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1 | //! Deflate format (RFC 1951) support. | |
2 | //! | |
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`]. | |
4 | //! | |
5 | //! [`Deflate`]: ./struct.Deflate.html | |
6 | //! [`Inflate`]: ./struct.Inflate.html | |
7 | //! [`gzip_decode`]: ./fn.gzip_decode.html | |
8 | //! | |
9 | //! # Examples | |
10 | //! | |
11 | //! Decompressing full input buffer into sufficiently large output buffer: | |
12 | //! ``` | |
13 | //! # use nihav_core::compr::DecompressError; | |
14 | //! use nihav_core::compr::deflate::Inflate; | |
15 | //! | |
16 | //! # fn decompress(input: &[u8]) -> Result<(), DecompressError> { | |
17 | //! # let mut output_buffer = [0u8; 16]; | |
18 | //! let output_length = Inflate::uncompress(input, &mut output_buffer)?; | |
19 | //! # Ok(()) | |
20 | //! # } | |
21 | //! ``` | |
22 | //! | |
23 | //! Decompressing input chunks into portions of output: | |
24 | //! ``` | |
25 | //! use nihav_core::compr::DecompressError; | |
26 | //! use nihav_core::compr::deflate::Inflate; | |
27 | //! | |
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; | |
34 | //! loop { | |
35 | //! let ret = inflate.decompress_data(src, &mut output_chunk, repeat); | |
36 | //! match ret { | |
37 | //! Ok(len) => { // we got a buffer decoded successfully to the end | |
38 | //! dst_buf.extend_from_slice(&output_chunk[..len]); | |
39 | //! break; | |
40 | //! }, | |
41 | //! Err(DecompressError::ShortData) => { // this block of data was fully read | |
42 | //! break; | |
43 | //! }, | |
44 | //! Err(DecompressError::OutputFull) => { | |
45 | //! // the output buffer is full, flush it and continue decoding the same block | |
46 | //! repeat = true; | |
47 | //! dst_buf.extend_from_slice(&output_chunk); | |
48 | //! }, | |
49 | //! Err(err) => { | |
50 | //! return Err(err); | |
51 | //! }, | |
52 | //! } | |
53 | //! } | |
54 | //! } | |
55 | //! # Ok(()) | |
56 | //! # } | |
57 | //! ``` | |
58 | //! | |
59 | //! Compressing input buffer into zlib stream: | |
60 | //! ``` | |
61 | //! use nihav_core::compr::deflate::{Deflate, DeflateMode, DeflateWriter}; | |
62 | //! | |
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(); | |
71 | //! # } | |
72 | //! ``` | |
73 | ||
74 | use crate::options::NAOptionDefinitionType; | |
75 | use crate::io::byteio::*; | |
76 | use crate::io::bitreader::*; | |
77 | use crate::io::codebook::*; | |
78 | use super::*; | |
79 | ||
80 | const NUM_LITERALS: usize = 287; | |
81 | const NUM_DISTS: usize = 32; | |
82 | ||
83 | struct FixedLenCodeReader {} | |
84 | ||
85 | impl CodebookDescReader<u16> for FixedLenCodeReader { | |
86 | fn bits(&mut self, idx: usize) -> u8 { | |
87 | if idx < 144 { 8 } | |
88 | else if idx < 256 { 9 } | |
89 | else if idx < 280 { 7 } | |
90 | else { 8 } | |
91 | } | |
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) } | |
100 | } | |
101 | fn sym (&mut self, idx: usize) -> u16 { idx as u16 } | |
102 | fn len(&mut self) -> usize { NUM_LITERALS + 1 } | |
103 | } | |
104 | ||
105 | #[derive(Clone,Copy,Default)] | |
106 | struct BitReaderState { | |
107 | pos: usize, | |
108 | bitbuf: u32, | |
109 | bits: u8, | |
110 | } | |
111 | ||
112 | struct CurrentSource<'a> { | |
113 | src: &'a [u8], | |
114 | br: BitReaderState, | |
115 | } | |
116 | ||
117 | impl<'a> CurrentSource<'a> { | |
118 | fn new(src: &'a [u8], br: BitReaderState) -> Self { | |
119 | let mut newsrc = Self { src, br }; | |
120 | newsrc.br.pos = 0; | |
121 | newsrc.refill(); | |
122 | newsrc | |
123 | } | |
124 | fn reinit(src: &'a [u8], br: BitReaderState) -> Self { | |
125 | let mut newsrc = Self { src, br }; | |
126 | newsrc.refill(); | |
127 | newsrc | |
128 | } | |
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; | |
132 | self.br.bits += 8; | |
133 | self.br.pos += 1; | |
134 | } | |
135 | } | |
136 | fn skip_cache(&mut self, nbits: u8) { | |
137 | self.br.bitbuf >>= nbits; | |
138 | self.br.bits -= nbits; | |
139 | } | |
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 { | |
144 | self.refill(); | |
145 | if self.br.bits < nbits { return Err(BitReaderError::BitstreamEnd); } | |
146 | } | |
147 | let ret = self.br.bitbuf & ((1 << nbits) - 1); | |
148 | self.skip_cache(nbits); | |
149 | Ok(ret) | |
150 | } | |
151 | fn read_bool(&mut self) -> BitReaderResult<bool> { | |
152 | if self.br.bits == 0 { | |
153 | self.refill(); | |
154 | if self.br.bits == 0 { return Err(BitReaderError::BitstreamEnd); } | |
155 | } | |
156 | let ret = (self.br.bitbuf & 1) != 0; | |
157 | self.skip_cache(1); | |
158 | Ok(ret) | |
159 | } | |
160 | fn peek(&mut self, nbits: u8) -> u32 { | |
161 | if nbits == 0 || nbits > 16 { return 0; } | |
162 | if self.br.bits < nbits { | |
163 | self.refill(); | |
164 | } | |
165 | self.br.bitbuf & ((1 << nbits) - 1) | |
166 | } | |
167 | fn skip(&mut self, nbits: u32) -> BitReaderResult<()> { | |
168 | if u32::from(self.br.bits) >= nbits { | |
169 | self.skip_cache(nbits as u8); | |
170 | } else { | |
171 | unreachable!(); | |
172 | } | |
173 | Ok(()) | |
174 | } | |
175 | fn align(&mut self) { | |
176 | let b = self.br.bits & 7; | |
177 | if b != 0 { | |
178 | self.skip_cache(b); | |
179 | } | |
180 | } | |
181 | fn left(&self) -> isize { | |
182 | ((self.src.len() as isize) - (self.br.pos as isize)) * 8 + (self.br.bits as isize) | |
183 | } | |
184 | } | |
185 | ||
186 | impl<'a, S: Copy> CodebookReader<S> for CurrentSource<'a> { | |
187 | fn read_cb(&mut self, cb: &Codebook<S>) -> CodebookResult<S> { | |
188 | let mut esc = true; | |
189 | let mut idx = 0; | |
190 | let mut lut_bits = cb.lut_bits; | |
191 | let orig_br = self.br; | |
192 | while esc { | |
193 | let lut_idx = (self.peek(lut_bits) as usize) + (idx as usize); | |
194 | if cb.table[lut_idx] == TABLE_FILL_VALUE { return Err(CodebookError::InvalidCode); } | |
195 | let bits = cb.table[lut_idx] & 0x7F; | |
196 | esc = (cb.table[lut_idx] & 0x80) != 0; | |
197 | idx = (cb.table[lut_idx] >> 8) as usize; | |
198 | let skip_bits = if esc { u32::from(lut_bits) } else { bits }; | |
199 | if (skip_bits as isize) > self.left() { | |
200 | self.br = orig_br; | |
201 | self.refill(); | |
202 | return Err(CodebookError::MemoryError); | |
203 | } | |
204 | self.skip(skip_bits as u32).unwrap(); | |
205 | lut_bits = bits as u8; | |
206 | } | |
207 | Ok(cb.syms[idx]) | |
208 | } | |
209 | } | |
210 | ||
211 | enum InflateState { | |
212 | Start, | |
213 | BlockStart, | |
214 | BlockMode, | |
215 | StaticBlockLen, | |
216 | StaticBlockInvLen(u32), | |
217 | StaticBlockCopy(usize), | |
218 | FixedBlock, | |
219 | FixedBlockLengthExt(usize, u8), | |
220 | FixedBlockDist(usize), | |
221 | FixedBlockDistExt(usize, usize, u8), | |
222 | FixedBlockCopy(usize, usize), | |
223 | FixedBlockLiteral(u8), | |
224 | DynBlockHlit, | |
225 | DynBlockHdist, | |
226 | DynBlockHclen, | |
227 | DynLengths(usize), | |
228 | DynCodeLengths, | |
229 | DynCodeLengthsAdd(usize), | |
230 | DynBlock, | |
231 | DynBlockLengthExt(usize, u8), | |
232 | DynBlockDist(usize), | |
233 | DynBlockDistExt(usize, usize, u8), | |
234 | DynCopy(usize, usize), | |
235 | DynBlockLiteral(u8), | |
236 | End, | |
237 | } | |
238 | ||
239 | ///! The decompressor for deflated streams (RFC 1951). | |
240 | pub struct Inflate { | |
241 | br: BitReaderState, | |
242 | fix_len_cb: Codebook<u16>, | |
243 | ||
244 | buf: [u8; 65536], | |
245 | bpos: usize, | |
246 | output_idx: usize, | |
247 | full_pos: usize, | |
248 | ||
249 | state: InflateState, | |
250 | final_block: bool, | |
251 | hlit: usize, | |
252 | hdist: usize, | |
253 | dyn_len_cb: Option<Codebook<u32>>, | |
254 | dyn_lit_cb: Option<Codebook<u32>>, | |
255 | dyn_dist_cb: Option<Codebook<u32>>, | |
256 | len_lengths: [u8; 19], | |
257 | all_lengths: [u8; NUM_LITERALS + NUM_DISTS], | |
258 | cur_len_idx: usize, | |
259 | } | |
260 | ||
261 | const LENGTH_ADD_BITS: [u8; 29] = [ | |
262 | 0, 0, 0, 0, 0, 0, 0, 0, 1, 1, | |
263 | 1, 1, 2, 2, 2, 2, 3, 3, 3, 3, | |
264 | 4, 4, 4, 4, 5, 5, 5, 5, 0 | |
265 | ]; | |
266 | const LENGTH_BASE: [u16; 29] = [ | |
267 | 3, 4, 5, 6, 7, 8, 9, 10, 11, 13, | |
268 | 15, 17, 19, 23, 27, 31, 35, 43, 51, 59, | |
269 | 67, 83, 99, 115, 131, 163, 195, 227, 258 | |
270 | ]; | |
271 | const DIST_ADD_BITS: [u8; 30] = [ | |
272 | 0, 0, 0, 0, 1, 1, 2, 2, 3, 3, | |
273 | 4, 4, 5, 5, 6, 6, 7, 7, 8, 8, | |
274 | 9, 9, 10, 10, 11, 11, 12, 12, 13, 13 | |
275 | ]; | |
276 | const DIST_BASE: [u16; 30] = [ | |
277 | 1, 2, 3, 4, 5, 7, 9, 13, 17, 25, | |
278 | 33, 49, 65, 97, 129, 193, 257, 385, 513, 769, | |
279 | 1025, 1537, 2049, 3073, 4097, 6145, 8193, 12289, 16385, 24577 | |
280 | ]; | |
281 | const LEN_RECODE: [usize; 19] = [ | |
282 | 16, 17, 18, 0, 8, 7, 9, 6, 10, 5, 11, 4, 12, 3, 13, 2, 14, 1, 15 | |
283 | ]; | |
284 | const REPEAT_BITS: [u8; 3] = [ 2, 3, 7 ]; | |
285 | const REPEAT_BASE: [u8; 3] = [ 3, 3, 11 ]; | |
286 | ||
287 | macro_rules! read_bits { | |
288 | ($self: expr, $csrc: expr, $bits: expr) => ({ | |
289 | if $csrc.left() < $bits as isize { | |
290 | $self.br = $csrc.br; | |
291 | return Err(DecompressError::ShortData); | |
292 | } | |
293 | $csrc.read($bits).unwrap() | |
294 | }) | |
295 | } | |
296 | ||
297 | macro_rules! read_cb { | |
298 | ($self: expr, $csrc: expr, $cb: expr) => ({ | |
299 | let ret = $csrc.read_cb($cb); | |
300 | if let Err(CodebookError::MemoryError) = ret { | |
301 | $self.br = $csrc.br; | |
302 | return Err(DecompressError::ShortData); | |
303 | } | |
304 | match ret { | |
305 | Ok(val) => val, | |
306 | Err(_) => { | |
307 | $self.state = InflateState::End; | |
308 | return Err(DecompressError::InvalidData); | |
309 | }, | |
310 | } | |
311 | }) | |
312 | } | |
313 | ||
314 | impl Inflate { | |
315 | ///! Creates a new instance of `Inflate` struct. | |
316 | pub fn new() -> Self { | |
317 | let mut cr = FixedLenCodeReader {}; | |
318 | let fix_len_cb = Codebook::new(&mut cr, CodebookMode::LSB).unwrap(); | |
319 | Self { | |
320 | br: BitReaderState::default(), | |
321 | fix_len_cb, | |
322 | ||
323 | buf: [0; 65536], | |
324 | bpos: 0, | |
325 | output_idx: 0, | |
326 | full_pos: 0, | |
327 | ||
328 | state: InflateState::Start, | |
329 | final_block: false, | |
330 | dyn_len_cb: None, | |
331 | dyn_lit_cb: None, | |
332 | dyn_dist_cb: None, | |
333 | hlit: 0, | |
334 | hdist: 0, | |
335 | len_lengths: [0; 19], | |
336 | all_lengths: [0; NUM_LITERALS + NUM_DISTS], | |
337 | cur_len_idx: 0, | |
338 | } | |
339 | } | |
340 | fn put_literal(&mut self, val: u8) { | |
341 | self.buf[self.bpos] = val; | |
342 | self.bpos = (self.bpos + 1) & (self.buf.len() - 1); | |
343 | self.full_pos += 1; | |
344 | } | |
345 | fn lz_copy(&mut self, offset: usize, len: usize, dst: &mut [u8]) -> DecompressResult<()> { | |
346 | let mask = self.buf.len() - 1; | |
347 | if offset > self.full_pos { | |
348 | return Err(DecompressError::InvalidData); | |
349 | } | |
350 | let cstart = (self.bpos.wrapping_sub(offset)) & mask; | |
351 | for i in 0..len { | |
352 | self.buf[(self.bpos + i) & mask] = self.buf[(cstart + i) & mask]; | |
353 | dst[i] = self.buf[(cstart + i) & mask]; | |
354 | } | |
355 | self.bpos = (self.bpos + len) & mask; | |
356 | self.full_pos += len; | |
357 | Ok(()) | |
358 | } | |
359 | ///! Sets custom history for decoding an update for already decoded data. | |
360 | pub fn set_dict(&mut self, dict: &[u8]) { | |
361 | let len = dict.len().min(self.buf.len()); | |
362 | let start = dict.len() - len; | |
363 | self.buf[..len].copy_from_slice(&dict[start..]); | |
364 | self.bpos = len; | |
365 | self.full_pos = len; | |
366 | } | |
367 | ///! Reports whether decoder has finished decoding the input. | |
368 | pub fn is_finished(&self) -> bool { | |
369 | matches!(self.state, InflateState::End) | |
370 | } | |
371 | ///! Reports the current amount of bytes output into the destination buffer after the last run. | |
372 | pub fn get_current_output_size(&self) -> usize { self.output_idx } | |
373 | ///! Reports the total amount of bytes decoded so far. | |
374 | pub fn get_total_output_size(&self) -> usize { self.bpos } | |
375 | ///! Tries to decompress input data and write it to the output buffer. | |
376 | ///! | |
377 | ///! Since the decompressor can work with arbitrary input and output chunks its return value may have several meanings: | |
378 | ///! * `Ok(len)` means the stream has been fully decoded and then number of bytes output into the destination buffer is returned. | |
379 | ///! * [`DecompressError::ShortData`] means the input stream has been fully read but more data is needed. | |
380 | ///! * [`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`. | |
381 | ///! | |
382 | ///! [`DecompressError::ShortData`]: ../enum.DecompressError.html#variant.ShortData | |
383 | ///! [`DecompressError::OutputFull`]: ../enum.DecompressError.html#variant.OutputFull | |
384 | pub fn decompress_data(&mut self, src: &[u8], dst: &mut [u8], continue_block: bool) -> DecompressResult<usize> { | |
385 | self.decompress_data_internal(src, dst, continue_block, false) | |
386 | } | |
387 | ///! Tries to decompress whole input chunk to the output buffer. | |
388 | pub fn decompress_block(&mut self, src: &[u8], dst: &mut [u8]) -> DecompressResult<usize> { | |
389 | self.decompress_data_internal(src, dst, false, true) | |
390 | } | |
391 | #[allow(clippy::comparison_chain)] | |
392 | fn decompress_data_internal(&mut self, src: &[u8], dst: &mut [u8], continue_block: bool, do_one_block: bool) -> DecompressResult<usize> { | |
393 | if src.is_empty() || dst.is_empty() { | |
394 | return Err(DecompressError::InvalidArgument); | |
395 | } | |
396 | let mut csrc = if !continue_block { | |
397 | CurrentSource::new(src, self.br) | |
398 | } else { | |
399 | self.output_idx = 0; | |
400 | CurrentSource::reinit(src, self.br) | |
401 | }; | |
402 | if do_one_block { | |
403 | self.output_idx = 0; | |
404 | } | |
405 | // check for zlib stream header | |
406 | if let (&InflateState::Start, true) = (&self.state, src.len() > 2) { | |
407 | let cm = src[0] & 0xF; | |
408 | let cinfo = src[0] >> 4; | |
409 | let hdr = (u16::from(src[0]) << 8) | u16::from(src[1]); | |
410 | if cm == 8 && cinfo <= 7 && (hdr % 31) == 0 { | |
411 | csrc.skip(16).unwrap(); | |
412 | } | |
413 | } | |
414 | 'main: loop { | |
415 | match self.state { | |
416 | InflateState::Start | InflateState::BlockStart => { | |
417 | if csrc.left() == 0 { | |
418 | if do_one_block { | |
419 | return Ok(self.output_idx); | |
420 | } | |
421 | self.br = csrc.br; | |
422 | return Err(DecompressError::ShortData); | |
423 | } | |
424 | self.final_block = csrc.read_bool().unwrap(); | |
425 | self.state = InflateState::BlockMode; | |
426 | }, | |
427 | InflateState::BlockMode => { | |
428 | let bmode = read_bits!(self, csrc, 2); | |
429 | match bmode { | |
430 | 0 => { | |
431 | csrc.align(); | |
432 | self.state = InflateState::StaticBlockLen; | |
433 | }, | |
434 | 1 => { self.state = InflateState::FixedBlock; }, | |
435 | 2 => { self.state = InflateState::DynBlockHlit; }, | |
436 | _ => { | |
437 | self.state = InflateState::End; | |
438 | return Err(DecompressError::InvalidHeader); | |
439 | }, | |
440 | }; | |
441 | }, | |
442 | InflateState::StaticBlockLen => { | |
443 | let len = read_bits!(self, csrc, 16); | |
444 | self.state = InflateState::StaticBlockInvLen(len); | |
445 | }, | |
446 | InflateState::StaticBlockInvLen(len) => { | |
447 | let inv_len = read_bits!(self, csrc, 16); | |
448 | if (len ^ inv_len) != 0xFFFF { | |
449 | self.state = InflateState::End; | |
450 | return Err(DecompressError::InvalidHeader); | |
451 | } | |
452 | self.state = InflateState::StaticBlockCopy(len as usize); | |
453 | }, | |
454 | InflateState::StaticBlockCopy(len) => { | |
455 | for i in 0..len { | |
456 | if csrc.left() < 8 { | |
457 | self.br = csrc.br; | |
458 | self.state = InflateState::StaticBlockCopy(len - i); | |
459 | return Err(DecompressError::ShortData); | |
460 | } | |
461 | let val = csrc.read(8).unwrap() as u8; | |
462 | self.put_literal(val); | |
463 | } | |
464 | self.state = InflateState::BlockStart; | |
465 | } | |
466 | InflateState::FixedBlock => { | |
467 | let val = read_cb!(self, csrc, &self.fix_len_cb); | |
468 | if val < 256 { | |
469 | if self.output_idx >= dst.len() { | |
470 | self.br = csrc.br; | |
471 | self.state = InflateState::FixedBlockLiteral(val as u8); | |
472 | return Err(DecompressError::OutputFull); | |
473 | } | |
474 | self.put_literal(val as u8); | |
475 | dst[self.output_idx] = val as u8; | |
476 | self.output_idx += 1; | |
477 | } else if val == 256 { | |
478 | if self.final_block { | |
479 | self.state = InflateState::End; | |
480 | return Ok(self.output_idx); | |
481 | } else { | |
482 | self.state = InflateState::BlockStart; | |
483 | } | |
484 | } else { | |
485 | let len_idx = (val - 257) as usize; | |
486 | if len_idx >= LENGTH_BASE.len() { | |
487 | self.state = InflateState::End; | |
488 | return Err(DecompressError::InvalidData); | |
489 | } | |
490 | let len_bits = LENGTH_ADD_BITS[len_idx]; | |
491 | let add_base = LENGTH_BASE[len_idx] as usize; | |
492 | if len_bits > 0 { | |
493 | self.state = InflateState::FixedBlockLengthExt(add_base, len_bits); | |
494 | } else { | |
495 | self.state = InflateState::FixedBlockDist(add_base); | |
496 | } | |
497 | } | |
498 | }, | |
499 | InflateState::FixedBlockLiteral(sym) => { | |
500 | if self.output_idx >= dst.len() { | |
501 | self.br = csrc.br; | |
502 | return Err(DecompressError::OutputFull); | |
503 | } | |
504 | self.put_literal(sym); | |
505 | dst[self.output_idx] = sym; | |
506 | self.output_idx += 1; | |
507 | self.state = InflateState::FixedBlock; | |
508 | }, | |
509 | InflateState::FixedBlockLengthExt(base, bits) => { | |
510 | let add = read_bits!(self, csrc, bits) as usize; | |
511 | self.state = InflateState::FixedBlockDist(base + add); | |
512 | }, | |
513 | InflateState::FixedBlockDist(length) => { | |
514 | let dist_idx = reverse_bits(read_bits!(self, csrc, 5), 5) as usize; | |
515 | if dist_idx >= DIST_BASE.len() { | |
516 | self.state = InflateState::End; | |
517 | return Err(DecompressError::InvalidData); | |
518 | } | |
519 | let dist_bits = DIST_ADD_BITS[dist_idx]; | |
520 | let dist_base = DIST_BASE[dist_idx] as usize; | |
521 | if dist_bits == 0 { | |
522 | self.state = InflateState::FixedBlockCopy(length, dist_base); | |
523 | } else { | |
524 | self.state = InflateState::FixedBlockDistExt(length, dist_base, dist_bits); | |
525 | } | |
526 | }, | |
527 | InflateState::FixedBlockDistExt(length, base, bits) => { | |
528 | let add = read_bits!(self, csrc, bits) as usize; | |
529 | self.state = InflateState::FixedBlockCopy(length, base + add); | |
530 | }, | |
531 | InflateState::FixedBlockCopy(length, dist) => { | |
532 | if self.output_idx + length > dst.len() { | |
533 | let copy_size = dst.len() - self.output_idx; | |
534 | let ret = self.lz_copy(dist, copy_size, &mut dst[self.output_idx..]); | |
535 | if ret.is_err() { | |
536 | self.state = InflateState::End; | |
537 | return Err(DecompressError::InvalidData); | |
538 | } | |
539 | self.output_idx += copy_size; | |
540 | self.br = csrc.br; | |
541 | self.state = InflateState::FixedBlockCopy(length - copy_size, dist); | |
542 | return Err(DecompressError::OutputFull); | |
543 | } | |
544 | let ret = self.lz_copy(dist, length, &mut dst[self.output_idx..]); | |
545 | if ret.is_err() { | |
546 | self.state = InflateState::End; | |
547 | return Err(DecompressError::InvalidData); | |
548 | } | |
549 | self.output_idx += length; | |
550 | self.state = InflateState::FixedBlock; | |
551 | } | |
552 | InflateState::DynBlockHlit => { | |
553 | self.hlit = (read_bits!(self, csrc, 5) as usize) + 257; | |
554 | if self.hlit >= 287 { | |
555 | self.state = InflateState::End; | |
556 | return Err(DecompressError::InvalidHeader); | |
557 | } | |
558 | self.state = InflateState::DynBlockHdist; | |
559 | } | |
560 | InflateState::DynBlockHdist => { | |
561 | self.hdist = (read_bits!(self, csrc, 5) as usize) + 1; | |
562 | self.state = InflateState::DynBlockHclen; | |
563 | }, | |
564 | InflateState::DynBlockHclen => { | |
565 | let hclen = (read_bits!(self, csrc, 4) as usize) + 4; | |
566 | self.cur_len_idx = 0; | |
567 | self.len_lengths = [0; 19]; | |
568 | self.all_lengths = [0; NUM_LITERALS + NUM_DISTS]; | |
569 | self.state = InflateState::DynLengths(hclen); | |
570 | }, | |
571 | InflateState::DynLengths(len) => { | |
572 | for i in 0..len { | |
573 | if csrc.left() < 3 { | |
574 | self.br = csrc.br; | |
575 | self.state = InflateState::DynLengths(len - i); | |
576 | return Err(DecompressError::ShortData); | |
577 | } | |
578 | self.len_lengths[LEN_RECODE[self.cur_len_idx]] = csrc.read(3).unwrap() as u8; | |
579 | self.cur_len_idx += 1; | |
580 | } | |
581 | let mut len_codes = [ShortCodebookDesc { code: 0, bits: 0 }; 19]; | |
582 | lengths_to_codes(&self.len_lengths, &mut len_codes)?; | |
583 | let mut cr = ShortCodebookDescReader::new(len_codes.to_vec()); | |
584 | let ret = Codebook::new(&mut cr, CodebookMode::LSB); | |
585 | if ret.is_err() { | |
586 | self.state = InflateState::End; | |
587 | return Err(DecompressError::InvalidHeader); | |
588 | } | |
589 | self.dyn_len_cb = Some(ret.unwrap()); | |
590 | self.cur_len_idx = 0; | |
591 | self.state = InflateState::DynCodeLengths; | |
592 | }, | |
593 | InflateState::DynCodeLengths => { | |
594 | if let Some(ref len_cb) = self.dyn_len_cb { | |
595 | while self.cur_len_idx < self.hlit + self.hdist { | |
596 | let ret = csrc.read_cb(len_cb); | |
597 | let val = match ret { | |
598 | Ok(val) => val, | |
599 | Err(CodebookError::MemoryError) => { | |
600 | self.br = csrc.br; | |
601 | return Err(DecompressError::ShortData); | |
602 | }, | |
603 | Err(_) => { | |
604 | self.state = InflateState::End; | |
605 | return Err(DecompressError::InvalidHeader); | |
606 | }, | |
607 | }; | |
608 | if val < 16 { | |
609 | self.all_lengths[self.cur_len_idx] = val as u8; | |
610 | self.cur_len_idx += 1; | |
611 | } else { | |
612 | let idx = (val as usize) - 16; | |
613 | if idx > 2 { | |
614 | self.state = InflateState::End; | |
615 | return Err(DecompressError::InvalidHeader); | |
616 | } | |
617 | self.state = InflateState::DynCodeLengthsAdd(idx); | |
618 | continue 'main; | |
619 | } | |
620 | } | |
621 | let (lit_lengths, dist_lengths) = self.all_lengths.split_at(self.hlit); | |
622 | ||
623 | let mut lit_codes = [ShortCodebookDesc { code: 0, bits: 0 }; NUM_LITERALS]; | |
624 | lengths_to_codes(lit_lengths, &mut lit_codes)?; | |
625 | let mut cr = ShortCodebookDescReader::new(lit_codes.to_vec()); | |
626 | let ret = Codebook::new(&mut cr, CodebookMode::LSB); | |
627 | if ret.is_err() { return Err(DecompressError::InvalidHeader); } | |
628 | self.dyn_lit_cb = Some(ret.unwrap()); | |
629 | ||
630 | let mut dist_codes = [ShortCodebookDesc { code: 0, bits: 0 }; NUM_DISTS]; | |
631 | lengths_to_codes(&dist_lengths[..self.hdist], &mut dist_codes)?; | |
632 | let mut cr = ShortCodebookDescReader::new(dist_codes.to_vec()); | |
633 | let ret = Codebook::new(&mut cr, CodebookMode::LSB); | |
634 | if ret.is_err() { return Err(DecompressError::InvalidHeader); } | |
635 | self.dyn_dist_cb = Some(ret.unwrap()); | |
636 | ||
637 | self.state = InflateState::DynBlock; | |
638 | } else { | |
639 | unreachable!(); | |
640 | } | |
641 | }, | |
642 | InflateState::DynCodeLengthsAdd(mode) => { | |
643 | let base = REPEAT_BASE[mode] as usize; | |
644 | let bits = REPEAT_BITS[mode]; | |
645 | let len = base + read_bits!(self, csrc, bits) as usize; | |
646 | if self.cur_len_idx + len > self.hlit + self.hdist { | |
647 | self.state = InflateState::End; | |
648 | return Err(DecompressError::InvalidHeader); | |
649 | } | |
650 | let rpt = if mode == 0 { | |
651 | if self.cur_len_idx == 0 { | |
652 | self.state = InflateState::End; | |
653 | return Err(DecompressError::InvalidHeader); | |
654 | } | |
655 | self.all_lengths[self.cur_len_idx - 1] | |
656 | } else { | |
657 | 0 | |
658 | }; | |
659 | for _ in 0..len { | |
660 | self.all_lengths[self.cur_len_idx] = rpt; | |
661 | self.cur_len_idx += 1; | |
662 | } | |
663 | self.state = InflateState::DynCodeLengths; | |
664 | }, | |
665 | InflateState::DynBlock => { | |
666 | if let Some(ref lit_cb) = self.dyn_lit_cb { | |
667 | let val = read_cb!(self, csrc, lit_cb); | |
668 | if val < 256 { | |
669 | if self.output_idx >= dst.len() { | |
670 | self.br = csrc.br; | |
671 | self.state = InflateState::DynBlockLiteral(val as u8); | |
672 | return Err(DecompressError::OutputFull); | |
673 | } | |
674 | self.put_literal(val as u8); | |
675 | dst[self.output_idx] = val as u8; | |
676 | self.output_idx += 1; | |
677 | } else if val == 256 { | |
678 | if self.final_block { | |
679 | self.state = InflateState::End; | |
680 | return Ok(self.output_idx); | |
681 | } else { | |
682 | self.state = InflateState::BlockStart; | |
683 | } | |
684 | } else { | |
685 | let len_idx = (val - 257) as usize; | |
686 | if len_idx >= LENGTH_BASE.len() { | |
687 | self.state = InflateState::End; | |
688 | return Err(DecompressError::InvalidData); | |
689 | } | |
690 | let len_bits = LENGTH_ADD_BITS[len_idx]; | |
691 | let add_base = LENGTH_BASE[len_idx] as usize; | |
692 | if len_bits > 0 { | |
693 | self.state = InflateState::DynBlockLengthExt(add_base, len_bits); | |
694 | } else { | |
695 | self.state = InflateState::DynBlockDist(add_base); | |
696 | } | |
697 | } | |
698 | } else { | |
699 | unreachable!(); | |
700 | } | |
701 | }, | |
702 | InflateState::DynBlockLiteral(sym) => { | |
703 | if self.output_idx >= dst.len() { | |
704 | self.br = csrc.br; | |
705 | return Err(DecompressError::OutputFull); | |
706 | } | |
707 | self.put_literal(sym); | |
708 | dst[self.output_idx] = sym; | |
709 | self.output_idx += 1; | |
710 | self.state = InflateState::DynBlock; | |
711 | }, | |
712 | InflateState::DynBlockLengthExt(base, bits) => { | |
713 | let add = read_bits!(self, csrc, bits) as usize; | |
714 | self.state = InflateState::DynBlockDist(base + add); | |
715 | }, | |
716 | InflateState::DynBlockDist(length) => { | |
717 | if let Some(ref dist_cb) = self.dyn_dist_cb { | |
718 | let dist_idx = read_cb!(self, csrc, dist_cb) as usize; | |
719 | if dist_idx >= DIST_BASE.len() { | |
720 | self.state = InflateState::End; | |
721 | return Err(DecompressError::InvalidData); | |
722 | } | |
723 | let dist_bits = DIST_ADD_BITS[dist_idx]; | |
724 | let dist_base = DIST_BASE[dist_idx] as usize; | |
725 | if dist_bits == 0 { | |
726 | self.state = InflateState::DynCopy(length, dist_base); | |
727 | } else { | |
728 | self.state = InflateState::DynBlockDistExt(length, dist_base, dist_bits); | |
729 | } | |
730 | } else { | |
731 | unreachable!(); | |
732 | } | |
733 | }, | |
734 | InflateState::DynBlockDistExt(length, base, bits) => { | |
735 | let add = read_bits!(self, csrc, bits) as usize; | |
736 | self.state = InflateState::DynCopy(length, base + add); | |
737 | }, | |
738 | InflateState::DynCopy(length, dist) => { | |
739 | if self.output_idx + length > dst.len() { | |
740 | let copy_size = dst.len() - self.output_idx; | |
741 | let ret = self.lz_copy(dist, copy_size, &mut dst[self.output_idx..]); | |
742 | if ret.is_err() { | |
743 | self.state = InflateState::End; | |
744 | return Err(DecompressError::InvalidData); | |
745 | } | |
746 | self.output_idx += copy_size; | |
747 | self.br = csrc.br; | |
748 | self.state = InflateState::DynCopy(length - copy_size, dist); | |
749 | return Err(DecompressError::OutputFull); | |
750 | } | |
751 | let ret = self.lz_copy(dist, length, &mut dst[self.output_idx..]); | |
752 | if ret.is_err() { | |
753 | self.state = InflateState::End; | |
754 | return Err(DecompressError::InvalidData); | |
755 | } | |
756 | self.output_idx += length; | |
757 | self.state = InflateState::DynBlock; | |
758 | } | |
759 | InflateState::End => { | |
760 | return Ok(0); | |
761 | }, | |
762 | } | |
763 | } | |
764 | } | |
765 | ///! Resets decoder state. | |
766 | pub fn reset(&mut self) { | |
767 | self.bpos = 0; | |
768 | self.output_idx = 0; | |
769 | self.full_pos = 0; | |
770 | self.state = InflateState::Start; | |
771 | } | |
772 | ||
773 | ///! Decompresses input data into output returning the uncompressed data length. | |
774 | pub fn uncompress(src: &[u8], dst: &mut [u8]) -> DecompressResult<usize> { | |
775 | let mut inflate = Self::new(); | |
776 | inflate.decompress_data(src, dst, false) | |
777 | } | |
778 | } | |
779 | ||
780 | impl Default for Inflate { | |
781 | fn default() -> Self { | |
782 | Self::new() | |
783 | } | |
784 | } | |
785 | ||
786 | fn lengths_to_codes(lens: &[u8], codes: &mut [ShortCodebookDesc]) -> DecompressResult<()> { | |
787 | let mut bits = [0u32; 32]; | |
788 | let mut pfx = [0u32; 33]; | |
789 | for len in lens.iter() { | |
790 | let len = *len as usize; | |
791 | if len >= bits.len() { | |
792 | return Err(DecompressError::InvalidHeader); | |
793 | } | |
794 | bits[len] += 1; | |
795 | } | |
796 | bits[0] = 0; | |
797 | let mut code = 0; | |
798 | for i in 0..bits.len() { | |
799 | code = (code + bits[i]) << 1; | |
800 | pfx[i + 1] = code; | |
801 | } | |
802 | ||
803 | for (len, codes) in lens.iter().zip(codes.iter_mut()) { | |
804 | let len = *len as usize; | |
805 | if len != 0 { | |
806 | let bits = len as u8; | |
807 | *codes = ShortCodebookDesc { code: reverse_bits(pfx[len], bits), bits }; | |
808 | pfx[len] += 1; | |
809 | } else { | |
810 | *codes = ShortCodebookDesc { code: 0, bits: 0 }; | |
811 | } | |
812 | } | |
813 | ||
814 | Ok(()) | |
815 | } | |
816 | ||
817 | struct GzipCRC32 { | |
818 | tab: [u32; 256], | |
819 | crc: u32, | |
820 | } | |
821 | ||
822 | impl GzipCRC32 { | |
823 | #[allow(clippy::unreadable_literal)] | |
824 | fn new() -> Self { | |
825 | let mut tab = [0u32; 256]; | |
826 | for i in 0..256 { | |
827 | let mut c = i as u32; | |
828 | for _ in 0..8 { | |
829 | if (c & 1) != 0 { | |
830 | c = 0xEDB88320 ^ (c >> 1); | |
831 | } else { | |
832 | c >>= 1; | |
833 | } | |
834 | } | |
835 | tab[i] = c; | |
836 | } | |
837 | Self { tab, crc: 0 } | |
838 | } | |
839 | fn update_crc(&mut self, src: &[u8]) { | |
840 | let mut c = !self.crc; | |
841 | for el in src.iter() { | |
842 | c = self.tab[((c ^ u32::from(*el)) & 0xFF) as usize] ^ (c >> 8); | |
843 | } | |
844 | self.crc = !c; | |
845 | } | |
846 | } | |
847 | ||
848 | ///! Decodes input data in gzip file format (RFC 1952) returning a vector containing decoded data. | |
849 | pub fn gzip_decode(br: &mut ByteReader, skip_crc: bool) -> DecompressResult<Vec<u8>> { | |
850 | const FLAG_HCRC: u8 = 0x02; | |
851 | const FLAG_EXTRA: u8 = 0x04; | |
852 | const FLAG_NAME: u8 = 0x08; | |
853 | const FLAG_COMMENT: u8 = 0x10; | |
854 | ||
855 | let id1 = br.read_byte()?; | |
856 | let id2 = br.read_byte()?; | |
857 | let cm = br.read_byte()?; | |
858 | let flg = br.read_byte()?; | |
859 | let _mtime = br.read_u32le()?; | |
860 | let _xfl = br.read_byte()?; | |
861 | let _os = br.read_byte()?; | |
862 | if id1 != 0x1F || id2 != 0x8B || cm != 8 { | |
863 | return Err(DecompressError::InvalidHeader); | |
864 | } | |
865 | ||
866 | if (flg & FLAG_EXTRA) != 0 { | |
867 | let xlen = br.read_u16le()? as usize; | |
868 | br.read_skip(xlen)?; | |
869 | } | |
870 | if (flg & FLAG_NAME) != 0 { | |
871 | loop { | |
872 | let b = br.read_byte()?; | |
873 | if b == 0 { | |
874 | break; | |
875 | } | |
876 | } | |
877 | } | |
878 | if (flg & FLAG_COMMENT) != 0 { | |
879 | loop { | |
880 | let b = br.read_byte()?; | |
881 | if b == 0 { | |
882 | break; | |
883 | } | |
884 | } | |
885 | } | |
886 | let _hcrc = if (flg & FLAG_HCRC) != 0 { | |
887 | br.read_u16le()? | |
888 | } else { | |
889 | 0 | |
890 | }; | |
891 | if (flg & 0xE0) != 0 { | |
892 | return Err(DecompressError::Unsupported); | |
893 | } | |
894 | ||
895 | let mut output: Vec<u8> = Vec::new(); | |
896 | let mut tail = [0u8; 8]; | |
897 | let mut inblk = [0u8; 1024]; | |
898 | let mut oblk = [0u8; 4096]; | |
899 | let mut inflate = Inflate::new(); | |
900 | let mut checker = GzipCRC32::new(); | |
901 | ||
902 | loop { | |
903 | let ret = br.read_buf_some(&mut inblk); | |
904 | if let Err(ByteIOError::EOF) = ret { | |
905 | break; | |
906 | } | |
907 | let inlen = match ret { | |
908 | Ok(val) => val, | |
909 | Err(_) => return Err(DecompressError::IOError), | |
910 | }; | |
911 | let mut repeat = false; | |
912 | loop { | |
913 | let ret = inflate.decompress_data(&inblk[..inlen], &mut oblk, repeat); | |
914 | match ret { | |
915 | Ok(outlen) => { | |
916 | checker.update_crc(&oblk[..outlen]); | |
917 | output.extend_from_slice(&oblk[..outlen]); | |
918 | break; | |
919 | }, | |
920 | Err(DecompressError::ShortData) => { | |
921 | break; | |
922 | }, | |
923 | Err(DecompressError::OutputFull) => { | |
924 | repeat = true; | |
925 | checker.update_crc(&oblk); | |
926 | output.extend_from_slice(&oblk); | |
927 | }, | |
928 | Err(err) => { | |
929 | return Err(err); | |
930 | }, | |
931 | } | |
932 | } | |
933 | // Save last 8 bytes for CRC and size. | |
934 | if inlen >= 8 { | |
935 | tail.copy_from_slice(&inblk[inlen - 8..][..8]); | |
936 | } else { | |
937 | let shift_len = 8 - inlen; | |
938 | for i in 0..shift_len { | |
939 | tail[i] = tail[i + inlen]; | |
940 | } | |
941 | for i in shift_len..8 { | |
942 | tail[i] = inblk[i - shift_len]; | |
943 | } | |
944 | } | |
945 | } | |
946 | if !skip_crc { | |
947 | if !inflate.is_finished() { println!("???"); } | |
948 | let crc = read_u32le(&tail[0..4])?; | |
949 | let size = read_u32le(&tail[4..8])?; | |
950 | if size != (output.len() as u32) { | |
951 | return Err(DecompressError::CRCError); | |
952 | } | |
953 | if crc != checker.crc { | |
954 | return Err(DecompressError::CRCError); | |
955 | } | |
956 | } | |
957 | ||
958 | Ok(output) | |
959 | } | |
960 | ||
961 | #[derive(Clone,Copy,Default)] | |
962 | struct Token { | |
963 | sym: u16, | |
964 | distsym: u8, | |
965 | len: u16, | |
966 | dist: u16, | |
967 | } | |
968 | ||
969 | const TOKEN_EOB: Token = Token { sym: 256, distsym: 0, len: 0, dist: 0 }; | |
970 | ||
971 | impl Token { | |
972 | fn from_literal(sym: u8) -> Self { | |
973 | Self { | |
974 | sym: u16::from(sym), | |
975 | distsym: 0, | |
976 | dist: 0, | |
977 | len: 0, | |
978 | } | |
979 | } | |
980 | fn from_match(dist: u16, len: u16) -> Self { | |
981 | let sym = match len { | |
982 | 3..= 10 => 257 + len - 3, | |
983 | 11..= 18 => 265 + (len - 11) / 2, | |
984 | 19..= 34 => 269 + (len - 19) / 4, | |
985 | 35..= 66 => 273 + (len - 35) / 8, | |
986 | 67..=130 => 277 + (len - 67) / 16, | |
987 | 131..=257 => 281 + (len - 131) / 32, | |
988 | _ => 285, | |
989 | }; | |
990 | let distsym = if dist <= 4 { | |
991 | (dist - 1) as u8 | |
992 | } else { | |
993 | let bits = 16 - (dist - 1).leading_zeros(); | |
994 | (bits as u8) * 2 - 2 + if ((dist - 1) & (1 << (bits - 2))) != 0 { 1 } else { 0 } | |
995 | }; | |
996 | Self { | |
997 | sym, distsym, len, dist | |
998 | } | |
999 | } | |
1000 | } | |
1001 | ||
1002 | fn add_codes(lens: &[u8], stats: &mut [u32], toks: &mut Vec<(u8, u8)>) { | |
1003 | let mut last = 42; | |
1004 | let mut lcount = 0; | |
1005 | ||
1006 | for &len in lens.iter() { | |
1007 | if len == last { | |
1008 | lcount += 1; | |
1009 | } else { | |
1010 | if last == 0 { | |
1011 | while lcount > 10 { | |
1012 | let run = lcount.min(138); | |
1013 | stats[18] += 1; | |
1014 | toks.push((18, run - 11)); | |
1015 | lcount -= run; | |
1016 | } | |
1017 | if lcount >= 3 { | |
1018 | stats[17] += 1; | |
1019 | toks.push((17, lcount - 3)); | |
1020 | lcount = 0; | |
1021 | } | |
1022 | for _ in 0..lcount { | |
1023 | stats[0] += 1; | |
1024 | toks.push((0, 0)); | |
1025 | } | |
1026 | } else { | |
1027 | while lcount >= 3 { | |
1028 | let run = lcount.min(6); | |
1029 | stats[16] += 1; | |
1030 | toks.push((16, run - 3)); | |
1031 | lcount -= run; | |
1032 | } | |
1033 | for _ in 0..lcount { | |
1034 | stats[last as usize] += 1; | |
1035 | toks.push((last, 0)); | |
1036 | } | |
1037 | } | |
1038 | stats[len as usize] += 1; | |
1039 | toks.push((len, 0)); | |
1040 | last = len; | |
1041 | lcount = 0; | |
1042 | } | |
1043 | } | |
1044 | if lcount > 0 { | |
1045 | if last == 0 { | |
1046 | while lcount > 10 { | |
1047 | let run = lcount.min(138); | |
1048 | stats[18] += 1; | |
1049 | toks.push((18, run - 11)); | |
1050 | lcount -= run; | |
1051 | } | |
1052 | if lcount >= 3 { | |
1053 | stats[17] += 1; | |
1054 | toks.push((17, lcount - 3)); | |
1055 | lcount = 0; | |
1056 | } | |
1057 | for _ in 0..lcount { | |
1058 | stats[0] += 1; | |
1059 | toks.push((0, 0)); | |
1060 | } | |
1061 | } else { | |
1062 | while lcount >= 3 { | |
1063 | let run = lcount.min(6); | |
1064 | stats[16] += 1; | |
1065 | toks.push((16, run - 3)); | |
1066 | lcount -= run; | |
1067 | } | |
1068 | for _ in 0..lcount { | |
1069 | stats[last as usize] += 1; | |
1070 | toks.push((last, 0)); | |
1071 | } | |
1072 | } | |
1073 | } | |
1074 | } | |
1075 | ||
1076 | ///! Deflate stream writer. | |
1077 | pub struct DeflateWriter { | |
1078 | dst: Vec<u8>, | |
1079 | bits: u8, | |
1080 | bbuf: u32, | |
1081 | } | |
1082 | ||
1083 | impl DeflateWriter { | |
1084 | ///! Creates a new instance of `DeflateWriter` for a provided output. | |
1085 | pub fn new(dst: Vec<u8>) -> Self { | |
1086 | Self { | |
1087 | dst, | |
1088 | bits: 0, | |
1089 | bbuf: 0, | |
1090 | } | |
1091 | } | |
1092 | fn align(&mut self) { | |
1093 | if (self.bits & 7) != 0 { | |
1094 | self.bits += 8 - (self.bits & 7); | |
1095 | } | |
1096 | } | |
1097 | fn flush(&mut self) { | |
1098 | while self.bits >= 8 { | |
1099 | self.dst.push(self.bbuf as u8); | |
1100 | self.bbuf >>= 8; | |
1101 | self.bits -= 8; | |
1102 | } | |
1103 | } | |
1104 | fn write(&mut self, val: u16, len: u8) { | |
1105 | self.flush(); | |
1106 | self.bbuf |= u32::from(val) << self.bits; | |
1107 | self.bits += len; | |
1108 | } | |
1109 | ///! Finishes writing the stream and returns the output vector. | |
1110 | pub fn end(mut self) -> Vec<u8> { | |
1111 | self.flush(); | |
1112 | if self.bits > 0 { | |
1113 | self.dst.push(self.bbuf as u8); | |
1114 | } | |
1115 | self.dst | |
1116 | } | |
1117 | ||
1118 | fn write_codes(&mut self, codes: &CodeHuff, dists: &DistHuff) { | |
1119 | let mut stats = [0u32; 19]; | |
1120 | let mut toks = Vec::with_capacity(NUM_LITERALS + NUM_DISTS); | |
1121 | let mut cw = [0u16; 19]; | |
1122 | let mut cl = [0u8; 19]; | |
1123 | let mut nc = 0; | |
1124 | ||
1125 | add_codes(&codes.lens[..codes.num_codes], &mut stats, &mut toks); | |
1126 | add_codes(&dists.lens[..dists.num_codes], &mut stats, &mut toks); | |
1127 | ||
1128 | gen_tree(&mut cw, &mut cl, &mut nc, &mut stats, 7); | |
1129 | ||
1130 | nc = cw.len(); | |
1131 | for &idx in LEN_RECODE.iter().rev() { | |
1132 | if cl[idx] == 0 { | |
1133 | nc -= 1; | |
1134 | } else { | |
1135 | break; | |
1136 | } | |
1137 | } | |
1138 | if nc < 4 { | |
1139 | nc = 4; | |
1140 | } | |
1141 | self.write((nc - 4) as u16, 4); | |
1142 | for &idx in LEN_RECODE.iter().take(nc) { | |
1143 | self.write(u16::from(cl[idx]), 3); | |
1144 | } | |
1145 | for &(sym, add) in toks.iter() { | |
1146 | self.write(cw[sym as usize], cl[sym as usize]); | |
1147 | match sym { | |
1148 | 16 => self.write(u16::from(add), 2), | |
1149 | 17 => self.write(u16::from(add), 3), | |
1150 | 18 => self.write(u16::from(add), 7), | |
1151 | _ => {}, | |
1152 | }; | |
1153 | } | |
1154 | } | |
1155 | fn write_tokens(&mut self, src: &[Token], codes: &CodeHuff, dists: &DistHuff) { | |
1156 | for &tok in src.iter() { | |
1157 | self.write(codes.codes[tok.sym as usize], codes.lens[tok.sym as usize]); | |
1158 | if tok.sym > 256 { | |
1159 | self.write_len_bits(tok.len); | |
1160 | self.write(dists.codes[tok.distsym as usize], dists.lens[tok.distsym as usize]); | |
1161 | self.write_dist_bits(tok.dist); | |
1162 | } | |
1163 | } | |
1164 | } | |
1165 | fn write_len_bits(&mut self, len: u16) { | |
1166 | let llen = len - 3; | |
1167 | if llen >= 8 && llen < 255 { | |
1168 | let bits = (16 - llen.leading_zeros() - 3) as u8; | |
1169 | self.write(llen & ((1 << bits) - 1), bits); | |
1170 | } | |
1171 | } | |
1172 | fn write_dist_bits(&mut self, dist: u16) { | |
1173 | let ddist = dist - 1; | |
1174 | if dist >= 4 { | |
1175 | let bits = (16 - ddist.leading_zeros() - 2) as u8; | |
1176 | self.write(ddist & ((1 << bits) - 1), bits); | |
1177 | } | |
1178 | } | |
1179 | } | |
1180 | ||
1181 | struct CodeHuff { | |
1182 | is_fixed: bool, | |
1183 | stats: [u32; NUM_LITERALS], | |
1184 | codes: [u16; NUM_LITERALS], | |
1185 | lens: [u8; NUM_LITERALS], | |
1186 | num_codes: usize, | |
1187 | } | |
1188 | ||
1189 | impl CodeHuff { | |
1190 | fn new(is_fixed: bool) -> Self { | |
1191 | Self { | |
1192 | is_fixed, | |
1193 | stats: [0; NUM_LITERALS], | |
1194 | codes: [0; NUM_LITERALS], | |
1195 | lens: [0; NUM_LITERALS], | |
1196 | num_codes: NUM_LITERALS, | |
1197 | } | |
1198 | } | |
1199 | fn make_codes(&mut self, src: &[Token]) { | |
1200 | if self.is_fixed { | |
1201 | for i in 0..=143 { | |
1202 | self.codes[i] = reverse_bits((i + 0x30) as u32, 8) as u16; | |
1203 | self.lens[i] = 8; | |
1204 | } | |
1205 | for i in 144..=255 { | |
1206 | self.codes[i] = reverse_bits((i + 0x100) as u32, 9) as u16; | |
1207 | self.lens[i] = 9; | |
1208 | } | |
1209 | for i in 256..=279 { | |
1210 | self.codes[i] = reverse_bits((i & 0x1F) as u32, 7) as u16; | |
1211 | self.lens[i] = 7; | |
1212 | } | |
1213 | for i in 280..NUM_LITERALS { | |
1214 | self.codes[i] = reverse_bits((i - 280 + 0xC0) as u32, 8) as u16; | |
1215 | self.lens[i] = 8; | |
1216 | } | |
1217 | } else { | |
1218 | for &tok in src.iter() { | |
1219 | self.stats[tok.sym as usize] += 1; | |
1220 | } | |
1221 | gen_tree(&mut self.codes, &mut self.lens, &mut self.num_codes, &mut self.stats, 15); | |
1222 | if self.num_codes < 257 { | |
1223 | self.num_codes = 257; | |
1224 | } | |
1225 | } | |
1226 | } | |
1227 | } | |
1228 | ||
1229 | struct DistHuff { | |
1230 | is_fixed: bool, | |
1231 | stats: [u32; NUM_DISTS], | |
1232 | codes: [u16; NUM_DISTS], | |
1233 | lens: [u8; NUM_DISTS], | |
1234 | num_codes: usize, | |
1235 | } | |
1236 | ||
1237 | impl DistHuff { | |
1238 | fn new(is_fixed: bool) -> Self { | |
1239 | Self { | |
1240 | is_fixed, | |
1241 | stats: [0; NUM_DISTS], | |
1242 | codes: [0; NUM_DISTS], | |
1243 | lens: [0; NUM_DISTS], | |
1244 | num_codes: NUM_DISTS, | |
1245 | } | |
1246 | } | |
1247 | fn make_codes(&mut self, src: &[Token]) { | |
1248 | if self.is_fixed { | |
1249 | for i in 0..NUM_DISTS { | |
1250 | self.codes[i] = reverse_bits(i as u32, 5) as u16; | |
1251 | self.lens[i] = 5; | |
1252 | } | |
1253 | } else { | |
1254 | for &tok in src.iter() { | |
1255 | if tok.sym > 256 { | |
1256 | self.stats[tok.distsym as usize] += 1; | |
1257 | } | |
1258 | } | |
1259 | gen_tree(&mut self.codes, &mut self.lens, &mut self.num_codes, &mut self.stats, 15); | |
1260 | if self.num_codes < 1 { | |
1261 | self.num_codes = 1; | |
1262 | } | |
1263 | } | |
1264 | } | |
1265 | } | |
1266 | ||
1267 | #[derive(Clone,Copy,Default)] | |
1268 | struct Node { | |
1269 | sym: u16, | |
1270 | w: u16, | |
1271 | idx0: u16, | |
1272 | idx1: u16, | |
1273 | } | |
1274 | ||
1275 | const NODE_SYM: u16 = 65500; | |
1276 | ||
1277 | struct Tree { | |
1278 | nodes: [Node; NUM_LITERALS * 2], | |
1279 | nnodes: usize, | |
1280 | } | |
1281 | ||
1282 | impl Tree { | |
1283 | fn new() -> Self { | |
1284 | Self { | |
1285 | nodes: [Node::default(); NUM_LITERALS * 2], | |
1286 | nnodes: 0, | |
1287 | } | |
1288 | } | |
1289 | fn insert(&mut self, val: Node) { | |
1290 | let mut idx = self.nnodes; | |
1291 | for (i, nn) in self.nodes[..self.nnodes].iter().enumerate() { | |
1292 | if nn.w > val.w { | |
1293 | idx = i; | |
1294 | break; | |
1295 | } | |
1296 | } | |
1297 | if idx < self.nnodes { | |
1298 | for i in (idx..self.nnodes).rev() { | |
1299 | self.nodes[i + 1] = self.nodes[i]; | |
1300 | } | |
1301 | } | |
1302 | self.nodes[idx] = val; | |
1303 | self.nnodes += 1; | |
1304 | } | |
1305 | fn trim(&mut self) { | |
1306 | let mut start = self.nnodes; | |
1307 | for (i, n) in self.nodes[..self.nnodes].iter().enumerate() { | |
1308 | if n.w != 0 { | |
1309 | start = i; | |
1310 | break; | |
1311 | } | |
1312 | } | |
1313 | if start != 0 { | |
1314 | for i in 0..self.nnodes - start { | |
1315 | self.nodes[i] = self.nodes[i + start]; | |
1316 | } | |
1317 | self.nnodes -= start; | |
1318 | } | |
1319 | } | |
1320 | fn build(&mut self) { | |
1321 | if self.nnodes == 1 { | |
1322 | self.nodes[0].w = 1; | |
1323 | return; | |
1324 | } | |
1325 | let mut start = 0; | |
1326 | while start + 1 < self.nnodes { | |
1327 | let nn1 = self.nodes[start]; | |
1328 | let nn2 = self.nodes[start + 1]; | |
1329 | let n = Node { | |
1330 | sym: NODE_SYM, | |
1331 | w: nn1.w + nn2.w, | |
1332 | idx0: start as u16, | |
1333 | idx1: (start + 1) as u16, | |
1334 | }; | |
1335 | self.nodes[start].w = 0; | |
1336 | self.nodes[start + 1].w = 0; | |
1337 | start += 2; | |
1338 | self.insert(n); | |
1339 | } | |
1340 | if self.nnodes > 1 { | |
1341 | self.assign_len(self.nnodes - 1, 0); | |
1342 | } | |
1343 | } | |
1344 | fn assign_len(&mut self, idx: usize, len: u16) { | |
1345 | if self.nodes[idx].sym == NODE_SYM { | |
1346 | self.assign_len(self.nodes[idx].idx0 as usize, len + 1); | |
1347 | self.assign_len(self.nodes[idx].idx1 as usize, len + 1); | |
1348 | } else { | |
1349 | self.nodes[idx].w = len; | |
1350 | } | |
1351 | } | |
1352 | } | |
1353 | ||
1354 | fn gen_tree(codes: &mut [u16], lens: &mut [u8], num_codes: &mut usize, stats: &mut [u32], max_bits: u8) { | |
1355 | let mut tot_w = 0; | |
1356 | for &w in stats.iter() { | |
1357 | tot_w += w; | |
1358 | } | |
1359 | if tot_w == 0 { | |
1360 | codes[0] = 0; | |
1361 | lens[0] = 0; | |
1362 | *num_codes = 0; | |
1363 | return; | |
1364 | } | |
1365 | while tot_w > (1 << max_bits) { | |
1366 | for w in stats.iter_mut() { | |
1367 | *w = (*w + 1) >> 1; | |
1368 | } | |
1369 | tot_w = 0; | |
1370 | for &w in stats.iter() { | |
1371 | tot_w += w; | |
1372 | } | |
1373 | } | |
1374 | let mut tree = Tree::new(); | |
1375 | for (sym, &w) in stats.iter().enumerate() { | |
1376 | tree.insert(Node{ sym: sym as u16, w: w as u16, idx0: 64000, idx1: 64000 }); | |
1377 | } | |
1378 | tree.trim(); | |
1379 | tree.build(); | |
1380 | ||
1381 | for n in tree.nodes[..tree.nnodes].iter() { | |
1382 | if n.sym != NODE_SYM { | |
1383 | lens[n.sym as usize] = n.w as u8; | |
1384 | } | |
1385 | } | |
1386 | lengths_to_codes16(lens, codes); | |
1387 | let mut sz = codes.len(); | |
1388 | for &len in lens.iter().rev() { | |
1389 | if len != 0 { | |
1390 | break; | |
1391 | } | |
1392 | sz -= 1; | |
1393 | } | |
1394 | *num_codes = sz; | |
1395 | } | |
1396 | ||
1397 | fn lengths_to_codes16(lens: &[u8], codes: &mut [u16]) { | |
1398 | let mut bits = [0u32; 32]; | |
1399 | let mut pfx = [0u32; 33]; | |
1400 | for len in lens.iter() { | |
1401 | let len = *len as usize; | |
1402 | bits[len] += 1; | |
1403 | } | |
1404 | bits[0] = 0; | |
1405 | let mut code = 0; | |
1406 | for i in 0..bits.len() { | |
1407 | code = (code + bits[i]) << 1; | |
1408 | pfx[i + 1] = code; | |
1409 | } | |
1410 | ||
1411 | for (len, codes) in lens.iter().zip(codes.iter_mut()) { | |
1412 | let len = *len as usize; | |
1413 | if len != 0 { | |
1414 | let bits = len as u8; | |
1415 | *codes = reverse_bits(pfx[len], bits) as u16; | |
1416 | pfx[len] += 1; | |
1417 | } else { | |
1418 | *codes = 0; | |
1419 | } | |
1420 | } | |
1421 | } | |
1422 | ||
1423 | trait LZParse { | |
1424 | fn parse(&mut self, src: &[u8], dst: &mut Vec<Token>); | |
1425 | } | |
1426 | ||
1427 | struct NoParser {} | |
1428 | impl LZParse for NoParser { | |
1429 | fn parse(&mut self, src: &[u8], dst: &mut Vec<Token>) { | |
1430 | dst.reserve(src.len()); | |
1431 | for &b in src.iter() { | |
1432 | dst.push(Token::from_literal(b)); | |
1433 | } | |
1434 | dst.push(TOKEN_EOB); | |
1435 | } | |
1436 | } | |
1437 | ||
1438 | fn check_match(src1: &[u8], src2: &[u8]) -> u16 { | |
1439 | let mut len = 0; | |
1440 | for (&a, &b) in src1.iter().zip(src2.iter()) { | |
1441 | if a != b { | |
1442 | break; | |
1443 | } | |
1444 | len += 1; | |
1445 | } | |
1446 | len | |
1447 | } | |
1448 | ||
1449 | const HASH_SIZE: usize = 4096; | |
1450 | const MAX_MATCH_LEN: usize = 258; | |
1451 | const WINDOW_SIZE: usize = 32768 - MAX_MATCH_LEN; | |
1452 | const NONEXT: usize = WINDOW_SIZE * 2; | |
1453 | ||
1454 | struct MatchFinder<'a> { | |
1455 | src: &'a [u8], | |
1456 | pos: usize, | |
1457 | hstart: [usize; HASH_SIZE], | |
1458 | hend: [usize; HASH_SIZE], | |
1459 | hnext: [usize; WINDOW_SIZE * 3], | |
1460 | } | |
1461 | ||
1462 | impl<'a> MatchFinder<'a> { | |
1463 | fn new(src: &'a [u8]) -> Self { | |
1464 | let mut obj = Self { | |
1465 | src, | |
1466 | pos: 0, | |
1467 | hstart: [0; HASH_SIZE], | |
1468 | hend: [0; HASH_SIZE], | |
1469 | hnext: [0; WINDOW_SIZE * 3], | |
1470 | }; | |
1471 | obj.build_hash(); | |
1472 | obj | |
1473 | } | |
1474 | fn hash(src: &[u8]) -> usize { | |
1475 | let _ = src[2]; | |
1476 | (((u16::from(src[0]) << 10) ^ (u16::from(src[1]) << 5) ^ u16::from(src[2])) & ((HASH_SIZE as u16) - 1)) as usize | |
1477 | } | |
1478 | fn build_hash(&mut self) { | |
1479 | for el in self.hstart.iter_mut() { *el = NONEXT; } | |
1480 | for el in self.hend.iter_mut() { *el = NONEXT; } | |
1481 | for el in self.hnext.iter_mut() { *el = NONEXT; } | |
1482 | if self.pos + 3 >= self.src.len() { | |
1483 | return; | |
1484 | } | |
1485 | let end = (self.src.len() - 3).min(self.pos + NONEXT); | |
1486 | for i in (self.pos .. end).rev() { | |
1487 | let key = Self::hash(&self.src[i..]); | |
1488 | if self.hstart[key] == NONEXT { | |
1489 | self.hstart[key] = i; | |
1490 | self.hend[key] = i; | |
1491 | self.hnext[key] = NONEXT; | |
1492 | } else { | |
1493 | self.hnext[self.hend[key]] = i; | |
1494 | self.hend[key] = i; | |
1495 | } | |
1496 | } | |
1497 | } | |
1498 | fn find_match(&mut self) -> (u16, u16) { | |
1499 | if self.pos == 0 || self.pos + 3 > self.src.len() { | |
1500 | return (0, 0); | |
1501 | } | |
1502 | let key = Self::hash(&self.src[self.pos..]) as usize; | |
1503 | ||
1504 | let mut best_pos = 0; | |
1505 | let mut best_len = 0; | |
1506 | let mut idx = self.hstart[key]; | |
1507 | while idx != NONEXT && idx + WINDOW_SIZE > self.pos { | |
1508 | if idx < self.pos { | |
1509 | let cur_len = check_match(&self.src[self.pos..], &self.src[idx..]); | |
1510 | if cur_len > best_len { | |
1511 | best_len = cur_len; | |
1512 | best_pos = self.pos - idx; | |
1513 | if best_len >= (MAX_MATCH_LEN as u16) { | |
1514 | return (best_pos as u16, MAX_MATCH_LEN as u16); | |
1515 | } | |
1516 | } | |
1517 | } | |
1518 | idx = self.hnext[idx]; | |
1519 | } | |
1520 | (best_pos as u16, best_len) | |
1521 | } | |
1522 | fn find_all_matches(&mut self, dists: &mut [u16; MAX_MATCH_LEN + 1]) { | |
1523 | if self.pos == 0 || self.pos + 3 > self.src.len() { | |
1524 | return; | |
1525 | } | |
1526 | let key = Self::hash(&self.src[self.pos..]) as usize; | |
1527 | let mut idx = self.hstart[key]; | |
1528 | while idx != NONEXT && idx + WINDOW_SIZE > self.pos { | |
1529 | if idx < self.pos { | |
1530 | let cur_len = (check_match(&self.src[self.pos..], &self.src[idx..]) as usize).min(MAX_MATCH_LEN); | |
1531 | if cur_len > 0 && dists[cur_len] == 0 { | |
1532 | dists[cur_len] = (self.pos - idx) as u16; | |
1533 | } | |
1534 | } | |
1535 | idx = self.hnext[idx]; | |
1536 | } | |
1537 | } | |
1538 | fn advance(&mut self, num: usize) { | |
1539 | self.pos += num; | |
1540 | ||
1541 | if self.pos >= NONEXT { | |
1542 | let (_, tail) = self.src.split_at(self.pos - WINDOW_SIZE); | |
1543 | self.src = tail; | |
1544 | self.pos = WINDOW_SIZE; | |
1545 | self.build_hash(); | |
1546 | } else { | |
1547 | for (start, end) in self.hstart.iter_mut().zip(self.hend.iter_mut()) { | |
1548 | let mut idx = *start; | |
1549 | while idx != NONEXT && idx + WINDOW_SIZE < self.pos { | |
1550 | idx = self.hnext[idx]; | |
1551 | *start = idx; | |
1552 | } | |
1553 | if idx == NONEXT { | |
1554 | *end = NONEXT; | |
1555 | } | |
1556 | } | |
1557 | } | |
1558 | } | |
1559 | fn get_sym(&self) -> u8 { self.src[self.pos] } | |
1560 | fn is_end(&self) -> bool { self.pos >= self.src.len() } | |
1561 | } | |
1562 | ||
1563 | struct GreedyParser {} | |
1564 | impl LZParse for GreedyParser { | |
1565 | fn parse(&mut self, src: &[u8], dst: &mut Vec<Token>) { | |
1566 | dst.reserve(src.len()); | |
1567 | ||
1568 | let mut matcher = MatchFinder::new(src); | |
1569 | while !matcher.is_end() { | |
1570 | let (best_pos, best_len) = matcher.find_match(); | |
1571 | ||
1572 | if best_len >= 3 { | |
1573 | dst.push(Token::from_match(best_pos, best_len)); | |
1574 | matcher.advance(best_len as usize); | |
1575 | } else { | |
1576 | dst.push(Token::from_literal(matcher.get_sym())); | |
1577 | matcher.advance(1); | |
1578 | } | |
1579 | } | |
1580 | dst.push(TOKEN_EOB); | |
1581 | } | |
1582 | } | |
1583 | ||
1584 | struct LazyParser {} | |
1585 | impl LZParse for LazyParser { | |
1586 | fn parse(&mut self, src: &[u8], dst: &mut Vec<Token>) { | |
1587 | dst.reserve(src.len()); | |
1588 | ||
1589 | let mut matcher = MatchFinder::new(src); | |
1590 | while !matcher.is_end() { | |
1591 | let (best_pos, best_len) = matcher.find_match(); | |
1592 | if best_len >= 3 { | |
1593 | let last_sym = matcher.get_sym(); | |
1594 | matcher.advance(1); | |
1595 | if !matcher.is_end() { | |
1596 | let (best_pos1, best_len1) = matcher.find_match(); | |
1597 | if best_len1 > best_len + 1 { | |
1598 | dst.push(Token::from_literal(last_sym)); | |
1599 | dst.push(Token::from_match(best_pos1, best_len1)); | |
1600 | matcher.advance(best_len1 as usize); | |
1601 | continue; | |
1602 | } | |
1603 | } | |
1604 | dst.push(Token::from_match(best_pos, best_len)); | |
1605 | matcher.advance((best_len - 1) as usize); | |
1606 | } else { | |
1607 | dst.push(Token::from_literal(matcher.get_sym())); | |
1608 | matcher.advance(1); | |
1609 | } | |
1610 | } | |
1611 | dst.push(TOKEN_EOB); | |
1612 | } | |
1613 | } | |
1614 | ||
1615 | #[derive(Clone,Copy)] | |
1616 | struct TNode { | |
1617 | price: u32, | |
1618 | dist: u16, | |
1619 | link: usize, | |
1620 | } | |
1621 | ||
1622 | impl Default for TNode { | |
1623 | fn default() -> Self { | |
1624 | Self { | |
1625 | price: std::u32::MAX, | |
1626 | dist: 0, | |
1627 | link: 0, | |
1628 | } | |
1629 | } | |
1630 | } | |
1631 | ||
1632 | struct OptimalParser { | |
1633 | trellis: Vec<TNode>, | |
1634 | } | |
1635 | impl OptimalParser { | |
1636 | fn new() -> Self { Self::default() } | |
1637 | fn sym_price(_sym: u8) -> u32 { 9 } | |
1638 | fn match_price(dist: u16, _len: u16) -> u32 { | |
1639 | if dist <= 4 { | |
1640 | 9 + 5 | |
1641 | } else { | |
1642 | let bits = 16 - (dist - 1).leading_zeros(); | |
1643 | 9 + 3 + bits | |
1644 | } | |
1645 | } | |
1646 | } | |
1647 | impl Default for OptimalParser { | |
1648 | fn default() -> Self { | |
1649 | Self { | |
1650 | trellis: Vec::with_capacity(WINDOW_SIZE), | |
1651 | } | |
1652 | } | |
1653 | } | |
1654 | impl LZParse for OptimalParser { | |
1655 | fn parse(&mut self, src: &[u8], dst: &mut Vec<Token>) { | |
1656 | if src.is_empty() { | |
1657 | dst.push(TOKEN_EOB); | |
1658 | return; | |
1659 | } | |
1660 | dst.reserve(src.len()); | |
1661 | ||
1662 | self.trellis.clear(); | |
1663 | self.trellis.reserve(src.len() + 1); | |
1664 | for _ in 0..=src.len() { | |
1665 | self.trellis.push(TNode::default()); | |
1666 | } | |
1667 | self.trellis[0].price = 0; | |
1668 | ||
1669 | let mut matcher = MatchFinder::new(src); | |
1670 | for i in 0..self.trellis.len() - 1 { | |
1671 | let mut dists = [0; MAX_MATCH_LEN + 1]; | |
1672 | matcher.find_all_matches(&mut dists); | |
1673 | ||
1674 | let sym = matcher.get_sym(); | |
1675 | let lprice = Self::sym_price(sym) + self.trellis[i].price; | |
1676 | if self.trellis[i + 1].price > lprice { | |
1677 | self.trellis[i + 1].price = lprice; | |
1678 | self.trellis[i + 1].link = i; | |
1679 | } | |
1680 | for (len, &dist) in dists.iter().enumerate() { | |
1681 | if dist != 0 { | |
1682 | let mprice = Self::match_price(dist, len as u16) + self.trellis[i].price; | |
1683 | if self.trellis[i + len].price > mprice { | |
1684 | self.trellis[i + len].price = mprice; | |
1685 | self.trellis[i + len].link = i; | |
1686 | self.trellis[i].dist = dist; | |
1687 | } | |
1688 | } | |
1689 | } | |
1690 | ||
1691 | matcher.advance(1); | |
1692 | } | |
1693 | let mut idx = self.trellis.len() - 1; | |
1694 | let mut nidx = self.trellis[idx].link; | |
1695 | while idx > 0 { | |
1696 | let oidx = idx; | |
1697 | idx = nidx; | |
1698 | nidx = self.trellis[idx].link; | |
1699 | self.trellis[idx].link = oidx; | |
1700 | } | |
1701 | ||
1702 | let mut idx = 0; | |
1703 | while idx < self.trellis.len() - 1 { | |
1704 | let len = self.trellis[idx].link - idx; | |
1705 | if len == 1 { | |
1706 | dst.push(Token::from_literal(src[idx])); | |
1707 | } else { | |
1708 | dst.push(Token::from_match(self.trellis[idx].dist, len as u16)); | |
1709 | } | |
1710 | idx = self.trellis[idx].link; | |
1711 | } | |
1712 | ||
1713 | dst.push(TOKEN_EOB); | |
1714 | } | |
1715 | } | |
1716 | ||
1717 | ///! Deflate compression mode. | |
1718 | #[derive(Clone,Copy,Debug,PartialEq)] | |
1719 | pub enum DeflateMode { | |
1720 | ///! No compression. | |
1721 | NoCompr, | |
1722 | ///! Fast compression. | |
1723 | Fast, | |
1724 | ///! Still fast but better compression. | |
1725 | Better, | |
1726 | ///! Slow but the best compression. | |
1727 | Best, | |
1728 | } | |
1729 | ||
1730 | impl Default for DeflateMode { | |
1731 | fn default() -> Self { DeflateMode::Better } | |
1732 | } | |
1733 | ||
1734 | pub const DEFLATE_MODE_DESCRIPTION: &str = "Deflate compression level."; | |
1735 | ///! Deflate option for no compression. | |
1736 | pub const DEFLATE_MODE_NONE: &str = "none"; | |
1737 | ///! Deflate option for fast compression. | |
1738 | pub const DEFLATE_MODE_FAST: &str = "fast"; | |
1739 | ///! Deflate option for better compression. | |
1740 | pub const DEFLATE_MODE_BETTER: &str = "better"; | |
1741 | ///! Deflate option for best compression. | |
1742 | pub const DEFLATE_MODE_BEST: &str = "best"; | |
1743 | ||
1744 | ///! All possible option values for deflate compression. | |
1745 | pub const DEFLATE_OPTION_VALUES: NAOptionDefinitionType = NAOptionDefinitionType::String(Some(&[DEFLATE_MODE_NONE, DEFLATE_MODE_FAST, DEFLATE_MODE_BETTER, DEFLATE_MODE_BEST])); | |
1746 | ||
1747 | impl std::str::FromStr for DeflateMode { | |
1748 | type Err = (); | |
1749 | ||
1750 | fn from_str(s: &str) -> Result<Self, Self::Err> { | |
1751 | match s { | |
1752 | DEFLATE_MODE_NONE => Ok(DeflateMode::NoCompr), | |
1753 | DEFLATE_MODE_FAST => Ok(DeflateMode::Fast), | |
1754 | DEFLATE_MODE_BETTER => Ok(DeflateMode::Better), | |
1755 | DEFLATE_MODE_BEST => Ok(DeflateMode::Best), | |
1756 | _ => Err(()), | |
1757 | } | |
1758 | } | |
1759 | } | |
1760 | ||
1761 | impl ToString for DeflateMode { | |
1762 | fn to_string(&self) -> String { | |
1763 | match *self { | |
1764 | DeflateMode::NoCompr => DEFLATE_MODE_NONE.to_string(), | |
1765 | DeflateMode::Fast => DEFLATE_MODE_FAST.to_string(), | |
1766 | DeflateMode::Better => DEFLATE_MODE_BETTER.to_string(), | |
1767 | DeflateMode::Best => DEFLATE_MODE_BEST.to_string(), | |
1768 | } | |
1769 | } | |
1770 | } | |
1771 | ||
1772 | #[derive(Clone,Copy,Debug,PartialEq)] | |
1773 | enum Mode { | |
1774 | Copy, | |
1775 | Fixed, | |
1776 | Dynamic, | |
1777 | } | |
1778 | ||
1779 | const MAX_BLOCK_SIZE: usize = 65535; | |
1780 | ||
1781 | ///! Deflate stream compressor. | |
1782 | pub struct Deflate { | |
1783 | mode: Mode, | |
1784 | tokens: Vec<Token>, | |
1785 | srcbuf: [u8; MAX_BLOCK_SIZE], | |
1786 | ssize: usize, | |
1787 | sum1: u32, | |
1788 | sum2: u32, | |
1789 | zlib_mode: bool, | |
1790 | parser: Box<dyn LZParse + Send>, | |
1791 | } | |
1792 | ||
1793 | impl Deflate { | |
1794 | ///! Creates a new instance of `Deflate`. | |
1795 | pub fn new(mode: DeflateMode) -> Self { | |
1796 | let (mode, parser) = match mode { | |
1797 | DeflateMode::NoCompr => (Mode::Copy, Box::new(NoParser{}) as Box<dyn LZParse + Send>), | |
1798 | DeflateMode::Fast => (Mode::Fixed, Box::new(GreedyParser{}) as Box<dyn LZParse + Send>), | |
1799 | DeflateMode::Better => (Mode::Dynamic, Box::new(LazyParser{}) as Box<dyn LZParse + Send>), | |
1800 | DeflateMode::Best => (Mode::Dynamic, Box::new(OptimalParser::new()) as Box<dyn LZParse + Send>), | |
1801 | }; | |
1802 | Self { | |
1803 | mode, parser, | |
1804 | tokens: Vec::with_capacity(MAX_BLOCK_SIZE), | |
1805 | srcbuf: [0; MAX_BLOCK_SIZE], | |
1806 | ssize: 0, | |
1807 | sum1: 1, | |
1808 | sum2: 0, | |
1809 | zlib_mode: false, | |
1810 | } | |
1811 | } | |
1812 | ///! Writes zlib stream header. | |
1813 | pub fn write_zlib_header(&mut self, wr: &mut DeflateWriter) { | |
1814 | wr.write(8, 4); | |
1815 | wr.write(7, 4); | |
1816 | let level = match self.mode { | |
1817 | Mode::Copy => 0x01, | |
1818 | Mode::Fixed => 0x5E, | |
1819 | Mode::Dynamic => 0x9C, | |
1820 | // 0xDA for the strongest one | |
1821 | }; | |
1822 | wr.write(level, 8); | |
1823 | self.zlib_mode = true; | |
1824 | } | |
1825 | fn write_zlib_footer(&self, wr: &mut DeflateWriter) { | |
1826 | wr.align(); | |
1827 | wr.write((self.sum2 >> 8) as u16, 8); | |
1828 | wr.write((self.sum2 & 0xFF) as u16, 8); | |
1829 | wr.write((self.sum1 >> 8) as u16, 8); | |
1830 | wr.write((self.sum1 & 0xFF) as u16, 8); | |
1831 | } | |
1832 | ///! Queues data for compression. | |
1833 | ///! | |
1834 | ///! The data might be not actually compressed until [`compress_end`] is called. | |
1835 | ///! | |
1836 | ///! [`compress_end`]: ./struct.Deflate.html#method.compress_end | |
1837 | pub fn compress(&mut self, src: &[u8], wr: &mut DeflateWriter) { | |
1838 | let mut src = src; | |
1839 | while !src.is_empty() { | |
1840 | let clen = src.len().min(MAX_BLOCK_SIZE - self.ssize); | |
1841 | let (head, tail) = src.split_at(clen); | |
1842 | src = tail; | |
1843 | self.srcbuf[self.ssize..][..clen].copy_from_slice(head); | |
1844 | self.ssize += clen; | |
1845 | if self.ssize == MAX_BLOCK_SIZE { | |
1846 | self.do_block(wr, false); | |
1847 | } | |
1848 | } | |
1849 | } | |
1850 | ///! Tells the encoder to finish data compression. | |
1851 | ///! | |
1852 | ///! Complete data will be output after this call. | |
1853 | pub fn compress_end(&mut self, wr: &mut DeflateWriter) { | |
1854 | if self.ssize > 0 { | |
1855 | self.do_block(wr, true); | |
1856 | } else { | |
1857 | wr.write(1, 1); | |
1858 | wr.write(1, 2); | |
1859 | wr.write(0, 7); //static EOF sym | |
1860 | } | |
1861 | if self.zlib_mode { | |
1862 | self.write_zlib_footer(wr); | |
1863 | } | |
1864 | } | |
1865 | ///! Tells the encoder to compress the data it received and flush it. | |
1866 | pub fn compress_flush(&mut self, wr: &mut DeflateWriter) { | |
1867 | if self.ssize > 0 { | |
1868 | self.do_block(wr, false); | |
1869 | } | |
1870 | if (wr.bits & 7) != 0 { | |
1871 | // write zero-length copy block for byte-alignment | |
1872 | wr.write(0, 1); | |
1873 | wr.write(0, 2); | |
1874 | wr.align(); | |
1875 | wr.write(0, 16); | |
1876 | wr.write(0xFFFF, 16); | |
1877 | } | |
1878 | } | |
1879 | fn do_block(&mut self, wr: &mut DeflateWriter, final_block: bool) { | |
1880 | const CRC_BASE: u32 = 65521; | |
1881 | for &b in self.srcbuf[..self.ssize].iter() { | |
1882 | self.sum1 += u32::from(b); | |
1883 | if self.sum1 >= CRC_BASE { | |
1884 | self.sum1 -= CRC_BASE; | |
1885 | } | |
1886 | self.sum2 += self.sum1; | |
1887 | if self.sum2 >= CRC_BASE { | |
1888 | self.sum2 -= CRC_BASE; | |
1889 | } | |
1890 | } | |
1891 | match self.mode { | |
1892 | Mode::Copy => { | |
1893 | wr.write(final_block as u16, 1); | |
1894 | wr.write(0, 2); | |
1895 | wr.align(); | |
1896 | wr.write(self.ssize as u16, 16); | |
1897 | wr.write(!self.ssize as u16, 16); | |
1898 | for &b in self.srcbuf[..self.ssize].iter() { | |
1899 | wr.write(u16::from(b), 8); | |
1900 | } | |
1901 | }, | |
1902 | Mode::Fixed => { | |
1903 | wr.write(final_block as u16, 1); | |
1904 | wr.write(1, 2); | |
1905 | self.tokens.clear(); | |
1906 | self.parser.parse(&self.srcbuf[..self.ssize], &mut self.tokens); | |
1907 | let mut codes = CodeHuff::new(true); | |
1908 | codes.make_codes(&self.tokens); | |
1909 | let mut dists = DistHuff::new(true); | |
1910 | dists.make_codes(&self.tokens); | |
1911 | wr.write_tokens(&self.tokens, &codes, &dists); | |
1912 | }, | |
1913 | Mode::Dynamic => { | |
1914 | wr.write(final_block as u16, 1); | |
1915 | wr.write(2, 2); | |
1916 | self.tokens.clear(); | |
1917 | self.parser.parse(&self.srcbuf[..self.ssize], &mut self.tokens); | |
1918 | let mut codes = CodeHuff::new(false); | |
1919 | codes.make_codes(&self.tokens); | |
1920 | let mut dists = DistHuff::new(false); | |
1921 | dists.make_codes(&self.tokens); | |
1922 | wr.write((codes.num_codes - 257) as u16, 5); | |
1923 | wr.write((dists.num_codes - 1) as u16, 5); | |
1924 | wr.write_codes(&codes, &dists); | |
1925 | wr.write_tokens(&self.tokens, &codes, &dists); | |
1926 | }, | |
1927 | } | |
1928 | self.ssize = 0; | |
1929 | } | |
1930 | } | |
1931 | ||
1932 | #[cfg(test)] | |
1933 | mod test { | |
1934 | use super::*; | |
1935 | ||
1936 | #[test] | |
1937 | fn test_inflate1() { | |
1938 | const TEST_DATA: &[u8] = &[ | |
1939 | 0xF3, 0x48, 0xCD, 0xC9, 0xC9, 0xD7, 0x51, 0x28, | |
1940 | 0xCF, 0x2F, 0xCA, 0x49, 0x51, 0x04, 0x00 ]; | |
1941 | const TEST_REF: &[u8] = b"Hello, world!"; | |
1942 | let mut dst_buf = [0u8; 13]; | |
1943 | let len = Inflate::uncompress(TEST_DATA, &mut dst_buf).unwrap(); | |
1944 | assert_eq!(len, 13); | |
1945 | for i in 0..len { | |
1946 | assert_eq!(dst_buf[i], TEST_REF[i]); | |
1947 | } | |
1948 | } | |
1949 | #[test] | |
1950 | fn test_inflate2() { | |
1951 | const TEST_DATA3: &[u8] = &[ 0x4B, 0x4C, 0x44, 0x80, 0x24, 0x54, 0x80, 0x2C, 0x06, 0x00 ]; | |
1952 | const TEST_REF3: &[u8] = b"aaaaaaaaaaaabbbbbbbbbbbbbbbaaaaabbbbbbb"; | |
1953 | let mut dst_buf = [0u8; 39]; | |
1954 | ||
1955 | let mut inflate = Inflate::new(); | |
1956 | let mut output_chunk = [0u8; 7]; | |
1957 | let mut output_pos = 0; | |
1958 | for input in TEST_DATA3.chunks(3) { | |
1959 | let mut repeat = false; | |
1960 | loop { | |
1961 | let ret = inflate.decompress_data(input, &mut output_chunk, repeat); | |
1962 | match ret { | |
1963 | Ok(len) => { | |
1964 | for i in 0..len { | |
1965 | dst_buf[output_pos + i] = output_chunk[i]; | |
1966 | } | |
1967 | output_pos += len; | |
1968 | break; | |
1969 | }, | |
1970 | Err(DecompressError::ShortData) => { | |
1971 | break; | |
1972 | }, | |
1973 | Err(DecompressError::OutputFull) => { | |
1974 | repeat = true; | |
1975 | for i in 0..output_chunk.len() { | |
1976 | dst_buf[output_pos + i] = output_chunk[i]; | |
1977 | } | |
1978 | output_pos += output_chunk.len(); | |
1979 | }, | |
1980 | _ => { | |
1981 | panic!("decompress error {:?}", ret.err().unwrap()); | |
1982 | }, | |
1983 | } | |
1984 | } | |
1985 | } | |
1986 | ||
1987 | assert_eq!(output_pos, dst_buf.len()); | |
1988 | for i in 0..output_pos { | |
1989 | assert_eq!(dst_buf[i], TEST_REF3[i]); | |
1990 | } | |
1991 | } | |
1992 | #[test] | |
1993 | fn test_inflate3() { | |
1994 | const TEST_DATA: &[u8] = &[ | |
1995 | 0x1F, 0x8B, 0x08, 0x08, 0xF6, 0x7B, 0x90, 0x5E, 0x02, 0x03, 0x31, 0x2E, 0x74, 0x78, 0x74, 0x00, | |
1996 | 0xE5, 0x95, 0x4B, 0x4E, 0xC3, 0x30, 0x10, 0x40, 0xF7, 0x39, 0xC5, 0x1C, 0x00, 0x16, 0x70, 0x83, | |
1997 | 0x0A, 0xB5, 0x3B, 0xE8, 0x82, 0x5E, 0x60, 0x1A, 0x4F, 0xE2, 0x11, 0xFE, 0x44, 0x1E, 0xA7, 0x69, | |
1998 | 0x6E, 0xCF, 0x38, 0xDD, 0xB0, 0x40, 0xA2, 0x46, 0x2D, 0x20, 0x2A, 0xE5, 0xAB, 0xCC, 0xE7, 0xBD, | |
1999 | 0x49, 0xAC, 0x6C, 0x03, 0x64, 0x4B, 0xD0, 0x71, 0x92, 0x0C, 0x06, 0x67, 0x88, 0x1D, 0x3C, 0xD9, | |
2000 | 0xC4, 0x92, 0x3D, 0x4A, 0xF3, 0x3C, 0x43, 0x4E, 0x23, 0x81, 0x8B, 0x07, 0x82, 0x1E, 0xF5, 0x90, | |
2001 | 0x23, 0x78, 0x6A, 0x56, 0x30, 0x60, 0xCA, 0x89, 0x4D, 0x4F, 0xC0, 0x01, 0x10, 0x06, 0xC2, 0xA4, | |
2002 | 0xA1, 0x44, 0xCD, 0xF6, 0x54, 0x50, 0xA8, 0x8D, 0xC1, 0x9C, 0x5F, 0x71, 0x37, 0x45, 0xC8, 0x63, | |
2003 | 0xCA, 0x8E, 0xC0, 0xE8, 0x23, 0x69, 0x56, 0x9A, 0x8D, 0x5F, 0xB6, 0xC9, 0x96, 0x53, 0x4D, 0x17, | |
2004 | 0xAB, 0xB9, 0xB0, 0x49, 0x14, 0x5A, 0x0B, 0x96, 0x82, 0x7C, 0xB7, 0x6F, 0x17, 0x35, 0xC7, 0x9E, | |
2005 | 0xDF, 0x78, 0xA3, 0xF1, 0xD0, 0xA2, 0x73, 0x1C, 0x7A, 0xD8, 0x2B, 0xB3, 0x5C, 0x90, 0x85, 0xBB, | |
2006 | 0x2A, 0x14, 0x2E, 0xF7, 0xD1, 0x19, 0x48, 0x0A, 0x23, 0x57, 0x45, 0x13, 0x3E, 0xD6, 0xA0, 0xBD, | |
2007 | 0xF2, 0x11, 0x7A, 0x22, 0x21, 0xAD, 0xE5, 0x70, 0x56, 0xA0, 0x9F, 0xA5, 0xA5, 0x03, 0x85, 0x2A, | |
2008 | 0xDE, 0x92, 0x00, 0x32, 0x61, 0x10, 0xAD, 0x27, 0x13, 0x7B, 0x5F, 0x98, 0x7F, 0x59, 0x83, 0xB8, | |
2009 | 0xB7, 0x35, 0x16, 0xEB, 0x12, 0x0F, 0x1E, 0xD9, 0x14, 0x0B, 0xCF, 0xEE, 0x6D, 0x91, 0xF8, 0x93, | |
2010 | 0x6E, 0x81, 0x3F, 0x7F, 0x41, 0xA4, 0x22, 0x1F, 0xB7, 0xE6, 0x85, 0x83, 0x9A, 0xA2, 0x61, 0x12, | |
2011 | 0x0D, 0x0F, 0x6D, 0x01, 0xBD, 0xB0, 0xE8, 0x1D, 0xEC, 0xD1, 0xA0, 0xBF, 0x1F, 0x4E, 0xFB, 0x55, | |
2012 | 0xBD, 0x73, 0xDD, 0x87, 0xB9, 0x53, 0x23, 0x17, 0xD3, 0xE2, 0xE9, 0x08, 0x87, 0x42, 0xFF, 0xCF, | |
2013 | 0x26, 0x42, 0xAE, 0x76, 0xB5, 0xAE, 0x97, 0x0C, 0x18, 0x78, 0xA0, 0x24, 0xE5, 0x54, 0x0C, 0x6E, | |
2014 | 0x60, 0x52, 0x79, 0x22, 0x57, 0xF5, 0x87, 0x78, 0x78, 0x04, 0x93, 0x46, 0xEF, 0xCB, 0x98, 0x96, | |
2015 | 0x8B, 0x65, 0x00, 0xB7, 0x36, 0xBD, 0x77, 0xA8, 0xBD, 0x5A, 0xAA, 0x1A, 0x09, 0x00, 0x00 | |
2016 | ]; | |
2017 | ||
2018 | let mut mr = MemoryReader::new_read(TEST_DATA); | |
2019 | let mut br = ByteReader::new(&mut mr); | |
2020 | let _dst_buf = gzip_decode(&mut br, false).unwrap(); | |
2021 | ||
2022 | // println!("{}", String::from_utf8_lossy(_dst_buf.as_slice())); | |
2023 | } | |
2024 | #[test] | |
2025 | fn test_deflate_crc() { | |
2026 | let output = Vec::with_capacity(20); | |
2027 | let mut writer = DeflateWriter::new(output); | |
2028 | let mut compr = Deflate::new(DeflateMode::NoCompr); | |
2029 | compr.write_zlib_header(&mut writer); | |
2030 | compr.compress(b"Hello, world!", &mut writer); | |
2031 | compr.compress_end(&mut writer); | |
2032 | let output = writer.end(); | |
2033 | assert_eq!(output.as_slice(), b"\x78\x01\x01\x0D\x00\xF2\xFFHello, world!\x20\x5E\x04\x8A"); | |
2034 | } | |
2035 | fn deflate_test(mode: DeflateMode) { | |
2036 | const SRC: &[u8] = | |
2037 | b"The first day of Christmas, | |
2038 | My true love sent to me | |
2039 | A partridge in a pear tree. | |
2040 | ||
2041 | The second day of Christmas, | |
2042 | My true love sent to me | |
2043 | Two turtle doves, and | |
2044 | A partridge in a pear tree. | |
2045 | ||
2046 | The third day of Christmas, | |
2047 | My true love sent to me | |
2048 | Three French hens, | |
2049 | Two turtle doves, and | |
2050 | A partridge in a pear tree. | |
2051 | ||
2052 | The fourth day of Christmas, | |
2053 | My true love sent to me | |
2054 | Four colly birds, | |
2055 | Three French hens, | |
2056 | Two turtle doves, and | |
2057 | A partridge in a pear tree. | |
2058 | ||
2059 | The fifth day of Christmas, | |
2060 | My true love sent to me | |
2061 | Five gold rings, | |
2062 | Four colly birds, | |
2063 | Three French hens, | |
2064 | Two turtle doves, and | |
2065 | A partridge in a pear tree."; | |
2066 | let output = Vec::with_capacity(SRC.len() + 16); | |
2067 | let mut writer = DeflateWriter::new(output); | |
2068 | let mut compr = Deflate::new(mode); | |
2069 | compr.write_zlib_header(&mut writer); | |
2070 | compr.compress(SRC, &mut writer); | |
2071 | compr.compress_end(&mut writer); | |
2072 | let output = writer.end(); | |
2073 | let mut uncompr = vec![0u8; SRC.len()]; | |
2074 | Inflate::uncompress(&output, &mut uncompr).unwrap(); | |
2075 | assert_eq!(SRC, uncompr.as_slice()); | |
2076 | } | |
2077 | #[test] | |
2078 | fn test_deflate_fast() { | |
2079 | deflate_test(DeflateMode::Fast); | |
2080 | } | |
2081 | #[test] | |
2082 | fn test_deflate_better() { | |
2083 | deflate_test(DeflateMode::Better); | |
2084 | } | |
2085 | #[test] | |
2086 | fn test_deflate_best() { | |
2087 | deflate_test(DeflateMode::Best); | |
2088 | } | |
2089 | } |