Code cleanup for pg_buffercache, from Mark Kirkwood.

diff --git a/contrib/pg_buffercache/pg_buffercache_pages.c b/contrib/pg_buffercache/pg_buffercache_pages.c
index a75e8a229b39d8ea4e3bf8f6d91fe2d327b871fb..ed7b6f60dd8495bcc747b8133dd197cb7de4f4ff 100644 (file)
--- 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);
-
 }