ceph/src/isa-l/igzip/bitbuf2.h

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   2   Copyright(c) 2011-2016 Intel Corporation All rights reserved.
   3
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  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
  45 static inline void init(struct BitBuf2 *me)
  46 {
  47         me->m_bits = 0;
  48         me->m_bit_count = 0;
  49 }
  50
  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
  58 static inline int is_full(struct BitBuf2 *me)
  59 {
  60         return (me->m_out_buf > me->m_out_end);
  61 }
  62
  63 static inline uint8_t * buffer_ptr(struct BitBuf2 *me)
  64 {
  65         return me->m_out_buf;
  66 }
  67
  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
  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
  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 */
  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
 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
 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
 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
 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