1996-07-09 08:22:35 +02:00
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/*-------------------------------------------------------------------------
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*
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1999-02-14 00:22:53 +01:00
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* hashfunc.c
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2007-06-01 17:33:19 +02:00
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* Support functions for hash access method.
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1996-07-09 08:22:35 +02:00
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*
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2016-01-02 19:33:40 +01:00
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* Portions Copyright (c) 1996-2016, PostgreSQL Global Development Group
|
2000-01-26 06:58:53 +01:00
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* Portions Copyright (c) 1994, Regents of the University of California
|
1996-07-09 08:22:35 +02:00
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*
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*
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* IDENTIFICATION
|
2010-09-20 22:08:53 +02:00
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* src/backend/access/hash/hashfunc.c
|
1996-07-09 08:22:35 +02:00
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*
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* NOTES
|
2014-05-06 18:12:18 +02:00
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* These functions are stored in pg_amproc. For each operator class
|
2007-06-01 17:33:19 +02:00
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* defined for hash indexes, they compute the hash value of the argument.
|
1996-07-09 08:22:35 +02:00
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*
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2007-06-01 17:33:19 +02:00
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* Additional hash functions appear in /utils/adt/ files for various
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* specialized datatypes.
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*
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* It is expected that every bit of a hash function's 32-bit result is
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* as random as every other; failure to ensure this is likely to lead
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* to poor performance of hash joins, for example. In most cases a hash
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* function should use hash_any() or its variant hash_uint32().
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1996-07-09 08:22:35 +02:00
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*-------------------------------------------------------------------------
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*/
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1996-10-20 08:34:30 +02:00
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1996-07-09 08:22:35 +02:00
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#include "postgres.h"
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|
1996-11-10 04:06:38 +01:00
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#include "access/hash.h"
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|
2000-06-19 05:55:01 +02:00
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2003-06-23 00:04:55 +02:00
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/* Note: this is used for both "char" and boolean datatypes */
|
2000-06-19 05:55:01 +02:00
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Datum
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|
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hashchar(PG_FUNCTION_ARGS)
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{
|
2007-06-01 17:33:19 +02:00
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|
|
return hash_uint32((int32) PG_GETARG_CHAR(0));
|
2000-06-19 05:55:01 +02:00
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|
|
}
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|
2000-06-05 09:29:25 +02:00
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|
|
Datum
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|
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|
hashint2(PG_FUNCTION_ARGS)
|
1996-07-09 08:22:35 +02:00
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{
|
2007-06-01 17:33:19 +02:00
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|
return hash_uint32((int32) PG_GETARG_INT16(0));
|
1996-07-09 08:22:35 +02:00
|
|
|
}
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|
2000-06-05 09:29:25 +02:00
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|
|
Datum
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|
hashint4(PG_FUNCTION_ARGS)
|
1996-07-09 08:22:35 +02:00
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|
|
{
|
2007-06-01 17:33:19 +02:00
|
|
|
return hash_uint32(PG_GETARG_INT32(0));
|
1996-07-09 08:22:35 +02:00
|
|
|
}
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|
2000-06-05 09:29:25 +02:00
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|
|
Datum
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|
|
|
hashint8(PG_FUNCTION_ARGS)
|
1999-03-14 06:09:05 +01:00
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|
|
{
|
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
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|
|
* produced by hashint4 and hashint2 for logically equal inputs; this is
|
|
|
|
* necessary to support cross-type hash joins across these input types.
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|
|
|
* 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
|
|
|
*/
|
|
|
|
int64 val = PG_GETARG_INT64(0);
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|
|
|
uint32 lohalf = (uint32) val;
|
|
|
|
uint32 hihalf = (uint32) (val >> 32);
|
|
|
|
|
|
|
|
lohalf ^= (val >= 0) ? hihalf : ~hihalf;
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|
|
|
|
2007-06-01 17:33:19 +02:00
|
|
|
return hash_uint32(lohalf);
|
2000-06-19 05:55:01 +02:00
|
|
|
}
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|
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|
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|
Datum
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|
|
|
hashoid(PG_FUNCTION_ARGS)
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|
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|
{
|
2007-06-01 17:33:19 +02:00
|
|
|
return hash_uint32((uint32) PG_GETARG_OID(0));
|
1999-03-14 06:09:05 +01:00
|
|
|
}
|
|
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|
|
2007-04-02 05:49:42 +02:00
|
|
|
Datum
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|
|
|
hashenum(PG_FUNCTION_ARGS)
|
|
|
|
{
|
2007-06-01 17:33:19 +02:00
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|
|
return hash_uint32((uint32) PG_GETARG_OID(0));
|
2007-04-02 05:49:42 +02:00
|
|
|
}
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|
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|
|
2000-06-05 09:29:25 +02:00
|
|
|
Datum
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|
|
|
hashfloat4(PG_FUNCTION_ARGS)
|
1996-07-09 08:22:35 +02:00
|
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|
{
|
2000-06-05 09:29:25 +02:00
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|
|
float4 key = PG_GETARG_FLOAT4(0);
|
2006-12-23 01:43:13 +01:00
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|
|
float8 key8;
|
1997-09-07 07:04:48 +02:00
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|
|
|
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)
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|
|
|
PG_RETURN_UINT32(0);
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|
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|
|
2006-12-23 01:43:13 +01:00
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|
|
/*
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|
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|
* To support cross-type hashing of float8 and float4, we want to return
|
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|
* 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
|
|
|
*/
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|
|
|
key8 = key;
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|
|
|
|
|
|
|
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
|
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|
|
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
|
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
|
2014-05-06 18:12:18 +02:00
|
|
|
* 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
|
|
|
*
|
2009-02-09 22:18:28 +01:00
|
|
|
* In the current code, we have adopted Bob's 2006 update of his hash
|
|
|
|
* function 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).
|
|
|
|
* It also uses two separate mixing functions mix() and final(), instead
|
|
|
|
* of a slower multi-purpose function.
|
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)
|
|
|
|
|
2009-02-09 22:18:28 +01:00
|
|
|
/* Rotate a uint32 value left by k bits - note multiple evaluation! */
|
|
|
|
#define rot(x,k) (((x)<<(k)) | ((x)>>(32-(k))))
|
|
|
|
|
2002-03-09 18:35:37 +01:00
|
|
|
/*----------
|
2002-03-06 21:49:46 +01:00
|
|
|
* mix -- mix 3 32-bit values reversibly.
|
2009-02-09 22:18:28 +01:00
|
|
|
*
|
|
|
|
* This is reversible, so any information in (a,b,c) before mix() is
|
|
|
|
* still in (a,b,c) after mix().
|
|
|
|
*
|
|
|
|
* If four pairs of (a,b,c) inputs are run through mix(), or through
|
|
|
|
* mix() in reverse, there are at least 32 bits of the output that
|
|
|
|
* are sometimes the same for one pair and different for another pair.
|
|
|
|
* This was tested for:
|
|
|
|
* * pairs that differed by one bit, by two bits, in any combination
|
2009-06-11 16:49:15 +02:00
|
|
|
* of top bits of (a,b,c), or in any combination of bottom bits of
|
|
|
|
* (a,b,c).
|
2009-02-09 22:18:28 +01:00
|
|
|
* * "differ" is defined as +, -, ^, or ~^. For + and -, I transformed
|
2009-06-11 16:49:15 +02:00
|
|
|
* the output delta to a Gray code (a^(a>>1)) so a string of 1's (as
|
|
|
|
* is commonly produced by subtraction) look like a single 1-bit
|
|
|
|
* difference.
|
2009-02-09 22:18:28 +01:00
|
|
|
* * the base values were pseudorandom, all zero but one bit set, or
|
2009-06-11 16:49:15 +02:00
|
|
|
* all zero plus a counter that starts at zero.
|
|
|
|
*
|
2009-02-09 22:18:28 +01:00
|
|
|
* This does not achieve avalanche. There are input bits of (a,b,c)
|
|
|
|
* that fail to affect some output bits of (a,b,c), especially of a. The
|
|
|
|
* most thoroughly mixed value is c, but it doesn't really even achieve
|
2009-06-11 16:49:15 +02:00
|
|
|
* avalanche in c.
|
|
|
|
*
|
2009-02-09 22:18:28 +01:00
|
|
|
* This allows some parallelism. Read-after-writes are good at doubling
|
|
|
|
* the number of bits affected, so the goal of mixing pulls in the opposite
|
2014-05-06 18:12:18 +02:00
|
|
|
* direction from the goal of parallelism. I did what I could. Rotates
|
2009-02-09 22:18:28 +01:00
|
|
|
* seem to cost as much as shifts on every machine I could lay my hands on,
|
|
|
|
* and rotates are much kinder to the top and bottom bits, so I used rotates.
|
2002-03-09 18:35:37 +01:00
|
|
|
*----------
|
2002-03-06 21:49:46 +01:00
|
|
|
*/
|
|
|
|
#define mix(a,b,c) \
|
|
|
|
{ \
|
2009-06-11 16:49:15 +02:00
|
|
|
a -= c; a ^= rot(c, 4); c += b; \
|
|
|
|
b -= a; b ^= rot(a, 6); a += c; \
|
|
|
|
c -= b; c ^= rot(b, 8); b += a; \
|
|
|
|
a -= c; a ^= rot(c,16); c += b; \
|
|
|
|
b -= a; b ^= rot(a,19); a += c; \
|
|
|
|
c -= b; c ^= rot(b, 4); b += a; \
|
2009-02-09 22:18:28 +01:00
|
|
|
}
|
|
|
|
|
|
|
|
/*----------
|
|
|
|
* final -- final mixing of 3 32-bit values (a,b,c) into c
|
|
|
|
*
|
|
|
|
* Pairs of (a,b,c) values differing in only a few bits will usually
|
|
|
|
* produce values of c that look totally different. This was tested for
|
|
|
|
* * pairs that differed by one bit, by two bits, in any combination
|
2009-06-11 16:49:15 +02:00
|
|
|
* of top bits of (a,b,c), or in any combination of bottom bits of
|
|
|
|
* (a,b,c).
|
2009-02-09 22:18:28 +01:00
|
|
|
* * "differ" is defined as +, -, ^, or ~^. For + and -, I transformed
|
2009-06-11 16:49:15 +02:00
|
|
|
* the output delta to a Gray code (a^(a>>1)) so a string of 1's (as
|
|
|
|
* is commonly produced by subtraction) look like a single 1-bit
|
|
|
|
* difference.
|
2009-02-09 22:18:28 +01:00
|
|
|
* * the base values were pseudorandom, all zero but one bit set, or
|
2009-06-11 16:49:15 +02:00
|
|
|
* all zero plus a counter that starts at zero.
|
|
|
|
*
|
2009-02-09 22:18:28 +01:00
|
|
|
* The use of separate functions for mix() and final() allow for a
|
|
|
|
* substantial performance increase since final() does not need to
|
|
|
|
* do well in reverse, but is does need to affect all output bits.
|
|
|
|
* mix(), on the other hand, does not need to affect all output
|
2014-05-06 18:12:18 +02:00
|
|
|
* bits (affecting 32 bits is enough). The original hash function had
|
2009-02-09 22:18:28 +01:00
|
|
|
* a single mixing operation that had to satisfy both sets of requirements
|
|
|
|
* and was slower as a result.
|
|
|
|
*----------
|
|
|
|
*/
|
|
|
|
#define final(a,b,c) \
|
|
|
|
{ \
|
|
|
|
c ^= b; c -= rot(b,14); \
|
|
|
|
a ^= c; a -= rot(c,11); \
|
|
|
|
b ^= a; b -= rot(a,25); \
|
|
|
|
c ^= b; c -= rot(b,16); \
|
|
|
|
a ^= c; a -= rot(c, 4); \
|
|
|
|
b ^= a; b -= rot(a,14); \
|
|
|
|
c ^= b; c -= rot(b,24); \
|
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
|
|
|
*
|
2014-05-06 18:12:18 +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
|
|
|
*
|
2016-01-26 21:20:22 +01:00
|
|
|
* This procedure must never throw elog(ERROR); the ResourceOwner code
|
|
|
|
* relies on this not to fail.
|
|
|
|
*
|
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;
|
2009-02-09 22:18:28 +01:00
|
|
|
a = b = c = 0x9e3779b9 + len + 3923095;
|
2002-03-09 18:35:37 +01:00
|
|
|
|
2008-04-06 18:54:49 +02:00
|
|
|
/* If the source pointer is word-aligned, we use word-wide fetches */
|
2013-10-21 03:04:52 +02:00
|
|
|
if (((uintptr_t) 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;
|
|
|
|
#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);
|
2009-06-11 16:49:15 +02:00
|
|
|
/* case 0: nothing left to add */
|
2008-04-06 18:54:49 +02:00
|
|
|
}
|
2009-06-11 16:49:15 +02:00
|
|
|
#else /* !WORDS_BIGENDIAN */
|
2008-04-06 18:54:49 +02:00
|
|
|
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];
|
2009-06-11 16:49:15 +02:00
|
|
|
/* case 0: nothing left to add */
|
2008-04-06 18:54:49 +02:00
|
|
|
}
|
2009-06-11 16:49:15 +02:00
|
|
|
#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));
|
2009-06-11 16:49:15 +02:00
|
|
|
#else /* !WORDS_BIGENDIAN */
|
2008-04-06 18:54:49 +02:00
|
|
|
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));
|
2009-06-11 16:49:15 +02:00
|
|
|
#endif /* WORDS_BIGENDIAN */
|
2008-04-06 18:54:49 +02:00
|
|
|
mix(a, b, c);
|
|
|
|
k += 12;
|
|
|
|
len -= 12;
|
|
|
|
}
|
|
|
|
|
|
|
|
/* handle the last 11 bytes */
|
|
|
|
#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);
|
2009-06-11 16:49:15 +02:00
|
|
|
/* case 0: nothing left to add */
|
2008-04-06 18:54:49 +02:00
|
|
|
}
|
2009-06-11 16:49:15 +02:00
|
|
|
#else /* !WORDS_BIGENDIAN */
|
2008-04-06 18:54:49 +02:00
|
|
|
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];
|
2009-06-11 16:49:15 +02:00
|
|
|
/* case 0: nothing left to add */
|
2008-04-06 18:54:49 +02:00
|
|
|
}
|
2009-06-11 16:49:15 +02:00
|
|
|
#endif /* WORDS_BIGENDIAN */
|
2002-03-09 18:35:37 +01:00
|
|
|
}
|
2008-04-06 18:54:49 +02:00
|
|
|
|
2009-02-09 22:18:28 +01:00
|
|
|
final(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;
|
|
|
|
|
2009-02-09 22:18:28 +01:00
|
|
|
a = b = c = 0x9e3779b9 + (uint32) sizeof(uint32) + 3923095;
|
|
|
|
a += k;
|
2007-06-01 17:33:19 +02:00
|
|
|
|
2009-02-09 22:18:28 +01:00
|
|
|
final(a, b, c);
|
2007-06-01 17:33:19 +02:00
|
|
|
|
2002-03-09 18:35:37 +01:00
|
|
|
/* report the result */
|
|
|
|
return UInt32GetDatum(c);
|
1997-09-07 07:04:48 +02:00
|
|
|
}
|