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Code review for improved-hashing patch. Fix some portability issues

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(char != unsigned char, Datum != uint32); make use of new hash code in
dynahash hash tables and hash joins.
This commit is contained in:
Tom Lane
2002-03-09 17:35:37 +00:00
parent 1eb31d197d
commit c422b5ca6b
11 changed files with 111 additions and 187 deletions
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37
src/backend/executor/nodeHash.c
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@ -7,7 +7,7 @@
* Portions Copyright (c) 1994, Regents of the University of California
*
*
* $Id: nodeHash.c,v 1.61 2002/03/06 20:49:44 momjian Exp $
* $Id: nodeHash.c,v 1.62 2002/03/09 17:35:35 tgl Exp $
*
*-------------------------------------------------------------------------
*/
@ -22,6 +22,7 @@
#include <sys/types.h>
#include <math.h>
#include "access/hash.h"
#include "executor/execdebug.h"
#include "executor/nodeHash.h"
#include "executor/nodeHashjoin.h"
@ -31,7 +32,7 @@
#include "utils/lsyscache.h"
static int hashFunc(Datum key, int len, bool byVal);
static uint32 hashFunc(Datum key, int len, bool byVal);
/* ----------------------------------------------------------------
* ExecHash
@ -553,7 +554,7 @@ ExecHashGetBucket(HashJoinTable hashtable,
bucketno = hashFunc(keyval,
(int) hashtable->typLen,
hashtable->typByVal)
% hashtable->totalbuckets;
% (uint32) hashtable->totalbuckets;
}
#ifdef HJDEBUG
@ -624,30 +625,29 @@ ExecScanHashBucket(HashJoinState *hjstate,
/* ----------------------------------------------------------------
* hashFunc
*
* the hash function, copied from Margo
* the hash function for hash joins
*
* XXX this probably ought to be replaced with datatype-specific
* hash functions, such as those already implemented for hash indexes.
* ----------------------------------------------------------------
*/
static int
static uint32
hashFunc(Datum key, int len, bool byVal)
{
unsigned int h = 0;
unsigned char *k;
if (byVal)
{
/*
* If it's a by-value data type, use the 'len' least significant
* bytes of the Datum value. This should do the right thing on
* either bigendian or littleendian hardware --- see the Datum
* access macros in c.h.
* If it's a by-value data type, just hash the whole Datum value.
* This assumes that datatypes narrower than Datum are consistently
* padded (either zero-extended or sign-extended, but not random
* bits) to fill Datum; see the XXXGetDatum macros in postgres.h.
* NOTE: it would not work to do hash_any(&key, len) since this
* would get the wrong bytes on a big-endian machine.
*/
while (len-- > 0)
{
h = (h * PRIME1) ^ (key & 0xFF);
key >>= 8;
}
k = (unsigned char *) &key;
len = sizeof(Datum);
}
else
{
@ -662,8 +662,6 @@ hashFunc(Datum key, int len, bool byVal)
* freeing the detoasted copy; that happens for free when the
* per-tuple memory context is reset in ExecHashGetBucket.)
*/
unsigned char *k;
if (len < 0)
{
struct varlena *vkey = PG_DETOAST_DATUM(key);
@ -673,12 +671,9 @@ hashFunc(Datum key, int len, bool byVal)
}
else
k = (unsigned char *) DatumGetPointer(key);
while (len-- > 0)
h = (h * PRIME1) ^ (*k++);
}
return h % PRIME2;
return DatumGetUInt32(hash_any(k, len));
}
/* ----------------------------------------------------------------