Digest-FNV-XS/XS.xs

#include "EXTERN.h"
#include "perl.h"
#include "XSUB.h"

#define INIT32 2166136261U
#define MULT32 16777619U
#define INIT64 14695981039346656037U
#define MULT64 1099511628211U

static UV
fnv1_32 (SV *data, U32 h)
{
  STRLEN l;
  U8 *p = (U8 *)SvPVbyte (data, l);

  while (l--)
    {
      h *= MULT32;
      h ^= *p++;
    }

  return h;
}

static UV
fnv1a_32 (SV *data, U32 h)
{
  STRLEN l;
  U8 *p = (U8 *)SvPVbyte (data, l);

  while (l--)
    {
      h ^= *p++;
      h *= MULT32;
    }

  return h;
}

#if UVSIZE >= 8

static UV
fnv1_64 (SV *data, UV h)
{
  STRLEN l;
  U8 *p = (U8 *)SvPVbyte (data, l);

  while (l--)
    {
      h *= MULT64;
      h ^= *p++;
    }

  return h;
}

static UV
fnv1a_64 (SV *data, UV h)
{
  STRLEN l;
  U8 *p = (U8 *)SvPVbyte (data, l);

  while (l--)
    {
      h ^= *p++;
      h *= MULT64;
    }

  return h;
}

#endif

#define fnv0_32 fnv1_32
#define fnv0_64 fnv1_64

static UV
xorfold (UV hash, int bits, int max)
{
  if (bits < max)
    hash = ((hash >> (max - bits)) ^ hash) & ((1 << bits) - 1);

  return hash;
}

#define xorfold_32(hash,bits) xorfold (hash, bits, 32)
#define xorfold_64(hash,bits) xorfold (hash, bits, 64)

static UV
reduce_32 (U32 hash, U32 range)
{
  U32 retry =         0xffffffffU / range * range;

  while (hash >= retry)
    hash = hash * MULT32 + INIT32;

  return hash % range;
}

static UV
reduce_64 (UV hash, UV range)
{
  U32 retry = 0xffffffffffffffffU / range * range;

  while (hash >= retry)
    hash = hash * MULT64 + INIT64;

  return hash % range;
}

MODULE = Digest::FNV::XS                PACKAGE = Digest::FNV::XS

PROTOTYPES: ENABLE

UV fnv0_32  (SV *data, SV *init = &PL_sv_undef)
        C_ARGS: data, SvUV (init)

UV fnv1_32  (SV *data, SV *init = &PL_sv_undef)
        C_ARGS: data, SvOK (init) ? SvUV (init) : INIT32

UV fnv1a_32 (SV *data, SV *init = &PL_sv_undef)
        C_ARGS: data, SvOK (init) ? SvUV (init) : INIT32

#if UVSIZE >= 8

UV fnv0_64  (SV *data, SV *init = &PL_sv_undef)
        C_ARGS: data, SvUV (init)

UV fnv1_64  (SV *data, SV *init = &PL_sv_undef)
        C_ARGS: data, SvOK (init) ? SvUV (init) : INIT64

UV fnv1a_64 (SV *data, SV *init = &PL_sv_undef)
        C_ARGS: data, SvOK (init) ? SvUV (init) : INIT64

#endif

UV xorfold_32 (UV hash, int bits)

UV xorfold_64 (UV hash, int bits)

UV reduce_32 (UV hash, UV range)

UV reduce_64 (UV hash, UV range)

Revision:	1.1
Committed:	Thu Oct 29 10:56:00 2015 UTC (8 years, 6 months ago) by root
Branch:	MAIN
CVS Tags:	rel-0_02, HEAD
Log Message:	* empty log message *
#	Content
1	#include "EXTERN.h"
2	#include "perl.h"
3	#include "XSUB.h"
4
5	#define INIT32 2166136261U
6	#define MULT32 16777619U
7	#define INIT64 14695981039346656037U
8	#define MULT64 1099511628211U
9
10	static UV
11	fnv1_32 (SV *data, U32 h)
12	{
13	STRLEN l;
14	U8 p = (U8 )SvPVbyte (data, l);
15
16	while (l--)
17	{
18	h *= MULT32;
19	h ^= *p++;
20	}
21
22	return h;
23	}
24
25	static UV
26	fnv1a_32 (SV *data, U32 h)
27	{
28	STRLEN l;
29	U8 p = (U8 )SvPVbyte (data, l);
30
31	while (l--)
32	{
33	h ^= *p++;
34	h *= MULT32;
35	}
36
37	return h;
38	}
39
40	#if UVSIZE >= 8
41
42	static UV
43	fnv1_64 (SV *data, UV h)
44	{
45	STRLEN l;
46	U8 p = (U8 )SvPVbyte (data, l);
47
48	while (l--)
49	{
50	h *= MULT64;
51	h ^= *p++;
52	}
53
54	return h;
55	}
56
57	static UV
58	fnv1a_64 (SV *data, UV h)
59	{
60	STRLEN l;
61	U8 p = (U8 )SvPVbyte (data, l);
62
63	while (l--)
64	{
65	h ^= *p++;
66	h *= MULT64;
67	}
68
69	return h;
70	}
71
72	#endif
73
74	#define fnv0_32 fnv1_32
75	#define fnv0_64 fnv1_64
76
77	static UV
78	xorfold (UV hash, int bits, int max)
79	{
80	if (bits < max)
81	hash = ((hash >> (max - bits)) ^ hash) & ((1 << bits) - 1);
82
83	return hash;
84	}
85
86	#define xorfold_32(hash,bits) xorfold (hash, bits, 32)
87	#define xorfold_64(hash,bits) xorfold (hash, bits, 64)
88
89	static UV
90	reduce_32 (U32 hash, U32 range)
91	{
92	U32 retry = 0xffffffffU / range * range;
93
94	while (hash >= retry)
95	hash = hash * MULT32 + INIT32;
96
97	return hash % range;
98	}
99
100	static UV
101	reduce_64 (UV hash, UV range)
102	{
103	U32 retry = 0xffffffffffffffffU / range * range;
104
105	while (hash >= retry)
106	hash = hash * MULT64 + INIT64;
107
108	return hash % range;
109	}
110
111	MODULE = Digest::FNV::XS PACKAGE = Digest::FNV::XS
112
113	PROTOTYPES: ENABLE
114
115	UV fnv0_32 (SV data, SV init = &PL_sv_undef)
116	C_ARGS: data, SvUV (init)
117
118	UV fnv1_32 (SV data, SV init = &PL_sv_undef)
119	C_ARGS: data, SvOK (init) ? SvUV (init) : INIT32
120
121	UV fnv1a_32 (SV data, SV init = &PL_sv_undef)
122	C_ARGS: data, SvOK (init) ? SvUV (init) : INIT32
123
124	#if UVSIZE >= 8
125
126	UV fnv0_64 (SV data, SV init = &PL_sv_undef)
127	C_ARGS: data, SvUV (init)
128
129	UV fnv1_64 (SV data, SV init = &PL_sv_undef)
130	C_ARGS: data, SvOK (init) ? SvUV (init) : INIT64
131
132	UV fnv1a_64 (SV data, SV init = &PL_sv_undef)
133	C_ARGS: data, SvOK (init) ? SvUV (init) : INIT64
134
135	#endif
136
137	UV xorfold_32 (UV hash, int bits)
138
139	UV xorfold_64 (UV hash, int bits)
140
141	UV reduce_32 (UV hash, UV range)
142
143	UV reduce_64 (UV hash, UV range)
144