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1 /* Copyright 2015 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 /* Function for fast encoding of an input fragment, independently from the input
8    history. This function uses two-pass processing: in the first pass we save
9    the found backward matches and literal bytes into a buffer, and in the
10    second pass we emit them into the bit stream using prefix codes built based
11    on the actual command and literal byte histograms. */
12 
13 #ifndef BROTLI_ENC_COMPRESS_FRAGMENT_TWO_PASS_H_
14 #define BROTLI_ENC_COMPRESS_FRAGMENT_TWO_PASS_H_
15 
16 #include "../common/platform.h"
17 #include <brotli/types.h>
18 #include "./memory.h"
19 
20 #if defined(__cplusplus) || defined(c_plusplus)
21 extern "C" {
22 #endif
23 
24 static const size_t kCompressFragmentTwoPassBlockSize = 1 << 17;
25 
26 /* Compresses "input" string to the "*storage" buffer as one or more complete
27    meta-blocks, and updates the "*storage_ix" bit position.
28 
29    If "is_last" is 1, emits an additional empty last meta-block.
30 
31    REQUIRES: "input_size" is greater than zero, or "is_last" is 1.
32    REQUIRES: "input_size" is less or equal to maximal metablock size (1 << 24).
33    REQUIRES: "command_buf" and "literal_buf" point to at least
34               kCompressFragmentTwoPassBlockSize long arrays.
35    REQUIRES: All elements in "table[0..table_size-1]" are initialized to zero.
36    REQUIRES: "table_size" is a power of two
37    OUTPUT: maximal copy distance <= |input_size|
38    OUTPUT: maximal copy distance <= BROTLI_MAX_BACKWARD_LIMIT(18) */
39 BROTLI_INTERNAL void BrotliCompressFragmentTwoPass(MemoryManager* m,
40                                                    const uint8_t* input,
41                                                    size_t input_size,
42                                                    BROTLI_BOOL is_last,
43                                                    uint32_t* command_buf,
44                                                    uint8_t* literal_buf,
45                                                    int* table,
46                                                    size_t table_size,
47                                                    size_t* storage_ix,
48                                                    uint8_t* storage);
49 
50 #if defined(__cplusplus) || defined(c_plusplus)
51 }  /* extern "C" */
52 #endif
53 
54 #endif  /* BROTLI_ENC_COMPRESS_FRAGMENT_TWO_PASS_H_ */
55