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Code cleanup for pg_buffercache, from Mark Kirkwood.
1 parent c2c0b14 commit bd95c74

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+34
-66
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1 file changed

+34
-66
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‎contrib/pg_buffercache/pg_buffercache_pages.c‎

Lines changed: 34 additions & 66 deletions
Original file line numberDiff line numberDiff line change
@@ -3,12 +3,14 @@
33
* pg_buffercache_pages.c
44
* display some contents of the buffer cache
55
*
6-
* $PostgreSQL: pgsql/contrib/pg_buffercache/pg_buffercache_pages.c,v 1.10 2006/10/19 18:32:46 tgl Exp $
6+
* $PostgreSQL: pgsql/contrib/pg_buffercache/pg_buffercache_pages.c,v 1.11 2006/10/22 17:49:21 tgl Exp $
77
*-------------------------------------------------------------------------
88
*/
99
#include "postgres.h"
10-
#include "funcapi.h"
10+
11+
#include "access/heapam.h"
1112
#include "catalog/pg_type.h"
13+
#include "funcapi.h"
1214
#include "storage/buf_internals.h"
1315
#include "storage/bufmgr.h"
1416
#include "utils/relcache.h"
@@ -26,15 +28,13 @@ Datum pg_buffercache_pages(PG_FUNCTION_ARGS);
2628
*/
2729
typedef struct
2830
{
29-
3031
uint32 bufferid;
3132
Oid relfilenode;
3233
Oid reltablespace;
3334
Oid reldatabase;
3435
BlockNumber blocknum;
3536
bool isvalid;
3637
bool isdirty;
37-
3838
} BufferCachePagesRec;
3939

4040

@@ -43,11 +43,8 @@ typedef struct
4343
*/
4444
typedef struct
4545
{
46-
47-
AttInMetadata *attinmeta;
46+
TupleDesc tupdesc;
4847
BufferCachePagesRec *record;
49-
char *values[NUM_BUFFERCACHE_PAGES_ELEM];
50-
5148
} BufferCachePagesContext;
5249

5350

@@ -56,10 +53,10 @@ typedef struct
5653
* relation node/tablespace/database/blocknum and dirty indicator.
5754
*/
5855
PG_FUNCTION_INFO_V1(pg_buffercache_pages);
56+
5957
Datum
6058
pg_buffercache_pages(PG_FUNCTION_ARGS)
6159
{
62-
6360
FuncCallContext *funcctx;
6461
Datum result;
6562
MemoryContext oldcontext;
@@ -77,7 +74,10 @@ pg_buffercache_pages(PG_FUNCTION_ARGS)
7774
/* Switch context when allocating stuff to be used in later calls */
7875
oldcontext = MemoryContextSwitchTo(funcctx->multi_call_memory_ctx);
7976

80-
/* Construct a tuple to return. */
77+
/* Create a user function context for cross-call persistence */
78+
fctx = (BufferCachePagesContext *) palloc(sizeof(BufferCachePagesContext));
79+
80+
/* Construct a tuple descriptor for the result rows. */
8181
tupledesc = CreateTemplateTupleDesc(NUM_BUFFERCACHE_PAGES_ELEM, false);
8282
TupleDescInitEntry(tupledesc, (AttrNumber) 1, "bufferid",
8383
INT4OID, -1, 0);
@@ -92,27 +92,14 @@ pg_buffercache_pages(PG_FUNCTION_ARGS)
9292
TupleDescInitEntry(tupledesc, (AttrNumber) 6, "isdirty",
9393
BOOLOID, -1, 0);
9494

95-
/* Generate attribute metadata needed later to produce tuples */
96-
funcctx->attinmeta = TupleDescGetAttInMetadata(tupledesc);
97-
98-
/*
99-
* Create a function context for cross-call persistence and initialize
100-
* the buffer counters.
101-
*/
102-
fctx = (BufferCachePagesContext *) palloc(sizeof(BufferCachePagesContext));
103-
funcctx->max_calls = NBuffers;
104-
funcctx->user_fctx = fctx;
95+
fctx->tupdesc = BlessTupleDesc(tupledesc);
10596

10697
/* Allocate NBuffers worth of BufferCachePagesRec records. */
10798
fctx->record = (BufferCachePagesRec *) palloc(sizeof(BufferCachePagesRec) * NBuffers);
10899

109-
/* allocate the strings for tuple formation */
110-
fctx->values[0] = (char *) palloc(3 * sizeof(uint32) + 1);
111-
fctx->values[1] = (char *) palloc(3 * sizeof(uint32) + 1);
112-
fctx->values[2] = (char *) palloc(3 * sizeof(uint32) + 1);
113-
fctx->values[3] = (char *) palloc(3 * sizeof(uint32) + 1);
114-
fctx->values[4] = (char *) palloc(3 * sizeof(uint32) + 1);
115-
fctx->values[5] = (char *) palloc(2);
100+
/* Set max calls and remember the user function context. */
101+
funcctx->max_calls = NBuffers;
102+
funcctx->user_fctx = fctx;
116103

117104
/* Return to original context when allocating transient memory */
118105
MemoryContextSwitchTo(oldcontext);
@@ -167,19 +154,11 @@ pg_buffercache_pages(PG_FUNCTION_ARGS)
167154
if (funcctx->call_cntr < funcctx->max_calls)
168155
{
169156
uint32 i = funcctx->call_cntr;
170-
char *values[NUM_BUFFERCACHE_PAGES_ELEM];
171-
int j;
172-
173-
/*
174-
* Use a temporary values array, initially pointing to fctx->values,
175-
* so it can be reassigned w/o losing the storage for subsequent
176-
* calls.
177-
*/
178-
for (j = 0; j < NUM_BUFFERCACHE_PAGES_ELEM; j++)
179-
{
180-
values[j] = fctx->values[j];
181-
}
157+
Datum values[NUM_BUFFERCACHE_PAGES_ELEM];
158+
bool nulls[NUM_BUFFERCACHE_PAGES_ELEM];
182159

160+
values[0] = Int32GetDatum(fctx->record[i].bufferid);
161+
nulls[0] = false;
183162

184163
/*
185164
* Set all fields except the bufferid to null if the buffer is unused
@@ -188,43 +167,32 @@ pg_buffercache_pages(PG_FUNCTION_ARGS)
188167
if (fctx->record[i].blocknum == InvalidBlockNumber ||
189168
fctx->record[i].isvalid == false)
190169
{
191-
192-
sprintf(values[0], "%u", fctx->record[i].bufferid);
193-
values[1] = NULL;
194-
values[2] = NULL;
195-
values[3] = NULL;
196-
values[4] = NULL;
197-
values[5] = NULL;
198-
170+
nulls[1] = true;
171+
nulls[2] = true;
172+
nulls[3] = true;
173+
nulls[4] = true;
174+
nulls[5] = true;
199175
}
200176
else
201177
{
202-
203-
sprintf(values[0], "%u", fctx->record[i].bufferid);
204-
sprintf(values[1], "%u", fctx->record[i].relfilenode);
205-
sprintf(values[2], "%u", fctx->record[i].reltablespace);
206-
sprintf(values[3], "%u", fctx->record[i].reldatabase);
207-
sprintf(values[4], "%u", fctx->record[i].blocknum);
208-
if (fctx->record[i].isdirty)
209-
{
210-
strcpy(values[5], "t");
211-
}
212-
else
213-
{
214-
strcpy(values[5], "f");
215-
}
216-
178+
values[1] = ObjectIdGetDatum(fctx->record[i].relfilenode);
179+
nulls[1] = false;
180+
values[2] = ObjectIdGetDatum(fctx->record[i].reltablespace);
181+
nulls[2] = false;
182+
values[3] = ObjectIdGetDatum(fctx->record[i].reldatabase);
183+
nulls[3] = false;
184+
values[4] = Int64GetDatum((int64) fctx->record[i].blocknum);
185+
nulls[4] = false;
186+
values[5] = BoolGetDatum(fctx->record[i].isdirty);
187+
nulls[5] = false;
217188
}
218189

219-
220190
/* Build and return the tuple. */
221-
tuple = BuildTupleFromCStrings(funcctx->attinmeta, values);
191+
tuple = heap_form_tuple(fctx->tupdesc, values, nulls);
222192
result = HeapTupleGetDatum(tuple);
223193

224-
225194
SRF_RETURN_NEXT(funcctx, result);
226195
}
227196
else
228197
SRF_RETURN_DONE(funcctx);
229-
230198
}

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