This is probably terrible timing, but I noticed Tom had done some nice
tidying up on pg_freespacemap to eliminate the clumsy conversion to and
from strings. This patch does a similar thing for pg_buffercache.
I did wonder about not showing buffers that are invalid or not in use
(currently displays all attributes bar the id as NULL). Comments?
Cheers
Mark
Index: contrib/pg_buffercache/pg_buffercache_pages.c
===================================================================
RCS file: /projects/cvsroot/pgsql/contrib/pg_buffercache/pg_buffercache_pages.c,v
retrieving revision 1.10
diff -c -r1.10 pg_buffercache_pages.c
*** contrib/pg_buffercache/pg_buffercache_pages.c 19 Oct 2006 18:32:46 -0000 1.10
--- contrib/pg_buffercache/pg_buffercache_pages.c 22 Oct 2006 06:27:52 -0000
***************
*** 8,13 ****
--- 8,14 ----
*/
#include "postgres.h"
#include "funcapi.h"
+ #include "access/heapam.h"
#include "catalog/pg_type.h"
#include "storage/buf_internals.h"
#include "storage/bufmgr.h"
***************
*** 44,52 ****
typedef struct
{
! AttInMetadata *attinmeta;
BufferCachePagesRec *record;
- char *values[NUM_BUFFERCACHE_PAGES_ELEM];
} BufferCachePagesContext;
--- 45,52 ----
typedef struct
{
! TupleDesc tupdesc;
BufferCachePagesRec *record;
} BufferCachePagesContext;
***************
*** 77,83 ****
/* Switch context when allocating stuff to be used in later calls */
oldcontext = MemoryContextSwitchTo(funcctx->multi_call_memory_ctx);
! /* Construct a tuple to return. */
tupledesc = CreateTemplateTupleDesc(NUM_BUFFERCACHE_PAGES_ELEM, false);
TupleDescInitEntry(tupledesc, (AttrNumber) 1, "bufferid",
INT4OID, -1, 0);
--- 77,87 ----
/* Switch context when allocating stuff to be used in later calls */
oldcontext = MemoryContextSwitchTo(funcctx->multi_call_memory_ctx);
!
! /* Create a user function context for cross-call persistence */
! fctx = (BufferCachePagesContext *) palloc(sizeof(BufferCachePagesContext));
!
! /* Construct a tuple to return, and save its descriptor. */
tupledesc = CreateTemplateTupleDesc(NUM_BUFFERCACHE_PAGES_ELEM, false);
TupleDescInitEntry(tupledesc, (AttrNumber) 1, "bufferid",
INT4OID, -1, 0);
***************
*** 92,118 ****
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;
/* 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);
/* Return to original context when allocating transient memory */
MemoryContextSwitchTo(oldcontext);
--- 96,109 ----
TupleDescInitEntry(tupledesc, (AttrNumber) 6, "isdirty",
BOOLOID, -1, 0);
! fctx->tupdesc = BlessTupleDesc(tupledesc);
/* Allocate NBuffers worth of BufferCachePagesRec records. */
fctx->record = (BufferCachePagesRec *) palloc(sizeof(BufferCachePagesRec) * NBuffers);
! /* 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);
***************
*** 167,184 ****
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];
! }
/*
--- 158,165 ----
if (funcctx->call_cntr < funcctx->max_calls)
{
uint32 i = funcctx->call_cntr;
! Datum values[NUM_BUFFERCACHE_PAGES_ELEM];
! bool nulls[NUM_BUFFERCACHE_PAGES_ELEM];
/*
***************
*** 189,224 ****
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;
}
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");
}
}
/* Build and return the tuple. */
! tuple = BuildTupleFromCStrings(funcctx->attinmeta, values);
result = HeapTupleGetDatum(tuple);
--- 170,212 ----
fctx->record[i].isvalid == false)
{
! values[0] = Int32GetDatum(fctx->record[i].bufferid);
! nulls[0] = false;
! nulls[1] = true;
! nulls[2] = true;
! nulls[3] = true;
! nulls[4] = true;
! nulls[5] = true;
}
else
{
! values[0] = Int32GetDatum(fctx->record[i].bufferid);
! nulls[0] = false;
! 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;
if (fctx->record[i].isdirty)
{
! values[5] = BoolGetDatum(true);
}
else
{
! values[5] = BoolGetDatum(false);
}
+ nulls[5] = false;
}
/* Build and return the tuple. */
! tuple = heap_form_tuple(fctx->tupdesc, values, nulls);
result = HeapTupleGetDatum(tuple);
