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pg_crc32c.h File Reference
#include "port/pg_bswap.h"
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Macros

#define  INIT_CRC32C(crc)   ((crc) = 0xFFFFFFFF)
 
#define  EQ_CRC32C(c1, c2)   ((c1) == (c2))
 
#define  COMP_CRC32C(crc, data, len)    ((crc) = pg_comp_crc32c_sb8((crc), (data), (len)))
 
#define  FIN_CRC32C(crc)   ((crc) ^= 0xFFFFFFFF)
 

Typedefs

typedef uint32  pg_crc32c
 

Functions

pg_crc32c  pg_comp_crc32c_sb8 (pg_crc32c crc, const void *data, size_t len)
 

Macro Definition Documentation

◆ COMP_CRC32C

#define COMP_CRC32C (   crc,
  data,
  len 
)     ((crc) = pg_comp_crc32c_sb8((crc), (data), (len)))

Definition at line 153 of file pg_crc32c.h.

◆ EQ_CRC32C

#define EQ_CRC32C (   c1,
  c2 
)    ((c1) == (c2))

Definition at line 42 of file pg_crc32c.h.

◆ FIN_CRC32C

#define FIN_CRC32C (   crc )    ((crc) ^= 0xFFFFFFFF)

Definition at line 158 of file pg_crc32c.h.

◆ INIT_CRC32C

#define INIT_CRC32C (   crc )    ((crc) = 0xFFFFFFFF)

Definition at line 41 of file pg_crc32c.h.

Typedef Documentation

◆ pg_crc32c

typedef uint32 pg_crc32c

Definition at line 38 of file pg_crc32c.h.

Function Documentation

◆ pg_comp_crc32c_sb8()

pg_crc32c pg_comp_crc32c_sb8 ( pg_crc32c  crc,
const void *  data,
size_t  len 
)

Definition at line 35 of file pg_crc32c_sb8.c.

36{
37 const unsigned char *p = data;
38 const uint32 *p4;
39
40 /*
41 * Handle 0-3 initial bytes one at a time, so that the loop below starts
42 * with a pointer aligned to four bytes.
43 */
44 while (len > 0 && ((uintptr_t) p & 3))
45 {
46 crc = CRC8(*p++);
47 len--;
48 }
49
50 /*
51 * Process eight bytes of data at a time.
52 */
53 p4 = (const uint32 *) p;
54 while (len >= 8)
55 {
56 uint32 a = *p4++ ^ crc;
57 uint32 b = *p4++;
58
59#ifdef WORDS_BIGENDIAN
60 const uint8 c0 = b;
61 const uint8 c1 = b >> 8;
62 const uint8 c2 = b >> 16;
63 const uint8 c3 = b >> 24;
64 const uint8 c4 = a;
65 const uint8 c5 = a >> 8;
66 const uint8 c6 = a >> 16;
67 const uint8 c7 = a >> 24;
68#else
69 const uint8 c0 = b >> 24;
70 const uint8 c1 = b >> 16;
71 const uint8 c2 = b >> 8;
72 const uint8 c3 = b;
73 const uint8 c4 = a >> 24;
74 const uint8 c5 = a >> 16;
75 const uint8 c6 = a >> 8;
76 const uint8 c7 = a;
77#endif
78
79 crc =
80 pg_crc32c_table[0][c0] ^ pg_crc32c_table[1][c1] ^
81 pg_crc32c_table[2][c2] ^ pg_crc32c_table[3][c3] ^
82 pg_crc32c_table[4][c4] ^ pg_crc32c_table[5][c5] ^
83 pg_crc32c_table[6][c6] ^ pg_crc32c_table[7][c7];
84
85 len -= 8;
86 }
87
88 /*
89 * Handle any remaining bytes one at a time.
90 */
91 p = (const unsigned char *) p4;
92 while (len > 0)
93 {
94 crc = CRC8(*p++);
95 len--;
96 }
97
98 return crc;
99}
uint8_t uint8
Definition: c.h:536
uint32_t uint32
Definition: c.h:538
b
int b
Definition: isn.c:74
a
int a
Definition: isn.c:73
static const uint32 pg_crc32c_table[8][256]
Definition: pg_crc32c_sb8.c:25
#define CRC8(x)
Definition: pg_crc32c_sb8.c:31
const void size_t len
const void * data
return crc

References a, b, crc, CRC8, data, len, and pg_crc32c_table.

Referenced by pg_comp_crc32c_choose().

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