From bd95c749852307885325ea5a2f3dce6b05326a3e Mon Sep 17 00:00:00 2001
From: Tom Lane <tgl@sss.pgh.pa.us>
Date: Sun, 22 Oct 2006 17:49:21 +0000
Subject: [PATCH] Code cleanup for pg_buffercache, from Mark Kirkwood.
---
contrib/pg_buffercache/pg_buffercache_pages.c | 100 ++++++------------
1 file changed, 34 insertions(+), 66 deletions(-)
diff --git a/contrib/pg_buffercache/pg_buffercache_pages.c b/contrib/pg_buffercache/pg_buffercache_pages.c
index a75e8a229b3..ed7b6f60dd8 100644
--- a/contrib/pg_buffercache/pg_buffercache_pages.c
+++ b/contrib/pg_buffercache/pg_buffercache_pages.c
@@ -3,12 +3,14 @@
* pg_buffercache_pages.c
* display some contents of the buffer cache
*
- * $PostgreSQL: pgsql/contrib/pg_buffercache/pg_buffercache_pages.c,v 1.10 2006/10/19 18:32:46 tgl Exp $
+ * $PostgreSQL: pgsql/contrib/pg_buffercache/pg_buffercache_pages.c,v 1.11 2006/10/22 17:49:21 tgl Exp $
*-------------------------------------------------------------------------
*/
#include "postgres.h"
-#include "funcapi.h"
+
+#include "access/heapam.h"
#include "catalog/pg_type.h"
+#include "funcapi.h"
#include "storage/buf_internals.h"
#include "storage/bufmgr.h"
#include "utils/relcache.h"
@@ -26,7 +28,6 @@ Datum pg_buffercache_pages(PG_FUNCTION_ARGS);
*/
typedef struct
{
-
uint32 bufferid;
Oid relfilenode;
Oid reltablespace;
@@ -34,7 +35,6 @@ typedef struct
BlockNumber blocknum;
bool isvalid;
bool isdirty;
-
} BufferCachePagesRec;
@@ -43,11 +43,8 @@ typedef struct
*/
typedef struct
{
-
- AttInMetadata *attinmeta;
+ TupleDesc tupdesc;
BufferCachePagesRec *record;
- char *values[NUM_BUFFERCACHE_PAGES_ELEM];
-
} BufferCachePagesContext;
@@ -56,10 +53,10 @@ typedef struct
* relation node/tablespace/database/blocknum and dirty indicator.
*/
PG_FUNCTION_INFO_V1(pg_buffercache_pages);
+
Datum
pg_buffercache_pages(PG_FUNCTION_ARGS)
{
-
FuncCallContext *funcctx;
Datum result;
MemoryContext oldcontext;
@@ -77,7 +74,10 @@ pg_buffercache_pages(PG_FUNCTION_ARGS)
/* Switch context when allocating stuff to be used in later calls */
oldcontext = MemoryContextSwitchTo(funcctx->multi_call_memory_ctx);
- /* Construct a tuple to return. */
+ /* Create a user function context for cross-call persistence */
+ fctx = (BufferCachePagesContext *) palloc(sizeof(BufferCachePagesContext));
+
+ /* Construct a tuple descriptor for the result rows. */
tupledesc = CreateTemplateTupleDesc(NUM_BUFFERCACHE_PAGES_ELEM, false);
TupleDescInitEntry(tupledesc, (AttrNumber) 1, "bufferid",
INT4OID, -1, 0);
@@ -92,27 +92,14 @@ pg_buffercache_pages(PG_FUNCTION_ARGS)
TupleDescInitEntry(tupledesc, (AttrNumber) 6, "isdirty",
BOOLOID, -1, 0);
- /* Generate attribute metadata needed later to produce tuples */
- funcctx->attinmeta = TupleDescGetAttInMetadata(tupledesc);
-
- /*
- * Create a function context for cross-call persistence and initialize
- * the buffer counters.
- */
- fctx = (BufferCachePagesContext *) palloc(sizeof(BufferCachePagesContext));
- funcctx->max_calls = NBuffers;
- funcctx->user_fctx = fctx;
+ fctx->tupdesc = BlessTupleDesc(tupledesc);
/* Allocate NBuffers worth of BufferCachePagesRec records. */
fctx->record = (BufferCachePagesRec *) palloc(sizeof(BufferCachePagesRec) * NBuffers);
- /* allocate the strings for tuple formation */
- fctx->values[0] = (char *) palloc(3 * sizeof(uint32) + 1);
- fctx->values[1] = (char *) palloc(3 * sizeof(uint32) + 1);
- fctx->values[2] = (char *) palloc(3 * sizeof(uint32) + 1);
- fctx->values[3] = (char *) palloc(3 * sizeof(uint32) + 1);
- fctx->values[4] = (char *) palloc(3 * sizeof(uint32) + 1);
- fctx->values[5] = (char *) palloc(2);
+ /* Set max calls and remember the user function context. */
+ funcctx->max_calls = NBuffers;
+ funcctx->user_fctx = fctx;
/* Return to original context when allocating transient memory */
MemoryContextSwitchTo(oldcontext);
@@ -167,19 +154,11 @@ pg_buffercache_pages(PG_FUNCTION_ARGS)
if (funcctx->call_cntr < funcctx->max_calls)
{
uint32 i = funcctx->call_cntr;
- char *values[NUM_BUFFERCACHE_PAGES_ELEM];
- int j;
-
- /*
- * Use a temporary values array, initially pointing to fctx->values,
- * so it can be reassigned w/o losing the storage for subsequent
- * calls.
- */
- for (j = 0; j < NUM_BUFFERCACHE_PAGES_ELEM; j++)
- {
- values[j] = fctx->values[j];
- }
+ Datum values[NUM_BUFFERCACHE_PAGES_ELEM];
+ bool nulls[NUM_BUFFERCACHE_PAGES_ELEM];
+ values[0] = Int32GetDatum(fctx->record[i].bufferid);
+ nulls[0] = false;
/*
* Set all fields except the bufferid to null if the buffer is unused
@@ -188,43 +167,32 @@ pg_buffercache_pages(PG_FUNCTION_ARGS)
if (fctx->record[i].blocknum == InvalidBlockNumber ||
fctx->record[i].isvalid == false)
{
-
- sprintf(values[0], "%u", fctx->record[i].bufferid);
- values[1] = NULL;
- values[2] = NULL;
- values[3] = NULL;
- values[4] = NULL;
- values[5] = NULL;
-
+ nulls[1] = true;
+ nulls[2] = true;
+ nulls[3] = true;
+ nulls[4] = true;
+ nulls[5] = true;
}
else
{
-
- sprintf(values[0], "%u", fctx->record[i].bufferid);
- sprintf(values[1], "%u", fctx->record[i].relfilenode);
- sprintf(values[2], "%u", fctx->record[i].reltablespace);
- sprintf(values[3], "%u", fctx->record[i].reldatabase);
- sprintf(values[4], "%u", fctx->record[i].blocknum);
- if (fctx->record[i].isdirty)
- {
- strcpy(values[5], "t");
- }
- else
- {
- strcpy(values[5], "f");
- }
-
+ values[1] = ObjectIdGetDatum(fctx->record[i].relfilenode);
+ nulls[1] = false;
+ values[2] = ObjectIdGetDatum(fctx->record[i].reltablespace);
+ nulls[2] = false;
+ values[3] = ObjectIdGetDatum(fctx->record[i].reldatabase);
+ nulls[3] = false;
+ values[4] = Int64GetDatum((int64) fctx->record[i].blocknum);
+ nulls[4] = false;
+ values[5] = BoolGetDatum(fctx->record[i].isdirty);
+ nulls[5] = false;
}
-
/* Build and return the tuple. */
- tuple = BuildTupleFromCStrings(funcctx->attinmeta, values);
+ tuple = heap_form_tuple(fctx->tupdesc, values, nulls);
result = HeapTupleGetDatum(tuple);
-
SRF_RETURN_NEXT(funcctx, result);
}
else
SRF_RETURN_DONE(funcctx);
-
}
--
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