1 //! Deflate format (RFC 1951) support.
3 //! This module provides functionality for decompressing raw deflated streams via [`Inflate`] and gzip files (RFC 1952) via [`gzip_decode`] and compressing raw or zlib streams via [`Deflate`].
5 //! [`Deflate`]: ./struct.Deflate.html
6 //! [`Inflate`]: ./struct.Inflate.html
7 //! [`gzip_decode`]: ./fn.gzip_decode.html
11 //! Decompressing full input buffer into sufficiently large output buffer:
13 //! # use nihav_core::compr::DecompressError;
14 //! use nihav_core::compr::deflate::Inflate;
16 //! # fn decompress(input: &[u8]) -> Result<(), DecompressError> {
17 //! # let mut output_buffer = [0u8; 16];
18 //! let output_length = Inflate::uncompress(input, &mut output_buffer)?;
23 //! Decompressing input chunks into portions of output:
25 //! use nihav_core::compr::DecompressError;
26 //! use nihav_core::compr::deflate::Inflate;
28 //! # fn decompress(input_data: &[u8]) -> Result<(), DecompressError> {
29 //! let mut inflate = Inflate::new();
30 //! let mut dst_buf: Vec<u8> = Vec::new();
31 //! let mut output_chunk = [0u8; 1024];
32 //! for src in input_data.chunks(512) {
33 //! let mut repeat = false;
35 //! let ret = inflate.decompress_data(src, &mut output_chunk, repeat);
37 //! Ok(len) => { // we got a buffer decoded successfully to the end
38 //! dst_buf.extend_from_slice(&output_chunk[..len]);
41 //! Err(DecompressError::ShortData) => { // this block of data was fully read
44 //! Err(DecompressError::OutputFull) => {
45 //! // the output buffer is full, flush it and continue decoding the same block
47 //! dst_buf.extend_from_slice(&output_chunk);
59 //! Compressing input buffer into zlib stream:
61 //! use nihav_core::compr::deflate::{Deflate, DeflateMode, DeflateWriter};
63 //! # fn compress(input: &[u8]) {
64 //! let output = Vec::with_capacity(input.len() * 65540 / 65535 + 6);
65 //! let mut writer = DeflateWriter::new(output);
66 //! let mut compr = Deflate::new(DeflateMode::Fast);
67 //! compr.write_zlib_header(&mut writer);
68 //! compr.compress(input, &mut writer);
69 //! compr.compress_end(&mut writer);
70 //! let output = writer.end();
74 use crate::options::NAOptionDefinitionType;
75 use crate::io::byteio::*;
76 use crate::io::bitreader::*;
77 use crate::io::codebook::*;
80 const NUM_LITERALS: usize = 287;
81 const NUM_DISTS: usize = 32;
83 struct FixedLenCodeReader {}
85 impl CodebookDescReader<u16> for FixedLenCodeReader {
86 fn bits(&mut self, idx: usize) -> u8 {
88 else if idx < 256 { 9 }
89 else if idx < 280 { 7 }
92 #[allow(clippy::identity_op)]
93 fn code(&mut self, idx: usize) -> u32 {
94 let base = idx as u32;
95 let bits = self.bits(idx);
96 if idx < 144 { reverse_bits(base + 0x30, bits) }
97 else if idx < 256 { reverse_bits(base + 0x190 - 144, bits) }
98 else if idx < 280 { reverse_bits(base + 0x000 - 256, bits) }
99 else { reverse_bits(base + 0xC0 - 280, bits) }
101 fn sym (&mut self, idx: usize) -> u16 { idx as u16 }
102 fn len(&mut self) -> usize { NUM_LITERALS + 1 }
105 #[derive(Clone,Copy,Default)]
106 struct BitReaderState {
112 struct CurrentSource<'a> {
117 impl<'a> CurrentSource<'a> {
118 fn new(src: &'a [u8], br: BitReaderState) -> Self {
119 let mut newsrc = Self { src, br };
124 fn reinit(src: &'a [u8], br: BitReaderState) -> Self {
125 let mut newsrc = Self { src, br };
129 fn refill(&mut self) {
130 while (self.br.bits <= 24) && (self.br.pos < self.src.len()) {
131 self.br.bitbuf |= u32::from(self.src[self.br.pos]) << self.br.bits;
136 fn skip_cache(&mut self, nbits: u8) {
137 self.br.bitbuf >>= nbits;
138 self.br.bits -= nbits;
140 fn read(&mut self, nbits: u8) -> BitReaderResult<u32> {
141 if nbits == 0 { return Ok(0); }
142 if nbits > 16 { return Err(BitReaderError::TooManyBitsRequested); }
143 if self.br.bits < nbits {
145 if self.br.bits < nbits { return Err(BitReaderError::BitstreamEnd); }
147 let ret = self.br.bitbuf & ((1 << nbits) - 1);
148 self.skip_cache(nbits);
151 fn read_bool(&mut self) -> BitReaderResult<bool> {
152 if self.br.bits == 0 {
154 if self.br.bits == 0 { return Err(BitReaderError::BitstreamEnd); }
156 let ret = (self.br.bitbuf & 1) != 0;
160 fn peek(&mut self, nbits: u8) -> u32 {
161 if nbits == 0 || nbits > 16 { return 0; }
162 if self.br.bits < nbits {
165 self.br.bitbuf & ((1 << nbits) - 1)
167 fn skip(&mut self, nbits: u32) -> BitReaderResult<()> {
168 if u32::from(self.br.bits) >= nbits {
169 self.skip_cache(nbits as u8);
175 fn skip_bytes(&mut self, nbytes: usize) -> BitReaderResult<()> {
177 let cached = usize::from(self.br.bits / 8);
178 if nbytes <= cached {
179 self.skip((nbytes as u32) * 8)?;
181 self.skip((cached as u32) * 8)?;
184 self.br.pos += nbytes - cached;
185 if self.br.pos > self.src.len() {
186 return Err(BitReaderError::BitstreamEnd);
192 fn align(&mut self) {
193 let b = self.br.bits & 7;
198 fn left(&self) -> isize {
199 ((self.src.len() as isize) - (self.br.pos as isize)) * 8 + (self.br.bits as isize)
201 fn tell(&self) -> usize {
202 self.br.pos - usize::from(self.br.bits / 8)
206 impl<'a, S: Copy> CodebookReader<S> for CurrentSource<'a> {
207 fn read_cb(&mut self, cb: &Codebook<S>) -> CodebookResult<S> {
210 let mut lut_bits = cb.lut_bits;
211 let orig_br = self.br;
213 let lut_idx = (self.peek(lut_bits) as usize) + (idx as usize);
214 if cb.table[lut_idx] == TABLE_FILL_VALUE { return Err(CodebookError::InvalidCode); }
215 let bits = cb.table[lut_idx] & 0x7F;
216 esc = (cb.table[lut_idx] & 0x80) != 0;
217 idx = (cb.table[lut_idx] >> 8) as usize;
218 let skip_bits = if esc { u32::from(lut_bits) } else { bits };
219 if (skip_bits as isize) > self.left() {
222 return Err(CodebookError::MemoryError);
224 self.skip(skip_bits as u32).unwrap();
225 lut_bits = bits as u8;
236 StaticBlockInvLen(u32),
237 StaticBlockCopy(usize),
239 FixedBlockLengthExt(usize, u8),
240 FixedBlockDist(usize),
241 FixedBlockDistExt(usize, usize, u8),
242 FixedBlockCopy(usize, usize),
243 FixedBlockLiteral(u8),
249 DynCodeLengthsAdd(usize),
251 DynBlockLengthExt(usize, u8),
253 DynBlockDistExt(usize, usize, u8),
254 DynCopy(usize, usize),
259 ///! The decompressor for deflated streams (RFC 1951).
262 fix_len_cb: Codebook<u16>,
273 dyn_len_cb: Option<Codebook<u32>>,
274 dyn_lit_cb: Option<Codebook<u32>>,
275 dyn_dist_cb: Option<Codebook<u32>>,
276 len_lengths: [u8; 19],
277 all_lengths: [u8; NUM_LITERALS + NUM_DISTS],
281 const LENGTH_ADD_BITS: [u8; 29] = [
282 0, 0, 0, 0, 0, 0, 0, 0, 1, 1,
283 1, 1, 2, 2, 2, 2, 3, 3, 3, 3,
284 4, 4, 4, 4, 5, 5, 5, 5, 0
286 const LENGTH_BASE: [u16; 29] = [
287 3, 4, 5, 6, 7, 8, 9, 10, 11, 13,
288 15, 17, 19, 23, 27, 31, 35, 43, 51, 59,
289 67, 83, 99, 115, 131, 163, 195, 227, 258
291 const DIST_ADD_BITS: [u8; 30] = [
292 0, 0, 0, 0, 1, 1, 2, 2, 3, 3,
293 4, 4, 5, 5, 6, 6, 7, 7, 8, 8,
294 9, 9, 10, 10, 11, 11, 12, 12, 13, 13
296 const DIST_BASE: [u16; 30] = [
297 1, 2, 3, 4, 5, 7, 9, 13, 17, 25,
298 33, 49, 65, 97, 129, 193, 257, 385, 513, 769,
299 1025, 1537, 2049, 3073, 4097, 6145, 8193, 12289, 16385, 24577
301 const LEN_RECODE: [usize; 19] = [
302 16, 17, 18, 0, 8, 7, 9, 6, 10, 5, 11, 4, 12, 3, 13, 2, 14, 1, 15
304 const REPEAT_BITS: [u8; 3] = [ 2, 3, 7 ];
305 const REPEAT_BASE: [u8; 3] = [ 3, 3, 11 ];
307 macro_rules! read_bits {
308 ($self: expr, $csrc: expr, $bits: expr) => ({
309 if $csrc.left() < $bits as isize {
311 return Err(DecompressError::ShortData);
313 $csrc.read($bits).unwrap()
317 macro_rules! read_cb {
318 ($self: expr, $csrc: expr, $cb: expr) => ({
319 let ret = $csrc.read_cb($cb);
320 if let Err(CodebookError::MemoryError) = ret {
322 return Err(DecompressError::ShortData);
327 $self.state = InflateState::End;
328 return Err(DecompressError::InvalidData);
335 ///! Creates a new instance of `Inflate` struct.
336 pub fn new() -> Self {
337 let mut cr = FixedLenCodeReader {};
338 let fix_len_cb = Codebook::new(&mut cr, CodebookMode::LSB).unwrap();
340 br: BitReaderState::default(),
348 state: InflateState::Start,
355 len_lengths: [0; 19],
356 all_lengths: [0; NUM_LITERALS + NUM_DISTS],
360 fn put_literal(&mut self, val: u8) {
361 self.buf[self.bpos] = val;
362 self.bpos = (self.bpos + 1) & (self.buf.len() - 1);
365 fn lz_copy(&mut self, offset: usize, len: usize, dst: &mut [u8]) -> DecompressResult<()> {
366 let mask = self.buf.len() - 1;
367 if offset > self.full_pos {
368 return Err(DecompressError::InvalidData);
370 let cstart = (self.bpos.wrapping_sub(offset)) & mask;
372 self.buf[(self.bpos + i) & mask] = self.buf[(cstart + i) & mask];
373 dst[i] = self.buf[(cstart + i) & mask];
375 self.bpos = (self.bpos + len) & mask;
376 self.full_pos += len;
379 ///! Sets custom history for decoding an update for already decoded data.
380 pub fn set_dict(&mut self, dict: &[u8]) {
381 let len = dict.len().min(self.buf.len());
382 let start = dict.len() - len;
383 self.buf[..len].copy_from_slice(&dict[start..]);
387 ///! Reports whether decoder has finished decoding the input.
388 pub fn is_finished(&self) -> bool {
389 matches!(self.state, InflateState::End)
391 ///! Reports the current amount of bytes output into the destination buffer after the last run.
392 pub fn get_current_output_size(&self) -> usize { self.output_idx }
393 ///! Reports the total amount of bytes decoded so far.
394 pub fn get_total_output_size(&self) -> usize { self.bpos }
395 ///! Tries to decompress input data and write it to the output buffer.
397 ///! Since the decompressor can work with arbitrary input and output chunks its return value may have several meanings:
398 ///! * `Ok(len)` means the stream has been fully decoded and then number of bytes output into the destination buffer is returned.
399 ///! * [`DecompressError::ShortData`] means the input stream has been fully read but more data is needed.
400 ///! * [`DecompressError::OutputFull`] means the output buffer is full and should be flushed. Then decoding should continue on the same input block with `continue_block` parameter set to `true`.
402 ///! [`DecompressError::ShortData`]: ../enum.DecompressError.html#variant.ShortData
403 ///! [`DecompressError::OutputFull`]: ../enum.DecompressError.html#variant.OutputFull
404 pub fn decompress_data(&mut self, src: &[u8], dst: &mut [u8], continue_block: bool) -> DecompressResult<usize> {
405 self.decompress_data_internal(src, dst, continue_block, false)
407 ///! Tries to decompress whole input chunk to the output buffer.
408 pub fn decompress_block(&mut self, src: &[u8], dst: &mut [u8]) -> DecompressResult<usize> {
409 self.decompress_data_internal(src, dst, false, true)
411 #[allow(clippy::comparison_chain)]
412 fn decompress_data_internal(&mut self, src: &[u8], dst: &mut [u8], continue_block: bool, do_one_block: bool) -> DecompressResult<usize> {
413 if src.is_empty() || dst.is_empty() {
414 return Err(DecompressError::InvalidArgument);
416 let mut csrc = if !continue_block {
417 CurrentSource::new(src, self.br)
420 CurrentSource::reinit(src, self.br)
425 // check for zlib stream header
426 if let (&InflateState::Start, true) = (&self.state, src.len() > 2) {
427 let cm = src[0] & 0xF;
428 let cinfo = src[0] >> 4;
429 let hdr = (u16::from(src[0]) << 8) | u16::from(src[1]);
430 if cm == 8 && cinfo <= 7 && (hdr % 31) == 0 {
431 csrc.skip(16).unwrap();
436 InflateState::Start | InflateState::BlockStart => {
437 if csrc.left() == 0 {
439 return Ok(self.output_idx);
442 return Err(DecompressError::ShortData);
444 self.final_block = csrc.read_bool().unwrap();
445 self.state = InflateState::BlockMode;
447 InflateState::BlockMode => {
448 let bmode = read_bits!(self, csrc, 2);
452 self.state = InflateState::StaticBlockLen;
454 1 => { self.state = InflateState::FixedBlock; },
455 2 => { self.state = InflateState::DynBlockHlit; },
457 self.state = InflateState::End;
458 return Err(DecompressError::InvalidHeader);
462 InflateState::StaticBlockLen => {
463 let len = read_bits!(self, csrc, 16);
464 self.state = InflateState::StaticBlockInvLen(len);
466 InflateState::StaticBlockInvLen(len) => {
467 let inv_len = read_bits!(self, csrc, 16);
468 if (len ^ inv_len) != 0xFFFF {
469 self.state = InflateState::End;
470 return Err(DecompressError::InvalidHeader);
472 self.state = InflateState::StaticBlockCopy(len as usize);
474 InflateState::StaticBlockCopy(len) => {
478 self.state = InflateState::StaticBlockCopy(len - i);
479 return Err(DecompressError::ShortData);
481 let val = csrc.read(8).unwrap() as u8;
482 self.put_literal(val);
484 self.state = InflateState::BlockStart;
486 InflateState::FixedBlock => {
487 let val = read_cb!(self, csrc, &self.fix_len_cb);
489 if self.output_idx >= dst.len() {
491 self.state = InflateState::FixedBlockLiteral(val as u8);
492 return Err(DecompressError::OutputFull);
494 self.put_literal(val as u8);
495 dst[self.output_idx] = val as u8;
496 self.output_idx += 1;
497 } else if val == 256 {
498 if self.final_block {
499 self.state = InflateState::End;
500 return Ok(self.output_idx);
502 self.state = InflateState::BlockStart;
505 let len_idx = (val - 257) as usize;
506 if len_idx >= LENGTH_BASE.len() {
507 self.state = InflateState::End;
508 return Err(DecompressError::InvalidData);
510 let len_bits = LENGTH_ADD_BITS[len_idx];
511 let add_base = LENGTH_BASE[len_idx] as usize;
513 self.state = InflateState::FixedBlockLengthExt(add_base, len_bits);
515 self.state = InflateState::FixedBlockDist(add_base);
519 InflateState::FixedBlockLiteral(sym) => {
520 if self.output_idx >= dst.len() {
522 return Err(DecompressError::OutputFull);
524 self.put_literal(sym);
525 dst[self.output_idx] = sym;
526 self.output_idx += 1;
527 self.state = InflateState::FixedBlock;
529 InflateState::FixedBlockLengthExt(base, bits) => {
530 let add = read_bits!(self, csrc, bits) as usize;
531 self.state = InflateState::FixedBlockDist(base + add);
533 InflateState::FixedBlockDist(length) => {
534 let dist_idx = reverse_bits(read_bits!(self, csrc, 5), 5) as usize;
535 if dist_idx >= DIST_BASE.len() {
536 self.state = InflateState::End;
537 return Err(DecompressError::InvalidData);
539 let dist_bits = DIST_ADD_BITS[dist_idx];
540 let dist_base = DIST_BASE[dist_idx] as usize;
542 self.state = InflateState::FixedBlockCopy(length, dist_base);
544 self.state = InflateState::FixedBlockDistExt(length, dist_base, dist_bits);
547 InflateState::FixedBlockDistExt(length, base, bits) => {
548 let add = read_bits!(self, csrc, bits) as usize;
549 self.state = InflateState::FixedBlockCopy(length, base + add);
551 InflateState::FixedBlockCopy(length, dist) => {
552 if self.output_idx + length > dst.len() {
553 let copy_size = dst.len() - self.output_idx;
554 let ret = self.lz_copy(dist, copy_size, &mut dst[self.output_idx..]);
556 self.state = InflateState::End;
557 return Err(DecompressError::InvalidData);
559 self.output_idx += copy_size;
561 self.state = InflateState::FixedBlockCopy(length - copy_size, dist);
562 return Err(DecompressError::OutputFull);
564 let ret = self.lz_copy(dist, length, &mut dst[self.output_idx..]);
566 self.state = InflateState::End;
567 return Err(DecompressError::InvalidData);
569 self.output_idx += length;
570 self.state = InflateState::FixedBlock;
572 InflateState::DynBlockHlit => {
573 self.hlit = (read_bits!(self, csrc, 5) as usize) + 257;
574 if self.hlit >= 287 {
575 self.state = InflateState::End;
576 return Err(DecompressError::InvalidHeader);
578 self.state = InflateState::DynBlockHdist;
580 InflateState::DynBlockHdist => {
581 self.hdist = (read_bits!(self, csrc, 5) as usize) + 1;
582 self.state = InflateState::DynBlockHclen;
584 InflateState::DynBlockHclen => {
585 let hclen = (read_bits!(self, csrc, 4) as usize) + 4;
586 self.cur_len_idx = 0;
587 self.len_lengths = [0; 19];
588 self.all_lengths = [0; NUM_LITERALS + NUM_DISTS];
589 self.state = InflateState::DynLengths(hclen);
591 InflateState::DynLengths(len) => {
595 self.state = InflateState::DynLengths(len - i);
596 return Err(DecompressError::ShortData);
598 self.len_lengths[LEN_RECODE[self.cur_len_idx]] = csrc.read(3).unwrap() as u8;
599 self.cur_len_idx += 1;
601 let mut len_codes = [ShortCodebookDesc { code: 0, bits: 0 }; 19];
602 lengths_to_codes(&self.len_lengths, &mut len_codes)?;
603 let mut cr = ShortCodebookDescReader::new(len_codes.to_vec());
604 let ret = Codebook::new(&mut cr, CodebookMode::LSB);
606 self.state = InflateState::End;
607 return Err(DecompressError::InvalidHeader);
609 self.dyn_len_cb = Some(ret.unwrap());
610 self.cur_len_idx = 0;
611 self.state = InflateState::DynCodeLengths;
613 InflateState::DynCodeLengths => {
614 if let Some(ref len_cb) = self.dyn_len_cb {
615 while self.cur_len_idx < self.hlit + self.hdist {
616 let ret = csrc.read_cb(len_cb);
617 let val = match ret {
619 Err(CodebookError::MemoryError) => {
621 return Err(DecompressError::ShortData);
624 self.state = InflateState::End;
625 return Err(DecompressError::InvalidHeader);
629 self.all_lengths[self.cur_len_idx] = val as u8;
630 self.cur_len_idx += 1;
632 let idx = (val as usize) - 16;
634 self.state = InflateState::End;
635 return Err(DecompressError::InvalidHeader);
637 self.state = InflateState::DynCodeLengthsAdd(idx);
641 let (lit_lengths, dist_lengths) = self.all_lengths.split_at(self.hlit);
643 let mut lit_codes = [ShortCodebookDesc { code: 0, bits: 0 }; NUM_LITERALS];
644 lengths_to_codes(lit_lengths, &mut lit_codes)?;
645 let mut cr = ShortCodebookDescReader::new(lit_codes.to_vec());
646 let ret = Codebook::new(&mut cr, CodebookMode::LSB);
647 if ret.is_err() { return Err(DecompressError::InvalidHeader); }
648 self.dyn_lit_cb = Some(ret.unwrap());
650 let mut dist_codes = [ShortCodebookDesc { code: 0, bits: 0 }; NUM_DISTS];
651 lengths_to_codes(&dist_lengths[..self.hdist], &mut dist_codes)?;
652 let mut cr = ShortCodebookDescReader::new(dist_codes.to_vec());
653 let ret = Codebook::new(&mut cr, CodebookMode::LSB);
654 if ret.is_err() { return Err(DecompressError::InvalidHeader); }
655 self.dyn_dist_cb = Some(ret.unwrap());
657 self.state = InflateState::DynBlock;
662 InflateState::DynCodeLengthsAdd(mode) => {
663 let base = REPEAT_BASE[mode] as usize;
664 let bits = REPEAT_BITS[mode];
665 let len = base + read_bits!(self, csrc, bits) as usize;
666 if self.cur_len_idx + len > self.hlit + self.hdist {
667 self.state = InflateState::End;
668 return Err(DecompressError::InvalidHeader);
670 let rpt = if mode == 0 {
671 if self.cur_len_idx == 0 {
672 self.state = InflateState::End;
673 return Err(DecompressError::InvalidHeader);
675 self.all_lengths[self.cur_len_idx - 1]
680 self.all_lengths[self.cur_len_idx] = rpt;
681 self.cur_len_idx += 1;
683 self.state = InflateState::DynCodeLengths;
685 InflateState::DynBlock => {
686 if let Some(ref lit_cb) = self.dyn_lit_cb {
687 let val = read_cb!(self, csrc, lit_cb);
689 if self.output_idx >= dst.len() {
691 self.state = InflateState::DynBlockLiteral(val as u8);
692 return Err(DecompressError::OutputFull);
694 self.put_literal(val as u8);
695 dst[self.output_idx] = val as u8;
696 self.output_idx += 1;
697 } else if val == 256 {
698 if self.final_block {
699 self.state = InflateState::End;
700 return Ok(self.output_idx);
702 self.state = InflateState::BlockStart;
705 let len_idx = (val - 257) as usize;
706 if len_idx >= LENGTH_BASE.len() {
707 self.state = InflateState::End;
708 return Err(DecompressError::InvalidData);
710 let len_bits = LENGTH_ADD_BITS[len_idx];
711 let add_base = LENGTH_BASE[len_idx] as usize;
713 self.state = InflateState::DynBlockLengthExt(add_base, len_bits);
715 self.state = InflateState::DynBlockDist(add_base);
722 InflateState::DynBlockLiteral(sym) => {
723 if self.output_idx >= dst.len() {
725 return Err(DecompressError::OutputFull);
727 self.put_literal(sym);
728 dst[self.output_idx] = sym;
729 self.output_idx += 1;
730 self.state = InflateState::DynBlock;
732 InflateState::DynBlockLengthExt(base, bits) => {
733 let add = read_bits!(self, csrc, bits) as usize;
734 self.state = InflateState::DynBlockDist(base + add);
736 InflateState::DynBlockDist(length) => {
737 if let Some(ref dist_cb) = self.dyn_dist_cb {
738 let dist_idx = read_cb!(self, csrc, dist_cb) as usize;
739 if dist_idx >= DIST_BASE.len() {
740 self.state = InflateState::End;
741 return Err(DecompressError::InvalidData);
743 let dist_bits = DIST_ADD_BITS[dist_idx];
744 let dist_base = DIST_BASE[dist_idx] as usize;
746 self.state = InflateState::DynCopy(length, dist_base);
748 self.state = InflateState::DynBlockDistExt(length, dist_base, dist_bits);
754 InflateState::DynBlockDistExt(length, base, bits) => {
755 let add = read_bits!(self, csrc, bits) as usize;
756 self.state = InflateState::DynCopy(length, base + add);
758 InflateState::DynCopy(length, dist) => {
759 if self.output_idx + length > dst.len() {
760 let copy_size = dst.len() - self.output_idx;
761 let ret = self.lz_copy(dist, copy_size, &mut dst[self.output_idx..]);
763 self.state = InflateState::End;
764 return Err(DecompressError::InvalidData);
766 self.output_idx += copy_size;
768 self.state = InflateState::DynCopy(length - copy_size, dist);
769 return Err(DecompressError::OutputFull);
771 let ret = self.lz_copy(dist, length, &mut dst[self.output_idx..]);
773 self.state = InflateState::End;
774 return Err(DecompressError::InvalidData);
776 self.output_idx += length;
777 self.state = InflateState::DynBlock;
779 InflateState::End => {
785 ///! Resets decoder state.
786 pub fn reset(&mut self) {
790 self.state = InflateState::Start;
793 ///! Decompresses input data into output returning the uncompressed data length.
794 pub fn uncompress(src: &[u8], dst: &mut [u8]) -> DecompressResult<usize> {
795 let mut csrc = CurrentSource::new(src, BitReaderState::default());
797 let cm = src[0] & 0xF;
798 let cinfo = src[0] >> 4;
799 let hdr = (u16::from(src[0]) << 8) | u16::from(src[1]);
800 if cm == 8 && cinfo <= 7 && (hdr % 31) == 0 {
801 csrc.skip(16).unwrap();
805 let mut fix_len_cb = None;
808 let mut final_block = false;
810 final_block = csrc.read_bool()?;
812 let bmode = csrc.read(2)?;
816 let len = csrc.read(16)? as usize;
817 let inv_len = csrc.read(16)? as usize;
818 if (len ^ inv_len) != 0xFFFF {
819 return Err(DecompressError::InvalidHeader);
821 let src_pos = csrc.tell();
822 if src_pos + len > src.len() {
823 return Err(DecompressError::ShortData);
825 if dst_idx + len > dst.len() {
826 return Err(DecompressError::OutputFull);
828 dst[dst_idx..][..len].copy_from_slice(&src[src_pos..][..len]);
830 csrc.skip_bytes(len)?;
833 if fix_len_cb.is_none() {
834 let mut cr = FixedLenCodeReader {};
835 fix_len_cb = Some(Codebook::new(&mut cr, CodebookMode::LSB).unwrap());
837 if let Some(ref len_cb) = &fix_len_cb {
839 let val = csrc.read_cb(len_cb)?;
841 if dst_idx >= dst.len() {
842 return Err(DecompressError::OutputFull);
844 dst[dst_idx] = val as u8;
846 } else if val == 256 {
849 let len_idx = (val - 257) as usize;
850 if len_idx >= LENGTH_BASE.len() {
851 return Err(DecompressError::InvalidData);
853 let len_bits = LENGTH_ADD_BITS[len_idx];
854 let mut length = LENGTH_BASE[len_idx] as usize;
856 length += csrc.read(len_bits)? as usize;
858 let dist_idx = reverse_bits(csrc.read(5)?, 5) as usize;
859 if dist_idx >= DIST_BASE.len() {
860 return Err(DecompressError::InvalidData);
862 let dist_bits = DIST_ADD_BITS[dist_idx];
863 let mut dist = DIST_BASE[dist_idx] as usize;
865 dist += csrc.read(dist_bits)? as usize;
868 if dst_idx + length > dst.len() {
869 return Err(DecompressError::OutputFull);
872 return Err(DecompressError::InvalidData);
874 lz_copy(dst, dst_idx, dist, length);
883 let hlit = csrc.read(5)? as usize + 257;
885 return Err(DecompressError::InvalidHeader);
887 let hdist = csrc.read(5)? as usize + 1;
888 let hclen = csrc.read(4)? as usize + 4;
889 let mut cur_len_idx = 0;
890 let mut len_lengths = [0; 19];
891 let mut all_lengths = [0; NUM_LITERALS + NUM_DISTS];
894 len_lengths[LEN_RECODE[cur_len_idx]] = csrc.read(3)? as u8;
897 let mut len_codes = [ShortCodebookDesc { code: 0, bits: 0 }; 19];
898 lengths_to_codes(&len_lengths, &mut len_codes)?;
899 let mut cr = ShortCodebookDescReader::new(len_codes.to_vec());
900 let ret = Codebook::new(&mut cr, CodebookMode::LSB);
902 return Err(DecompressError::InvalidHeader);
904 let dyn_len_cb = ret.unwrap();
906 let mut cur_len_idx = 0;
907 while cur_len_idx < hlit + hdist {
908 let val = csrc.read_cb(&dyn_len_cb)?;
910 all_lengths[cur_len_idx] = val as u8;
913 let mode = (val as usize) - 16;
915 return Err(DecompressError::InvalidHeader);
917 let base = REPEAT_BASE[mode] as usize;
918 let bits = REPEAT_BITS[mode];
919 let len = base + (csrc.read(bits)? as usize);
920 if cur_len_idx + len > hlit + hdist {
921 return Err(DecompressError::InvalidHeader);
923 let rpt = if mode == 0 {
924 if cur_len_idx == 0 {
925 return Err(DecompressError::InvalidHeader);
927 all_lengths[cur_len_idx - 1]
932 all_lengths[cur_len_idx] = rpt;
937 let (lit_lengths, dist_lengths) = all_lengths.split_at(hlit);
939 let mut lit_codes = [ShortCodebookDesc { code: 0, bits: 0 }; NUM_LITERALS];
940 lengths_to_codes(lit_lengths, &mut lit_codes)?;
941 let mut cr = ShortCodebookDescReader::new(lit_codes.to_vec());
942 let ret = Codebook::new(&mut cr, CodebookMode::LSB);
943 if ret.is_err() { return Err(DecompressError::InvalidHeader); }
944 let dyn_lit_cb = ret.unwrap();
946 let mut dist_codes = [ShortCodebookDesc { code: 0, bits: 0 }; NUM_DISTS];
947 lengths_to_codes(&dist_lengths[..hdist], &mut dist_codes)?;
948 let mut cr = ShortCodebookDescReader::new(dist_codes.to_vec());
949 let ret = Codebook::new(&mut cr, CodebookMode::LSB);
950 if ret.is_err() { return Err(DecompressError::InvalidHeader); }
951 let dyn_dist_cb = ret.unwrap();
954 let val = csrc.read_cb(&dyn_lit_cb)?;
956 if dst_idx >= dst.len() {
957 return Err(DecompressError::OutputFull);
959 dst[dst_idx] = val as u8;
961 } else if val == 256 {
964 let len_idx = (val - 257) as usize;
965 if len_idx >= LENGTH_BASE.len() {
966 return Err(DecompressError::InvalidData);
968 let len_bits = LENGTH_ADD_BITS[len_idx];
969 let mut length = LENGTH_BASE[len_idx] as usize;
971 length += csrc.read(len_bits)? as usize;
974 let dist_idx = csrc.read_cb(&dyn_dist_cb)? as usize;
975 if dist_idx >= DIST_BASE.len() {
976 return Err(DecompressError::InvalidData);
978 let dist_bits = DIST_ADD_BITS[dist_idx];
979 let mut dist = DIST_BASE[dist_idx] as usize;
981 dist += csrc.read(dist_bits)? as usize;
984 if dst_idx + length > dst.len() {
985 return Err(DecompressError::OutputFull);
988 return Err(DecompressError::InvalidData);
990 lz_copy(dst, dst_idx, dist, length);
995 _ => return Err(DecompressError::InvalidHeader),
1002 impl Default for Inflate {
1003 fn default() -> Self {
1008 fn lengths_to_codes(lens: &[u8], codes: &mut [ShortCodebookDesc]) -> DecompressResult<()> {
1009 let mut bits = [0u32; 32];
1010 let mut pfx = [0u32; 33];
1011 for len in lens.iter() {
1012 let len = *len as usize;
1013 if len >= bits.len() {
1014 return Err(DecompressError::InvalidHeader);
1020 for i in 0..bits.len() {
1021 code = (code + bits[i]) << 1;
1025 for (len, codes) in lens.iter().zip(codes.iter_mut()) {
1026 let len = *len as usize;
1028 let bits = len as u8;
1029 *codes = ShortCodebookDesc { code: reverse_bits(pfx[len], bits), bits };
1032 *codes = ShortCodebookDesc { code: 0, bits: 0 };
1045 #[allow(clippy::unreadable_literal)]
1047 let mut tab = [0u32; 256];
1049 let mut c = i as u32;
1052 c = 0xEDB88320 ^ (c >> 1);
1059 Self { tab, crc: 0 }
1061 fn update_crc(&mut self, src: &[u8]) {
1062 let mut c = !self.crc;
1063 for el in src.iter() {
1064 c = self.tab[((c ^ u32::from(*el)) & 0xFF) as usize] ^ (c >> 8);
1070 ///! Decodes input data in gzip file format (RFC 1952) returning a vector containing decoded data.
1071 pub fn gzip_decode(br: &mut ByteReader, skip_crc: bool) -> DecompressResult<Vec<u8>> {
1072 const FLAG_HCRC: u8 = 0x02;
1073 const FLAG_EXTRA: u8 = 0x04;
1074 const FLAG_NAME: u8 = 0x08;
1075 const FLAG_COMMENT: u8 = 0x10;
1077 let id1 = br.read_byte()?;
1078 let id2 = br.read_byte()?;
1079 let cm = br.read_byte()?;
1080 let flg = br.read_byte()?;
1081 let _mtime = br.read_u32le()?;
1082 let _xfl = br.read_byte()?;
1083 let _os = br.read_byte()?;
1084 if id1 != 0x1F || id2 != 0x8B || cm != 8 {
1085 return Err(DecompressError::InvalidHeader);
1088 if (flg & FLAG_EXTRA) != 0 {
1089 let xlen = br.read_u16le()? as usize;
1090 br.read_skip(xlen)?;
1092 if (flg & FLAG_NAME) != 0 {
1094 let b = br.read_byte()?;
1100 if (flg & FLAG_COMMENT) != 0 {
1102 let b = br.read_byte()?;
1108 let _hcrc = if (flg & FLAG_HCRC) != 0 {
1113 if (flg & 0xE0) != 0 {
1114 return Err(DecompressError::Unsupported);
1117 let mut output: Vec<u8> = Vec::new();
1118 let mut tail = [0u8; 8];
1119 let mut inblk = [0u8; 1024];
1120 let mut oblk = [0u8; 4096];
1121 let mut inflate = Inflate::new();
1122 let mut checker = GzipCRC32::new();
1125 let ret = br.read_buf_some(&mut inblk);
1126 if let Err(ByteIOError::EOF) = ret {
1129 let inlen = match ret {
1131 Err(_) => return Err(DecompressError::IOError),
1133 let mut repeat = false;
1135 let ret = inflate.decompress_data(&inblk[..inlen], &mut oblk, repeat);
1138 checker.update_crc(&oblk[..outlen]);
1139 output.extend_from_slice(&oblk[..outlen]);
1142 Err(DecompressError::ShortData) => {
1145 Err(DecompressError::OutputFull) => {
1147 checker.update_crc(&oblk);
1148 output.extend_from_slice(&oblk);
1155 // Save last 8 bytes for CRC and size.
1157 tail.copy_from_slice(&inblk[inlen - 8..][..8]);
1159 let shift_len = 8 - inlen;
1160 for i in 0..shift_len {
1161 tail[i] = tail[i + inlen];
1163 for i in shift_len..8 {
1164 tail[i] = inblk[i - shift_len];
1169 if !inflate.is_finished() { println!("???"); }
1170 let crc = read_u32le(&tail[0..4])?;
1171 let size = read_u32le(&tail[4..8])?;
1172 if size != (output.len() as u32) {
1173 return Err(DecompressError::CRCError);
1175 if crc != checker.crc {
1176 return Err(DecompressError::CRCError);
1183 #[derive(Clone,Copy,Default)]
1191 const TOKEN_EOB: Token = Token { sym: 256, distsym: 0, len: 0, dist: 0 };
1194 fn from_literal(sym: u8) -> Self {
1196 sym: u16::from(sym),
1202 fn from_match(dist: u16, len: u16) -> Self {
1203 let sym = match len {
1204 3..= 10 => 257 + len - 3,
1205 11..= 18 => 265 + (len - 11) / 2,
1206 19..= 34 => 269 + (len - 19) / 4,
1207 35..= 66 => 273 + (len - 35) / 8,
1208 67..=130 => 277 + (len - 67) / 16,
1209 131..=257 => 281 + (len - 131) / 32,
1212 let distsym = if dist <= 4 {
1215 let bits = 16 - (dist - 1).leading_zeros();
1216 (bits as u8) * 2 - 2 + if ((dist - 1) & (1 << (bits - 2))) != 0 { 1 } else { 0 }
1219 sym, distsym, len, dist
1224 fn add_codes(lens: &[u8], stats: &mut [u32], toks: &mut Vec<(u8, u8)>) {
1228 for &len in lens.iter() {
1234 let run = lcount.min(138);
1236 toks.push((18, run - 11));
1241 toks.push((17, lcount - 3));
1244 for _ in 0..lcount {
1250 let run = lcount.min(6);
1252 toks.push((16, run - 3));
1255 for _ in 0..lcount {
1256 stats[last as usize] += 1;
1257 toks.push((last, 0));
1260 stats[len as usize] += 1;
1261 toks.push((len, 0));
1269 let run = lcount.min(138);
1271 toks.push((18, run - 11));
1276 toks.push((17, lcount - 3));
1279 for _ in 0..lcount {
1285 let run = lcount.min(6);
1287 toks.push((16, run - 3));
1290 for _ in 0..lcount {
1291 stats[last as usize] += 1;
1292 toks.push((last, 0));
1298 ///! Deflate stream writer.
1299 pub struct DeflateWriter {
1305 impl DeflateWriter {
1306 ///! Creates a new instance of `DeflateWriter` for a provided output.
1307 pub fn new(dst: Vec<u8>) -> Self {
1314 fn align(&mut self) {
1315 if (self.bits & 7) != 0 {
1316 self.bits += 8 - (self.bits & 7);
1319 fn flush(&mut self) {
1320 while self.bits >= 8 {
1321 self.dst.push(self.bbuf as u8);
1326 fn write(&mut self, val: u16, len: u8) {
1328 self.bbuf |= u32::from(val) << self.bits;
1331 ///! Finishes writing the stream and returns the output vector.
1332 pub fn end(mut self) -> Vec<u8> {
1335 self.dst.push(self.bbuf as u8);
1340 fn write_codes(&mut self, codes: &CodeHuff, dists: &DistHuff) {
1341 let mut stats = [0u32; 19];
1342 let mut toks = Vec::with_capacity(NUM_LITERALS + NUM_DISTS);
1343 let mut cw = [0u16; 19];
1344 let mut cl = [0u8; 19];
1347 add_codes(&codes.lens[..codes.num_codes], &mut stats, &mut toks);
1348 add_codes(&dists.lens[..dists.num_codes], &mut stats, &mut toks);
1350 gen_tree(&mut cw, &mut cl, &mut nc, &mut stats, 7);
1353 for &idx in LEN_RECODE.iter().rev() {
1363 self.write((nc - 4) as u16, 4);
1364 for &idx in LEN_RECODE.iter().take(nc) {
1365 self.write(u16::from(cl[idx]), 3);
1367 for &(sym, add) in toks.iter() {
1368 self.write(cw[sym as usize], cl[sym as usize]);
1370 16 => self.write(u16::from(add), 2),
1371 17 => self.write(u16::from(add), 3),
1372 18 => self.write(u16::from(add), 7),
1377 fn write_tokens(&mut self, src: &[Token], codes: &CodeHuff, dists: &DistHuff) {
1378 for &tok in src.iter() {
1379 self.write(codes.codes[tok.sym as usize], codes.lens[tok.sym as usize]);
1381 self.write_len_bits(tok.len);
1382 self.write(dists.codes[tok.distsym as usize], dists.lens[tok.distsym as usize]);
1383 self.write_dist_bits(tok.dist);
1387 fn write_len_bits(&mut self, len: u16) {
1389 if llen >= 8 && llen < 255 {
1390 let bits = (16 - llen.leading_zeros() - 3) as u8;
1391 self.write(llen & ((1 << bits) - 1), bits);
1394 fn write_dist_bits(&mut self, dist: u16) {
1395 let ddist = dist - 1;
1397 let bits = (16 - ddist.leading_zeros() - 2) as u8;
1398 self.write(ddist & ((1 << bits) - 1), bits);
1405 stats: [u32; NUM_LITERALS],
1406 codes: [u16; NUM_LITERALS],
1407 lens: [u8; NUM_LITERALS],
1412 fn new(is_fixed: bool) -> Self {
1415 stats: [0; NUM_LITERALS],
1416 codes: [0; NUM_LITERALS],
1417 lens: [0; NUM_LITERALS],
1418 num_codes: NUM_LITERALS,
1421 fn make_codes(&mut self, src: &[Token]) {
1424 self.codes[i] = reverse_bits((i + 0x30) as u32, 8) as u16;
1427 for i in 144..=255 {
1428 self.codes[i] = reverse_bits((i + 0x100) as u32, 9) as u16;
1431 for i in 256..=279 {
1432 self.codes[i] = reverse_bits((i & 0x1F) as u32, 7) as u16;
1435 for i in 280..NUM_LITERALS {
1436 self.codes[i] = reverse_bits((i - 280 + 0xC0) as u32, 8) as u16;
1440 for &tok in src.iter() {
1441 self.stats[tok.sym as usize] += 1;
1443 gen_tree(&mut self.codes, &mut self.lens, &mut self.num_codes, &mut self.stats, 15);
1444 if self.num_codes < 257 {
1445 self.num_codes = 257;
1453 stats: [u32; NUM_DISTS],
1454 codes: [u16; NUM_DISTS],
1455 lens: [u8; NUM_DISTS],
1460 fn new(is_fixed: bool) -> Self {
1463 stats: [0; NUM_DISTS],
1464 codes: [0; NUM_DISTS],
1465 lens: [0; NUM_DISTS],
1466 num_codes: NUM_DISTS,
1469 fn make_codes(&mut self, src: &[Token]) {
1471 for i in 0..NUM_DISTS {
1472 self.codes[i] = reverse_bits(i as u32, 5) as u16;
1476 for &tok in src.iter() {
1478 self.stats[tok.distsym as usize] += 1;
1481 gen_tree(&mut self.codes, &mut self.lens, &mut self.num_codes, &mut self.stats, 15);
1482 if self.num_codes < 1 {
1489 #[derive(Clone,Copy,Default)]
1497 const NODE_SYM: u16 = 65500;
1500 nodes: [Node; NUM_LITERALS * 2],
1507 nodes: [Node::default(); NUM_LITERALS * 2],
1511 fn insert(&mut self, val: Node) {
1512 let mut idx = self.nnodes;
1513 for (i, nn) in self.nodes[..self.nnodes].iter().enumerate() {
1519 if idx < self.nnodes {
1520 for i in (idx..self.nnodes).rev() {
1521 self.nodes[i + 1] = self.nodes[i];
1524 self.nodes[idx] = val;
1527 fn trim(&mut self) {
1528 let mut start = self.nnodes;
1529 for (i, n) in self.nodes[..self.nnodes].iter().enumerate() {
1536 for i in 0..self.nnodes - start {
1537 self.nodes[i] = self.nodes[i + start];
1539 self.nnodes -= start;
1542 fn build(&mut self) {
1543 if self.nnodes == 1 {
1544 self.nodes[0].w = 1;
1548 while start + 1 < self.nnodes {
1549 let nn1 = self.nodes[start];
1550 let nn2 = self.nodes[start + 1];
1555 idx1: (start + 1) as u16,
1557 self.nodes[start].w = 0;
1558 self.nodes[start + 1].w = 0;
1562 if self.nnodes > 1 {
1563 self.assign_len(self.nnodes - 1, 0);
1566 fn assign_len(&mut self, idx: usize, len: u16) {
1567 if self.nodes[idx].sym == NODE_SYM {
1568 self.assign_len(self.nodes[idx].idx0 as usize, len + 1);
1569 self.assign_len(self.nodes[idx].idx1 as usize, len + 1);
1571 self.nodes[idx].w = len;
1576 fn gen_tree(codes: &mut [u16], lens: &mut [u8], num_codes: &mut usize, stats: &mut [u32], max_bits: u8) {
1578 for &w in stats.iter() {
1587 while tot_w > (1 << max_bits) {
1588 for w in stats.iter_mut() {
1592 for &w in stats.iter() {
1596 let mut tree = Tree::new();
1597 for (sym, &w) in stats.iter().enumerate() {
1598 tree.insert(Node{ sym: sym as u16, w: w as u16, idx0: 64000, idx1: 64000 });
1603 for n in tree.nodes[..tree.nnodes].iter() {
1604 if n.sym != NODE_SYM {
1605 lens[n.sym as usize] = n.w as u8;
1608 lengths_to_codes16(lens, codes);
1609 let mut sz = codes.len();
1610 for &len in lens.iter().rev() {
1619 fn lengths_to_codes16(lens: &[u8], codes: &mut [u16]) {
1620 let mut bits = [0u32; 32];
1621 let mut pfx = [0u32; 33];
1622 for len in lens.iter() {
1623 let len = *len as usize;
1628 for i in 0..bits.len() {
1629 code = (code + bits[i]) << 1;
1633 for (len, codes) in lens.iter().zip(codes.iter_mut()) {
1634 let len = *len as usize;
1636 let bits = len as u8;
1637 *codes = reverse_bits(pfx[len], bits) as u16;
1646 fn parse(&mut self, src: &[u8], dst: &mut Vec<Token>);
1650 impl LZParse for NoParser {
1651 fn parse(&mut self, src: &[u8], dst: &mut Vec<Token>) {
1652 dst.reserve(src.len());
1653 for &b in src.iter() {
1654 dst.push(Token::from_literal(b));
1656 dst.push(TOKEN_EOB);
1660 fn check_match(src1: &[u8], src2: &[u8]) -> u16 {
1662 for (&a, &b) in src1.iter().zip(src2.iter()) {
1671 const HASH_SIZE: usize = 4096;
1672 const MAX_MATCH_LEN: usize = 258;
1673 const WINDOW_SIZE: usize = 32768 - MAX_MATCH_LEN;
1674 const NONEXT: usize = WINDOW_SIZE * 2;
1676 struct MatchFinder<'a> {
1679 hstart: [usize; HASH_SIZE],
1680 hend: [usize; HASH_SIZE],
1681 hnext: [usize; WINDOW_SIZE * 3],
1684 impl<'a> MatchFinder<'a> {
1685 fn new(src: &'a [u8]) -> Self {
1686 let mut obj = Self {
1689 hstart: [0; HASH_SIZE],
1690 hend: [0; HASH_SIZE],
1691 hnext: [0; WINDOW_SIZE * 3],
1696 fn hash(src: &[u8]) -> usize {
1698 (((u16::from(src[0]) << 10) ^ (u16::from(src[1]) << 5) ^ u16::from(src[2])) & ((HASH_SIZE as u16) - 1)) as usize
1700 fn build_hash(&mut self) {
1701 for el in self.hstart.iter_mut() { *el = NONEXT; }
1702 for el in self.hend.iter_mut() { *el = NONEXT; }
1703 for el in self.hnext.iter_mut() { *el = NONEXT; }
1704 if self.pos + 3 >= self.src.len() {
1707 let end = (self.src.len() - 3).min(self.pos + NONEXT);
1708 for i in (self.pos .. end).rev() {
1709 let key = Self::hash(&self.src[i..]);
1710 if self.hstart[key] == NONEXT {
1711 self.hstart[key] = i;
1713 self.hnext[key] = NONEXT;
1715 self.hnext[self.hend[key]] = i;
1720 fn find_match(&mut self) -> (u16, u16) {
1721 if self.pos == 0 || self.pos + 3 > self.src.len() {
1724 let key = Self::hash(&self.src[self.pos..]) as usize;
1726 let mut best_pos = 0;
1727 let mut best_len = 0;
1728 let mut idx = self.hstart[key];
1729 while idx != NONEXT && idx + WINDOW_SIZE > self.pos {
1731 let cur_len = check_match(&self.src[self.pos..], &self.src[idx..]);
1732 if cur_len > best_len {
1734 best_pos = self.pos - idx;
1735 if best_len >= (MAX_MATCH_LEN as u16) {
1736 return (best_pos as u16, MAX_MATCH_LEN as u16);
1740 idx = self.hnext[idx];
1742 (best_pos as u16, best_len)
1744 fn find_all_matches(&mut self, dists: &mut [u16; MAX_MATCH_LEN + 1]) {
1745 if self.pos == 0 || self.pos + 3 > self.src.len() {
1748 let key = Self::hash(&self.src[self.pos..]) as usize;
1749 let mut idx = self.hstart[key];
1750 while idx != NONEXT && idx + WINDOW_SIZE > self.pos {
1752 let cur_len = (check_match(&self.src[self.pos..], &self.src[idx..]) as usize).min(MAX_MATCH_LEN);
1753 if cur_len > 0 && dists[cur_len] == 0 {
1754 dists[cur_len] = (self.pos - idx) as u16;
1757 idx = self.hnext[idx];
1760 fn advance(&mut self, num: usize) {
1763 if self.pos >= NONEXT {
1764 let (_, tail) = self.src.split_at(self.pos - WINDOW_SIZE);
1766 self.pos = WINDOW_SIZE;
1769 for (start, end) in self.hstart.iter_mut().zip(self.hend.iter_mut()) {
1770 let mut idx = *start;
1771 while idx != NONEXT && idx + WINDOW_SIZE < self.pos {
1772 idx = self.hnext[idx];
1781 fn get_sym(&self) -> u8 { self.src[self.pos] }
1782 fn is_end(&self) -> bool { self.pos >= self.src.len() }
1785 struct GreedyParser {}
1786 impl LZParse for GreedyParser {
1787 fn parse(&mut self, src: &[u8], dst: &mut Vec<Token>) {
1788 dst.reserve(src.len());
1790 let mut matcher = MatchFinder::new(src);
1791 while !matcher.is_end() {
1792 let (best_pos, best_len) = matcher.find_match();
1795 dst.push(Token::from_match(best_pos, best_len));
1796 matcher.advance(best_len as usize);
1798 dst.push(Token::from_literal(matcher.get_sym()));
1802 dst.push(TOKEN_EOB);
1806 struct LazyParser {}
1807 impl LZParse for LazyParser {
1808 fn parse(&mut self, src: &[u8], dst: &mut Vec<Token>) {
1809 dst.reserve(src.len());
1811 let mut matcher = MatchFinder::new(src);
1812 while !matcher.is_end() {
1813 let (best_pos, best_len) = matcher.find_match();
1815 let last_sym = matcher.get_sym();
1817 if !matcher.is_end() {
1818 let (best_pos1, best_len1) = matcher.find_match();
1819 if best_len1 > best_len + 1 {
1820 dst.push(Token::from_literal(last_sym));
1821 dst.push(Token::from_match(best_pos1, best_len1));
1822 matcher.advance(best_len1 as usize);
1826 dst.push(Token::from_match(best_pos, best_len));
1827 matcher.advance((best_len - 1) as usize);
1829 dst.push(Token::from_literal(matcher.get_sym()));
1833 dst.push(TOKEN_EOB);
1837 #[derive(Clone,Copy)]
1844 impl Default for TNode {
1845 fn default() -> Self {
1847 price: std::u32::MAX,
1854 struct OptimalParser {
1855 trellis: Vec<TNode>,
1857 impl OptimalParser {
1858 fn new() -> Self { Self::default() }
1859 fn sym_price(_sym: u8) -> u32 { 9 }
1860 fn match_price(dist: u16, _len: u16) -> u32 {
1864 let bits = 16 - (dist - 1).leading_zeros();
1869 impl Default for OptimalParser {
1870 fn default() -> Self {
1872 trellis: Vec::with_capacity(WINDOW_SIZE),
1876 impl LZParse for OptimalParser {
1877 fn parse(&mut self, src: &[u8], dst: &mut Vec<Token>) {
1879 dst.push(TOKEN_EOB);
1882 dst.reserve(src.len());
1884 self.trellis.clear();
1885 self.trellis.reserve(src.len() + 1);
1886 for _ in 0..=src.len() {
1887 self.trellis.push(TNode::default());
1889 self.trellis[0].price = 0;
1891 let mut matcher = MatchFinder::new(src);
1892 for i in 0..self.trellis.len() - 1 {
1893 let mut dists = [0; MAX_MATCH_LEN + 1];
1894 matcher.find_all_matches(&mut dists);
1896 let sym = matcher.get_sym();
1897 let lprice = Self::sym_price(sym) + self.trellis[i].price;
1898 if self.trellis[i + 1].price > lprice {
1899 self.trellis[i + 1].price = lprice;
1900 self.trellis[i + 1].link = i;
1902 for (len, &dist) in dists.iter().enumerate() {
1904 let mprice = Self::match_price(dist, len as u16) + self.trellis[i].price;
1905 if self.trellis[i + len].price > mprice {
1906 self.trellis[i + len].price = mprice;
1907 self.trellis[i + len].link = i;
1908 self.trellis[i].dist = dist;
1915 let mut idx = self.trellis.len() - 1;
1916 let mut nidx = self.trellis[idx].link;
1920 nidx = self.trellis[idx].link;
1921 self.trellis[idx].link = oidx;
1925 while idx < self.trellis.len() - 1 {
1926 let len = self.trellis[idx].link - idx;
1928 dst.push(Token::from_literal(src[idx]));
1930 dst.push(Token::from_match(self.trellis[idx].dist, len as u16));
1932 idx = self.trellis[idx].link;
1935 dst.push(TOKEN_EOB);
1939 ///! Deflate compression mode.
1940 #[derive(Clone,Copy,Debug,PartialEq)]
1941 pub enum DeflateMode {
1942 ///! No compression.
1944 ///! Fast compression.
1946 ///! Still fast but better compression.
1948 ///! Slow but the best compression.
1952 impl Default for DeflateMode {
1953 fn default() -> Self { DeflateMode::Better }
1956 pub const DEFLATE_MODE_DESCRIPTION: &str = "Deflate compression level.";
1957 ///! Deflate option for no compression.
1958 pub const DEFLATE_MODE_NONE: &str = "none";
1959 ///! Deflate option for fast compression.
1960 pub const DEFLATE_MODE_FAST: &str = "fast";
1961 ///! Deflate option for better compression.
1962 pub const DEFLATE_MODE_BETTER: &str = "better";
1963 ///! Deflate option for best compression.
1964 pub const DEFLATE_MODE_BEST: &str = "best";
1966 ///! All possible option values for deflate compression.
1967 pub const DEFLATE_OPTION_VALUES: NAOptionDefinitionType = NAOptionDefinitionType::String(Some(&[DEFLATE_MODE_NONE, DEFLATE_MODE_FAST, DEFLATE_MODE_BETTER, DEFLATE_MODE_BEST]));
1969 impl std::str::FromStr for DeflateMode {
1972 fn from_str(s: &str) -> Result<Self, Self::Err> {
1974 DEFLATE_MODE_NONE => Ok(DeflateMode::NoCompr),
1975 DEFLATE_MODE_FAST => Ok(DeflateMode::Fast),
1976 DEFLATE_MODE_BETTER => Ok(DeflateMode::Better),
1977 DEFLATE_MODE_BEST => Ok(DeflateMode::Best),
1983 impl ToString for DeflateMode {
1984 fn to_string(&self) -> String {
1986 DeflateMode::NoCompr => DEFLATE_MODE_NONE.to_string(),
1987 DeflateMode::Fast => DEFLATE_MODE_FAST.to_string(),
1988 DeflateMode::Better => DEFLATE_MODE_BETTER.to_string(),
1989 DeflateMode::Best => DEFLATE_MODE_BEST.to_string(),
1994 #[derive(Clone,Copy,Debug,PartialEq)]
2001 const MAX_BLOCK_SIZE: usize = 65535;
2003 ///! Deflate stream compressor.
2004 pub struct Deflate {
2007 srcbuf: [u8; MAX_BLOCK_SIZE],
2012 parser: Box<dyn LZParse + Send>,
2016 ///! Creates a new instance of `Deflate`.
2017 pub fn new(mode: DeflateMode) -> Self {
2018 let (mode, parser) = match mode {
2019 DeflateMode::NoCompr => (Mode::Copy, Box::new(NoParser{}) as Box<dyn LZParse + Send>),
2020 DeflateMode::Fast => (Mode::Fixed, Box::new(GreedyParser{}) as Box<dyn LZParse + Send>),
2021 DeflateMode::Better => (Mode::Dynamic, Box::new(LazyParser{}) as Box<dyn LZParse + Send>),
2022 DeflateMode::Best => (Mode::Dynamic, Box::new(OptimalParser::new()) as Box<dyn LZParse + Send>),
2026 tokens: Vec::with_capacity(MAX_BLOCK_SIZE),
2027 srcbuf: [0; MAX_BLOCK_SIZE],
2034 ///! Writes zlib stream header.
2035 pub fn write_zlib_header(&mut self, wr: &mut DeflateWriter) {
2038 let level = match self.mode {
2040 Mode::Fixed => 0x5E,
2041 Mode::Dynamic => 0x9C,
2042 // 0xDA for the strongest one
2045 self.zlib_mode = true;
2047 fn write_zlib_footer(&self, wr: &mut DeflateWriter) {
2049 wr.write((self.sum2 >> 8) as u16, 8);
2050 wr.write((self.sum2 & 0xFF) as u16, 8);
2051 wr.write((self.sum1 >> 8) as u16, 8);
2052 wr.write((self.sum1 & 0xFF) as u16, 8);
2054 ///! Queues data for compression.
2056 ///! The data might be not actually compressed until [`compress_end`] is called.
2058 ///! [`compress_end`]: ./struct.Deflate.html#method.compress_end
2059 pub fn compress(&mut self, src: &[u8], wr: &mut DeflateWriter) {
2061 while !src.is_empty() {
2062 let clen = src.len().min(MAX_BLOCK_SIZE - self.ssize);
2063 let (head, tail) = src.split_at(clen);
2065 self.srcbuf[self.ssize..][..clen].copy_from_slice(head);
2067 if self.ssize == MAX_BLOCK_SIZE {
2068 self.do_block(wr, false);
2072 ///! Tells the encoder to finish data compression.
2074 ///! Complete data will be output after this call.
2075 pub fn compress_end(&mut self, wr: &mut DeflateWriter) {
2077 self.do_block(wr, true);
2081 wr.write(0, 7); //static EOF sym
2084 self.write_zlib_footer(wr);
2087 ///! Tells the encoder to compress the data it received and flush it.
2088 pub fn compress_flush(&mut self, wr: &mut DeflateWriter) {
2090 self.do_block(wr, false);
2092 if (wr.bits & 7) != 0 {
2093 // write zero-length copy block for byte-alignment
2098 wr.write(0xFFFF, 16);
2101 fn do_block(&mut self, wr: &mut DeflateWriter, final_block: bool) {
2102 const CRC_BASE: u32 = 65521;
2103 for &b in self.srcbuf[..self.ssize].iter() {
2104 self.sum1 += u32::from(b);
2105 if self.sum1 >= CRC_BASE {
2106 self.sum1 -= CRC_BASE;
2108 self.sum2 += self.sum1;
2109 if self.sum2 >= CRC_BASE {
2110 self.sum2 -= CRC_BASE;
2115 wr.write(final_block as u16, 1);
2118 wr.write(self.ssize as u16, 16);
2119 wr.write(!self.ssize as u16, 16);
2120 for &b in self.srcbuf[..self.ssize].iter() {
2121 wr.write(u16::from(b), 8);
2125 wr.write(final_block as u16, 1);
2127 self.tokens.clear();
2128 self.parser.parse(&self.srcbuf[..self.ssize], &mut self.tokens);
2129 let mut codes = CodeHuff::new(true);
2130 codes.make_codes(&self.tokens);
2131 let mut dists = DistHuff::new(true);
2132 dists.make_codes(&self.tokens);
2133 wr.write_tokens(&self.tokens, &codes, &dists);
2136 wr.write(final_block as u16, 1);
2138 self.tokens.clear();
2139 self.parser.parse(&self.srcbuf[..self.ssize], &mut self.tokens);
2140 let mut codes = CodeHuff::new(false);
2141 codes.make_codes(&self.tokens);
2142 let mut dists = DistHuff::new(false);
2143 dists.make_codes(&self.tokens);
2144 wr.write((codes.num_codes - 257) as u16, 5);
2145 wr.write((dists.num_codes - 1) as u16, 5);
2146 wr.write_codes(&codes, &dists);
2147 wr.write_tokens(&self.tokens, &codes, &dists);
2159 fn test_inflate1() {
2160 const TEST_DATA: &[u8] = &[
2161 0xF3, 0x48, 0xCD, 0xC9, 0xC9, 0xD7, 0x51, 0x28,
2162 0xCF, 0x2F, 0xCA, 0x49, 0x51, 0x04, 0x00 ];
2163 const TEST_REF: &[u8] = b"Hello, world!";
2164 let mut dst_buf = [0u8; 13];
2165 let len = Inflate::uncompress(TEST_DATA, &mut dst_buf).unwrap();
2166 assert_eq!(len, 13);
2168 assert_eq!(dst_buf[i], TEST_REF[i]);
2172 fn test_inflate2() {
2173 const TEST_DATA3: &[u8] = &[ 0x4B, 0x4C, 0x44, 0x80, 0x24, 0x54, 0x80, 0x2C, 0x06, 0x00 ];
2174 const TEST_REF3: &[u8] = b"aaaaaaaaaaaabbbbbbbbbbbbbbbaaaaabbbbbbb";
2175 let mut dst_buf = [0u8; 39];
2177 let mut inflate = Inflate::new();
2178 let mut output_chunk = [0u8; 7];
2179 let mut output_pos = 0;
2180 for input in TEST_DATA3.chunks(3) {
2181 let mut repeat = false;
2183 let ret = inflate.decompress_data(input, &mut output_chunk, repeat);
2187 dst_buf[output_pos + i] = output_chunk[i];
2192 Err(DecompressError::ShortData) => {
2195 Err(DecompressError::OutputFull) => {
2197 for i in 0..output_chunk.len() {
2198 dst_buf[output_pos + i] = output_chunk[i];
2200 output_pos += output_chunk.len();
2203 panic!("decompress error {:?}", ret.err().unwrap());
2209 assert_eq!(output_pos, dst_buf.len());
2210 for i in 0..output_pos {
2211 assert_eq!(dst_buf[i], TEST_REF3[i]);
2215 fn test_inflate3() {
2216 const TEST_DATA: &[u8] = &[
2217 0x1F, 0x8B, 0x08, 0x08, 0xF6, 0x7B, 0x90, 0x5E, 0x02, 0x03, 0x31, 0x2E, 0x74, 0x78, 0x74, 0x00,
2218 0xE5, 0x95, 0x4B, 0x4E, 0xC3, 0x30, 0x10, 0x40, 0xF7, 0x39, 0xC5, 0x1C, 0x00, 0x16, 0x70, 0x83,
2219 0x0A, 0xB5, 0x3B, 0xE8, 0x82, 0x5E, 0x60, 0x1A, 0x4F, 0xE2, 0x11, 0xFE, 0x44, 0x1E, 0xA7, 0x69,
2220 0x6E, 0xCF, 0x38, 0xDD, 0xB0, 0x40, 0xA2, 0x46, 0x2D, 0x20, 0x2A, 0xE5, 0xAB, 0xCC, 0xE7, 0xBD,
2221 0x49, 0xAC, 0x6C, 0x03, 0x64, 0x4B, 0xD0, 0x71, 0x92, 0x0C, 0x06, 0x67, 0x88, 0x1D, 0x3C, 0xD9,
2222 0xC4, 0x92, 0x3D, 0x4A, 0xF3, 0x3C, 0x43, 0x4E, 0x23, 0x81, 0x8B, 0x07, 0x82, 0x1E, 0xF5, 0x90,
2223 0x23, 0x78, 0x6A, 0x56, 0x30, 0x60, 0xCA, 0x89, 0x4D, 0x4F, 0xC0, 0x01, 0x10, 0x06, 0xC2, 0xA4,
2224 0xA1, 0x44, 0xCD, 0xF6, 0x54, 0x50, 0xA8, 0x8D, 0xC1, 0x9C, 0x5F, 0x71, 0x37, 0x45, 0xC8, 0x63,
2225 0xCA, 0x8E, 0xC0, 0xE8, 0x23, 0x69, 0x56, 0x9A, 0x8D, 0x5F, 0xB6, 0xC9, 0x96, 0x53, 0x4D, 0x17,
2226 0xAB, 0xB9, 0xB0, 0x49, 0x14, 0x5A, 0x0B, 0x96, 0x82, 0x7C, 0xB7, 0x6F, 0x17, 0x35, 0xC7, 0x9E,
2227 0xDF, 0x78, 0xA3, 0xF1, 0xD0, 0xA2, 0x73, 0x1C, 0x7A, 0xD8, 0x2B, 0xB3, 0x5C, 0x90, 0x85, 0xBB,
2228 0x2A, 0x14, 0x2E, 0xF7, 0xD1, 0x19, 0x48, 0x0A, 0x23, 0x57, 0x45, 0x13, 0x3E, 0xD6, 0xA0, 0xBD,
2229 0xF2, 0x11, 0x7A, 0x22, 0x21, 0xAD, 0xE5, 0x70, 0x56, 0xA0, 0x9F, 0xA5, 0xA5, 0x03, 0x85, 0x2A,
2230 0xDE, 0x92, 0x00, 0x32, 0x61, 0x10, 0xAD, 0x27, 0x13, 0x7B, 0x5F, 0x98, 0x7F, 0x59, 0x83, 0xB8,
2231 0xB7, 0x35, 0x16, 0xEB, 0x12, 0x0F, 0x1E, 0xD9, 0x14, 0x0B, 0xCF, 0xEE, 0x6D, 0x91, 0xF8, 0x93,
2232 0x6E, 0x81, 0x3F, 0x7F, 0x41, 0xA4, 0x22, 0x1F, 0xB7, 0xE6, 0x85, 0x83, 0x9A, 0xA2, 0x61, 0x12,
2233 0x0D, 0x0F, 0x6D, 0x01, 0xBD, 0xB0, 0xE8, 0x1D, 0xEC, 0xD1, 0xA0, 0xBF, 0x1F, 0x4E, 0xFB, 0x55,
2234 0xBD, 0x73, 0xDD, 0x87, 0xB9, 0x53, 0x23, 0x17, 0xD3, 0xE2, 0xE9, 0x08, 0x87, 0x42, 0xFF, 0xCF,
2235 0x26, 0x42, 0xAE, 0x76, 0xB5, 0xAE, 0x97, 0x0C, 0x18, 0x78, 0xA0, 0x24, 0xE5, 0x54, 0x0C, 0x6E,
2236 0x60, 0x52, 0x79, 0x22, 0x57, 0xF5, 0x87, 0x78, 0x78, 0x04, 0x93, 0x46, 0xEF, 0xCB, 0x98, 0x96,
2237 0x8B, 0x65, 0x00, 0xB7, 0x36, 0xBD, 0x77, 0xA8, 0xBD, 0x5A, 0xAA, 0x1A, 0x09, 0x00, 0x00
2240 let mut mr = MemoryReader::new_read(TEST_DATA);
2241 let mut br = ByteReader::new(&mut mr);
2242 let _dst_buf = gzip_decode(&mut br, false).unwrap();
2244 // println!("{}", String::from_utf8_lossy(_dst_buf.as_slice()));
2247 fn test_deflate_crc() {
2248 let output = Vec::with_capacity(20);
2249 let mut writer = DeflateWriter::new(output);
2250 let mut compr = Deflate::new(DeflateMode::NoCompr);
2251 compr.write_zlib_header(&mut writer);
2252 compr.compress(b"Hello, world!", &mut writer);
2253 compr.compress_end(&mut writer);
2254 let output = writer.end();
2255 assert_eq!(output.as_slice(), b"\x78\x01\x01\x0D\x00\xF2\xFFHello, world!\x20\x5E\x04\x8A");
2257 fn deflate_test(mode: DeflateMode) {
2259 b"The first day of Christmas,
2260 My true love sent to me
2261 A partridge in a pear tree.
2263 The second day of Christmas,
2264 My true love sent to me
2265 Two turtle doves, and
2266 A partridge in a pear tree.
2268 The third day of Christmas,
2269 My true love sent to me
2271 Two turtle doves, and
2272 A partridge in a pear tree.
2274 The fourth day of Christmas,
2275 My true love sent to me
2278 Two turtle doves, and
2279 A partridge in a pear tree.
2281 The fifth day of Christmas,
2282 My true love sent to me
2286 Two turtle doves, and
2287 A partridge in a pear tree.";
2288 let output = Vec::with_capacity(SRC.len() + 16);
2289 let mut writer = DeflateWriter::new(output);
2290 let mut compr = Deflate::new(mode);
2291 compr.write_zlib_header(&mut writer);
2292 compr.compress(SRC, &mut writer);
2293 compr.compress_end(&mut writer);
2294 let output = writer.end();
2295 let mut uncompr = vec![0u8; SRC.len()];
2296 Inflate::uncompress(&output, &mut uncompr).unwrap();
2297 assert_eq!(SRC, uncompr.as_slice());
2300 fn test_deflate_fast() {
2301 deflate_test(DeflateMode::Fast);
2304 fn test_deflate_better() {
2305 deflate_test(DeflateMode::Better);
2308 fn test_deflate_best() {
2309 deflate_test(DeflateMode::Best);