzhead.extra_len as u16).to_le_bytes();
stream.state.bit_writer.pending.extend(&bytes);
}
if gzhead.hcrc > 0 {
stream.adler = crc32(
stream.adler as u32,
stream.state.bit_writer.pending.pending(),
) as z_checksum
}
stream.state.gzindex = 0;
stream.state.status = Status::Extra;
}
}
}
if stream.state.status == Status::Extra {
if let Some(gzhead) = stream.state.gzhead.as_ref() {
if !gzhead.extra.is_null() {
let gzhead_extra = gzhead.extra;
let extra = unsafe {
core::slice::from_raw_parts(
gzhead_extra.add(stream.state.gzindex),
(gzhead.extra_len & 0xffff) as usize - stream.state.gzindex,
)
};
if let ControlFlow::Break(err) = flush_bytes(stream, extra) {
return err;
}
}
}
stream.state.status = Status::Name;
}
if stream.state.status == Status::Name {
if let Some(gzhead) = stream.state.gzhead.as_ref() {
if !gzhead.name.is_null() {
let gzhead_name = unsafe { CStr::from_ptr(gzhead.name.cast()) };
let bytes = gzhead_name.to_bytes_with_nul();
if let ControlFlow::Break(err) = flush_bytes(stream, bytes) {
return err;
}
}
stream.state.status = Status::Comment;
}
}
if stream.state.status == Status::Comment {
if let Some(gzhead) = stream.state.gzhead.as_ref() {
if !gzhead.comment.is_null() {
let gzhead_comment = unsafe { CStr::from_ptr(gzhead.comment.cast()) };
let bytes = gzhead_comment.to_bytes_with_nul();
if let ControlFlow::Break(err) = flush_bytes(stream, bytes) {
return err;
}
}
stream.state.status = Status::Hcrc;
}
}
if stream.state.status == Status::Hcrc {
if let Some(gzhead) = stream.state.gzhead.as_ref() {
if gzhead.hcrc != 0 {
let bytes = (stream.adler as u16).to_le_bytes();
if let ControlFlow::Break(err) = flush_bytes(stream, &bytes) {
return err;
}
}
}
stream.state.status = Status::Busy;
// compression must start with an empty pending buffer
flush_pending(stream);
if !stream.state.bit_writer.pending.pending().is_empty() {
stream.state.last_flush = -1;
return ReturnCode::Ok;
}
}
// Start a new block or continue the current one.
let state = &mut stream.state;
if stream.avail_in != 0
|| state.lookahead != 0
|| (flush != DeflateFlush::NoFlush && state.status != Status::Finish)
{
let bstate = self::algorithm::run(stream, flush);
let state = &mut stream.state;
if matches!(bstate, BlockState::FinishStarted | BlockState::FinishDone) {
state.status = Status::Finish;
}
match bstate {
BlockState::NeedMore | BlockState::FinishStarted => {
if stream.avail_out == 0 {
state.last_flush = -1; /* avoid BUF_ERROR next call, see above */
}
return ReturnCode::Ok;
/* If flush != Z_NO_FLUSH && avail_out == 0, the next call
* of deflate should use the same flush parameter to make sure
* that the flush is complete. So we don't have to output an
* empty block here, this will be done at next call. This also
* ensures that for a very small output buffer, we emit at most
* one empty block.
*/
}
BlockState::BlockDone => {
match flush {
DeflateFlush::NoFlush => unreachable!("condition of inner surrounding if"),
DeflateFlush::PartialFlush => {
state.bit_writer.align();
}
DeflateFlush::SyncFlush => {
// add an empty stored block that is marked as not final. This is useful for
// parallel deflate where we want to make sure the intermediate blocks are not
// marked as "last block".
zng_tr_stored_block(state, 0..0, false);
}
DeflateFlush::FullFlush => {
// add an empty stored block that is marked as not final. This is useful for
// parallel deflate where we want to make sure the intermediate blocks are not
// marked as "last block".
zng_tr_stored_block(state, 0..0, false);
state.head.fill(0); // forget history
if state.lookahead == 0 {
state.strstart = 0;
state.block_start = 0;
state.insert = 0;
}
}
DeflateFlush::Block => { /* fall through */ }
DeflateFlush::Finish => unreachable!("condition of outer surrounding if"),
}
flush_pending(stream);
if stream.avail_out == 0 {
stream.state.last_flush = -1; /* avoid BUF_ERROR at next call, see above */
return ReturnCode::Ok;
}
}
BlockState::FinishDone => { /* do nothing */ }
}
}
if flush != DeflateFlush::Finish {
return ReturnCode::Ok;
}
// write the trailer
if stream.state.wrap == 2 {
let crc_fold = core::mem::take(&mut stream.state.crc_fold);
stream.adler = crc_fold.finish() as z_checksum;
let adler = stream.adler as u32;
stream.state.bit_writer.pending.extend(&adler.to_le_bytes());
let total_in = stream.total_in as u32;
stream
.state
.bit_writer
.pending
.extend(&total_in.to_le_bytes());
} else if stream.state.wrap == 1 {
let adler = stream.adler as u32;
stream.state.bit_writer.pending.extend(&adler.to_be_bytes());
}
flush_pending(stream);
// If avail_out is zero, the application will call deflate again to flush the rest.
if stream.state.wrap > 0 {
stream.state.wrap = -stream.state.wrap; /* write the trailer only once! */
}
if stream.state.bit_writer.pending.pending().is_empty() {
assert_eq!(stream.state.bit_writer.bits_used, 0, "bi_buf not flushed");
return ReturnCode::StreamEnd;
}
ReturnCode::Ok
}
pub(crate) fn flush_pending(stream: &mut DeflateStream) {
let state = &mut stream.state;
state.bit_writer.flush_bits();
let pending = state.bit_writer.pending.pending();
let len = Ord::min(pending.len(), stream.avail_out as usize);
if len == 0 {
return;
}
trace!("\n[FLUSH {len} bytes]");
unsafe { core::ptr::copy_nonoverlapping(pending.as_ptr(), stream.next_out, len) };
stream.next_out = stream.next_out.wrapping_add(len);
stream.total_out += len as crate::c_api::z_size;
stream.avail_out -= len as crate::c_api::uInt;
state.bit_writer.pending.advance(len);
}
pub fn compress_slice<'a>(
output: &'a mut [u8],
input: &[u8],
config: DeflateConfig,
) -> (&'a mut [u8], ReturnCode) {
let output_uninit = unsafe {
core::slice::from_raw_parts_mut(output.as_mut_ptr() as *mut MaybeUninit<u8>, output.len())
};
compress(output_uninit, input, config)
}
pub fn compress<'a>(
output: &'a mut [MaybeUninit<u8>],
input: &[u8],
config: DeflateConfig,
) -> (&'a mut [u8], ReturnCode) {
compress_with_flush(output, input, config, DeflateFlush::Finish)
}
pub fn compress_slice_with_flush<'a>(
output: &'a mut [u8],
input: &[u8],
config: DeflateConfig,
flush: DeflateFlush,
) -> (&'a mut [u8], ReturnCode) {
let output_uninit = unsafe {
core::slice::from_raw_parts_mut(output.as_mut_ptr() as *mut MaybeUninit<u8>, output.len())
};
compress_with_flush(output_uninit, input, config, flush)
}
pub fn compress_with_flush<'a>(
output: &'a mut [MaybeUninit<u8>],
input: &[u8],
config: DeflateConfig,
final_flush: DeflateFlush,
) -> (&'a mut [u8], ReturnCode) {
let mut stream = z_stream {
next_in: input.as_ptr() as *mut u8,
avail_in: 0, // for special logic in the first iteration
total_in: 0,
next_out: output.as_mut_ptr() as *mut u8,
avail_out: 0, // for special logic on the first iteration
total_out: 0,
msg: core::ptr::null_mut(),
state: core::ptr::null_mut(),
zalloc: None,
zfree: None,
opaque: core::ptr::null_mut(),
data_type: 0,
adler: 0,
reserved: 0,
};
let err = init(&mut stream, config);
if err != ReturnCode::Ok {
return (&mut [], err);
}
let max = core::ffi::c_uint::MAX as usize;
let mut left = output.len();
let mut source_len = input.len();
loop {
if stream.avail_out == 0 {
stream.avail_out = Ord::min(left, max) as _;
left -= stream.avail_out as usize;
}
if stream.avail_in == 0 {
stream.avail_in = Ord::min(source_len, max) as _;
source_len -= stream.avail_in as usize;
}
let flush = if source_len > 0 {
DeflateFlush::NoFlush
} else {
final_flush
};
let err = if let Some(stream) = unsafe { DeflateStream::from_stream_mut(&mut stream) } {
deflate(stream, flush)
} else {
ReturnCode::StreamError
};
if err != ReturnCode::Ok {
break;
}
}
// SAFETY: we have now initialized these bytes
let output_slice = unsafe {
core::slice::from_raw_parts_mut(output.as_mut_ptr() as *mut u8, stream.total_out as usize)
};
// may DataError if insufficient output space
let return_code = if let Some(stream) = unsafe { DeflateStream::from_stream_mut(&mut stream) } {
match end(stream) {
Ok(_) => ReturnCode::Ok,
Err(_) => ReturnCode::DataError,
}
} else {
ReturnCode::Ok
};
(output_slice, return_code)
}
pub const fn compress_bound(source_len: usize) -> usize {
compress_bound_help(source_len, ZLIB_WRAPLEN)
}
const fn compress_bound_help(source_len: usize, wrap_len: usize) -> usize {
source_len // The source size itself */
// Always at least one byte for any input
.wrapping_add(if source_len == 0 { 1 } else { 0 })
// One extra byte for lengths less than 9
.wrapping_add(if source_len < 9 { 1 } else { 0 })
// Source encoding overhead, padded to next full byte
.wrapping_add(deflate_quick_overhead(source_len))
// Deflate block overhead bytes
.wrapping_add(DEFLATE_BLOCK_OVERHEAD)
// none, zlib or gzip wrapper
.wrapping_add(wrap_len)
}
/// heap used to build the Huffman trees
/// The sons of heap[n] are heap[2*n] and heap[2*n+1]. heap[0] is not used.
/// The same heap array is used to build all trees.
#[derive(Clone)]
struct Heap {
heap: [u32; 2 * L_CODES + 1],
/// number of elements in the heap
heap_len: usize,
/// element of the largest frequency
heap_max: usize,
depth: [u8; 2 * L_CODES + 1],
}
impl Heap {
// an empty heap
fn new() -> Self {
Self {
heap: [0; 2 * L_CODES + 1],
heap_len: 0,
heap_max: 0,
depth: [0; 2 * L_CODES + 1],
}
}
/// Construct the initial heap, with least frequent element in
/// heap[SMALLEST]. The sons of heap[n] are heap[2*n] and heap[2*n+1]. heap[0] is not used.
fn initialize(&mut self, tree: &mut [Value]) -> isize {
let mut max_code = -1;
self.heap_len = 0;
self.heap_max = HEAP_SIZE;
for (n, node) in tree.iter_mut().enumerate() {
if node.freq() > 0 {
self.heap_len += 1;
self.heap[self.heap_len] = n as u32;
max_code = n as isize;
self.depth[n] = 0;
} else {
*node.len_mut() = 0;
}
}
max_code
}
/// Index within the heap array of least frequent node in the Huffman tree
const SMALLEST: usize = 1;
fn smaller(tree: &[Value], n: u32, m: u32, depth: &[u8]) -> bool {
let (n, m) = (n as usize, m as usize);
match Ord::cmp(&tree[n].freq(), &tree[m].freq()) {
core::cmp::Ordering::Less => true,
core::cmp::Ordering::Equal => depth[n] <= depth[m],
core::cmp::Ordering::Greater => false,
}
}
fn pqdownheap(&mut self, tree: &[Value], mut k: usize) {
/* tree: the tree to restore */
/* k: node to move down */
let v = self.heap[k];
let mut j = k << 1; /* left son of k */
while j <= self.heap_len {
/* Set j to the smallest of the two sons: */
if j < self.heap_len {
let cond = Self::smaller(tree, self.heap[j + 1], self.heap[j], &self.depth);
if cond {
j += 1;
}
}
/* Exit if v is smaller than both sons */
if Self::smaller(tree, v, self.heap[j], &self.depth) {
break;
}
/* Exchange v with the smallest son */
self.heap[k] = self.heap[j];
k = j;
/* And continue down the tree, setting j to the left son of k */
j <<= 1;
}
self.heap[k] = v;
}
/// Remove the smallest element from the heap and recreate the heap with
/// one less element. Updates heap and heap_len.
fn pqremove(&mut self, tree: &[Value]) -> u32 {
let top = self.heap[Self::SMALLEST];
self.heap[Self::SMALLEST] = self.heap[self.heap_len];
self.heap_len -= 1;
self.pqdownheap(tree, Self::SMALLEST);
top
}
/// Construct the Huffman tree by repeatedly combining the least two frequent nodes.
fn construct_huffman_tree(&mut self, tree: &mut [Value], mut node: usize) {
loop {
let n = self.pqremove(tree) as usize; /* n = node of least frequency */
let m = self.heap[Heap::SMALLEST] as usize; /* m = node of next least frequency */
self.heap_max -= 1;
self.heap[self.heap_max] = n as u32; /* keep the nodes sorted by frequency */
self.heap_max -= 1;
self.heap[self.heap_max] = m as u32;
/* Create a new node father of n and m */
*tree[node].freq_mut() = tree[n].freq() + tree[m].freq();
self.depth[node] = Ord::max(self.depth[n], self.depth[m]) + 1;
*tree[n].dad_mut() = node as u16;
*tree[m].dad_mut() = node as u16;
/* and insert the new node in the heap */
self.heap[Heap::SMALLEST] = node as u32;
node += 1;
self.pqdownheap(tree, Heap::SMALLEST);
if self.heap_len < 2 {
break;
}
}
self.heap_max -= 1;
self.heap[self.heap_max] = self.heap[Heap::SMALLEST];
}
}
pub fn set_header<'a>(
stream: &mut DeflateStream<'a>,
head: Option<&'a mut gz_header>,
) -> ReturnCode {
if stream.state.wrap != 2 {
ReturnCode::StreamError as _
} else {
stream.state.gzhead = head;
ReturnCode::Ok as _
}
}
// zlib format overhead
const ZLIB_WRAPLEN: usize = 6;
// gzip format overhead
const GZIP_WRAPLEN: usize = 18;
const DEFLATE_HEADER_BITS: usize = 3;
const DEFLATE_EOBS_BITS: usize = 15;
const DEFLATE_PAD_BITS: usize = 6;
const DEFLATE_BLOCK_OVERHEAD: usize =
(DEFLATE_HEADER_BITS + DEFLATE_EOBS_BITS + DEFLATE_PAD_BITS) >> 3;
const DEFLATE_QUICK_LIT_MAX_BITS: usize = 9;
const fn deflate_quick_overhead(x: usize) -> usize {
let sum = x
.wrapping_mul(DEFLATE_QUICK_LIT_MAX_BITS - 8)
.wrapping_add(7);
// imitate zlib-ng rounding behavior (on windows, c_ulong is 32 bits)
(sum as core::ffi::c_ulong >> 3) as usize
}
/// For the default windowBits of 15 and memLevel of 8, this function returns
/// a close to exact, as well as small, upper bound on the compressed size.
/// They are coded as constants here for a reason--if the #define's are
/// changed, then this function needs to be changed as well. The return
/// value for 15 and 8 only works for those exact settings.
///
/// For any setting other than those defaults for windowBits and memLevel,
/// the value returned is a conservative worst case for the maximum expansion
/// resulting from using fixed blocks instead of stored blocks, which deflate
/// can emit on compressed data for some combinations of the parameters.
///
/// This function could be more sophisticated to provide closer upper bounds for
/// every combination of windowBits and memLevel. But even the conservative
/// upper bound of about 14% expansion does not seem onerous for output buffer
/// allocation.
pub fn bound(stream: Option<&mut DeflateStream>, source_len: usize) -> usize {
// on windows, c_ulong is only a 32-bit integer
let mask = core::ffi::c_ulong::MAX as usize;
// conservative upper bound for compressed data
let comp_len = source_len
.wrapping_add((source_len.wrapping_add(7) & mask) >> 3)
.wrapping_add((source_len.wrapping_add(63) & mask) >> 6)
.wrapping_add(5);
let Some(stream) = stream else {
// return conservative bound plus zlib wrapper
return comp_len.wrapping_add(6);
};
/* compute wrapper length */
let wrap_len = match stream.state.wrap {
0 => {
// raw deflate
0
}
1 => {
// zlib wrapper
if stream.state.strstart != 0 {
ZLIB_WRAPLEN + 4
} else {
ZLIB_WRAPLEN
}
}
2 => {
// gzip wrapper
let mut gz_wrap_len = GZIP_WRAPLEN;
if let Some(header) = &stream.state.gzhead {
if !header.extra.is_null() {
gz_wrap_len += 2 + header.extra_len as usize;
}
let mut c_string = header.name;
if !c_string.is_null() {
loop {
gz_wrap_len += 1;
unsafe {
if *c_string == 0 {
break;
}
c_string = c_string.add(1);
}
}
}
let mut c_string = header.comment;
if !c_string.is_null() {
loop {
gz_wrap_len += 1;
unsafe {
if *c_string == 0 {
break;
}
c_string = c_string.add(1);
}
}
}
if header.hcrc != 0 {
gz_wrap_len += 2;
}
}
gz_wrap_len
}
_ => {
// default
ZLIB_WRAPLEN
}
};
if stream.state.w_bits != MAX_WBITS as usize || HASH_BITS < 15 {
if stream.state.level == 0 {
/* upper bound for stored blocks with length 127 (memLevel == 1) ~4% overhead plus a small constant */
source_len
.wrapping_add(source_len >> 5)
.wrapping_add(source_len >> 7)
.wrapping_add(source_len >> 11)
.wrapping_add(7)
.wrapping_add(wrap_len)
} else {
comp_len.wrapping_add(wrap_len)
}
} else {
compress_bound_help(source_len, wrap_len)
}
}
#[cfg(test)]
mod test {
use crate::{
inflate::{uncompress_slice, InflateConfig, InflateStream},
InflateFlush,
};
use super::*;
use core::{ffi::CStr, sync::atomic::AtomicUsize};
#[test]
fn detect_data_type_basic() {
let empty = || [Value::new(0, 0); LITERALS];
assert_eq!(State::detect_data_type(&empty()), DataType::Binary);
let mut binary = empty();
binary[0] = Value::new(1, 0);
assert_eq!(State::detect_data_type(&binary), DataType::Binary);
let mut text = empty();
text[b'\r' as usize] = Value::new(1, 0);
assert_eq!(State::detect_data_type(&text), DataType::Text);
let mut text = empty();
text[b'a' as usize] = Value::new(1, 0);
assert_eq!(State::detect_data_type(&text), DataType::Text);
let mut non_text = empty();
non_text[7] = Value::new(1, 0);
assert_eq!(State::detect_data_type(&non_text), DataType::Binary);
}
#[test]
fn from_stream_mut() {
unsafe {
assert!(DeflateStream::from_stream_mut(core::ptr::null_mut()).is_none());
let mut stream = z_stream::default();
assert!(DeflateStream::from_stream_mut(&mut stream).is_none());
// state is still NULL
assert!(DeflateStream::from_stream_mut(&mut stream).is_none());
init(&mut stream, DeflateConfig::default());
let stream = DeflateStream::from_stream_mut(&mut stream);
assert!(stream.is_some());
assert!(end(stream.unwrap()).is_ok());
}
}
unsafe extern "C" fn fail_nth_allocation<const N: usize>(
opaque: crate::c_api::voidpf,
items: crate::c_api::uInt,
size: crate::c_api::uInt,
) -> crate::c_api::voidpf {
let count = unsafe { &*(opaque as *const AtomicUsize) };
if count.fetch_add(1, core::sync::atomic::Ordering::Relaxed) != N {
// must use the C allocator internally because (de)allocation is based on function
// pointer values and because we don't use the rust allocator directly, the allocation
// logic will store the pointer to the start at the start of the allocation.
(crate::allocate::Allocator::C.zalloc)(opaque, items, size)
} else {
core::ptr::null_mut()
}
}
#[test]
fn init_invalid_allocator() {
{
let atomic = AtomicUsize::new(0);
let mut stream = z_stream {
zalloc: Some(fail_nth_allocation::<0>),
zfree: Some(crate::allocate::Allocator::C.zfree),
opaque: &atomic as *const _ as *const core::ffi::c_void as *mut _,
..z_stream::default()
};
assert_eq!(
init(&mut stream, DeflateConfig::default()),
ReturnCode::MemError
);
}
{
let atomic = AtomicUsize::new(0);
let mut stream = z_stream {
zalloc: Some(fail_nth_allocation::<3>),
zfree: Some(crate::allocate::Allocator::C.zfree),
opaque: &atomic as *const _ as *const core::ffi::c_void as *mut _,
..z_stream::default()
};
assert_eq!(
init(&mut stream, DeflateConfig::default()),
ReturnCode::MemError
);
}
{
let atomic = AtomicUsize::new(0);
let mut stream = z_stream {
zalloc: Some(fail_nth_allocation::<5>),
zfree: Some(crate::allocate::Allocator::C.zfree),
opaque: &atomic as *const _ as *const core::ffi::c_void as *mut _,
..z_stream::default()
};
assert_eq!(
init(&mut stream, DeflateConfig::default()),
ReturnCode::MemError
);
}
}
mod copy_invalid_allocator {
use super::*;
#[test]
fn fail_0() {
let mut stream = z_stream::default();
let atomic = AtomicUsize::new(0);
stream.opaque = &atomic as *const _ as *const core::ffi::c_void as *mut _;
stream.zalloc = Some(fail_nth_allocation::<6>);
stream.zfree = Some(crate::allocate::Allocator::C.zfree);
// init performs 6 allocations; we don't want those to fail
assert_eq!(init(&mut stream, DeflateConfig::default()), ReturnCode::Ok);
let Some(stream) = (unsafe { DeflateStream::from_stream_mut(&mut stream) }) else {
unreachable!()
};
let mut stream_copy = MaybeUninit::<DeflateStream>::zeroed();
assert_eq!(copy(&mut stream_copy, stream), ReturnCode::MemError);
assert!(end(stream).is_ok());
}
#[test]
fn fail_3() {
let mut stream = z_stream::default();
let atomic = AtomicUsize::new(0);
stream.zalloc = Some(fail_nth_allocation::<{ 6 + 3 }>);
stream.zfree = Some(crate::allocate::Allocator::C.zfree);
stream.opaque = &atomic as *const _ as *const core::ffi::c_void as *mut _;
// init performs 6 allocations; we don't want those to fail
assert_eq!(init(&mut stream, DeflateConfig::default()), ReturnCode::Ok);
let Some(stream) = (unsafe { DeflateStream::from_stream_mut(&mut stream) }) else {
unreachable!()
};
let mut stream_copy = MaybeUninit::<DeflateStream>::zeroed();
assert_eq!(copy(&mut stream_copy, stream), ReturnCode::MemError);
assert!(end(stream).is_ok());
}
#[test]
fn fail_5() {
let mut stream = z_stream::default();
let atomic = AtomicUsize::new(0);
stream.zalloc = Some(fail_nth_allocation::<{ 6 + 5 }>);
stream.zfree = Some(crate::allocate::Allocator::C.zfree);
stream.opaque = &atomic as *const _ as *const core::ffi::c_void as *mut _;
// init performs 6 allocations; we don't want those to fail
assert_eq!(init(&mut stream, DeflateConfig::default()), ReturnCode::Ok);
let Some(stream) = (unsafe { DeflateStream::from_stream_mut(&mut stream) }) else {
unreachable!()
};
let mut stream_copy = MaybeUninit::<DeflateStream>::zeroed();
assert_eq!(copy(&mut stream_copy, stream), ReturnCode::MemError);
assert!(end(stream).is_ok());
}
}
mod invalid_deflate_config {
use super::*;
#[test]
fn sanity_check() {
let mut stream = z_stream::default();
assert_eq!(init(&mut stream, DeflateConfig::default()), ReturnCode::Ok);
assert!(stream.zalloc.is_some());
assert!(stream.zfree.is_some());
// this should be the default level
let stream = unsafe { DeflateStream::from_stream_mut(&mut stream) }.unwrap();
assert_eq!(stream.state.level, 6);
assert!(end(stream).is_ok());
}
#[test]
fn window_bits_correction() {
// window_bits of 8 gets turned into 9 internally
let mut stream = z_stream::default();
let config = DeflateConfig {
window_bits: 8,
..Default::default()
};
assert_eq!(init(&mut stream, config), ReturnCode::Ok);
let stream = unsafe { DeflateStream::from_stream_mut(&mut stream) }.unwrap();
assert_eq!(stream.state.w_bits, 9);
assert!(end(stream).is_ok());
}
#[test]
fn window_bits_too_low() {
let mut stream = z_stream::default();
let config = DeflateConfig {
window_bits: -16,
..Default::default()
};
assert_eq!(init(&mut stream, config), ReturnCode::StreamError);
}
#[test]
fn window_bits_too_high() {
// window bits too high
let mut stream = z_stream::default();
let config = DeflateConfig {
window_bits: 42,
..Default::default()
};
assert_eq!(init(&mut stream, config), ReturnCode::StreamError);
}
}
#[test]
fn end_data_error() {
let mut stream = z_stream::default();
assert_eq!(init(&mut stream, DeflateConfig::default()), ReturnCode::Ok);
let stream = unsafe { DeflateStream::from_stream_mut(&mut stream) }.unwrap();
// next deflate into too little space
let input = b"Hello World\n";
stream.next_in = input.as_ptr() as *mut u8;
stream.avail_in = input.len() as _;
let output = &mut [0, 0, 0];
stream.next_out = output.as_mut_ptr();
stream.avail_out = output.len() as _;
// the deflate is fine
assert_eq!(deflate(stream, DeflateFlush::NoFlush), ReturnCode::Ok);
// but end is not
assert!(end(stream).is_err());
}
#[test]
fn test_reset_keep() {
let mut stream = z_stream::default();
assert_eq!(init(&mut stream, DeflateConfig::default()), ReturnCode::Ok);
let stream = unsafe { DeflateStream::from_stream_mut(&mut stream) }.unwrap();
// next deflate into too little space
let input = b"Hello World\n";
stream.next_in = input.as_ptr() as *mut u8;
stream.avail_in = input.len() as _;
let output = &mut [0; 1024];
stream.next_out = output.as_mut_ptr();
stream.avail_out = output.len() as _;
assert_eq!(deflate(stream, DeflateFlush::Finish), ReturnCode::StreamEnd);
assert_eq!(reset_keep(stream), ReturnCode::Ok);
let output = &mut [0; 1024];
stream.next_out = output.as_mut_ptr();
stream.avail_out = output.len() as _;
assert_eq!(deflate(stream, DeflateFlush::Finish), ReturnCode::StreamEnd);
assert!(end(stream).is_ok());
}
#[test]
fn hello_world_huffman_only() {
const EXPECTED: &[u8] = &[
0x78, 0x01, 0xf3, 0x48, 0xcd, 0xc9, 0xc9, 0x57, 0x08, 0xcf, 0x2f, 0xca, 0x49, 0x51,
0xe4, 0x02, 0x00, 0x20, 0x91, 0x04, 0x48,
];
let input = "Hello World!\n";
let mut output = vec![0; 128];
let config = DeflateConfig {
level: 6,
method: Method::Deflated,
window_bits: crate::MAX_WBITS,
mem_level: DEF_MEM_LEVEL,
strategy: Strategy::HuffmanOnly,
};
let (output, err) = compress_slice(&mut output, input.as_bytes(), config);
assert_eq!(err, ReturnCode::Ok);
assert_eq!(output.len(), EXPECTED.len());
assert_eq!(EXPECTED, output);
}
#[test]
fn hello_world_quick() {
const EXPECTED: &[u8] = &[
0x78, 0x01, 0xf3, 0x48, 0xcd, 0xc9, 0xc9, 0x57, 0x08, 0xcf, 0x2f, 0xca, 0x49, 0x51,
0xe4, 0x02, 0x00, 0x20, 0x91, 0x04, 0x48,
];
let input = "Hello World!\n";
let mut output = vec![0; 128];
let config = DeflateConfig {
level: 1,
method: Method::Deflated,
window_bits: crate::MAX_WBITS,
mem_level: DEF_MEM_LEVEL,
strategy: Strategy::Default,
};
let (output, err) = compress_slice(&mut output, input.as_bytes(), config);
assert_eq!(err, ReturnCode::Ok);
assert_eq!(output.len(), EXPECTED.len());
assert_eq!(EXPECTED, output);
}
#[test]
fn hello_world_quick_random() {
const EXPECTED: &[u8] = &[
0x78, 0x01, 0x53, 0xe1, 0x50, 0x51, 0xe1, 0x52, 0x51, 0x51, 0x01, 0x00, 0x03, 0xec,
0x00, 0xeb,
];
let input = "$\u{8}$$\n$$$";
let mut output = vec![0; 128];
let config = DeflateConfig {
level: 1,
method: Method::Deflated,
window_bits: crate::MAX_WBITS,
mem_level: DEF_MEM_LEVEL,
strategy: Strategy::Default,
};
let (output, err) = compress_slice(&mut output, input.as_bytes(), config);
assert_eq!(err, ReturnCode::Ok);
assert_eq!(output.len(), EXPECTED.len());
assert_eq!(EXPECTED, output);
}
fn fuzz_based_test(input: &[u8], config: DeflateConfig, expected: &[u8]) {
let mut output_rs = [0; 1 << 17];
let (output_rs, err) = compress_slice(&mut output_rs, input, config);
assert_eq!(err, ReturnCode::Ok);
assert_eq!(output_rs, expected);
}
#[test]
fn simple_rle() {
fuzz_based_test(
"\0\0\0\0\u{6}".as_bytes(),
DeflateConfig {
level: -1,
method: Method::Deflated,
window_bits: 11,
mem_level: 4,
strategy: Strategy::Rle,
},
&[56, 17, 99, 0, 2, 54, 0, 0, 11, 0, 7],
)
}
#[test]
fn fill_window_out_of_bounds() {
const INPUT: &[u8] = &[
0x71, 0x71, 0x71, 0x71, 0x71, 0x6a, 0x71, 0x71, 0x71, 0x71, 0x71, 0x71, 0x71, 0x71,
0x71, 0x71, 0x71, 0x71, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x1d, 0x1d, 0x1d, 0x1d, 0x63,
0x63, 0x63, 0x63, 0x63, 0x1d, 0x1d, 0x1d, 0x1d, 0x1d, 0x1d, 0x1d, 0x1d, 0x1d, 0x1d,
0x1d, 0x27, 0x0, 0x0, 0x0, 0x1d, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x71, 0x71, 0x71,
0x71, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x31, 0x0, 0x0,
0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0,
0x0, 0x0, 0x0, 0x0, 0x1d, 0x1d, 0x0, 0x0, 0x0, 0x0, 0x50, 0x50, 0x50, 0x50, 0x50, 0x50,
0x50, 0x50, 0x50, 0x50, 0x50, 0x50, 0x50, 0x50, 0x50, 0x50, 0x50, 0x50, 0x48, 0x50,
0x50, 0x50, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x2c, 0x0, 0x0, 0x0, 0x0, 0x4a,
0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x71, 0x71, 0x71, 0x71, 0x71, 0x71,
0x71, 0x71, 0x71, 0x71, 0x71, 0x71, 0x71, 0x71, 0x71, 0x71, 0x70, 0x71, 0x71, 0x0, 0x0,
0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x71, 0x71, 0x71, 0x71, 0x6a, 0x0, 0x0, 0x0, 0x0,
0x71, 0x0, 0x71, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0,
0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0,
0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0,
0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x31, 0x0, 0x0, 0x0, 0x0,
0x0, 0x0, 0x0, 0x0, 0x71, 0x71, 0x71, 0x71, 0x71, 0x71, 0x71, 0x71, 0x71, 0x71, 0x71,
0x71, 0x71, 0x0, 0x4a, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x71, 0x71,
0x71, 0x71, 0x71, 0x71, 0x71, 0x71, 0x71, 0x71, 0x71, 0x71, 0x71, 0x71, 0x71, 0x71,
0x70, 0x71, 0x71, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x71, 0x71, 0x71, 0x71,
0x6a, 0x0, 0x0, 0x0, 0x0, 0x71, 0x0, 0x71, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0,
0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0,
0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0,
0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0,
0x31, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x1d, 0x1d, 0x0, 0x0, 0x0, 0x0,
0x50, 0x50, 0x50, 0x50, 0x50, 0x50, 0x50, 0x50, 0x50, 0x50, 0x50, 0x50, 0x50, 0x50,
0x50, 0x50, 0x50, 0x50, 0x48, 0x50, 0x0, 0x0, 0x71, 0x71, 0x71, 0x71, 0x3b, 0x3f, 0x71,
0x71, 0x71, 0x71, 0x71, 0x71, 0x71, 0x50, 0x50, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0,
0x2c, 0x0, 0x0, 0x0, 0x0, 0x4a, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x71,
0x71, 0x71, 0x71, 0x71, 0x71, 0x71, 0x71, 0x71, 0x71, 0x71, 0x71, 0x71, 0x71, 0x71,
0x71, 0x70, 0x71, 0x71, 0x0, 0x0, 0x0, 0x6, 0x0, 0x0, 0x0, 0x0, 0x0, 0x71, 0x71, 0x71,
0x71, 0x71, 0x71, 0x70, 0x71, 0x71, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0,
0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x71, 0x71, 0x71, 0x71, 0x3b, 0x3f, 0x71, 0x71, 0x71,
0x71, 0x71, 0x71, 0x71, 0x71, 0x71, 0x71, 0x71, 0x71, 0x71, 0x71, 0x71, 0x71, 0x71,
0x71, 0x3b, 0x3f, 0x71, 0x71, 0x71, 0x71, 0x71, 0x71, 0x71, 0x20, 0x0, 0x0, 0x0, 0x0,
0x0, 0x0, 0x0, 0x71, 0x75, 0x71, 0x71, 0x71, 0x71, 0x71, 0x71, 0x71, 0x71, 0x71, 0x71,
0x71, 0x71, 0x71, 0x71, 0x71, 0x71, 0x71, 0x71, 0x71, 0x71, 0x10, 0x0, 0x71, 0x71,
0x71, 0x71, 0x71, 0x71, 0x71, 0x71, 0x71, 0x71, 0x3b, 0x71, 0x71, 0x71, 0x71, 0x71,
0x71, 0x76, 0x71, 0x34, 0x34, 0x34, 0x34, 0x34, 0x34, 0x71, 0x71, 0x71, 0x71, 0x71,
0x71, 0x71, 0x71, 0x10, 0x0, 0x71, 0x71, 0x71, 0x71, 0x71, 0x71, 0x71, 0x71, 0x71,
0x71, 0x3b, 0x71, 0x71, 0x71, 0x71, 0x71, 0x71, 0x76, 0x71, 0x34, 0x34, 0x34, 0x34,
0x34, 0x34, 0x34, 0x34, 0x34, 0x34, 0x34, 0x34, 0x34, 0x34, 0x34, 0x34, 0x34, 0x34,
0x34, 0x34, 0x34, 0x34, 0x34, 0x34, 0x0, 0x0, 0x0, 0x0, 0x0, 0x34, 0x34, 0x34, 0x34,
0x34, 0x34, 0x34, 0x34, 0x34, 0x34, 0x34, 0x34, 0x34, 0x34, 0x34, 0x34, 0x34, 0x34,
0x34, 0x34, 0x34, 0x34, 0x34, 0x34, 0x34, 0x34, 0x34, 0x34, 0x34, 0x34, 0x34, 0x34,
0x34, 0x34, 0x34, 0x34, 0x34, 0x34, 0x34, 0x34, 0x34, 0x34, 0x34, 0x34, 0x34, 0x34,
0x34, 0x34, 0x30, 0x34, 0x34, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0,
0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0,
0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0,
0x0, 0x0, 0x71, 0x0, 0x0, 0x0, 0x0, 0x6,
];
fuzz_based_test(
INPUT,
DeflateConfig {
level: -1,
method: Method::Deflated,
window_bits: 9,
mem_level: 1,
strategy: Strategy::HuffmanOnly,
},
&[
0x18, 0x19, 0x4, 0xc1, 0x21, 0x1, 0xc4, 0x0, 0x10, 0x3, 0xb0, 0x18, 0x29, 0x1e,
0x7e, 0x17, 0x83, 0xf5, 0x70, 0x6c, 0xac, 0xfe, 0xc9, 0x27, 0xdb, 0xb6, 0x6f, 0xdb,
0xb6, 0x6d, 0xdb, 0x80, 0x24, 0xb9, 0xbb, 0xbb, 0x24, 0x49, 0x92, 0x24, 0xf, 0x2,
0xd8, 0x36, 0x0, 0xf0, 0x3, 0x0, 0x0, 0x24, 0xd0, 0xb6, 0x6d, 0xdb, 0xb6, 0x6d,
0xdb, 0xbe, 0x6d, 0xf9, 0x13, 0x4, 0xc7, 0x4, 0x0, 0x80, 0x30, 0x0, 0xc3, 0x22,
0x68, 0xf, 0x36, 0x90, 0xc2, 0xb5, 0xfa, 0x7f, 0x48, 0x80, 0x81, 0xb, 0x40, 0x55,
0x55, 0x55, 0xd5, 0x16, 0x80, 0xaa, 0x7, 0x9, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0,
0xe, 0x7c, 0x82, 0xe0, 0x98, 0x0, 0x0, 0x0, 0x4, 0x60, 0x10, 0xf9, 0x8c, 0xe2,
0xe5, 0xfa, 0x3f, 0x2, 0x54, 0x55, 0x55, 0x65, 0x0, 0xa8, 0xaa, 0xaa, 0xaa, 0xba,
0x2, 0x50, 0xb5, 0x90, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x78, 0x82, 0xe0, 0xd0,
0x8a, 0x41, 0x0, 0x0, 0xa2, 0x58, 0x54, 0xb7, 0x60, 0x83, 0x9a, 0x6a, 0x4, 0x96,
0x87, 0xba, 0x51, 0xf8, 0xfb, 0x9b, 0x26, 0xfc, 0x0, 0x1c, 0x7, 0x6c, 0xdb, 0xb6,
0x6d, 0xdb, 0xb6, 0x6d, 0xf7, 0xa8, 0x3a, 0xaf, 0xaa, 0x6a, 0x3, 0xf8, 0xc2, 0x3,
0x40, 0x55, 0x55, 0x55, 0xd5, 0x5b, 0xf8, 0x80, 0xaa, 0x7a, 0xb, 0x0, 0x7f, 0x82,
0xe0, 0x98, 0x0, 0x40, 0x18, 0x0, 0x82, 0xd8, 0x49, 0x40, 0x2, 0x22, 0x7e, 0xeb,
0x80, 0xa6, 0xc, 0xa0, 0x9f, 0xa4, 0x2a, 0x38, 0xf, 0x0, 0x0, 0xe7, 0x1, 0xdc,
0x55, 0x95, 0x17, 0x0, 0x0, 0xae, 0x0, 0x38, 0xc0, 0x67, 0xdb, 0x36, 0x80, 0x2b,
0x0, 0xe, 0xf0, 0xd9, 0xf6, 0x13, 0x4, 0xc7, 0x4, 0x0, 0x0, 0x30, 0xc, 0x83, 0x22,
0x69, 0x7, 0xc6, 0xea, 0xff, 0x19, 0x0, 0x0, 0x80, 0xaa, 0x0, 0x0, 0x0, 0x0, 0x0,
0x0, 0x8e, 0xaa, 0xaa, 0xaa, 0xaa, 0xaa, 0xaa, 0xaa, 0xaa, 0xaa, 0xaa, 0xaa, 0x6a,
0xf5, 0x63, 0x60, 0x60, 0x3, 0x0, 0xee, 0x8a, 0x88, 0x67,
],
)
}
#[test]
fn gzip_no_header() {
let config = DeflateConfig {
level: 9,
method: Method::Deflated,
window_bits: 31, // gzip
..Default::default()
};
let input = b"Hello World!";
let os = gz_header::OS_CODE;
fuzz_based_test(
input,
config,
&[
31, 139, 8, 0, 0, 0, 0, 0, 2, os, 243, 72, 205, 201, 201, 87, 8, 207, 47, 202, 73,
81, 4, 0, 163, 28, 41, 28, 12, 0, 0, 0,
],
)
}
#[test]
#[rustfmt::skip]
fn gzip_stored_block_checksum() {
fuzz_based_test(
&[
27, 27, 27, 27, 27, 27, 27, 27, 27, 27, 27, 27, 27, 27, 27, 27, 9, 0,
],
DeflateConfig {
level: 0,
method: Method::Deflated,
window_bits: 26,
mem_level: 6,
strategy: Strategy::Default,
},
&[
31, 139, 8, 0, 0, 0, 0, 0, 4, gz_header::OS_CODE, 1, 18, 0, 237, 255, 27, 27, 27, 27, 27, 27, 27,
27, 27, 27, 27, 27, 27, 27, 27, 27, 9, 0, 60, 101, 156, 55, 18, 0, 0, 0,
],
)
}
#[test]
fn gzip_header_pending_flush() {
let extra = "aaaaaaaaaaaaaaaaaaaa\0";
let name = "bbbbbbbbbbbbbbbbbbbb\0";
let comment = "cccccccccccccccccccc\0";
let mut header = gz_header {
text: 0,
time: 0,
xflags: 0,
os: 0,
extra: extra.as_ptr() as *mut _,
extra_len: extra.len() as _,
extra_max: 0,
name: name.as_ptr() as *mut _,
name_max: 0,
comment: comment.as_ptr() as *mut _,
comm_max: 0,
hcrc: 1,
done: 0,
};
let config = DeflateConfig {
window_bits: 31,
mem_level: 1,
..Default::default()
};
let mut stream = z_stream::default();
assert_eq!(init(&mut stream, config), ReturnCode::Ok);
let Some(stream) = (unsafe { DeflateStream::from_stream_mut(&mut stream) }) else {
unreachable!()
};
set_header(stream, Some(&mut header));
let input = b"Hello World\n";
stream.next_in = input.as_ptr() as *mut _;
stream.avail_in = input.len() as _;
let mut output = [0u8; 1024];
stream.next_out = output.as_mut_ptr();
stream.avail_out = 100;
assert_eq!(stream.state.bit_writer.pending.capacity(), 512);
// only 12 bytes remain, so to write the name the pending buffer must be flushed.
// but there is insufficient output space to flush (only 100 bytes)
stream.state.bit_writer.pending.extend(&[0; 500]);
assert_eq!(deflate(stream, DeflateFlush::Finish), ReturnCode::Ok);
// now try that again but with sufficient output space
stream.avail_out = output.len() as _;
assert_eq!(deflate(stream, DeflateFlush::Finish), ReturnCode::StreamEnd);
let n = stream.total_out as usize;
assert!(end(stream).is_ok());
let output_rs = &mut output[..n];
assert_eq!(output_rs.len(), 500 + 99);
}
#[test]
fn gzip_with_header() {
// this test is here mostly so we get some MIRI action on the gzip header. A test that
// compares behavior with zlib-ng is in the libz-rs-sys test suite
let extra = "some extra stuff\0";
let name = "nomen est omen\0";
let comment = "such comment\0";
let mut header = gz_header {
text: 0,
time: 0,
xflags: 0,
os: 0,
extra: extra.as_ptr() as *mut _,
extra_len: extra.len() as _,
extra_max: 0,
name: name.as_ptr() as *mut _,
name_max: 0,
comment: comment.as_ptr() as *mut _,
comm_max: 0,
hcrc: 1,
done: 0,
};
let config = DeflateConfig {
window_bits: 31,
..Default::default()
};
let mut stream = z_stream::default();
assert_eq!(init(&mut stream, config), ReturnCode::Ok);
let Some(stream) = (unsafe { DeflateStream::from_stream_mut(&mut stream) }) else {
unreachable!()
};
set_header(stream, Some(&mut header));
let input = b"Hello World\n";
stream.next_in = input.as_ptr() as *mut _;
stream.avail_in = input.len() as _;
let mut output = [0u8; 256];
stream.next_out = output.as_mut_ptr();
stream.avail_out = output.len() as _;
assert_eq!(deflate(stream, DeflateFlush::Finish), ReturnCode::StreamEnd);
let n = stream.total_out as usize;
assert!(end(stream).is_ok());
let output_rs = &mut output[..n];
assert_eq!(output_rs.len(), 81);
{
let mut stream = z_stream::default();
let config = InflateConfig {
window_bits: config.window_bits,
};
assert_eq!(crate::inflate::init(&mut stream, config), ReturnCode::Ok);
let Some(stream) = (unsafe { InflateStream::from_stream_mut(&mut stream) }) else {
unreachable!();
};
stream.next_in = output_rs.as_mut_ptr() as _;
stream.avail_in = output_rs.len() as _;
let mut output = [0u8; 12];
stream.next_out = output.as_mut_ptr();
stream.avail_out = output.len() as _;
let mut extra_buf = [0u8; 64];
let mut name_buf = [0u8; 64];
let mut comment_buf = [0u8; 64];
let mut header = gz_header {
text: 0,
time: 0,
xflags: 0,
os: 0,
extra: extra_buf.as_mut_ptr(),
extra_len: 0,
extra_max: extra_buf.len() as _,
name: name_buf.as_mut_ptr(),
name_max: name_buf.len() as _,
comment: comment_buf.as_mut_ptr(),
comm_max: comment_buf.len() as _,
hcrc: 0,
done: 0,
};
assert_eq!(
crate::inflate::get_header(stream, Some(&mut header)),
ReturnCode::Ok
);
assert_eq!(
unsafe { crate::inflate::inflate(stream, InflateFlush::Finish) },
ReturnCode::StreamEnd
);
crate::inflate::end(stream);
assert!(!header.comment.is_null());
assert_eq!(
unsafe { CStr::from_ptr(header.comment.cast()) }
.to_str()
.unwrap(),
comment.trim_end_matches('\0')
);
assert!(!header.name.is_null());
assert_eq!(
unsafe { CStr::from_ptr(header.name.cast()) }
.to_str()
.unwrap(),
name.trim_end_matches('\0')
);
assert!(!header.extra.is_null());
assert_eq!(
unsafe { CStr::from_ptr(header.extra.cast()) }
.to_str()
.unwrap(),
extra.trim_end_matches('\0')
);
}
}
#[test]
#[cfg_attr(miri, ignore)]
fn insufficient_compress_space() {
const DATA: &[u8] = include_bytes!("deflate/test-data/inflate_buf_error.dat");
fn helper(deflate_buf: &mut [u8]) -> ReturnCode {
let config = DeflateConfig {
level: 0,
method: Method::Deflated,
window_bits: 10,
mem_level: 6,
strategy: Strategy::Default,
};
let (output, err) = compress_slice(deflate_buf, DATA, config);
assert_eq!(err, ReturnCode::Ok);
let config = InflateConfig {
window_bits: config.window_bits,
};
let mut uncompr = [0; 1 << 17];
let (uncompr, err) = uncompress_slice(&mut uncompr, output, config);
if err == ReturnCode::Ok {
assert_eq!(DATA, uncompr);
}
err
}
let mut output = [0; 1 << 17];
// this is too little space
assert_eq!(helper(&mut output[..1 << 16]), ReturnCode::DataError);
// this is sufficient space
assert_eq!(helper(&mut output), ReturnCode::Ok);
}
fn test_flush(flush: DeflateFlush, expected: &[u8]) {
let input = b"Hello World!\n";
let config = DeflateConfig {
level: 6, // use gzip
method: Method::Deflated,
window_bits: 16 + crate::MAX_WBITS,
mem_level: DEF_MEM_LEVEL,
strategy: Strategy::Default,
};
let mut output_rs = vec![0; 128];
// with the flush modes that we test here, the deflate process still has `Status::Busy`,
// and the `deflateEnd` function will return `DataError`.
let expected_err = ReturnCode::DataError;
let (rs, err) = compress_slice_with_flush(&mut output_rs, input, config, flush);
assert_eq!(expected_err, err);
assert_eq!(rs, expected);
}
#[test]
#[rustfmt::skip]
fn sync_flush() {
test_flush(
DeflateFlush::SyncFlush,
&[
31, 139, 8, 0, 0, 0, 0, 0, 0, gz_header::OS_CODE, 242, 72, 205, 201, 201, 87, 8, 207, 47, 202, 73,
81, 228, 2, 0, 0, 0, 255, 255,
],
)
}
#[test]
#[rustfmt::skip]
fn partial_flush() {
test_flush(
DeflateFlush::PartialFlush,
&[
31, 139, 8, 0, 0, 0, 0, 0, 0, gz_header::OS_CODE, 242, 72, 205, 201, 201, 87, 8, 207, 47, 202, 73,
81, 228, 2, 8,
],
);
}
#[test]
#[rustfmt::skip]
fn full_flush() {
test_flush(
DeflateFlush::FullFlush,
&[
31, 139, 8, 0, 0, 0, 0, 0, 0, gz_header::OS_CODE, 242, 72, 205, 201, 201, 87, 8, 207, 47, 202, 73,
81, 228, 2, 0, 0, 0, 255, 255,
],
);
}
#[test]
#[rustfmt::skip]
fn block_flush() {
test_flush(
DeflateFlush::Block,
&[
31, 139, 8, 0, 0, 0, 0, 0, 0, gz_header::OS_CODE, 242, 72, 205, 201, 201, 87, 8, 207, 47, 202, 73,
81, 228, 2,
],
);
}
#[test]
// splits the input into two, deflates them seperately and then joins the deflated byte streams
// into something that can be correctly inflated again. This is the basic idea behind pigz, and
// allows for parallel compression.
fn split_deflate() {
let input = "Hello World!\n";
let (input1, input2) = input.split_at(6);
let mut output1 = vec![0; 128];
let mut output2 = vec![0; 128];
let config = DeflateConfig {
level: 6, // use gzip
method: Method::Deflated,
window_bits: 16 + crate::MAX_WBITS,
mem_level: DEF_MEM_LEVEL,
strategy: Strategy::Default,
};
// see also the docs on `SyncFlush`. it makes sure everything is flushed, ends on a byte
// boundary, and that the final block does not have the "last block" bit set.
let (prefix, err) = compress_slice_with_flush(
&mut output1,
input1.as_bytes(),
config,
DeflateFlush::SyncFlush,
);
assert_eq!(err, ReturnCode::DataError);
let (output2, err) = compress_slice_with_flush(
&mut output2,
input2.as_bytes(),
config,
DeflateFlush::Finish,
);
assert_eq!(err, ReturnCode::Ok);
let inflate_config = crate::inflate::InflateConfig {
window_bits: 16 + 15,
};
// cuts off the length and crc
let (suffix, end) = output2.split_at(output2.len() - 8);
let (crc2, len2) = end.split_at(4);
let crc2 = u32::from_le_bytes(crc2.try_into().unwrap());
// cuts off the gzip header (10 bytes) from the front
let suffix = &suffix[10..];
let mut result: Vec<u8> = Vec::new();
result.extend(prefix.iter());
result.extend(suffix);
// it would be more proper to use `stream.total_in` here, but the slice helpers hide the
// stream so we're cheating a bit here
let len1 = input1.len() as u32;
let len2 = u32::from_le_bytes(len2.try_into().unwrap());
assert_eq!(len2 as usize, input2.len());
let crc1 = crate::crc32(0, input1.as_bytes());
let crc = crate::crc32_combine(crc1, crc2, len2 as u64);
// combined crc of the parts should be the crc of the whole
let crc_cheating = crate::crc32(0, input.as_bytes());
assert_eq!(crc, crc_cheating);
// write the trailer
result.extend(crc.to_le_bytes());
result.extend((len1 + len2).to_le_bytes());
let mut output = vec![0; 128];
let (output, err) = crate::inflate::uncompress_slice(&mut output, &result, inflate_config);
assert_eq!(err, ReturnCode::Ok);
assert_eq!(output, input.as_bytes());
}
#[test]
fn inflate_window_copy_slice() {
let uncompressed = [
9, 126, 0, 0, 0, 0, 0, 0, 9, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 4, 76, 33, 8, 2, 0, 0,
0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 17, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 3, 0, 0, 0, 0, 0, 0, 0, 0, 0, 12,
10, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 4, 76, 33, 8, 2, 0, 0, 0, 0, 0, 3, 0, 0, 0, 0, 0, 0,
0, 0, 0, 12, 10, 0, 0, 0, 0, 14, 0, 0, 0, 0, 0, 69, 69, 69, 69, 69, 69, 69, 69, 69, 69,
69, 69, 69, 69, 69, 69, 69, 69, 69, 69, 14, 0, 0, 0, 0, 0, 69, 69, 69, 69, 69, 69, 69,
69, 69, 69, 69, 69, 69, 69, 69, 9, 69, 69, 69, 69, 69, 69, 69, 69, 69, 69, 69, 69, 69,
69, 69, 69, 69, 69, 69, 69, 69, 69, 69, 69, 69, 69, 69, 69, 69, 69, 69, 69, 69, 69, 69,
69, 69, 69, 69, 69, 69, 69, 69, 69, 69, 69, 69, 69, 69, 69, 69, 69, 69, 69, 69, 69, 69,
69, 69, 69, 69, 69, 69, 69, 69, 69, 69, 69, 69, 12, 28, 0, 0, 3, 0, 0, 0, 0, 0, 0, 0,
0, 0, 12, 10, 0, 0, 0, 0, 14, 0, 0, 0, 0, 0, 69, 69, 69, 69, 69, 69, 69, 69, 69, 69,
69, 69, 69, 69, 69, 69, 69, 69, 69, 69, 14, 0, 0, 0, 0, 0, 69, 69, 69, 69, 69, 69, 69,
69, 69, 69, 69, 69, 69, 69, 69, 9, 69, 69, 69, 69, 69, 69, 69, 69, 69, 69, 69, 69, 69,
69, 69, 69, 69, 69, 69, 69, 69, 69, 69, 69, 69, 69, 69, 69, 69, 69, 69, 69, 69, 69, 69,
69, 69, 69, 69, 69, 69, 69, 69, 69, 69, 69, 69, 69, 69, 69, 69, 69, 69, 69, 69, 69, 69,
69, 69, 69, 69, 69, 69, 69, 69, 69, 69, 69, 69, 12, 28, 0, 2, 0, 0, 0, 63, 1, 0, 12, 2,
36, 0, 28, 0, 0, 0, 1, 0, 0, 63, 63, 13, 0, 0, 0, 0, 0, 0, 0, 63, 63, 63, 63, 0, 0, 0,
0, 0, 0, 65, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 16, 0,
0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 45, 0, 0, 0, 0, 0, 0, 0, 0, 0,
0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 91, 0, 0, 0, 9, 0, 0, 0, 9, 0, 0, 12, 33, 2, 0, 0, 8,
0, 4, 0, 0, 0, 12, 10, 41, 12, 10, 47,
];
let compressed = &[
31, 139, 8, 0, 0, 0, 0, 0, 4, 3, 181, 193, 49, 14, 194, 32, 24, 128, 209, 175, 192, 0,
228, 151, 232, 206, 66, 226, 226, 96, 60, 2, 113, 96, 235, 13, 188, 139, 103, 23, 106,
104, 108, 100, 49, 169, 239, 185, 39, 11, 199, 7, 51, 39, 171, 248, 118, 226, 63, 52,
157, 120, 86, 102, 78, 86, 209, 104, 58, 241, 84, 129, 166, 12, 4, 154, 178, 229, 202,
30, 36, 130, 166, 19, 79, 21, 104, 202, 64, 160, 41, 91, 174, 236, 65, 34, 10, 200, 19,
162, 206, 68, 96, 130, 156, 15, 188, 229, 138, 197, 157, 161, 35, 3, 87, 126, 245, 0,
28, 224, 64, 146, 2, 139, 1, 196, 95, 196, 223, 94, 10, 96, 92, 33, 86, 2, 0, 0,
];
let config = InflateConfig { window_bits: 25 };
let mut dest_vec_rs = vec![0u8; uncompressed.len()];
let (output_rs, error) =
crate::inflate::uncompress_slice(&mut dest_vec_rs, compressed, config);
assert_eq!(ReturnCode::Ok, error);
assert_eq!(output_rs, uncompressed);
}
#[test]
fn hash_calc_difference() {
let input = [
0, 0, 0, 0, 0, 43, 0, 0, 0, 0, 0, 0, 43, 0, 0, 0, 0, 0, 0, 0, 0, 48, 0, 0, 0, 0, 0, 0,
0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 49, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 29, 0, 0, 0,
0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 19, 0, 0, 0, 0, 0,
0, 0, 64, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 55, 0, 64, 0, 0,
0, 0, 0, 0, 0, 0, 0, 0, 48, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 102, 102, 102, 102, 102,
102, 102, 102, 102, 102, 102, 102, 102, 102, 102, 102, 102, 102, 102, 102, 102, 102,
102, 102, 102, 102, 102, 102, 102, 102, 112, 102, 102, 102, 102, 102, 102, 102, 102,
102, 102, 102, 102, 102, 102, 102, 102, 102, 102, 102, 102, 102, 102, 102, 102, 102, 0,
0, 0, 0, 0, 0, 49, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 19, 0, 0, 0, 0, 0, 0, 0, 64, 0, 0,
0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 55, 0, 64, 0, 0, 0, 0, 0, 0, 0,
0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 42, 0, 0, 0,
50, 0,
];
let config = DeflateConfig {
level: 6,
method: Method::Deflated,
window_bits: 9,
mem_level: 8,
strategy: Strategy::Default,
};
let crc32 = [
24, 149, 99, 96, 96, 96, 96, 208, 6, 17, 112, 138, 129, 193, 128, 1, 29, 24, 50, 208,
1, 200, 146, 169, 79, 24, 74, 59, 96, 147, 52, 71, 22, 70, 246, 88, 26, 94, 80, 128,
83, 6, 162, 219, 144, 76, 183, 210, 5, 8, 67, 105, 7, 108, 146, 230, 216, 133, 145,
129, 22, 3, 3, 131, 17, 3, 0, 3, 228, 25, 128,
];
let other = [
24, 149, 99, 96, 96, 96, 96, 208, 6, 17, 112, 138, 129, 193, 128, 1, 29, 24, 50, 208,
1, 200, 146, 169, 79, 24, 74, 59, 96, 147, 52, 71, 22, 70, 246, 88, 26, 94, 80, 128,
83, 6, 162, 219, 144, 76, 183, 210, 5, 8, 67, 105, 36, 159, 35, 128, 57, 118, 97, 100,
160, 197, 192, 192, 96, 196, 0, 0, 3, 228, 25, 128,
];
// the output is slightly different based on what hashing algorithm is used
match HashCalcVariant::for_compression_level(config.level as usize) {
HashCalcVariant::Crc32 => {
// the aarch64 hashing algorithm is different from the standard algorithm, but in
// this case they turn out to give the same output. Beware!
if cfg!(target_arch = "x86") || cfg!(target_arch = "x86_64") {
fuzz_based_test(&input, config, &crc32);
} else {
fuzz_based_test(&input, config, &other);
}
}
HashCalcVariant::Standard | HashCalcVariant::Roll => {
fuzz_based_test(&input, config, &other);
}
}
}
}
[Dauer der Verarbeitung: 0.95 Sekunden, vorverarbeitet 2026-04-28]
|
2026-05-26
|
