1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 192 193 194 195 196 197 198 199 200 201 202 203 204 205 206 207 208 209 210 211 212 213 214 215 216 217 218 219 220 221 222 223 224 225 226 227 228 229 230 231 232 233 234 235 236 237 238 239 240 241 242 243 244 245 246 247 248 249 250 251 252 253 254 255 256 257 258 259 260 261 262 263 264 265 266 267 268 269 270 271 272 273 274 275 276 277 278 279 280 281 282 283 284 285 286 287 288 289 290 291 292 293 294 295 296 297 298 299 300 301 302 303 304 305 306 307 308 309 310 311 312 313 314 315 316 317 318 319 320 321 322 323 324 325 326 327 328 329 330 331 332 333 334 335 336 337 338 339 340 341 342 343 344 345 346 347 348 349 350 351 352 353 354 355 356 357 358 359 360 361 362 363 364 365 366 367 368 369 370 371 372 373 374 375 376 377 378 379 380 381 382 383 384 385 386 387 388 389 390 391 392 393 394 395 396 397 398 399 400 401 402 403 404 405 406 407 408 409 410 411 412 413 414 415 416 417 418
//! Extra streaming decompression functionality.
//!
//! As of now this is mainly intended for use to build a higher-level wrapper.
#[cfg(feature = "with-alloc")]
use crate::alloc::boxed::Box;
use core::{cmp, mem};
use crate::inflate::core::{decompress, inflate_flags, DecompressorOxide, TINFL_LZ_DICT_SIZE};
use crate::inflate::TINFLStatus;
use crate::{DataFormat, MZError, MZFlush, MZResult, MZStatus, StreamResult};
/// Tag that determines reset policy of [InflateState](struct.InflateState.html)
pub trait ResetPolicy {
/// Performs reset
fn reset(&self, state: &mut InflateState);
}
/// Resets state, without performing expensive ops (e.g. zeroing buffer)
///
/// Note that not zeroing buffer can lead to security issues when dealing with untrusted input.
pub struct MinReset;
impl ResetPolicy for MinReset {
fn reset(&self, state: &mut InflateState) {
state.decompressor().init();
state.dict_ofs = 0;
state.dict_avail = 0;
state.first_call = true;
state.has_flushed = false;
state.last_status = TINFLStatus::NeedsMoreInput;
}
}
/// Resets state and zero memory, continuing to use the same data format.
pub struct ZeroReset;
impl ResetPolicy for ZeroReset {
#[inline]
fn reset(&self, state: &mut InflateState) {
MinReset.reset(state);
state.dict = [0; TINFL_LZ_DICT_SIZE];
}
}
/// Full reset of the state, including zeroing memory.
///
/// Requires to provide new data format.
pub struct FullReset(pub DataFormat);
impl ResetPolicy for FullReset {
#[inline]
fn reset(&self, state: &mut InflateState) {
ZeroReset.reset(state);
state.data_format = self.0;
}
}
/// A struct that compbines a decompressor with extra data for streaming decompression.
///
pub struct InflateState {
/// Inner decompressor struct
decomp: DecompressorOxide,
/// Buffer of input bytes for matches.
/// TODO: Could probably do this a bit cleaner with some
/// Cursor-like class.
/// We may also look into whether we need to keep a buffer here, or just one in the
/// decompressor struct.
dict: [u8; TINFL_LZ_DICT_SIZE],
/// Where in the buffer are we currently at?
dict_ofs: usize,
/// How many bytes of data to be flushed is there currently in the buffer?
dict_avail: usize,
first_call: bool,
has_flushed: bool,
/// Whether the input data is wrapped in a zlib header and checksum.
/// TODO: This should be stored in the decompressor.
data_format: DataFormat,
last_status: TINFLStatus,
}
impl Default for InflateState {
fn default() -> Self {
InflateState {
decomp: DecompressorOxide::default(),
dict: [0; TINFL_LZ_DICT_SIZE],
dict_ofs: 0,
dict_avail: 0,
first_call: true,
has_flushed: false,
data_format: DataFormat::Raw,
last_status: TINFLStatus::NeedsMoreInput,
}
}
}
impl InflateState {
/// Create a new state.
///
/// Note that this struct is quite large due to internal buffers, and as such storing it on
/// the stack is not recommended.
///
/// # Parameters
/// `data_format`: Determines whether the compressed data is assumed to wrapped with zlib
/// metadata.
pub fn new(data_format: DataFormat) -> InflateState {
InflateState {
data_format,
..Default::default()
}
}
/// Create a new state on the heap.
///
/// # Parameters
/// `data_format`: Determines whether the compressed data is assumed to wrapped with zlib
/// metadata.
#[cfg(feature = "with-alloc")]
pub fn new_boxed(data_format: DataFormat) -> Box<InflateState> {
let mut b: Box<InflateState> = Box::default();
b.data_format = data_format;
b
}
/// Access the innner decompressor.
pub fn decompressor(&mut self) -> &mut DecompressorOxide {
&mut self.decomp
}
/// Return the status of the last call to `inflate` with this `InflateState`.
pub const fn last_status(&self) -> TINFLStatus {
self.last_status
}
/// Create a new state using miniz/zlib style window bits parameter.
///
/// The decompressor does not support different window sizes. As such,
/// any positive (>0) value will set the zlib header flag, while a negative one
/// will not.
#[cfg(feature = "with-alloc")]
pub fn new_boxed_with_window_bits(window_bits: i32) -> Box<InflateState> {
let mut b: Box<InflateState> = Box::default();
b.data_format = DataFormat::from_window_bits(window_bits);
b
}
#[inline]
/// Reset the decompressor without re-allocating memory, using the given
/// data format.
pub fn reset(&mut self, data_format: DataFormat) {
self.reset_as(FullReset(data_format));
}
#[inline]
/// Resets the state according to specified policy.
pub fn reset_as<T: ResetPolicy>(&mut self, policy: T) {
policy.reset(self)
}
}
/// Try to decompress from `input` to `output` with the given [`InflateState`]
///
/// # `flush`
///
/// Generally, the various [`MZFlush`] flags have meaning only on the compression side. They can be
/// supplied here, but the only one that has any semantic meaning is [`MZFlush::Finish`], which is a
/// signal that the stream is expected to finish, and failing to do so is an error. It isn't
/// necessary to specify it when the stream ends; you'll still get returned a
/// [`MZStatus::StreamEnd`] anyway. Other values either have no effect or cause errors. It's
/// likely that you'll almost always just want to use [`MZFlush::None`].
///
/// # Errors
///
/// Returns [`MZError::Buf`] if the size of the `output` slice is empty or no progress was made due
/// to lack of expected input data, or if called with [`MZFlush::Finish`] and input wasn't all
/// consumed.
///
/// Returns [`MZError::Data`] if this or a a previous call failed with an error return from
/// [`TINFLStatus`]; probably indicates corrupted data.
///
/// Returns [`MZError::Stream`] when called with [`MZFlush::Full`] (meaningless on
/// decompression), or when called without [`MZFlush::Finish`] after an earlier call with
/// [`MZFlush::Finish`] has been made.
pub fn inflate(
state: &mut InflateState,
input: &[u8],
output: &mut [u8],
flush: MZFlush,
) -> StreamResult {
let mut bytes_consumed = 0;
let mut bytes_written = 0;
let mut next_in = input;
let mut next_out = output;
if flush == MZFlush::Full {
return StreamResult::error(MZError::Stream);
}
let mut decomp_flags = if state.data_format == DataFormat::Zlib {
inflate_flags::TINFL_FLAG_COMPUTE_ADLER32
} else {
inflate_flags::TINFL_FLAG_IGNORE_ADLER32
};
if (state.data_format == DataFormat::Zlib)
| (state.data_format == DataFormat::ZLibIgnoreChecksum)
{
decomp_flags |= inflate_flags::TINFL_FLAG_PARSE_ZLIB_HEADER;
}
let first_call = state.first_call;
state.first_call = false;
if (state.last_status as i32) < 0 {
return StreamResult::error(MZError::Data);
}
if state.has_flushed && (flush != MZFlush::Finish) {
return StreamResult::error(MZError::Stream);
}
state.has_flushed |= flush == MZFlush::Finish;
if (flush == MZFlush::Finish) && first_call {
decomp_flags |= inflate_flags::TINFL_FLAG_USING_NON_WRAPPING_OUTPUT_BUF;
let status = decompress(&mut state.decomp, next_in, next_out, 0, decomp_flags);
let in_bytes = status.1;
let out_bytes = status.2;
let status = status.0;
state.last_status = status;
bytes_consumed += in_bytes;
bytes_written += out_bytes;
let ret_status = {
if (status as i32) < 0 {
Err(MZError::Data)
} else if status != TINFLStatus::Done {
state.last_status = TINFLStatus::Failed;
Err(MZError::Buf)
} else {
Ok(MZStatus::StreamEnd)
}
};
return StreamResult {
bytes_consumed,
bytes_written,
status: ret_status,
};
}
if flush != MZFlush::Finish {
decomp_flags |= inflate_flags::TINFL_FLAG_HAS_MORE_INPUT;
}
if state.dict_avail != 0 {
bytes_written += push_dict_out(state, &mut next_out);
return StreamResult {
bytes_consumed,
bytes_written,
status: Ok(
if (state.last_status == TINFLStatus::Done) && (state.dict_avail == 0) {
MZStatus::StreamEnd
} else {
MZStatus::Ok
},
),
};
}
let status = inflate_loop(
state,
&mut next_in,
&mut next_out,
&mut bytes_consumed,
&mut bytes_written,
decomp_flags,
flush,
);
StreamResult {
bytes_consumed,
bytes_written,
status,
}
}
fn inflate_loop(
state: &mut InflateState,
next_in: &mut &[u8],
next_out: &mut &mut [u8],
total_in: &mut usize,
total_out: &mut usize,
decomp_flags: u32,
flush: MZFlush,
) -> MZResult {
let orig_in_len = next_in.len();
loop {
let status = decompress(
&mut state.decomp,
*next_in,
&mut state.dict,
state.dict_ofs,
decomp_flags,
);
let in_bytes = status.1;
let out_bytes = status.2;
let status = status.0;
state.last_status = status;
*next_in = &next_in[in_bytes..];
*total_in += in_bytes;
state.dict_avail = out_bytes;
*total_out += push_dict_out(state, next_out);
// The stream was corrupted, and decompression failed.
if (status as i32) < 0 {
return Err(MZError::Data);
}
// The decompressor has flushed all it's data and is waiting for more input, but
// there was no more input provided.
if (status == TINFLStatus::NeedsMoreInput) && orig_in_len == 0 {
return Err(MZError::Buf);
}
if flush == MZFlush::Finish {
if status == TINFLStatus::Done {
// There is not enough space in the output buffer to flush the remaining
// decompressed data in the internal buffer.
return if state.dict_avail != 0 {
Err(MZError::Buf)
} else {
Ok(MZStatus::StreamEnd)
};
// No more space in the output buffer, but we're not done.
} else if next_out.is_empty() {
return Err(MZError::Buf);
}
} else {
// We're not expected to finish, so it's fine if we can't flush everything yet.
let empty_buf = next_in.is_empty() || next_out.is_empty();
if (status == TINFLStatus::Done) || empty_buf || (state.dict_avail != 0) {
return if (status == TINFLStatus::Done) && (state.dict_avail == 0) {
// No more data left, we're done.
Ok(MZStatus::StreamEnd)
} else {
// Ok for now, still waiting for more input data or output space.
Ok(MZStatus::Ok)
};
}
}
}
}
fn push_dict_out(state: &mut InflateState, next_out: &mut &mut [u8]) -> usize {
let n = cmp::min(state.dict_avail as usize, next_out.len());
(next_out[..n]).copy_from_slice(&state.dict[state.dict_ofs..state.dict_ofs + n]);
*next_out = &mut mem::take(next_out)[n..];
state.dict_avail -= n;
state.dict_ofs = (state.dict_ofs + (n)) & (TINFL_LZ_DICT_SIZE - 1);
n
}
#[cfg(test)]
mod test {
use super::{inflate, InflateState};
use crate::{DataFormat, MZFlush, MZStatus};
use alloc::vec;
#[test]
fn test_state() {
let encoded = [
120u8, 156, 243, 72, 205, 201, 201, 215, 81, 168, 202, 201, 76, 82, 4, 0, 27, 101, 4,
19,
];
let mut out = vec![0; 50];
let mut state = InflateState::new_boxed(DataFormat::Zlib);
let res = inflate(&mut state, &encoded, &mut out, MZFlush::Finish);
let status = res.status.expect("Failed to decompress!");
assert_eq!(status, MZStatus::StreamEnd);
assert_eq!(out[..res.bytes_written as usize], b"Hello, zlib!"[..]);
assert_eq!(res.bytes_consumed, encoded.len());
state.reset_as(super::ZeroReset);
out.iter_mut().map(|x| *x = 0).count();
let res = inflate(&mut state, &encoded, &mut out, MZFlush::Finish);
let status = res.status.expect("Failed to decompress!");
assert_eq!(status, MZStatus::StreamEnd);
assert_eq!(out[..res.bytes_written as usize], b"Hello, zlib!"[..]);
assert_eq!(res.bytes_consumed, encoded.len());
state.reset_as(super::MinReset);
out.iter_mut().map(|x| *x = 0).count();
let res = inflate(&mut state, &encoded, &mut out, MZFlush::Finish);
let status = res.status.expect("Failed to decompress!");
assert_eq!(status, MZStatus::StreamEnd);
assert_eq!(out[..res.bytes_written as usize], b"Hello, zlib!"[..]);
assert_eq!(res.bytes_consumed, encoded.len());
assert_eq!(state.decompressor().adler32(), Some(459605011));
// Test state when not computing adler.
state = InflateState::new_boxed(DataFormat::ZLibIgnoreChecksum);
out.iter_mut().map(|x| *x = 0).count();
let res = inflate(&mut state, &encoded, &mut out, MZFlush::Finish);
let status = res.status.expect("Failed to decompress!");
assert_eq!(status, MZStatus::StreamEnd);
assert_eq!(out[..res.bytes_written as usize], b"Hello, zlib!"[..]);
assert_eq!(res.bytes_consumed, encoded.len());
// Not computed, so should be Some(1)
assert_eq!(state.decompressor().adler32(), Some(1));
// Should still have the checksum read from the header file.
assert_eq!(state.decompressor().adler32_header(), Some(459605011))
}
}