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/cvs/Digest-FNV-XS/XS.xs
Revision: 1.1
Committed: Thu Oct 29 10:56:00 2015 UTC (9 years ago) by root
Branch: MAIN
CVS Tags: rel-0_02, HEAD
Log Message:
*** empty log message ***

File Contents

# User Rev Content
1 root 1.1 #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