1 /**********************************************************************
2 Copyright(c) 2011-2016 Intel Corporation All rights reserved.
3
4 Redistribution and use in source and binary forms, with or without
5 modification, are permitted provided that the following conditions
6 are met:
7 * Redistributions of source code must retain the above copyright
8 notice, this list of conditions and the following disclaimer.
9 * Redistributions in binary form must reproduce the above copyright
10 notice, this list of conditions and the following disclaimer in
11 the documentation and/or other materials provided with the
12 distribution.
13 * Neither the name of Intel Corporation nor the names of its
14 contributors may be used to endorse or promote products derived
15 from this software without specific prior written permission.
16
17 THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
18 "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
19 LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
20 A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
21 OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
22 SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
23 LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
24 DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
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27 OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
28 **********************************************************************/
29 #ifndef BITBUF2_H
30 #define BITBUF2_H
31
32 #include "igzip_lib.h"
33 #include "unaligned.h"
34
35 #ifdef _MSC_VER
36 #define inline __inline
37 #endif
38
39
40 /* MAX_BITBUF_BIT WRITE is the maximum number of bits than can be safely written
41 * by consecutive calls of write_bits. Note this assumes the bitbuf is in a
42 * state that is possible at the exit of write_bits */
43 #define MAX_BITBUF_BIT_WRITE 56
44
init(struct BitBuf2 * me)45 static inline void init(struct BitBuf2 *me)
46 {
47 me->m_bits = 0;
48 me->m_bit_count = 0;
49 }
50
set_buf(struct BitBuf2 * me,unsigned char * buf,unsigned int len)51 static inline void set_buf(struct BitBuf2 *me, unsigned char *buf, unsigned int len)
52 {
53 unsigned int slop = 8;
54 me->m_out_buf = me->m_out_start = buf;
55 me->m_out_end = buf + len - slop;
56 }
57
is_full(struct BitBuf2 * me)58 static inline int is_full(struct BitBuf2 *me)
59 {
60 return (me->m_out_buf > me->m_out_end);
61 }
62
buffer_ptr(struct BitBuf2 * me)63 static inline uint8_t * buffer_ptr(struct BitBuf2 *me)
64 {
65 return me->m_out_buf;
66 }
67
buffer_used(struct BitBuf2 * me)68 static inline uint32_t buffer_used(struct BitBuf2 *me)
69 {
70 return (uint32_t)(me->m_out_buf - me->m_out_start);
71 }
72
buffer_bits_used(struct BitBuf2 * me)73 static inline uint32_t buffer_bits_used(struct BitBuf2 *me)
74 {
75 return (8 * (uint32_t)(me->m_out_buf - me->m_out_start) + me->m_bit_count);
76 }
77
flush_bits(struct BitBuf2 * me)78 static inline void flush_bits(struct BitBuf2 *me)
79 {
80 uint32_t bits;
81 store_u64(me->m_out_buf, me->m_bits);
82 bits = me->m_bit_count & ~7;
83 me->m_bit_count -= bits;
84 me->m_out_buf += bits/8;
85 me->m_bits >>= bits;
86
87 }
88
89 /* Can write up to 8 bytes to output buffer */
flush(struct BitBuf2 * me)90 static inline void flush(struct BitBuf2 *me)
91 {
92 uint32_t bytes;
93 if (me->m_bit_count) {
94 store_u64(me->m_out_buf, me->m_bits);
95 bytes = (me->m_bit_count + 7) / 8;
96 me->m_out_buf += bytes;
97 }
98 me->m_bits = 0;
99 me->m_bit_count = 0;
100 }
101
check_space(struct BitBuf2 * me,uint32_t num_bits)102 static inline void check_space(struct BitBuf2 *me, uint32_t num_bits)
103 {
104 /* Checks if bitbuf has num_bits extra space and flushes the bytes in
105 * the bitbuf if it doesn't. */
106 if (63 - me->m_bit_count < num_bits)
107 flush_bits(me);
108 }
109
write_bits_unsafe(struct BitBuf2 * me,uint64_t code,uint32_t count)110 static inline void write_bits_unsafe(struct BitBuf2 *me, uint64_t code, uint32_t count)
111 {
112 me->m_bits |= code << me->m_bit_count;
113 me->m_bit_count += count;
114 }
115
write_bits(struct BitBuf2 * me,uint64_t code,uint32_t count)116 static inline void write_bits(struct BitBuf2 *me, uint64_t code, uint32_t count)
117 { /* Assumes there is space to fit code into m_bits. */
118 me->m_bits |= code << me->m_bit_count;
119 me->m_bit_count += count;
120 flush_bits(me);
121 }
122
write_bits_flush(struct BitBuf2 * me,uint64_t code,uint32_t count)123 static inline void write_bits_flush(struct BitBuf2 *me, uint64_t code, uint32_t count)
124 { /* Assumes there is space to fit code into m_bits. */
125 me->m_bits |= code << me->m_bit_count;
126 me->m_bit_count += count;
127 flush(me);
128 }
129
130 #endif //BITBUF2_H
131