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1 /* Copyright 2014 Google Inc. All Rights Reserved.
2 
3    Distributed under MIT license.
4    See file LICENSE for detail or copy at https://opensource.org/licenses/MIT
5 */
6 
7 /* Functions to convert brotli-related data structures into the
8    brotli bit stream. The functions here operate under
9    assumption that there is enough space in the storage, i.e., there are
10    no out-of-range checks anywhere.
11 
12    These functions do bit addressing into a byte array. The byte array
13    is called "storage" and the index to the bit is called storage_ix
14    in function arguments. */
15 
16 #ifndef BROTLI_ENC_BROTLI_BIT_STREAM_H_
17 #define BROTLI_ENC_BROTLI_BIT_STREAM_H_
18 
19 #include <brotli/types.h>
20 
21 #include "../common/context.h"
22 #include "../common/platform.h"
23 #include "command.h"
24 #include "entropy_encode.h"
25 #include "memory.h"
26 #include "metablock.h"
27 
28 #if defined(__cplusplus) || defined(c_plusplus)
29 extern "C" {
30 #endif
31 
32 /* All Store functions here will use a storage_ix, which is always the bit
33    position for the current storage. */
34 
35 BROTLI_INTERNAL void BrotliStoreHuffmanTree(const uint8_t* depths, size_t num,
36     HuffmanTree* tree, size_t* storage_ix, uint8_t* storage);
37 
38 BROTLI_INTERNAL void BrotliBuildAndStoreHuffmanTreeFast(
39     HuffmanTree* tree, const uint32_t* histogram, const size_t histogram_total,
40     const size_t max_bits, uint8_t* depth, uint16_t* bits, size_t* storage_ix,
41     uint8_t* storage);
42 
43 /* REQUIRES: length > 0 */
44 /* REQUIRES: length <= (1 << 24) */
45 BROTLI_INTERNAL void BrotliStoreMetaBlock(MemoryManager* m,
46     const uint8_t* input, size_t start_pos, size_t length, size_t mask,
47     uint8_t prev_byte, uint8_t prev_byte2, BROTLI_BOOL is_last,
48     const BrotliEncoderParams* params, ContextType literal_context_mode,
49     const Command* commands, size_t n_commands, const MetaBlockSplit* mb,
50     size_t* storage_ix, uint8_t* storage);
51 
52 /* Stores the meta-block without doing any block splitting, just collects
53    one histogram per block category and uses that for entropy coding.
54    REQUIRES: length > 0
55    REQUIRES: length <= (1 << 24) */
56 BROTLI_INTERNAL void BrotliStoreMetaBlockTrivial(MemoryManager* m,
57     const uint8_t* input, size_t start_pos, size_t length, size_t mask,
58     BROTLI_BOOL is_last, const BrotliEncoderParams* params,
59     const Command* commands, size_t n_commands,
60     size_t* storage_ix, uint8_t* storage);
61 
62 /* Same as above, but uses static prefix codes for histograms with a only a few
63    symbols, and uses static code length prefix codes for all other histograms.
64    REQUIRES: length > 0
65    REQUIRES: length <= (1 << 24) */
66 BROTLI_INTERNAL void BrotliStoreMetaBlockFast(MemoryManager* m,
67     const uint8_t* input, size_t start_pos, size_t length, size_t mask,
68     BROTLI_BOOL is_last, const BrotliEncoderParams* params,
69     const Command* commands, size_t n_commands,
70     size_t* storage_ix, uint8_t* storage);
71 
72 /* This is for storing uncompressed blocks (simple raw storage of
73    bytes-as-bytes).
74    REQUIRES: length > 0
75    REQUIRES: length <= (1 << 24) */
76 BROTLI_INTERNAL void BrotliStoreUncompressedMetaBlock(
77     BROTLI_BOOL is_final_block, const uint8_t* BROTLI_RESTRICT input,
78     size_t position, size_t mask, size_t len,
79     size_t* BROTLI_RESTRICT storage_ix, uint8_t* BROTLI_RESTRICT storage);
80 
81 #if defined(BROTLI_TEST)
82 void GetBlockLengthPrefixCodeForTest(uint32_t, size_t*, uint32_t*, uint32_t*);
83 #endif
84 
85 #if defined(__cplusplus) || defined(c_plusplus)
86 }  /* extern "C" */
87 #endif
88 
89 #endif  /* BROTLI_ENC_BROTLI_BIT_STREAM_H_ */
90