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Use C-style comments in the brotli decoder.

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This commit is contained in:
Zoltan Szabadka 2013-12-16 14:45:57 +01:00
parent 29bb7cb1af
commit b8a1008569
13 changed files with 491 additions and 476 deletions
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33
dec/bit_reader.c
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@ -1,18 +1,19 @@
// Copyright 2013 Google Inc. All Rights Reserved.
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
// http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.
//
// Bit reading helpers
/* Copyright 2013 Google Inc. All Rights Reserved.
Licensed under the Apache License, Version 2.0 (the "License");
you may not use this file except in compliance with the License.
You may obtain a copy of the License at
http://www.apache.org/licenses/LICENSE-2.0
Unless required by applicable law or agreed to in writing, software
distributed under the License is distributed on an "AS IS" BASIS,
WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
See the License for the specific language governing permissions and
limitations under the License.
Bit reading helpers
*/
#include <assert.h>
#include <stdlib.h>
@ -44,5 +45,5 @@ int BrotliInitBitReader(BrotliBitReader* const br, BrotliInput input) {
}
#if defined(__cplusplus) || defined(c_plusplus)
} // extern "C"
} /* extern "C" */
#endif

96
dec/bit_reader.h
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@ -1,18 +1,19 @@
// Copyright 2013 Google Inc. All Rights Reserved.
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
// http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.
//
// Bit reading helpers
/* Copyright 2013 Google Inc. All Rights Reserved.
Licensed under the Apache License, Version 2.0 (the "License");
you may not use this file except in compliance with the License.
You may obtain a copy of the License at
http://www.apache.org/licenses/LICENSE-2.0
Unless required by applicable law or agreed to in writing, software
distributed under the License is distributed on an "AS IS" BASIS,
WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
See the License for the specific language governing permissions and
limitations under the License.
Bit reading helpers
*/
#ifndef BROTLI_DEC_BIT_READER_H_
#define BROTLI_DEC_BIT_READER_H_
@ -38,26 +39,26 @@ static const uint32_t kBitMask[BROTLI_MAX_NUM_BIT_READ] = {
};
typedef struct {
// Input byte buffer, consist of a ringbuffer and a "slack" region where
// bytes from the start of the ringbuffer are copied.
/* Input byte buffer, consist of a ringbuffer and a "slack" region where */
/* bytes from the start of the ringbuffer are copied. */
uint8_t buf_[BROTLI_IBUF_SIZE];
BrotliInput input_; // input callback
uint64_t val_; // pre-fetched bits
size_t pos_; // byte position in stream
int bit_pos_; // current bit-reading position in val_
size_t end_pos_; // current end position in stream
int eos_; // input stream is finished
BrotliInput input_; /* input callback */
uint64_t val_; /* pre-fetched bits */
size_t pos_; /* byte position in stream */
int bit_pos_; /* current bit-reading position in val_ */
size_t end_pos_; /* current end position in stream */
int eos_; /* input stream is finished */
} BrotliBitReader;
int BrotliInitBitReader(BrotliBitReader* const br, BrotliInput input);
// Return the prefetched bits, so they can be looked up.
/* Return the prefetched bits, so they can be looked up. */
static BROTLI_INLINE uint32_t BrotliPrefetchBits(BrotliBitReader* const br) {
return (uint32_t)(br->val_ >> br->bit_pos_);
}
// For jumping over a number of bits in the bit stream when accessed with
// BrotliPrefetchBits and BrotliFillBitWindow.
/* For jumping over a number of bits in the bit stream when accessed with */
/* BrotliPrefetchBits and BrotliFillBitWindow. */
static BROTLI_INLINE void BrotliSetBitPos(BrotliBitReader* const br, int val) {
#ifdef BROTLI_DECODE_DEBUG
int n_bits = val - br->bit_pos_;
@ -68,7 +69,7 @@ static BROTLI_INLINE void BrotliSetBitPos(BrotliBitReader* const br, int val) {
br->bit_pos_ = val;
}
// Reload up to 64 bits byte-by-byte
/* Reload up to 64 bits byte-by-byte */
static BROTLI_INLINE void ShiftBytes(BrotliBitReader* const br) {
while (br->bit_pos_ >= 8) {
br->val_ >>= 8;
@ -78,17 +79,18 @@ static BROTLI_INLINE void ShiftBytes(BrotliBitReader* const br) {
}
}
// Fills up the input ringbuffer by calling the input callback.
//
// Does nothing if there are at least 32 bytes present after current position.
//
// Returns 0 if either:
// - the input callback returned an error, or
// - there is no more input and the position is past the end of the stream.
//
// After encountering the end of the input stream, 32 additional zero bytes are
// copied to the ringbuffer, therefore it is safe to call this function after
// every 32 bytes of input is read.
/* Fills up the input ringbuffer by calling the input callback.
Does nothing if there are at least 32 bytes present after current position.
Returns 0 if either:
- the input callback returned an error, or
- there is no more input and the position is past the end of the stream.
After encountering the end of the input stream, 32 additional zero bytes are
copied to the ringbuffer, therefore it is safe to call this function after
every 32 bytes of input is read.
*/
static BROTLI_INLINE int BrotliReadMoreInput(BrotliBitReader* const br) {
if (br->pos_ + 32 < br->end_pos_) {
return 1;
@ -102,7 +104,7 @@ static BROTLI_INLINE int BrotliReadMoreInput(BrotliBitReader* const br) {
}
if (bytes_read < BROTLI_READ_SIZE) {
br->eos_ = 1;
// Store 32 bytes of zero after the stream end.
/* Store 32 bytes of zero after the stream end. */
#if (defined(__x86_64__) || defined(_M_X64))
*(uint64_t*)(dst + bytes_read) = 0;
*(uint64_t*)(dst + bytes_read + 8) = 0;
@ -113,7 +115,7 @@ static BROTLI_INLINE int BrotliReadMoreInput(BrotliBitReader* const br) {
#endif
}
if (dst == br->buf_) {
// Copy the head of the ringbuffer to the slack region.
/* Copy the head of the ringbuffer to the slack region. */
#if (defined(__x86_64__) || defined(_M_X64))
UNALIGNED_COPY64(br->buf_ + BROTLI_IBUF_SIZE - 32, br->buf_);
UNALIGNED_COPY64(br->buf_ + BROTLI_IBUF_SIZE - 24, br->buf_ + 8);
@ -128,14 +130,14 @@ static BROTLI_INLINE int BrotliReadMoreInput(BrotliBitReader* const br) {
}
}
// Advances the Read buffer by 5 bytes to make room for reading next 24 bits.
/* Advances the Read buffer by 5 bytes to make room for reading next 24 bits. */
static BROTLI_INLINE void BrotliFillBitWindow(BrotliBitReader* const br) {
if (br->bit_pos_ >= 40) {
#if (defined(__x86_64__) || defined(_M_X64))
br->val_ >>= 40;
br->bit_pos_ -= 40;
// The expression below needs a little-endian arch to work correctly.
// This gives a large speedup for decoding speed.
/* The expression below needs a little-endian arch to work correctly. */
/* This gives a large speedup for decoding speed. */
br->val_ |= *(const uint64_t*)(
br->buf_ + (br->pos_ & BROTLI_IBUF_MASK)) << 24;
br->pos_ += 5;
@ -145,8 +147,8 @@ static BROTLI_INLINE void BrotliFillBitWindow(BrotliBitReader* const br) {
}
}
// Reads the specified number of bits from Read Buffer.
// Requires that n_bits is positive.
/* Reads the specified number of bits from Read Buffer. */
/* Requires that n_bits is positive. */
static BROTLI_INLINE uint32_t BrotliReadBits(
BrotliBitReader* const br, int n_bits) {
uint32_t val;
@ -161,7 +163,7 @@ static BROTLI_INLINE uint32_t BrotliReadBits(
}
#if defined(__cplusplus) || defined(c_plusplus)
} // extern "C"
} /* extern "C" */
#endif
#endif // BROTLI_DEC_BIT_READER_H_
#endif /* BROTLI_DEC_BIT_READER_H_ */

249
dec/context.h
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@ -1,107 +1,108 @@
// Copyright 2013 Google Inc. All Rights Reserved.
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
// http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.
//
// Lookup table to map the previous two bytes to a context id.
//
// There are four different context modeling modes defined here:
// CONTEXT_LSB6: context id is the least significant 6 bits of the last byte,
// CONTEXT_MSB6: context id is the most significant 6 bits of the last byte,
// CONTEXT_UTF8: second-order context model tuned for UTF8-encoded text,
// CONTEXT_SIGNED: second-order context model tuned for signed integers.
//
// The context id for the UTF8 context model is calculated as follows. If p1
// and p2 are the previous two bytes, we calcualte the context as
//
// context = kContextLookup[p1] | kContextLookup[p2 + 256].
//
// If the previous two bytes are ASCII characters (i.e. < 128), this will be
// equivalent to
//
// context = 4 * context1(p1) + context2(p2),
//
// where context1 is based on the previous byte in the following way:
//
// 0 : non-ASCII control
// 1 : \t, \n, \r
// 2 : space
// 3 : other punctuation
// 4 : " '
// 5 : %
// 6 : ( < [ {
// 7 : ) > ] }
// 8 : , ; :
// 9 : .
// 10 : =
// 11 : number
// 12 : upper-case vowel
// 13 : upper-case consonant
// 14 : lower-case vowel
// 15 : lower-case consonant
//
// and context2 is based on the second last byte:
//
// 0 : control, space
// 1 : punctuation
// 2 : upper-case letter, number
// 3 : lower-case letter
//
// If the last byte is ASCII, and the second last byte is not (in a valid UTF8
// stream it will be a continuation byte, value between 128 and 191), the
// context is the same as if the second last byte was an ASCII control or space.
//
// If the last byte is a UTF8 lead byte (value >= 192), then the next byte will
// be a continuation byte and the context id is 2 or 3 depending on the LSB of
// the last byte and to a lesser extent on the second last byte if it is ASCII.
//
// If the last byte is a UTF8 continuation byte, the second last byte can be:
// - continuation byte: the next byte is probably ASCII or lead byte (assuming
// 4-byte UTF8 characters are rare) and the context id is 0 or 1.
// - lead byte (192 - 207): next byte is ASCII or lead byte, context is 0 or 1
// - lead byte (208 - 255): next byte is continuation byte, context is 2 or 3
//
// The possible value combinations of the previous two bytes, the range of
// context ids and the type of the next byte is summarized in the table below:
//
// |--------\-----------------------------------------------------------------|
// | \ Last byte |
// | Second \---------------------------------------------------------------|
// | last byte \ ASCII | cont. byte | lead byte |
// | \ (0-127) | (128-191) | (192-) |
// |=============|===================|=====================|==================|
// | ASCII | next: ASCII/lead | not valid | next: cont. |
// | (0-127) | context: 4 - 63 | | context: 2 - 3 |
// |-------------|-------------------|---------------------|------------------|
// | cont. byte | next: ASCII/lead | next: ASCII/lead | next: cont. |
// | (128-191) | context: 4 - 63 | context: 0 - 1 | context: 2 - 3 |
// |-------------|-------------------|---------------------|------------------|
// | lead byte | not valid | next: ASCII/lead | not valid |
// | (192-207) | | context: 0 - 1 | |
// |-------------|-------------------|---------------------|------------------|
// | lead byte | not valid | next: cont. | not valid |
// | (208-) | | context: 2 - 3 | |
// |-------------|-------------------|---------------------|------------------|
//
// The context id for the signed context mode is calculated as:
//
// context = (kContextLookup[512 + p1] << 3) | kContextLookup[512 + p2].
//
// For any context modeling modes, the context ids can be calculated by |-ing
// together two lookups from one table using context model dependent offsets:
//
// context = kContextLookup[offset1 + p1] | kContextLookup[offset2 + p2].
//
// where offset1 and offset2 are dependent on the context mode.
/* Copyright 2013 Google Inc. All Rights Reserved.
Licensed under the Apache License, Version 2.0 (the "License");
you may not use this file except in compliance with the License.
You may obtain a copy of the License at
http://www.apache.org/licenses/LICENSE-2.0
Unless required by applicable law or agreed to in writing, software
distributed under the License is distributed on an "AS IS" BASIS,
WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
See the License for the specific language governing permissions and
limitations under the License.
Lookup table to map the previous two bytes to a context id.
There are four different context modeling modes defined here:
CONTEXT_LSB6: context id is the least significant 6 bits of the last byte,
CONTEXT_MSB6: context id is the most significant 6 bits of the last byte,
CONTEXT_UTF8: second-order context model tuned for UTF8-encoded text,
CONTEXT_SIGNED: second-order context model tuned for signed integers.
The context id for the UTF8 context model is calculated as follows. If p1
and p2 are the previous two bytes, we calcualte the context as
context = kContextLookup[p1] | kContextLookup[p2 + 256].
If the previous two bytes are ASCII characters (i.e. < 128), this will be
equivalent to
context = 4 * context1(p1) + context2(p2),
where context1 is based on the previous byte in the following way:
0 : non-ASCII control
1 : \t, \n, \r
2 : space
3 : other punctuation
4 : " '
5 : %
6 : ( < [ {
7 : ) > ] }
8 : , ; :
9 : .
10 : =
11 : number
12 : upper-case vowel
13 : upper-case consonant
14 : lower-case vowel
15 : lower-case consonant
and context2 is based on the second last byte:
0 : control, space
1 : punctuation
2 : upper-case letter, number
3 : lower-case letter
If the last byte is ASCII, and the second last byte is not (in a valid UTF8
stream it will be a continuation byte, value between 128 and 191), the
context is the same as if the second last byte was an ASCII control or space.
If the last byte is a UTF8 lead byte (value >= 192), then the next byte will
be a continuation byte and the context id is 2 or 3 depending on the LSB of
the last byte and to a lesser extent on the second last byte if it is ASCII.
If the last byte is a UTF8 continuation byte, the second last byte can be:
- continuation byte: the next byte is probably ASCII or lead byte (assuming
4-byte UTF8 characters are rare) and the context id is 0 or 1.
- lead byte (192 - 207): next byte is ASCII or lead byte, context is 0 or 1
- lead byte (208 - 255): next byte is continuation byte, context is 2 or 3
The possible value combinations of the previous two bytes, the range of
context ids and the type of the next byte is summarized in the table below:
|--------\-----------------------------------------------------------------|
| \ Last byte |
| Second \---------------------------------------------------------------|
| last byte \ ASCII | cont. byte | lead byte |
| \ (0-127) | (128-191) | (192-) |
|=============|===================|=====================|==================|
| ASCII | next: ASCII/lead | not valid | next: cont. |
| (0-127) | context: 4 - 63 | | context: 2 - 3 |
|-------------|-------------------|---------------------|------------------|
| cont. byte | next: ASCII/lead | next: ASCII/lead | next: cont. |
| (128-191) | context: 4 - 63 | context: 0 - 1 | context: 2 - 3 |
|-------------|-------------------|---------------------|------------------|
| lead byte | not valid | next: ASCII/lead | not valid |
| (192-207) | | context: 0 - 1 | |
|-------------|-------------------|---------------------|------------------|
| lead byte | not valid | next: cont. | not valid |
| (208-) | | context: 2 - 3 | |
|-------------|-------------------|---------------------|------------------|
The context id for the signed context mode is calculated as:
context = (kContextLookup[512 + p1] << 3) | kContextLookup[512 + p2].
For any context modeling modes, the context ids can be calculated by |-ing
together two lookups from one table using context model dependent offsets:
context = kContextLookup[offset1 + p1] | kContextLookup[offset2 + p2].
where offset1 and offset2 are dependent on the context mode.
*/
#ifndef BROTLI_DEC_CONTEXT_H_
#define BROTLI_DEC_CONTEXT_H_
@ -115,11 +116,10 @@ enum ContextType {
CONTEXT_SIGNED = 3
};
// Common context lookup table for all context modes.
/* Common context lookup table for all context modes. */
static const uint8_t kContextLookup[1792] = {
// CONTEXT_UTF8, last byte.
//
// ASCII range.
/* CONTEXT_UTF8, last byte. */
/* ASCII range. */
0, 0, 0, 0, 0, 0, 0, 0, 0, 4, 4, 0, 0, 4, 0, 0,
0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
8, 12, 16, 12, 12, 20, 12, 16, 24, 28, 12, 12, 32, 12, 36, 12,
@ -128,19 +128,18 @@ static const uint8_t kContextLookup[1792] = {
52, 52, 52, 52, 52, 48, 52, 52, 52, 52, 52, 24, 12, 28, 12, 12,
12, 56, 60, 60, 60, 56, 60, 60, 60, 56, 60, 60, 60, 60, 60, 56,
60, 60, 60, 60, 60, 56, 60, 60, 60, 60, 60, 24, 12, 28, 12, 0,
// UTF8 continuation byte range.
/* UTF8 continuation byte range. */
0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1,
0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1,
0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1,
0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1,
// UTF8 lead byte range.
/* UTF8 lead byte range. */
2, 3, 2, 3, 2, 3, 2, 3, 2, 3, 2, 3, 2, 3, 2, 3,
2, 3, 2, 3, 2, 3, 2, 3, 2, 3, 2, 3, 2, 3, 2, 3,
2, 3, 2, 3, 2, 3, 2, 3, 2, 3, 2, 3, 2, 3, 2, 3,
2, 3, 2, 3, 2, 3, 2, 3, 2, 3, 2, 3, 2, 3, 2, 3,
// CONTEXT_UTF8 second last byte.
//
// ASCII range.
/* CONTEXT_UTF8 second last byte. */
/* ASCII range. */
0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
0, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1,
@ -149,17 +148,17 @@ static const uint8_t kContextLookup[1792] = {
2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 1, 1, 1, 1, 1,
1, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3,
3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 1, 1, 1, 1, 0,
// UTF8 continuation byte range.
/* UTF8 continuation byte range. */
0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
// UTF8 lead byte range.
/* UTF8 lead byte range. */
0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2,
2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2,
// CONTEXT_SIGNED, second last byte.
/* CONTEXT_SIGNED, second last byte. */
0, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1,
2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2,
2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2,
@ -176,7 +175,7 @@ static const uint8_t kContextLookup[1792] = {
5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5,
5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5,
6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 7,
// CONTEXT_SIGNED, last byte, same as the above values shifted by 3 bits.
/* CONTEXT_SIGNED, last byte, same as the above values shifted by 3 bits. */
0, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8,
16, 16, 16, 16, 16, 16, 16, 16, 16, 16, 16, 16, 16, 16, 16, 16,
16, 16, 16, 16, 16, 16, 16, 16, 16, 16, 16, 16, 16, 16, 16, 16,
@ -193,7 +192,7 @@ static const uint8_t kContextLookup[1792] = {
40, 40, 40, 40, 40, 40, 40, 40, 40, 40, 40, 40, 40, 40, 40, 40,
40, 40, 40, 40, 40, 40, 40, 40, 40, 40, 40, 40, 40, 40, 40, 40,
48, 48, 48, 48, 48, 48, 48, 48, 48, 48, 48, 48, 48, 48, 48, 56,
// CONTEXT_LSB6, last byte.
/* CONTEXT_LSB6, last byte. */
0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15,
16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30, 31,
32, 33, 34, 35, 36, 37, 38, 39, 40, 41, 42, 43, 44, 45, 46, 47,
@ -210,7 +209,7 @@ static const uint8_t kContextLookup[1792] = {
16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30, 31,
32, 33, 34, 35, 36, 37, 38, 39, 40, 41, 42, 43, 44, 45, 46, 47,
48, 49, 50, 51, 52, 53, 54, 55, 56, 57, 58, 59, 60, 61, 62, 63,
// CONTEXT_MSB6, last byte.
/* CONTEXT_MSB6, last byte. */
0, 0, 0, 0, 1, 1, 1, 1, 2, 2, 2, 2, 3, 3, 3, 3,
4, 4, 4, 4, 5, 5, 5, 5, 6, 6, 6, 6, 7, 7, 7, 7,
8, 8, 8, 8, 9, 9, 9, 9, 10, 10, 10, 10, 11, 11, 11, 11,
@ -227,7 +226,7 @@ static const uint8_t kContextLookup[1792] = {
52, 52, 52, 52, 53, 53, 53, 53, 54, 54, 54, 54, 55, 55, 55, 55,
56, 56, 56, 56, 57, 57, 57, 57, 58, 58, 58, 58, 59, 59, 59, 59,
60, 60, 60, 60, 61, 61, 61, 61, 62, 62, 62, 62, 63, 63, 63, 63,
// CONTEXT_{M,L}SB6, second last byte,
/* CONTEXT_{M,L}SB6, second last byte, */
0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
@ -247,14 +246,14 @@ static const uint8_t kContextLookup[1792] = {
};
static const int kContextLookupOffsets[8] = {
// CONTEXT_LSB6
/* CONTEXT_LSB6 */
1024, 1536,
// CONTEXT_MSB6
/* CONTEXT_MSB6 */
1280, 1536,
// CONTEXT_UTF8
/* CONTEXT_UTF8 */
0, 256,
// CONTEXT_SIGNED
/* CONTEXT_SIGNED */
768, 512,
};
#endif // BROTLI_DEC_CONTEXT_H_
#endif /* BROTLI_DEC_CONTEXT_H_ */

122
dec/decode.c
View File

@ -1,16 +1,17 @@
// Copyright 2013 Google Inc. All Rights Reserved.
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
// http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.
/* Copyright 2013 Google Inc. All Rights Reserved.
Licensed under the Apache License, Version 2.0 (the "License");
you may not use this file except in compliance with the License.
You may obtain a copy of the License at
http://www.apache.org/licenses/LICENSE-2.0
Unless required by applicable law or agreed to in writing, software
distributed under the License is distributed on an "AS IS" BASIS,
WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
See the License for the specific language governing permissions and
limitations under the License.
*/
#include <stdlib.h>
#include <stdio.h>
@ -67,7 +68,7 @@ static BROTLI_INLINE int DecodeWindowBits(BrotliBitReader* br) {
}
}
// Decodes a number in the range [0..255], by reading 1 - 11 bits.
/* Decodes a number in the range [0..255], by reading 1 - 11 bits. */
static BROTLI_INLINE int DecodeVarLenUint8(BrotliBitReader* br) {
if (BrotliReadBits(br, 1)) {
int nbits = BrotliReadBits(br, 3);
@ -102,7 +103,7 @@ static void DecodeMetaBlockLength(BrotliBitReader* br,
}
}
// Decodes the next Huffman code from bit-stream.
/* Decodes the next Huffman code from bit-stream. */
static BROTLI_INLINE int ReadSymbol(const HuffmanTree* tree,
BrotliBitReader* br) {
uint32_t bits;
@ -113,7 +114,7 @@ static BROTLI_INLINE int ReadSymbol(const HuffmanTree* tree,
BrotliFillBitWindow(br);
bits = BrotliPrefetchBits(br);
bitpos = br->bit_pos_;
// Check if we find the bit combination from the Huffman lookup table.
/* Check if we find the bit combination from the Huffman lookup table. */
lut_ix = bits & (HUFF_LUT - 1);
lut_bits = tree->lut_bits_[lut_ix];
if (lut_bits <= HUFF_LUT_BITS) {
@ -124,7 +125,7 @@ static BROTLI_INLINE int ReadSymbol(const HuffmanTree* tree,
bitpos += HUFF_LUT_BITS;
bits >>= HUFF_LUT_BITS;
// Decode the value from a binary tree.
/* Decode the value from a binary tree. */
assert(node != NULL);
do {
node = HuffmanTreeNextNode(node, bits & 1);
@ -249,7 +250,7 @@ static int ReadHuffmanCode(int alphabet_size,
}
simple_code = BrotliReadBits(br, 1);
BROTLI_LOG_UINT(simple_code);
if (simple_code) { // Read symbols, codes & code lengths directly.
if (simple_code) { /* Read symbols, codes & code lengths directly. */
int i;
int max_bits_counter = alphabet_size - 1;
int max_bits = 0;
@ -282,7 +283,7 @@ static int ReadHuffmanCode(int alphabet_size,
break;
}
BROTLI_LOG_UINT(num_symbols);
} else { // Decode Huffman-coded code lengths.
} else { /* Decode Huffman-coded code lengths. */
int i;
uint8_t code_length_code_lengths[CODE_LENGTH_CODES] = { 0 };
const int num_codes = BrotliReadBits(br, 4) + 3;
@ -421,7 +422,7 @@ static void InverseMoveToFrontTransform(uint8_t* v, int v_len) {
}
}
// Contains a collection of huffman trees with the same alphabet size.
/* Contains a collection of huffman trees with the same alphabet size. */
typedef struct {
int alphabet_size;
int num_htrees;
@ -539,36 +540,37 @@ static BROTLI_INLINE void DecodeBlockType(const HuffmanTree* trees,
++(*index);
}
// Copy len bytes from src to dst. It can write up to ten extra bytes
// after the end of the copy.
//
// The main part of this loop is a simple copy of eight bytes at a time until
// we've copied (at least) the requested amount of bytes. However, if dst and
// src are less than eight bytes apart (indicating a repeating pattern of
// length < 8), we first need to expand the pattern in order to get the correct
// results. For instance, if the buffer looks like this, with the eight-byte
// <src> and <dst> patterns marked as intervals:
//
// abxxxxxxxxxxxx
// [------] src
// [------] dst
//
// a single eight-byte copy from <src> to <dst> will repeat the pattern once,
// after which we can move <dst> two bytes without moving <src>:
//
// ababxxxxxxxxxx
// [------] src
// [------] dst
//
// and repeat the exercise until the two no longer overlap.
//
// This allows us to do very well in the special case of one single byte
// repeated many times, without taking a big hit for more general cases.
//
// The worst case of extra writing past the end of the match occurs when
// dst - src == 1 and len == 1; the last copy will read from byte positions
// [0..7] and write to [4..11], whereas it was only supposed to write to
// position 1. Thus, ten excess bytes.
/* Copy len bytes from src to dst. It can write up to ten extra bytes
after the end of the copy.
The main part of this loop is a simple copy of eight bytes at a time until
we've copied (at least) the requested amount of bytes. However, if dst and
src are less than eight bytes apart (indicating a repeating pattern of
length < 8), we first need to expand the pattern in order to get the correct
results. For instance, if the buffer looks like this, with the eight-byte
<src> and <dst> patterns marked as intervals:
abxxxxxxxxxxxx
[------] src
[------] dst
a single eight-byte copy from <src> to <dst> will repeat the pattern once,
after which we can move <dst> two bytes without moving <src>:
ababxxxxxxxxxx
[------] src
[------] dst
and repeat the exercise until the two no longer overlap.
This allows us to do very well in the special case of one single byte
repeated many times, without taking a big hit for more general cases.
The worst case of extra writing past the end of the match occurs when
dst - src == 1 and len == 1; the last copy will read from byte positions
[0..7] and write to [4..11], whereas it was only supposed to write to
position 1. Thus, ten excess bytes.
*/
static BROTLI_INLINE void IncrementalCopyFastPath(
uint8_t* dst, const uint8_t* src, int len) {
if (src < dst) {
@ -631,11 +633,11 @@ int BrotliDecompress(BrotliInput input, BrotliOutput output) {
size_t ringbuffer_mask;
uint8_t* ringbuffer;
uint8_t* ringbuffer_end;
// This ring buffer holds a few past copy distances that will be used by
// some special distance codes.
/* This ring buffer holds a few past copy distances that will be used by */
/* some special distance codes. */
int dist_rb[4] = { 16, 15, 11, 4 };
size_t dist_rb_idx = 0;
// The previous 2 bytes used for context.
/* The previous 2 bytes used for context. */
uint8_t prev_byte1 = 0;
uint8_t prev_byte2 = 0;
HuffmanTreeGroup hgroup[3];
@ -649,7 +651,7 @@ int BrotliDecompress(BrotliInput input, BrotliOutput output) {
return 0;
}
// Decode window size.
/* Decode window size. */
window_bits = DecodeWindowBits(&br);
max_backward_distance = (1ULL << window_bits) - 16;
@ -877,8 +879,8 @@ int BrotliDecompress(BrotliInput input, BrotliOutput output) {
&br);
}
// Convert the distance code to the actual distance by possibly looking
// up past distnaces from the ringbuffer.
/* Convert the distance code to the actual distance by possibly looking */
/* up past distnaces from the ringbuffer. */
distance = TranslateShortCodes(distance_code, dist_rb, dist_rb_idx);
if (distance_code > 0) {
dist_rb[dist_rb_idx & 3] = distance;
@ -937,9 +939,9 @@ int BrotliDecompress(BrotliInput input, BrotliOutput output) {
}
}
// When we get here, we must have inserted at least one literal and made
// a copy of at least length two, therefore accessing the last 2 bytes is
// valid.
/* When we get here, we must have inserted at least one literal and */
/* made a copy of at least length two, therefore accessing the last 2 */
/* bytes is valid. */
prev_byte1 = ringbuffer[(pos - 1) & ringbuffer_mask];
prev_byte2 = ringbuffer[(pos - 2) & ringbuffer_mask];
}
@ -962,5 +964,5 @@ int BrotliDecompress(BrotliInput input, BrotliOutput output) {
}
#if defined(__cplusplus) || defined(c_plusplus)
} // extern "C"
} /* extern "C" */
#endif

53
dec/decode.h
View File

@ -1,18 +1,19 @@
// Copyright 2013 Google Inc. All Rights Reserved.
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
// http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.
//
// API for Brotli decompression
/* Copyright 2013 Google Inc. All Rights Reserved.
Licensed under the Apache License, Version 2.0 (the "License");
you may not use this file except in compliance with the License.
You may obtain a copy of the License at
http://www.apache.org/licenses/LICENSE-2.0
Unless required by applicable law or agreed to in writing, software
distributed under the License is distributed on an "AS IS" BASIS,
WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
See the License for the specific language governing permissions and
limitations under the License.
API for Brotli decompression
*/
#ifndef BROTLI_DEC_DECODE_H_
#define BROTLI_DEC_DECODE_H_
@ -24,28 +25,28 @@
extern "C" {
#endif
// Sets *decoded_size to the decompressed size of the given encoded stream.
// Returns 1 on success, 0 on failure.
/* Sets *decoded_size to the decompressed size of the given encoded stream. */
/* Returns 1 on success, 0 on failure. */
int BrotliDecompressedSize(size_t encoded_size,
const uint8_t* encoded_buffer,
size_t* decoded_size);
// Decompresses the data in encoded_buffer into decoded_buffer, and sets
// *decoded_size to the decompressed length.
// Returns 0 if there was either a bit stream error or memory allocation error,
// and 1 otherwise.
// If decoded size is zero, returns 1 and keeps decoded_buffer unchanged.
/* Decompresses the data in encoded_buffer into decoded_buffer, and sets */
/* *decoded_size to the decompressed length. */
/* Returns 0 if there was either a bit stream error or memory allocation */
/* error, and 1 otherwise. */
/* If decoded size is zero, returns 1 and keeps decoded_buffer unchanged. */
int BrotliDecompressBuffer(size_t encoded_size,
const uint8_t* encoded_buffer,
size_t* decoded_size,
uint8_t* decoded_buffer);
// Same as above, but uses the specified input and output callbacks instead of
// reading from and writing to pre-allocated memory buffers.
/* Same as above, but uses the specified input and output callbacks instead */
/* of reading from and writing to pre-allocated memory buffers. */
int BrotliDecompress(BrotliInput input, BrotliOutput output);
#if defined(__cplusplus) || defined(c_plusplus)
} // extern "C"
} /* extern "C" */
#endif
#endif // BROTLI_DEC_DECODE_H_
#endif /* BROTLI_DEC_DECODE_H_ */

92
dec/huffman.c
View File

@ -1,18 +1,19 @@
// Copyright 2013 Google Inc. All Rights Reserved.
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
// http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.
//
// Utilities for building and looking up Huffman trees.
/* Copyright 2013 Google Inc. All Rights Reserved.
Licensed under the Apache License, Version 2.0 (the "License");
you may not use this file except in compliance with the License.
You may obtain a copy of the License at
http://www.apache.org/licenses/LICENSE-2.0
Unless required by applicable law or agreed to in writing, software
distributed under the License is distributed on an "AS IS" BASIS,
WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
See the License for the specific language governing permissions and
limitations under the License.
Utilities for building and looking up Huffman trees.
*/
#include <assert.h>
#include <stdlib.h>
@ -28,7 +29,7 @@ extern "C" {
#define MAX_ALLOWED_CODE_LENGTH 15
static void TreeNodeInit(HuffmanTreeNode* const node) {
node->children_ = -1; // means: 'unassigned so far'
node->children_ = -1; /* means: 'unassigned so far' */
}
static int NodeIsEmpty(const HuffmanTreeNode* const node) {
@ -52,15 +53,15 @@ static void AssignChildren(HuffmanTree* const tree,
static int TreeInit(HuffmanTree* const tree, int num_leaves) {
assert(tree != NULL);
if (num_leaves == 0) return 0;
// We allocate maximum possible nodes in the tree at once.
// Note that a Huffman tree is a full binary tree; and in a full binary tree
// with L leaves, the total number of nodes N = 2 * L - 1.
/* We allocate maximum possible nodes in the tree at once. */
/* Note that a Huffman tree is a full binary tree; and in a full binary */
/* tree with L leaves, the total number of nodes N = 2 * L - 1. */
tree->max_nodes_ = 2 * num_leaves - 1;
assert(tree->max_nodes_ < (1 << 16)); // limit for the lut_jump_ table
assert(tree->max_nodes_ < (1 << 16)); /* limit for the lut_jump_ table */
tree->root_ = (HuffmanTreeNode*)BrotliSafeMalloc((uint64_t)tree->max_nodes_,
sizeof(*tree->root_));
if (tree->root_ == NULL) return 0;
TreeNodeInit(tree->root_); // Initialize root.
TreeNodeInit(tree->root_); /* Initialize root. */
tree->num_nodes_ = 1;
memset(tree->lut_bits_, 255, sizeof(tree->lut_bits_));
memset(tree->lut_jump_, 0, sizeof(tree->lut_jump_));
@ -76,9 +77,9 @@ void BrotliHuffmanTreeRelease(HuffmanTree* const tree) {
}
}
// Utility: converts Huffman code lengths to corresponding Huffman codes.
// 'huff_codes' should be pre-allocated.
// Returns false in case of error (memory allocation, invalid codes).
/* Utility: converts Huffman code lengths to corresponding Huffman codes. */
/* 'huff_codes' should be pre-allocated. */
/* Returns false in case of error (memory allocation, invalid codes). */
static int HuffmanCodeLengthsToCodes(const uint8_t* const code_lengths,
int code_lengths_size,
int* const huff_codes) {
@ -93,7 +94,7 @@ static int HuffmanCodeLengthsToCodes(const uint8_t* const code_lengths,
assert(code_lengths_size > 0);
assert(huff_codes != NULL);
// Calculate max code length.
/* Calculate max code length. */
for (symbol = 0; symbol < code_lengths_size; ++symbol) {
if (code_lengths[symbol] > max_code_length) {
max_code_length = code_lengths[symbol];
@ -101,23 +102,24 @@ static int HuffmanCodeLengthsToCodes(const uint8_t* const code_lengths,
}
if (max_code_length > MAX_ALLOWED_CODE_LENGTH) return 0;
// Calculate code length histogram.
/* Calculate code length histogram. */
for (symbol = 0; symbol < code_lengths_size; ++symbol) {
++code_length_hist[code_lengths[symbol]];
}
code_length_hist[0] = 0;
// Calculate the initial values of 'next_codes' for each code length.
// next_codes[code_len] denotes the code to be assigned to the next symbol
// of code length 'code_len'.
/* Calculate the initial values of 'next_codes' for each code length. */
/* next_codes[code_len] denotes the code to be assigned to the next symbol */
/* of code length 'code_len'. */
curr_code = 0;
next_codes[0] = -1; // Unused, as code length = 0 implies code doesn't exist.
next_codes[0] = -1; /* Unused, as code length = 0 implies */
/* code doesn't exist. */
for (code_len = 1; code_len <= max_code_length; ++code_len) {
curr_code = (curr_code + code_length_hist[code_len - 1]) << 1;
next_codes[code_len] = curr_code;
}
// Get symbols.
/* Get symbols. */
for (symbol = 0; symbol < code_lengths_size; ++symbol) {
if (code_lengths[symbol] > 0) {
huff_codes[symbol] = next_codes[code_lengths[symbol]]++;
@ -169,10 +171,10 @@ static int TreeAddSymbol(HuffmanTree* const tree,
return 0;
}
if (NodeIsEmpty(node)) {
if (IsFull(tree)) return 0; // error: too many symbols.
if (IsFull(tree)) return 0; /* error: too many symbols. */
AssignChildren(tree, node);
} else if (!HuffmanTreeNodeIsNotLeaf(node)) {
return 0; // leaf is already occupied.
return 0; /* leaf is already occupied. */
}
node += node->children_ + ((code >> code_length) & 1);
if (--step == 0) {
@ -180,11 +182,11 @@ static int TreeAddSymbol(HuffmanTree* const tree,
}
}
if (NodeIsEmpty(node)) {
node->children_ = 0; // turn newly created node into a leaf.
node->children_ = 0; /* turn newly created node into a leaf. */
} else if (HuffmanTreeNodeIsNotLeaf(node)) {
return 0; // trying to assign a symbol to already used code.
return 0; /* trying to assign a symbol to already used code. */
}
node->symbol_ = symbol; // Add symbol in this node.
node->symbol_ = symbol; /* Add symbol in this node. */
return 1;
}
@ -198,30 +200,30 @@ int BrotliHuffmanTreeBuildImplicit(HuffmanTree* const tree,
assert(tree != NULL);
assert(code_lengths != NULL);
// Find out number of symbols and the root symbol.
/* Find out number of symbols and the root symbol. */
for (symbol = 0; symbol < code_lengths_size; ++symbol) {
if (code_lengths[symbol] > 0) {
// Note: code length = 0 indicates non-existent symbol.
/* Note: code length = 0 indicates non-existent symbol. */
++num_symbols;
root_symbol = symbol;
}
}
// Initialize the tree. Will fail for num_symbols = 0
/* Initialize the tree. Will fail for num_symbols = 0 */
if (!TreeInit(tree, num_symbols)) return 0;
// Build tree.
if (num_symbols == 1) { // Trivial case.
/* Build tree. */
if (num_symbols == 1) { /* Trivial case. */
const int max_symbol = code_lengths_size;
if (root_symbol < 0 || root_symbol >= max_symbol) {
BrotliHuffmanTreeRelease(tree);
return 0;
}
return TreeAddSymbol(tree, root_symbol, 0, 0);
} else { // Normal case.
} else { /* Normal case. */
int ok = 0;
// Get Huffman codes from the code lengths.
/* Get Huffman codes from the code lengths. */
int* const codes =
(int*)BrotliSafeMalloc((uint64_t)code_lengths_size, sizeof(*codes));
if (codes == NULL) goto End;
@ -230,7 +232,7 @@ int BrotliHuffmanTreeBuildImplicit(HuffmanTree* const tree,
goto End;
}
// Add symbols one-by-one.
/* Add symbols one-by-one. */
for (symbol = 0; symbol < code_lengths_size; ++symbol) {
if (code_lengths[symbol] > 0) {
if (!TreeAddSymbol(tree, symbol, codes[symbol], code_lengths[symbol])) {
@ -248,5 +250,5 @@ int BrotliHuffmanTreeBuildImplicit(HuffmanTree* const tree,
}
#if defined(__cplusplus) || defined(c_plusplus)
} // extern "C"
} /* extern "C" */
#endif

63
dec/huffman.h
View File

@ -1,18 +1,19 @@
// Copyright 2013 Google Inc. All Rights Reserved.
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
// http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.
//
// Utilities for building and looking up Huffman trees.
/* Copyright 2013 Google Inc. All Rights Reserved.
Licensed under the Apache License, Version 2.0 (the "License");
you may not use this file except in compliance with the License.
You may obtain a copy of the License at
http://www.apache.org/licenses/LICENSE-2.0
Unless required by applicable law or agreed to in writing, software
distributed under the License is distributed on an "AS IS" BASIS,
WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
See the License for the specific language governing permissions and
limitations under the License.
Utilities for building and looking up Huffman trees.
*/
#ifndef BROTLI_DEC_HUFFMAN_H_
#define BROTLI_DEC_HUFFMAN_H_
@ -24,51 +25,51 @@
extern "C" {
#endif
// A node of a Huffman tree.
/* A node of a Huffman tree. */
typedef struct {
int symbol_;
int children_; // delta offset to both children (contiguous) or 0 if leaf.
int children_; /* delta offset to both children (contiguous) or 0 if leaf. */
} HuffmanTreeNode;
// Huffman Tree.
/* Huffman Tree. */
#define HUFF_LUT_BITS 7
#define HUFF_LUT (1U << HUFF_LUT_BITS)
typedef struct HuffmanTree HuffmanTree;
struct HuffmanTree {
// Fast lookup for short bit lengths.
/* Fast lookup for short bit lengths. */
uint8_t lut_bits_[HUFF_LUT];
int16_t lut_symbol_[HUFF_LUT];
int16_t lut_jump_[HUFF_LUT];
// Complete tree for lookups.
HuffmanTreeNode* root_; // all the nodes, starting at root.
int max_nodes_; // max number of nodes
int num_nodes_; // number of currently occupied nodes
/* Complete tree for lookups. */
HuffmanTreeNode* root_; /* all the nodes, starting at root. */
int max_nodes_; /* max number of nodes */
int num_nodes_; /* number of currently occupied nodes */
};
// Returns true if the given node is not a leaf of the Huffman tree.
/* Returns true if the given node is not a leaf of the Huffman tree. */
static BROTLI_INLINE int HuffmanTreeNodeIsNotLeaf(
const HuffmanTreeNode* const node) {
return node->children_;
}
// Go down one level. Most critical function. 'right_child' must be 0 or 1.
/* Go down one level. Most critical function. 'right_child' must be 0 or 1. */
static BROTLI_INLINE const HuffmanTreeNode* HuffmanTreeNextNode(
const HuffmanTreeNode* node, int right_child) {
return node + node->children_ + right_child;
}
// Releases the nodes of the Huffman tree.
// Note: It does NOT free 'tree' itself.
/* Releases the nodes of the Huffman tree. */
/* Note: It does NOT free 'tree' itself. */
void BrotliHuffmanTreeRelease(HuffmanTree* const tree);
// Builds Huffman tree assuming code lengths are implicitly in symbol order.
// Returns false in case of error (invalid tree or memory error).
/* Builds Huffman tree assuming code lengths are implicitly in symbol order. */
/* Returns false in case of error (invalid tree or memory error). */
int BrotliHuffmanTreeBuildImplicit(HuffmanTree* const tree,
const uint8_t* const code_lengths,
int code_lengths_size);
#if defined(__cplusplus) || defined(c_plusplus)
} // extern "C"
} /* extern "C" */
#endif
#endif // BROTLI_DEC_HUFFMAN_H_
#endif /* BROTLI_DEC_HUFFMAN_H_ */

39
dec/prefix.h
View File

@ -1,25 +1,26 @@
// Copyright 2013 Google Inc. All Rights Reserved.
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
// http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.
//
// Lookup tables to map prefix codes to value ranges. This is used during
// decoding of the block lengths, literal insertion lengths and copy lengths.
/* Copyright 2013 Google Inc. All Rights Reserved.
Licensed under the Apache License, Version 2.0 (the "License");
you may not use this file except in compliance with the License.
You may obtain a copy of the License at
http://www.apache.org/licenses/LICENSE-2.0
Unless required by applicable law or agreed to in writing, software
distributed under the License is distributed on an "AS IS" BASIS,
WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
See the License for the specific language governing permissions and
limitations under the License.
Lookup tables to map prefix codes to value ranges. This is used during
decoding of the block lengths, literal insertion lengths and copy lengths.
*/
#ifndef BROTLI_DEC_PREFIX_H_
#define BROTLI_DEC_PREFIX_H_
// Represents the range of values belonging to a prefix code:
// [offset, offset + 2^nbits)
/* Represents the range of values belonging to a prefix code: */
/* [offset, offset + 2^nbits) */
struct PrefixCodeRange {
int offset;
int nbits;
@ -61,4 +62,4 @@ static const int kCopyRangeLut[9] = {
0, 8, 0, 8, 16, 0, 16, 8, 16,
};
#endif // BROTLI_DEC_PREFIX_H_
#endif /* BROTLI_DEC_PREFIX_H_ */

35
dec/safe_malloc.c
View File

@ -1,18 +1,19 @@
// Copyright 2013 Google Inc. All Rights Reserved.
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
// http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.
//
// Size-checked memory allocation.
/* Copyright 2013 Google Inc. All Rights Reserved.
Licensed under the Apache License, Version 2.0 (the "License");
you may not use this file except in compliance with the License.
You may obtain a copy of the License at
http://www.apache.org/licenses/LICENSE-2.0
Unless required by applicable law or agreed to in writing, software
distributed under the License is distributed on an "AS IS" BASIS,
WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
See the License for the specific language governing permissions and
limitations under the License.
Size-checked memory allocation.
*/
#include <stdlib.h>
#include "./safe_malloc.h"
@ -21,7 +22,7 @@
extern "C" {
#endif
// Returns 0 in case of overflow of nmemb * size.
/* Returns 0 in case of overflow of nmemb * size. */
static int CheckSizeArgumentsOverflow(uint64_t nmemb, size_t size) {
const uint64_t total_size = nmemb * size;
if (nmemb == 0) return 1;
@ -37,5 +38,5 @@ void* BrotliSafeMalloc(uint64_t nmemb, size_t size) {
}
#if defined(__cplusplus) || defined(c_plusplus)
} // extern "C"
} /* extern "C" */
#endif

48
dec/safe_malloc.h
View File

@ -1,18 +1,19 @@
// Copyright 2013 Google Inc. All Rights Reserved.
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
// http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.
//
// Size-checked memory allocation.
/* Copyright 2013 Google Inc. All Rights Reserved.
Licensed under the Apache License, Version 2.0 (the "License");
you may not use this file except in compliance with the License.
You may obtain a copy of the License at
http://www.apache.org/licenses/LICENSE-2.0
Unless required by applicable law or agreed to in writing, software
distributed under the License is distributed on an "AS IS" BASIS,
WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
See the License for the specific language governing permissions and
limitations under the License.
Size-checked memory allocation.
*/
#ifndef BROTLI_UTILS_UTILS_H_
#define BROTLI_UTILS_UTILS_H_
@ -25,19 +26,20 @@
extern "C" {
#endif
// This is the maximum memory amount that we will ever try to allocate.
/* This is the maximum memory amount that we will ever try to allocate. */
#define BROTLI_MAX_ALLOCABLE_MEMORY (1ULL << 40)
// size-checking safe malloc/calloc: verify that the requested size is not too
// large, or return NULL. You don't need to call these for constructs like
// malloc(sizeof(foo)), but only if there's font-dependent size involved
// somewhere (like: malloc(decoded_size * sizeof(*something))). That's why this
// safe malloc() borrows the signature from calloc(), pointing at the dangerous
// underlying multiply involved.
/* size-checking safe malloc/calloc: verify that the requested size is not too
large, or return NULL. You don't need to call these for constructs like
malloc(sizeof(foo)), but only if there's font-dependent size involved
somewhere (like: malloc(decoded_size * sizeof(*something))). That's why this
safe malloc() borrows the signature from calloc(), pointing at the dangerous
underlying multiply involved.
*/
void* BrotliSafeMalloc(uint64_t nmemb, size_t size);
#if defined(__cplusplus) || defined(c_plusplus)
} // extern "C"
} /* extern "C" */
#endif
#endif /* BROTLI_UTILS_UTILS_H_ */

33
dec/streams.c
View File

@ -1,18 +1,19 @@
// Copyright 2013 Google Inc. All Rights Reserved.
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
// http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.
//
// Functions for streaming input and output.
/* Copyright 2013 Google Inc. All Rights Reserved.
Licensed under the Apache License, Version 2.0 (the "License");
you may not use this file except in compliance with the License.
You may obtain a copy of the License at
http://www.apache.org/licenses/LICENSE-2.0
Unless required by applicable law or agreed to in writing, software
distributed under the License is distributed on an "AS IS" BASIS,
WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
See the License for the specific language governing permissions and
limitations under the License.
Functions for streaming input and output.
*/
#include <string.h>
#ifndef _WIN32
@ -112,5 +113,5 @@ BrotliOutput BrotliFileOutput(FILE* f) {
#if defined(__cplusplus) || defined(c_plusplus)
} // extern "C"
} /* extern "C" */
#endif

69
dec/streams.h
View File

@ -1,18 +1,19 @@
// Copyright 2013 Google Inc. All Rights Reserved.
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
// http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.
//
// Functions for streaming input and output.
/* Copyright 2013 Google Inc. All Rights Reserved.
Licensed under the Apache License, Version 2.0 (the "License");
you may not use this file except in compliance with the License.
You may obtain a copy of the License at
http://www.apache.org/licenses/LICENSE-2.0
Unless required by applicable law or agreed to in writing, software
distributed under the License is distributed on an "AS IS" BASIS,
WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
See the License for the specific language governing permissions and
limitations under the License.
Functions for streaming input and output.
*/
#ifndef BROTLI_DEC_STREAMS_H_
#define BROTLI_DEC_STREAMS_H_
@ -24,79 +25,79 @@
extern "C" {
#endif
// Function pointer type used to read len bytes into buf. Returns the
// number of bytes read or -1 on error.
/* Function pointer type used to read len bytes into buf. Returns the */
/* number of bytes read or -1 on error. */
typedef int (*BrotliInputFunction)(void* data, uint8_t* buf, size_t len);
// Input callback function with associated data.
/* Input callback function with associated data. */
typedef struct {
BrotliInputFunction cb_;
void* data_;
} BrotliInput;
// Reads len bytes into buf, using the in callback.
/* Reads len bytes into buf, using the in callback. */
static BROTLI_INLINE int BrotliRead(BrotliInput in, uint8_t* buf, size_t len) {
return in.cb_(in.data_, buf, len);
}
// Function pointer type used to write len bytes into buf. Returns the
// number of bytes written or -1 on error.
/* Function pointer type used to write len bytes into buf. Returns the */
/* number of bytes written or -1 on error. */
typedef int (*BrotliOutputFunction)(void* data, const uint8_t* buf, size_t len);
// Output callback function with associated data.
/* Output callback function with associated data. */
typedef struct {
BrotliOutputFunction cb_;
void* data_;
} BrotliOutput;
// Writes len bytes into buf, using the out callback.
/* Writes len bytes into buf, using the out callback. */
static BROTLI_INLINE int BrotliWrite(BrotliOutput out,
const uint8_t* buf, size_t len) {
return out.cb_(out.data_, buf, len);
}
// Memory region with position.
/* Memory region with position. */
typedef struct {
const uint8_t* buffer;
size_t length;
size_t pos;
} BrotliMemInput;
// Input callback where *data is a BrotliMemInput struct.
/* Input callback where *data is a BrotliMemInput struct. */
int BrotliMemInputFunction(void* data, uint8_t* buf, size_t count);
// Returns an input callback that wraps the given memory region.
/* Returns an input callback that wraps the given memory region. */
BrotliInput BrotliInitMemInput(const uint8_t* buffer, size_t length,
BrotliMemInput* mem_input);
// Output buffer with position.
/* Output buffer with position. */
typedef struct {
uint8_t* buffer;
size_t length;
size_t pos;
} BrotliMemOutput;
// Output callback where *data is a BrotliMemOutput struct.
/* Output callback where *data is a BrotliMemOutput struct. */
int BrotliMemOutputFunction(void* data, const uint8_t* buf, size_t count);
// Returns an output callback that wraps the given memory region.
/* Returns an output callback that wraps the given memory region. */
BrotliOutput BrotliInitMemOutput(uint8_t* buffer, size_t length,
BrotliMemOutput* mem_output);
// Input callback that reads from standard input.
/* Input callback that reads from standard input. */
int BrotliStdinInputFunction(void* data, uint8_t* buf, size_t count);
BrotliInput BrotliStdinInput();
// Output callback that writes to standard output.
/* Output callback that writes to standard output. */
int BrotliStdoutOutputFunction(void* data, const uint8_t* buf, size_t count);
BrotliOutput BrotliStdoutOutput();
// Output callback that writes to a file.
/* Output callback that writes to a file. */
int BrotliFileOutputFunction(void* data, const uint8_t* buf, size_t count);
BrotliOutput BrotliFileOutput(FILE* f);
#if defined(__cplusplus) || defined(c_plusplus)
} // extern "C"
} /* extern "C" */
#endif
#endif // BROTLI_DEC_STREAMS_H_
#endif /* BROTLI_DEC_STREAMS_H_ */

35
dec/types.h
View File

@ -1,23 +1,24 @@
// Copyright 2013 Google Inc. All Rights Reserved.
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
// http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.
//
// Common types
/* Copyright 2013 Google Inc. All Rights Reserved.
Licensed under the Apache License, Version 2.0 (the "License");
you may not use this file except in compliance with the License.
You may obtain a copy of the License at
http://www.apache.org/licenses/LICENSE-2.0
Unless required by applicable law or agreed to in writing, software
distributed under the License is distributed on an "AS IS" BASIS,
WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
See the License for the specific language governing permissions and
limitations under the License.
Common types
*/
#ifndef BROTLI_DEC_TYPES_H_
#define BROTLI_DEC_TYPES_H_
#include <stddef.h> // for size_t
#include <stddef.h> /* for size_t */
#ifndef _MSC_VER
#include <inttypes.h>
@ -38,4 +39,4 @@ typedef long long int int64_t;
#define BROTLI_INLINE __forceinline
#endif /* _MSC_VER */
#endif // BROTLI_DEC_TYPES_H_
#endif /* BROTLI_DEC_TYPES_H_ */