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Create a new file executor/execGrouping.c to centralize utility routines

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shared by nodeGroup, nodeAgg, and soon nodeSubplan.
This commit is contained in:
Tom Lane
2003-01-10 23:54:24 +00:00
parent c83702606c
commit 1afac12910
12 changed files with 498 additions and 337 deletions
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74
src/backend/executor/nodeHash.c
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@ -8,7 +8,7 @@
*
*
* IDENTIFICATION
* $Header: /cvsroot/pgsql/src/backend/executor/nodeHash.c,v 1.73 2002/12/30 15:21:18 tgl Exp $
* $Header: /cvsroot/pgsql/src/backend/executor/nodeHash.c,v 1.74 2003/01/10 23:54:24 tgl Exp $
*
*-------------------------------------------------------------------------
*/
@ -20,10 +20,6 @@
*/
#include "postgres.h"
#include <limits.h>
#include <math.h>
#include "access/hash.h"
#include "executor/execdebug.h"
#include "executor/nodeHash.h"
#include "executor/nodeHashjoin.h"
@ -642,74 +638,6 @@ ExecScanHashBucket(HashJoinState *hjstate,
return NULL;
}
/* ----------------------------------------------------------------
* ComputeHashFunc
*
* the hash function for hash joins (also used for hash aggregation)
*
* XXX this probably ought to be replaced with datatype-specific
* hash functions, such as those already implemented for hash indexes.
* ----------------------------------------------------------------
*/
uint32
ComputeHashFunc(Datum key, int typLen, bool byVal)
{
unsigned char *k;
if (byVal)
{
/*
* 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.
*/
k = (unsigned char *) &key;
typLen = sizeof(Datum);
}
else
{
if (typLen > 0)
{
/* fixed-width pass-by-reference type */
k = (unsigned char *) DatumGetPointer(key);
}
else if (typLen == -1)
{
/*
* It's a varlena type, so 'key' points to a "struct varlena".
* NOTE: VARSIZE returns the "real" data length plus the
* sizeof the "vl_len" attribute of varlena (the length
* information). 'key' points to the beginning of the varlena
* struct, so we have to use "VARDATA" to find the beginning
* of the "real" data. Also, we have to be careful to detoast
* the datum if it's toasted. (We don't worry about freeing
* the detoasted copy; that happens for free when the
* per-tuple memory context is reset in ExecHashGetBucket.)
*/
struct varlena *vkey = PG_DETOAST_DATUM(key);
typLen = VARSIZE(vkey) - VARHDRSZ;
k = (unsigned char *) VARDATA(vkey);
}
else if (typLen == -2)
{
/* It's a null-terminated C string */
typLen = strlen(DatumGetCString(key)) + 1;
k = (unsigned char *) DatumGetPointer(key);
}
else
{
elog(ERROR, "ComputeHashFunc: Invalid typLen %d", typLen);
k = NULL; /* keep compiler quiet */
}
}
return DatumGetUInt32(hash_any(k, typLen));
}
/* ----------------------------------------------------------------
* ExecHashTableReset
*