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kamailio/hashes.h

345 lines
8.4 KiB

/*
* $Id$
*
* Copyright (C) 2006 iptelorg GmbH
*
* Permission to use, copy, modify, and distribute this software for any
* purpose with or without fee is hereby granted, provided that the above
* copyright notice and this permission notice appear in all copies.
*
* THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
* WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
* MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
* ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
* WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
* ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
* OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
*/
/*
* History:
* --------
* 2006-02-02 created by andrei
* 2006-11-24 added numeric string optimized hash function (andrei)
* 2006-12-13 split into hashes.h (more generic) and str_hash.h (andrei)
* 2007-02-22 added case insensitive versions (andrei)
*/
#ifndef _hashes_h
#define _hashes_h
#include "str.h"
/* internal use: hash update
* params: char* s - string start,
* char* end - end
* char* p, and unsigned v temporary vars (used)
* unsigned h - result
* h should be initialized (e.g. set it to 0), the result in h */
#define hash_update_str(s, end, p, v, h) \
do{ \
for ((p)=(s); (p)<=((end)-4); (p)+=4){ \
(v)=(*(p)<<24)+((p)[1]<<16)+((p)[2]<<8)+(p)[3]; \
(h)+=(v)^((v)>>3); \
} \
switch((end)-(p)){\
case 3: \
(v)=(*(p)<<16)+((p)[1]<<8)+(p)[2]; break; \
case 2: \
(v)=(*(p)<<8)+p[1]; break; \
case 1: \
(v)=*p; break; \
default: \
(v)=0; break; \
} \
(h)+=(v)^((v)>>3); \
}while(0)
/* like hash_update_str, but case insensitive
* params: char* s - string start,
* char* end - end
* char* p, and unsigned v temporary vars (used)
* unsigned h - result
* h should be initialized (e.g. set it to 0), the result in h */
#define hash_update_case_str(s, end, p, v, h) \
do{ \
for ((p)=(s); (p)<=((end)-4); (p)+=4){ \
(v)=((*(p)<<24)+((p)[1]<<16)+((p)[2]<<8)+(p)[3])|0x20202020; \
(h)+=(v)^((v)>>3); \
} \
(v)=0; \
for (;(p)<(end); (p)++){ (v)<<=8; (v)+=*(p)|0x20;} \
(h)+=(v)^((v)>>3); \
}while(0)
/* internal use: call it to adjust the h from hash_update_str */
#define hash_finish(h) (((h)+((h)>>11))+(((h)>>13)+((h)>>23)))
/* "raw" 2 strings hash
* returns an unsigned int (which you can use modulo table_size as hash value)
*/
inline static unsigned int get_hash2_raw(const str* key1, const str* key2)
{
char* p;
register unsigned v;
register unsigned h;
h=0;
hash_update_str(key1->s, key1->s+key1->len, p, v, h);
hash_update_str(key2->s, key2->s+key2->len, p, v, h);
return hash_finish(h);
}
/* "raw" 1 string hash
* returns an unsigned int (which you can use modulo table_size as hash value)
*/
inline static unsigned int get_hash1_raw(const char* s, int len)
{
const char* p;
register unsigned v;
register unsigned h;
h=0;
hash_update_str(s, s+len, p, v, h);
return hash_finish(h);
}
/* a little slower than hash_* , but better distribution for
* numbers and about the same for strings */
#define hash_update_str2(s, end, p, v, h) \
do{ \
for ((p)=(s); (p)<=((end)-4); (p)+=4){ \
(v)=(*(p)*16777213)+((p)[1]*65537)+((p)[2]*257)+(p)[3]; \
(h)=16777259*(h)+((v)^((v)<<17)); \
} \
(v)=0; \
for (;(p)<(end); (p)++){ (v)*=251; (v)+=*(p);} \
(h)=16777259*(h)+((v)^((v)<<17)); \
}while(0)
/* like hash_update_str2 but case insensitive */
#define hash_update_case_str2(s, end, p, v, h) \
do{ \
for ((p)=(s); (p)<=((end)-4); (p)+=4){ \
(v)=((*(p)|0x20)*16777213)+(((p)[1]|0x20)*65537)+\
(((p)[2]|0x20)*257)+((p)[3]|0x20); \
(h)=16777259*(h)+((v)^((v)<<17)); \
} \
(v)=0; \
for (;(p)<(end); (p)++){ (v)*=251; (v)+=*(p)|0x20;} \
(h)=16777259*(h)+((v)^((v)<<17)); \
}while(0)
/* internal use: call it to adjust the h from hash_update_str */
#define hash_finish2(h) (((h)+((h)>>7))+(((h)>>13)+((h)>>23)))
/* a little slower than get_hash1_raw() , but better distribution for
* numbers and about the same for strings */
inline static unsigned int get_hash1_raw2(const char* s, int len)
{
const char* p;
register unsigned v;
register unsigned h;
h=0;
hash_update_str2(s, s+len, p, v, h);
return hash_finish2(h);
}
/* "raw" 2 strings hash optimized for numeric strings (see above)
* returns an unsigned int (which you can use modulo table_size as hash value)
*/
inline static unsigned int get_hash2_raw2(const str* key1, const str* key2)
{
char* p;
register unsigned v;
register unsigned h;
h=0;
hash_update_str2(key1->s, key1->s+key1->len, p, v, h);
hash_update_str2(key2->s, key2->s+key2->len, p, v, h);
return hash_finish2(h);
}
/* "raw" 2 strings case insensitive hash (like get_hash2_raw but case
* insensitive)
* returns an unsigned int (which you can use modulo table_size as hash value)
*/
inline static unsigned int get_hash2_case_raw(const str* key1, const str* key2)
{
char* p;
register unsigned v;
register unsigned h;
h=0;
hash_update_case_str(key1->s, key1->s+key1->len, p, v, h);
hash_update_case_str(key2->s, key2->s+key2->len, p, v, h);
return hash_finish(h);
}
/* "raw" 1 string case insensitive hash
* returns an unsigned int (which you can use modulo table_size as hash value)
*/
inline static unsigned int get_hash1_case_raw(const char* s, int len)
{
const char* p;
register unsigned v;
register unsigned h;
h=0;
hash_update_case_str(s, s+len, p, v, h);
return hash_finish(h);
}
/* same as get_hash1_raw2, but case insensitive and slower
* returns an unsigned int (which you can use modulo table_size as hash value)
*/
inline static unsigned int get_hash1_case_raw2(const char* s, int len)
{
const char* p;
register unsigned v;
register unsigned h;
h=0;
hash_update_case_str2(s, s+len, p, v, h);
return hash_finish2(h);
}
/* "raw" 2 strings hash optimized for numeric strings (see above)
* same as get_hash2_raw2 but case insensitive and slower
* returns an unsigned int (which you can use modulo table_size as hash value)
*/
inline static unsigned int get_hash2_case_raw2(const str* key1,
const str* key2)
{
char* p;
register unsigned v;
register unsigned h;
h=0;
hash_update_case_str2(key1->s, key1->s+key1->len, p, v, h);
hash_update_case_str2(key2->s, key2->s+key2->len, p, v, h);
return hash_finish2(h);
}
/*
* generic hashing - from the intial origins of ser
*/
#define ch_h_inc h+=v^(v>>3)
#define ch_icase(_c) (((_c)>='A'&&(_c)<='Z')?((_c)|0x20):(_c))
/*
* case sensitive hashing
* - s1 - str to hash
* - s2 - optional - continue hashing over s2
* - size - optional - size of hash table (must be power of 1); if set (!=0),
* instead of hash id, returned value is slot index
* return computed hash id or hash table slot index
*/
static inline unsigned int core_hash(const str *s1, const str *s2,
const unsigned int size)
{
char *p, *end;
register unsigned v;
register unsigned h;
h=0;
end=s1->s+s1->len;
for ( p=s1->s ; p<=(end-4) ; p+=4 ){
v=(*p<<24)+(p[1]<<16)+(p[2]<<8)+p[3];
ch_h_inc;
}
v=0;
for (; p<end ; p++){ v<<=8; v+=*p;}
ch_h_inc;
if (s2) {
end=s2->s+s2->len;
for (p=s2->s; p<=(end-4); p+=4){
v=(*p<<24)+(p[1]<<16)+(p[2]<<8)+p[3];
ch_h_inc;
}
v=0;
for (; p<end ; p++){ v<<=8; v+=*p;}
ch_h_inc;
}
h=((h)+(h>>11))+((h>>13)+(h>>23));
return size?((h)&(size-1)):h;
}
/*
* case insensitive hashing
* - s1 - str to hash
* - s2 - optional - continue hashing over s2
* - size - optional - size of hash table (must be power of 1); if set (!=0),
* instead of hash id, returned value is slot index
* return computed hash id or hash table slot index
*/
static inline unsigned int core_case_hash( str *s1, str *s2,
unsigned int size)
{
char *p, *end;
register unsigned v;
register unsigned h;
h=0;
end=s1->s+s1->len;
for ( p=s1->s ; p<=(end-4) ; p+=4 ){
v=(ch_icase(*p)<<24)+(ch_icase(p[1])<<16)+(ch_icase(p[2])<<8)
+ ch_icase(p[3]);
ch_h_inc;
}
v=0;
for (; p<end ; p++){ v<<=8; v+=ch_icase(*p);}
ch_h_inc;
if (s2) {
end=s2->s+s2->len;
for (p=s2->s; p<=(end-4); p+=4){
v=(ch_icase(*p)<<24)+(ch_icase(p[1])<<16)+(ch_icase(p[2])<<8)
+ ch_icase(p[3]);
ch_h_inc;
}
v=0;
for (; p<end ; p++){ v<<=8; v+=ch_icase(*p);}
ch_h_inc;
}
h=((h)+(h>>11))+((h>>13)+(h>>23));
return size?((h)&(size-1)):h;
}
#endif