1996-07-09 08:22:35 +02:00
|
|
|
/*-------------------------------------------------------------------------
|
|
|
|
*
|
1999-02-14 00:22:53 +01:00
|
|
|
* hashfunc.c
|
2007-06-01 17:33:19 +02:00
|
|
|
* Support functions for hash access method.
|
1996-07-09 08:22:35 +02:00
|
|
|
*
|
2009-01-01 18:24:05 +01:00
|
|
|
* Portions Copyright (c) 1996-2009, PostgreSQL Global Development Group
|
2000-01-26 06:58:53 +01:00
|
|
|
* Portions Copyright (c) 1994, Regents of the University of California
|
1996-07-09 08:22:35 +02:00
|
|
|
*
|
|
|
|
*
|
|
|
|
* IDENTIFICATION
|
2009-01-01 18:24:05 +01:00
|
|
|
* $PostgreSQL: pgsql/src/backend/access/hash/hashfunc.c,v 1.57 2009/01/01 17:23:35 momjian Exp $
|
1996-07-09 08:22:35 +02:00
|
|
|
*
|
|
|
|
* NOTES
|
1997-09-07 07:04:48 +02:00
|
|
|
* These functions are stored in pg_amproc. For each operator class
|
2007-06-01 17:33:19 +02:00
|
|
|
* defined for hash indexes, they compute the hash value of the argument.
|
1996-07-09 08:22:35 +02:00
|
|
|
*
|
2007-06-01 17:33:19 +02:00
|
|
|
* Additional hash functions appear in /utils/adt/ files for various
|
|
|
|
* specialized datatypes.
|
|
|
|
*
|
|
|
|
* It is expected that every bit of a hash function's 32-bit result is
|
|
|
|
* as random as every other; failure to ensure this is likely to lead
|
|
|
|
* to poor performance of hash joins, for example. In most cases a hash
|
|
|
|
* function should use hash_any() or its variant hash_uint32().
|
1996-07-09 08:22:35 +02:00
|
|
|
*-------------------------------------------------------------------------
|
|
|
|
*/
|
1996-10-20 08:34:30 +02:00
|
|
|
|
1996-07-09 08:22:35 +02:00
|
|
|
#include "postgres.h"
|
|
|
|
|
1996-11-10 04:06:38 +01:00
|
|
|
#include "access/hash.h"
|
|
|
|
|
2000-06-19 05:55:01 +02:00
|
|
|
|
2003-06-23 00:04:55 +02:00
|
|
|
/* Note: this is used for both "char" and boolean datatypes */
|
2000-06-19 05:55:01 +02:00
|
|
|
Datum
|
|
|
|
hashchar(PG_FUNCTION_ARGS)
|
|
|
|
{
|
2007-06-01 17:33:19 +02:00
|
|
|
return hash_uint32((int32) PG_GETARG_CHAR(0));
|
2000-06-19 05:55:01 +02:00
|
|
|
}
|
|
|
|
|
2000-06-05 09:29:25 +02:00
|
|
|
Datum
|
|
|
|
hashint2(PG_FUNCTION_ARGS)
|
1996-07-09 08:22:35 +02:00
|
|
|
{
|
2007-06-01 17:33:19 +02:00
|
|
|
return hash_uint32((int32) PG_GETARG_INT16(0));
|
1996-07-09 08:22:35 +02:00
|
|
|
}
|
|
|
|
|
2000-06-05 09:29:25 +02:00
|
|
|
Datum
|
|
|
|
hashint4(PG_FUNCTION_ARGS)
|
1996-07-09 08:22:35 +02:00
|
|
|
{
|
2007-06-01 17:33:19 +02:00
|
|
|
return hash_uint32(PG_GETARG_INT32(0));
|
1996-07-09 08:22:35 +02:00
|
|
|
}
|
|
|
|
|
2000-06-05 09:29:25 +02:00
|
|
|
Datum
|
|
|
|
hashint8(PG_FUNCTION_ARGS)
|
1999-03-14 06:09:05 +01:00
|
|
|
{
|
2004-06-13 23:57:28 +02:00
|
|
|
/*
|
|
|
|
* The idea here is to produce a hash value compatible with the values
|
2006-12-23 01:43:13 +01:00
|
|
|
* produced by hashint4 and hashint2 for logically equal inputs; this is
|
|
|
|
* necessary to support cross-type hash joins across these input types.
|
|
|
|
* Since all three types are signed, we can xor the high half of the int8
|
|
|
|
* value if the sign is positive, or the complement of the high half when
|
|
|
|
* the sign is negative.
|
2004-06-13 23:57:28 +02:00
|
|
|
*/
|
|
|
|
#ifndef INT64_IS_BUSTED
|
|
|
|
int64 val = PG_GETARG_INT64(0);
|
|
|
|
uint32 lohalf = (uint32) val;
|
|
|
|
uint32 hihalf = (uint32) (val >> 32);
|
|
|
|
|
|
|
|
lohalf ^= (val >= 0) ? hihalf : ~hihalf;
|
|
|
|
|
2007-06-01 17:33:19 +02:00
|
|
|
return hash_uint32(lohalf);
|
2004-06-13 23:57:28 +02:00
|
|
|
#else
|
|
|
|
/* here if we can't count on "x >> 32" to work sanely */
|
2007-06-01 17:33:19 +02:00
|
|
|
return hash_uint32((int32) PG_GETARG_INT64(0));
|
2004-06-13 23:57:28 +02:00
|
|
|
#endif
|
2000-06-19 05:55:01 +02:00
|
|
|
}
|
|
|
|
|
|
|
|
Datum
|
|
|
|
hashoid(PG_FUNCTION_ARGS)
|
|
|
|
{
|
2007-06-01 17:33:19 +02:00
|
|
|
return hash_uint32((uint32) PG_GETARG_OID(0));
|
1999-03-14 06:09:05 +01:00
|
|
|
}
|
|
|
|
|
2007-04-02 05:49:42 +02:00
|
|
|
Datum
|
|
|
|
hashenum(PG_FUNCTION_ARGS)
|
|
|
|
{
|
2007-06-01 17:33:19 +02:00
|
|
|
return hash_uint32((uint32) PG_GETARG_OID(0));
|
2007-04-02 05:49:42 +02:00
|
|
|
}
|
|
|
|
|
2000-06-05 09:29:25 +02:00
|
|
|
Datum
|
|
|
|
hashfloat4(PG_FUNCTION_ARGS)
|
1996-07-09 08:22:35 +02:00
|
|
|
{
|
2000-06-05 09:29:25 +02:00
|
|
|
float4 key = PG_GETARG_FLOAT4(0);
|
2006-12-23 01:43:13 +01:00
|
|
|
float8 key8;
|
1997-09-07 07:04:48 +02:00
|
|
|
|
2003-06-23 00:04:55 +02:00
|
|
|
/*
|
2005-10-15 04:49:52 +02:00
|
|
|
* On IEEE-float machines, minus zero and zero have different bit patterns
|
|
|
|
* but should compare as equal. We must ensure that they have the same
|
2006-12-23 01:43:13 +01:00
|
|
|
* hash value, which is most reliably done this way:
|
2003-06-23 00:04:55 +02:00
|
|
|
*/
|
|
|
|
if (key == (float4) 0)
|
|
|
|
PG_RETURN_UINT32(0);
|
|
|
|
|
2006-12-23 01:43:13 +01:00
|
|
|
/*
|
|
|
|
* To support cross-type hashing of float8 and float4, we want to return
|
|
|
|
* the same hash value hashfloat8 would produce for an equal float8 value.
|
|
|
|
* So, widen the value to float8 and hash that. (We must do this rather
|
2007-11-15 22:14:46 +01:00
|
|
|
* than have hashfloat8 try to narrow its value to float4; that could fail
|
|
|
|
* on overflow.)
|
2006-12-23 01:43:13 +01:00
|
|
|
*/
|
|
|
|
key8 = key;
|
|
|
|
|
|
|
|
return hash_any((unsigned char *) &key8, sizeof(key8));
|
1997-09-07 07:04:48 +02:00
|
|
|
}
|
1996-07-09 08:22:35 +02:00
|
|
|
|
2000-06-05 09:29:25 +02:00
|
|
|
Datum
|
|
|
|
hashfloat8(PG_FUNCTION_ARGS)
|
1996-07-09 08:22:35 +02:00
|
|
|
{
|
2000-06-05 09:29:25 +02:00
|
|
|
float8 key = PG_GETARG_FLOAT8(0);
|
1996-07-09 08:22:35 +02:00
|
|
|
|
2003-06-23 00:04:55 +02:00
|
|
|
/*
|
2005-10-15 04:49:52 +02:00
|
|
|
* On IEEE-float machines, minus zero and zero have different bit patterns
|
|
|
|
* but should compare as equal. We must ensure that they have the same
|
2006-12-23 01:43:13 +01:00
|
|
|
* hash value, which is most reliably done this way:
|
2003-06-23 00:04:55 +02:00
|
|
|
*/
|
|
|
|
if (key == (float8) 0)
|
|
|
|
PG_RETURN_UINT32(0);
|
|
|
|
|
2002-03-09 18:35:37 +01:00
|
|
|
return hash_any((unsigned char *) &key, sizeof(key));
|
1996-07-09 08:22:35 +02:00
|
|
|
}
|
|
|
|
|
2000-06-05 09:29:25 +02:00
|
|
|
Datum
|
|
|
|
hashoidvector(PG_FUNCTION_ARGS)
|
1998-08-19 04:04:17 +02:00
|
|
|
{
|
2005-03-29 02:17:27 +02:00
|
|
|
oidvector *key = (oidvector *) PG_GETARG_POINTER(0);
|
1998-08-19 04:04:17 +02:00
|
|
|
|
2005-03-29 02:17:27 +02:00
|
|
|
return hash_any((unsigned char *) key->values, key->dim1 * sizeof(Oid));
|
2000-02-21 04:36:59 +01:00
|
|
|
}
|
|
|
|
|
2000-06-05 09:29:25 +02:00
|
|
|
Datum
|
|
|
|
hashint2vector(PG_FUNCTION_ARGS)
|
2000-02-21 04:36:59 +01:00
|
|
|
{
|
2005-03-29 02:17:27 +02:00
|
|
|
int2vector *key = (int2vector *) PG_GETARG_POINTER(0);
|
2000-02-21 04:36:59 +01:00
|
|
|
|
2005-03-29 02:17:27 +02:00
|
|
|
return hash_any((unsigned char *) key->values, key->dim1 * sizeof(int2));
|
1998-08-19 04:04:17 +02:00
|
|
|
}
|
|
|
|
|
2000-06-05 09:29:25 +02:00
|
|
|
Datum
|
2000-06-19 05:55:01 +02:00
|
|
|
hashname(PG_FUNCTION_ARGS)
|
1996-07-09 08:22:35 +02:00
|
|
|
{
|
2001-03-22 05:01:46 +01:00
|
|
|
char *key = NameStr(*PG_GETARG_NAME(0));
|
2002-03-09 18:35:37 +01:00
|
|
|
int keylen = strlen(key);
|
1996-07-09 08:22:35 +02:00
|
|
|
|
2005-10-15 04:49:52 +02:00
|
|
|
Assert(keylen < NAMEDATALEN); /* else it's not truncated correctly */
|
2002-03-06 21:49:46 +01:00
|
|
|
|
2002-03-09 18:35:37 +01:00
|
|
|
return hash_any((unsigned char *) key, keylen);
|
1996-07-09 08:22:35 +02:00
|
|
|
}
|
|
|
|
|
2003-06-23 00:04:55 +02:00
|
|
|
Datum
|
|
|
|
hashtext(PG_FUNCTION_ARGS)
|
|
|
|
{
|
2007-09-22 00:52:52 +02:00
|
|
|
text *key = PG_GETARG_TEXT_PP(0);
|
2003-06-23 00:04:55 +02:00
|
|
|
Datum result;
|
|
|
|
|
|
|
|
/*
|
2006-10-04 02:30:14 +02:00
|
|
|
* Note: this is currently identical in behavior to hashvarlena, but keep
|
|
|
|
* it as a separate function in case we someday want to do something
|
|
|
|
* different in non-C locales. (See also hashbpchar, if so.)
|
2003-06-23 00:04:55 +02:00
|
|
|
*/
|
2007-09-22 00:52:52 +02:00
|
|
|
result = hash_any((unsigned char *) VARDATA_ANY(key),
|
|
|
|
VARSIZE_ANY_EXHDR(key));
|
2003-06-23 00:04:55 +02:00
|
|
|
|
|
|
|
/* Avoid leaking memory for toasted inputs */
|
|
|
|
PG_FREE_IF_COPY(key, 0);
|
|
|
|
|
|
|
|
return result;
|
|
|
|
}
|
|
|
|
|
2000-06-19 05:55:01 +02:00
|
|
|
/*
|
|
|
|
* hashvarlena() can be used for any varlena datatype in which there are
|
|
|
|
* no non-significant bits, ie, distinct bitpatterns never compare as equal.
|
|
|
|
*/
|
2000-06-05 09:29:25 +02:00
|
|
|
Datum
|
2000-06-19 05:55:01 +02:00
|
|
|
hashvarlena(PG_FUNCTION_ARGS)
|
1996-07-09 08:22:35 +02:00
|
|
|
{
|
2007-09-22 00:52:52 +02:00
|
|
|
struct varlena *key = PG_GETARG_VARLENA_PP(0);
|
2000-12-09 00:57:03 +01:00
|
|
|
Datum result;
|
1997-09-07 07:04:48 +02:00
|
|
|
|
2007-09-22 00:52:52 +02:00
|
|
|
result = hash_any((unsigned char *) VARDATA_ANY(key),
|
|
|
|
VARSIZE_ANY_EXHDR(key));
|
2000-12-09 00:57:03 +01:00
|
|
|
|
|
|
|
/* Avoid leaking memory for toasted inputs */
|
|
|
|
PG_FREE_IF_COPY(key, 0);
|
|
|
|
|
|
|
|
return result;
|
1996-07-09 08:22:35 +02:00
|
|
|
}
|
|
|
|
|
2002-03-09 18:35:37 +01:00
|
|
|
/*
|
|
|
|
* This hash function was written by Bob Jenkins
|
2002-03-06 21:49:46 +01:00
|
|
|
* (bob_jenkins@burtleburtle.net), and superficially adapted
|
|
|
|
* for PostgreSQL by Neil Conway. For more information on this
|
2002-03-09 18:35:37 +01:00
|
|
|
* hash function, see http://burtleburtle.net/bob/hash/doobs.html,
|
|
|
|
* or Bob's article in Dr. Dobb's Journal, Sept. 1997.
|
2008-04-06 18:54:49 +02:00
|
|
|
*
|
|
|
|
* In the current code, we have adopted an idea from Bob's 2006 update
|
|
|
|
* of his hash function, which is to fetch the data a word at a time when
|
|
|
|
* it is suitably aligned. This makes for a useful speedup, at the cost
|
|
|
|
* of having to maintain four code paths (aligned vs unaligned, and
|
|
|
|
* little-endian vs big-endian). Note that we have NOT adopted his newer
|
|
|
|
* mix() function, which is faster but may sacrifice some randomness.
|
2002-03-06 21:49:46 +01:00
|
|
|
*/
|
2000-06-19 05:55:01 +02:00
|
|
|
|
2008-04-06 18:54:49 +02:00
|
|
|
/* Get a bit mask of the bits set in non-uint32 aligned addresses */
|
|
|
|
#define UINT32_ALIGN_MASK (sizeof(uint32) - 1)
|
|
|
|
|
2002-03-09 18:35:37 +01:00
|
|
|
/*----------
|
2002-03-06 21:49:46 +01:00
|
|
|
* mix -- mix 3 32-bit values reversibly.
|
|
|
|
* For every delta with one or two bits set, and the deltas of all three
|
|
|
|
* high bits or all three low bits, whether the original value of a,b,c
|
|
|
|
* is almost all zero or is uniformly distributed,
|
|
|
|
* - If mix() is run forward or backward, at least 32 bits in a,b,c
|
2002-09-04 22:31:48 +02:00
|
|
|
* have at least 1/4 probability of changing.
|
2002-03-06 21:49:46 +01:00
|
|
|
* - If mix() is run forward, every bit of c will change between 1/3 and
|
2002-09-04 22:31:48 +02:00
|
|
|
* 2/3 of the time. (Well, 22/100 and 78/100 for some 2-bit deltas.)
|
2002-03-09 18:35:37 +01:00
|
|
|
*----------
|
2002-03-06 21:49:46 +01:00
|
|
|
*/
|
|
|
|
#define mix(a,b,c) \
|
|
|
|
{ \
|
2005-05-25 23:40:43 +02:00
|
|
|
a -= b; a -= c; a ^= ((c)>>13); \
|
|
|
|
b -= c; b -= a; b ^= ((a)<<8); \
|
|
|
|
c -= a; c -= b; c ^= ((b)>>13); \
|
|
|
|
a -= b; a -= c; a ^= ((c)>>12); \
|
|
|
|
b -= c; b -= a; b ^= ((a)<<16); \
|
|
|
|
c -= a; c -= b; c ^= ((b)>>5); \
|
|
|
|
a -= b; a -= c; a ^= ((c)>>3); \
|
|
|
|
b -= c; b -= a; b ^= ((a)<<10); \
|
|
|
|
c -= a; c -= b; c ^= ((b)>>15); \
|
2002-03-06 21:49:46 +01:00
|
|
|
}
|
|
|
|
|
|
|
|
/*
|
|
|
|
* hash_any() -- hash a variable-length key into a 32-bit value
|
2002-09-04 22:31:48 +02:00
|
|
|
* k : the key (the unaligned variable-length array of bytes)
|
|
|
|
* len : the length of the key, counting by bytes
|
2002-03-09 18:35:37 +01:00
|
|
|
*
|
2002-09-04 22:31:48 +02:00
|
|
|
* Returns a uint32 value. Every bit of the key affects every bit of
|
2002-03-06 21:49:46 +01:00
|
|
|
* the return value. Every 1-bit and 2-bit delta achieves avalanche.
|
|
|
|
* About 6*len+35 instructions. The best hash table sizes are powers
|
|
|
|
* of 2. There is no need to do mod a prime (mod is sooo slow!).
|
|
|
|
* If you need less than 32 bits, use a bitmask.
|
2008-04-06 18:54:49 +02:00
|
|
|
*
|
|
|
|
* Note: we could easily change this function to return a 64-bit hash value
|
|
|
|
* by using the final values of both b and c. b is perhaps a little less
|
|
|
|
* well mixed than c, however.
|
1996-07-09 08:22:35 +02:00
|
|
|
*/
|
2000-06-05 09:29:25 +02:00
|
|
|
Datum
|
2002-03-09 18:35:37 +01:00
|
|
|
hash_any(register const unsigned char *k, register int keylen)
|
1996-07-09 08:22:35 +02:00
|
|
|
{
|
2002-09-04 22:31:48 +02:00
|
|
|
register uint32 a,
|
|
|
|
b,
|
|
|
|
c,
|
|
|
|
len;
|
2002-03-09 18:35:37 +01:00
|
|
|
|
|
|
|
/* Set up the internal state */
|
|
|
|
len = keylen;
|
|
|
|
a = b = 0x9e3779b9; /* the golden ratio; an arbitrary value */
|
|
|
|
c = 3923095; /* initialize with an arbitrary value */
|
|
|
|
|
2008-04-06 18:54:49 +02:00
|
|
|
/* If the source pointer is word-aligned, we use word-wide fetches */
|
|
|
|
if (((long) k & UINT32_ALIGN_MASK) == 0)
|
2002-03-09 18:35:37 +01:00
|
|
|
{
|
2008-04-06 18:54:49 +02:00
|
|
|
/* Code path for aligned source data */
|
|
|
|
register const uint32 *ka = (const uint32 *) k;
|
|
|
|
|
|
|
|
/* handle most of the key */
|
|
|
|
while (len >= 12)
|
|
|
|
{
|
|
|
|
a += ka[0];
|
|
|
|
b += ka[1];
|
|
|
|
c += ka[2];
|
|
|
|
mix(a, b, c);
|
|
|
|
ka += 3;
|
|
|
|
len -= 12;
|
|
|
|
}
|
|
|
|
|
|
|
|
/* handle the last 11 bytes */
|
|
|
|
k = (const unsigned char *) ka;
|
|
|
|
c += keylen;
|
|
|
|
#ifdef WORDS_BIGENDIAN
|
|
|
|
switch (len)
|
|
|
|
{
|
|
|
|
case 11:
|
|
|
|
c += ((uint32) k[10] << 8);
|
|
|
|
/* fall through */
|
|
|
|
case 10:
|
|
|
|
c += ((uint32) k[9] << 16);
|
|
|
|
/* fall through */
|
|
|
|
case 9:
|
|
|
|
c += ((uint32) k[8] << 24);
|
|
|
|
/* the lowest byte of c is reserved for the length */
|
|
|
|
/* fall through */
|
|
|
|
case 8:
|
|
|
|
b += ka[1];
|
|
|
|
a += ka[0];
|
|
|
|
break;
|
|
|
|
case 7:
|
|
|
|
b += ((uint32) k[6] << 8);
|
|
|
|
/* fall through */
|
|
|
|
case 6:
|
|
|
|
b += ((uint32) k[5] << 16);
|
|
|
|
/* fall through */
|
|
|
|
case 5:
|
|
|
|
b += ((uint32) k[4] << 24);
|
|
|
|
/* fall through */
|
|
|
|
case 4:
|
|
|
|
a += ka[0];
|
|
|
|
break;
|
|
|
|
case 3:
|
|
|
|
a += ((uint32) k[2] << 8);
|
|
|
|
/* fall through */
|
|
|
|
case 2:
|
|
|
|
a += ((uint32) k[1] << 16);
|
|
|
|
/* fall through */
|
|
|
|
case 1:
|
|
|
|
a += ((uint32) k[0] << 24);
|
|
|
|
/* case 0: nothing left to add */
|
|
|
|
}
|
|
|
|
#else /* !WORDS_BIGENDIAN */
|
|
|
|
switch (len)
|
|
|
|
{
|
|
|
|
case 11:
|
|
|
|
c += ((uint32) k[10] << 24);
|
|
|
|
/* fall through */
|
|
|
|
case 10:
|
|
|
|
c += ((uint32) k[9] << 16);
|
|
|
|
/* fall through */
|
|
|
|
case 9:
|
|
|
|
c += ((uint32) k[8] << 8);
|
|
|
|
/* the lowest byte of c is reserved for the length */
|
|
|
|
/* fall through */
|
|
|
|
case 8:
|
|
|
|
b += ka[1];
|
|
|
|
a += ka[0];
|
|
|
|
break;
|
|
|
|
case 7:
|
|
|
|
b += ((uint32) k[6] << 16);
|
|
|
|
/* fall through */
|
|
|
|
case 6:
|
|
|
|
b += ((uint32) k[5] << 8);
|
|
|
|
/* fall through */
|
|
|
|
case 5:
|
|
|
|
b += k[4];
|
|
|
|
/* fall through */
|
|
|
|
case 4:
|
|
|
|
a += ka[0];
|
|
|
|
break;
|
|
|
|
case 3:
|
|
|
|
a += ((uint32) k[2] << 16);
|
|
|
|
/* fall through */
|
|
|
|
case 2:
|
|
|
|
a += ((uint32) k[1] << 8);
|
|
|
|
/* fall through */
|
|
|
|
case 1:
|
|
|
|
a += k[0];
|
|
|
|
/* case 0: nothing left to add */
|
|
|
|
}
|
|
|
|
#endif /* WORDS_BIGENDIAN */
|
2002-03-09 18:35:37 +01:00
|
|
|
}
|
2008-04-06 18:54:49 +02:00
|
|
|
else
|
2002-03-09 18:35:37 +01:00
|
|
|
{
|
2008-04-06 18:54:49 +02:00
|
|
|
/* Code path for non-aligned source data */
|
|
|
|
|
|
|
|
/* handle most of the key */
|
|
|
|
while (len >= 12)
|
|
|
|
{
|
|
|
|
#ifdef WORDS_BIGENDIAN
|
|
|
|
a += (k[3] + ((uint32) k[2] << 8) + ((uint32) k[1] << 16) + ((uint32) k[0] << 24));
|
|
|
|
b += (k[7] + ((uint32) k[6] << 8) + ((uint32) k[5] << 16) + ((uint32) k[4] << 24));
|
|
|
|
c += (k[11] + ((uint32) k[10] << 8) + ((uint32) k[9] << 16) + ((uint32) k[8] << 24));
|
|
|
|
#else /* !WORDS_BIGENDIAN */
|
|
|
|
a += (k[0] + ((uint32) k[1] << 8) + ((uint32) k[2] << 16) + ((uint32) k[3] << 24));
|
|
|
|
b += (k[4] + ((uint32) k[5] << 8) + ((uint32) k[6] << 16) + ((uint32) k[7] << 24));
|
|
|
|
c += (k[8] + ((uint32) k[9] << 8) + ((uint32) k[10] << 16) + ((uint32) k[11] << 24));
|
|
|
|
#endif /* WORDS_BIGENDIAN */
|
|
|
|
mix(a, b, c);
|
|
|
|
k += 12;
|
|
|
|
len -= 12;
|
|
|
|
}
|
|
|
|
|
|
|
|
/* handle the last 11 bytes */
|
|
|
|
c += keylen;
|
|
|
|
#ifdef WORDS_BIGENDIAN
|
|
|
|
switch (len) /* all the case statements fall through */
|
|
|
|
{
|
|
|
|
case 11:
|
|
|
|
c += ((uint32) k[10] << 8);
|
|
|
|
case 10:
|
|
|
|
c += ((uint32) k[9] << 16);
|
|
|
|
case 9:
|
|
|
|
c += ((uint32) k[8] << 24);
|
|
|
|
/* the lowest byte of c is reserved for the length */
|
|
|
|
case 8:
|
|
|
|
b += k[7];
|
|
|
|
case 7:
|
|
|
|
b += ((uint32) k[6] << 8);
|
|
|
|
case 6:
|
|
|
|
b += ((uint32) k[5] << 16);
|
|
|
|
case 5:
|
|
|
|
b += ((uint32) k[4] << 24);
|
|
|
|
case 4:
|
|
|
|
a += k[3];
|
|
|
|
case 3:
|
|
|
|
a += ((uint32) k[2] << 8);
|
|
|
|
case 2:
|
|
|
|
a += ((uint32) k[1] << 16);
|
|
|
|
case 1:
|
|
|
|
a += ((uint32) k[0] << 24);
|
2002-03-09 18:35:37 +01:00
|
|
|
/* case 0: nothing left to add */
|
2008-04-06 18:54:49 +02:00
|
|
|
}
|
|
|
|
#else /* !WORDS_BIGENDIAN */
|
|
|
|
switch (len) /* all the case statements fall through */
|
|
|
|
{
|
|
|
|
case 11:
|
|
|
|
c += ((uint32) k[10] << 24);
|
|
|
|
case 10:
|
|
|
|
c += ((uint32) k[9] << 16);
|
|
|
|
case 9:
|
|
|
|
c += ((uint32) k[8] << 8);
|
|
|
|
/* the lowest byte of c is reserved for the length */
|
|
|
|
case 8:
|
|
|
|
b += ((uint32) k[7] << 24);
|
|
|
|
case 7:
|
|
|
|
b += ((uint32) k[6] << 16);
|
|
|
|
case 6:
|
|
|
|
b += ((uint32) k[5] << 8);
|
|
|
|
case 5:
|
|
|
|
b += k[4];
|
|
|
|
case 4:
|
|
|
|
a += ((uint32) k[3] << 24);
|
|
|
|
case 3:
|
|
|
|
a += ((uint32) k[2] << 16);
|
|
|
|
case 2:
|
|
|
|
a += ((uint32) k[1] << 8);
|
|
|
|
case 1:
|
|
|
|
a += k[0];
|
|
|
|
/* case 0: nothing left to add */
|
|
|
|
}
|
|
|
|
#endif /* WORDS_BIGENDIAN */
|
2002-03-09 18:35:37 +01:00
|
|
|
}
|
2008-04-06 18:54:49 +02:00
|
|
|
|
2002-09-04 22:31:48 +02:00
|
|
|
mix(a, b, c);
|
2007-06-01 17:33:19 +02:00
|
|
|
|
|
|
|
/* report the result */
|
|
|
|
return UInt32GetDatum(c);
|
|
|
|
}
|
|
|
|
|
|
|
|
/*
|
|
|
|
* hash_uint32() -- hash a 32-bit value
|
|
|
|
*
|
2008-04-06 18:54:49 +02:00
|
|
|
* This has the same result as
|
2007-06-01 17:33:19 +02:00
|
|
|
* hash_any(&k, sizeof(uint32))
|
|
|
|
* but is faster and doesn't force the caller to store k into memory.
|
|
|
|
*/
|
|
|
|
Datum
|
|
|
|
hash_uint32(uint32 k)
|
|
|
|
{
|
|
|
|
register uint32 a,
|
|
|
|
b,
|
|
|
|
c;
|
|
|
|
|
|
|
|
a = 0x9e3779b9 + k;
|
|
|
|
b = 0x9e3779b9;
|
|
|
|
c = 3923095 + (uint32) sizeof(uint32);
|
|
|
|
|
|
|
|
mix(a, b, c);
|
|
|
|
|
2002-03-09 18:35:37 +01:00
|
|
|
/* report the result */
|
|
|
|
return UInt32GetDatum(c);
|
1997-09-07 07:04:48 +02:00
|
|
|
}
|