/src/duckdb/third_party/brotli/enc/prefix.h

Source
/* Copyright 2013 Google Inc. All Rights Reserved.

   Distributed under MIT license.
   See file LICENSE for detail or copy at https://opensource.org/licenses/MIT
*/

/* Functions for encoding of integers into prefix codes the amount of extra
   bits, and the actual values of the extra bits. */

#ifndef BROTLI_ENC_PREFIX_H_
#define BROTLI_ENC_PREFIX_H_

#include <brotli/types.h>

#include "../common/brotli_constants.h"
#include "../common/brotli_platform.h"
#include "fast_log.h"

namespace duckdb_brotli {

/* Here distance_code is an intermediate code, i.e. one of the special codes or
   the actual distance increased by BROTLI_NUM_DISTANCE_SHORT_CODES - 1. */
static BROTLI_INLINE void PrefixEncodeCopyDistance(size_t distance_code,
                                                   size_t num_direct_codes,
                                                   size_t postfix_bits,
                                                   uint16_t* code,
                                                   uint32_t* extra_bits) {
  if (distance_code < BROTLI_NUM_DISTANCE_SHORT_CODES + num_direct_codes) {
    *code = (uint16_t)distance_code;
    *extra_bits = 0;
    return;
  } else {
    size_t dist = ((size_t)1 << (postfix_bits + 2u)) +
        (distance_code - BROTLI_NUM_DISTANCE_SHORT_CODES - num_direct_codes);
    size_t bucket = Log2FloorNonZero(dist) - 1;
    size_t postfix_mask = (1u << postfix_bits) - 1;
    size_t postfix = dist & postfix_mask;
    size_t prefix = (dist >> bucket) & 1;
    size_t offset = (2 + prefix) << bucket;
    size_t nbits = bucket - postfix_bits;
    *code = (uint16_t)((nbits << 10) |
        (BROTLI_NUM_DISTANCE_SHORT_CODES + num_direct_codes +
         ((2 * (nbits - 1) + prefix) << postfix_bits) + postfix));
    *extra_bits = (uint32_t)((dist - offset) >> postfix_bits);
  }
}

}

#endif  /* BROTLI_ENC_PREFIX_H_ */

Coverage Report

Created: 2026-03-31 07:54

Line	Count	Source
1		/* Copyright 2013 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 for encoding of integers into prefix codes the amount of extra
8		bits, and the actual values of the extra bits. */
9
10		#ifndef BROTLI_ENC_PREFIX_H_
11		#define BROTLI_ENC_PREFIX_H_
12
13		#include <brotli/types.h>
14
15		#include "../common/brotli_constants.h"
16		#include "../common/brotli_platform.h"
17		#include "fast_log.h"
18
19		namespace duckdb_brotli {
20
21		/* Here distance_code is an intermediate code, i.e. one of the special codes or
22		the actual distance increased by BROTLI_NUM_DISTANCE_SHORT_CODES - 1. */
23		static BROTLI_INLINE void PrefixEncodeCopyDistance(size_t distance_code,
24		size_t num_direct_codes,
25		size_t postfix_bits,
26		uint16_t* code,
27	0	uint32_t* extra_bits) {
28	0	if (distance_code < BROTLI_NUM_DISTANCE_SHORT_CODES + num_direct_codes) {
29	0	*code = (uint16_t)distance_code;
30	0	*extra_bits = 0;
31	0	return;
32	0	} else {
33	0	size_t dist = ((size_t)1 << (postfix_bits + 2u)) +
34	0	(distance_code - BROTLI_NUM_DISTANCE_SHORT_CODES - num_direct_codes);
35	0	size_t bucket = Log2FloorNonZero(dist) - 1;
36	0	size_t postfix_mask = (1u << postfix_bits) - 1;
37	0	size_t postfix = dist & postfix_mask;
38	0	size_t prefix = (dist >> bucket) & 1;
39	0	size_t offset = (2 + prefix) << bucket;
40	0	size_t nbits = bucket - postfix_bits;
41	0	*code = (uint16_t)((nbits << 10) \|
42	0	(BROTLI_NUM_DISTANCE_SHORT_CODES + num_direct_codes +
43	0	((2 * (nbits - 1) + prefix) << postfix_bits) + postfix));
44	0	*extra_bits = (uint32_t)((dist - offset) >> postfix_bits);
45	0	}
46	0	} Unexecuted instantiation: encode.cpp:duckdb_brotli::PrefixEncodeCopyDistance(unsigned long, unsigned long, unsigned long, unsigned short, unsigned int) Unexecuted instantiation: backward_references.cpp:duckdb_brotli::PrefixEncodeCopyDistance(unsigned long, unsigned long, unsigned long, unsigned short, unsigned int) Unexecuted instantiation: compress_fragment.cpp:duckdb_brotli::PrefixEncodeCopyDistance(unsigned long, unsigned long, unsigned long, unsigned short, unsigned int) Unexecuted instantiation: brotli_bit_stream.cpp:duckdb_brotli::PrefixEncodeCopyDistance(unsigned long, unsigned long, unsigned long, unsigned short, unsigned int) Unexecuted instantiation: metablock.cpp:duckdb_brotli::PrefixEncodeCopyDistance(unsigned long, unsigned long, unsigned long, unsigned short, unsigned int) Unexecuted instantiation: backward_references_hq.cpp:duckdb_brotli::PrefixEncodeCopyDistance(unsigned long, unsigned long, unsigned long, unsigned short, unsigned int) Unexecuted instantiation: histogram.cpp:duckdb_brotli::PrefixEncodeCopyDistance(unsigned long, unsigned long, unsigned long, unsigned short, unsigned int) Unexecuted instantiation: compress_fragment_two_pass.cpp:duckdb_brotli::PrefixEncodeCopyDistance(unsigned long, unsigned long, unsigned long, unsigned short, unsigned int) Unexecuted instantiation: block_splitter.cpp:duckdb_brotli::PrefixEncodeCopyDistance(unsigned long, unsigned long, unsigned long, unsigned short, unsigned int) Unexecuted instantiation: command.cpp:duckdb_brotli::PrefixEncodeCopyDistance(unsigned long, unsigned long, unsigned long, unsigned short, unsigned int) Unexecuted instantiation: cluster.cpp:duckdb_brotli::PrefixEncodeCopyDistance(unsigned long, unsigned long, unsigned long, unsigned short, unsigned int) Unexecuted instantiation: bit_cost.cpp:duckdb_brotli::PrefixEncodeCopyDistance(unsigned long, unsigned long, unsigned long, unsigned short, unsigned int)
47
48		}
49
50		#endif /* BROTLI_ENC_PREFIX_H_ */