minor refactoring for fetch_next_pair()

funbringer · funbringer · commit 56187becbd15 · 2016-03-15T18:56:42.000+03:00
diff --git a/init.c b/init.c
@@ -28,6 +28,13 @@ extern void _PG_init(void);
 
 static set_join_pathlist_hook_type set_join_pathlist_next;
 
+typedef enum
+{
+	FetchTidPairFinished = 0,
+	FetchTidPairInvalid,
+	FetchTidPairReady
+} FetchTidPairState;
+
 typedef struct
 {
 	CustomPath		cpath;
@@ -528,7 +535,7 @@ crossmatch_begin(CustomScanState *node, EState *estate, int eflags)
 	}
 }
 
-static bool
+static FetchTidPairState
 fetch_next_pair(CrossmatchScanState *scan_state)
 {
 	ScanState		   *ss = &scan_state->css.ss;
@@ -549,7 +556,7 @@ fetch_next_pair(CrossmatchScanState *scan_state)
 
 	if (!ItemPointerIsValid(&p_tids[0]) || !ItemPointerIsValid(&p_tids[1]))
 	{
-		return false;
+		return FetchTidPairFinished;
 	}
 
 	/* We don't have to fetch tuples if scan tlist is empty */
@@ -573,9 +580,11 @@ fetch_next_pair(CrossmatchScanState *scan_state)
 				if (!htup_outer_ready)
 				{
 					htup_outer_ready = true;
-					/* TODO: check result */
-					heap_fetch(scan_state->outer, SnapshotSelf,
-								&htup_outer, &buf1, false, NULL);
+					if(!heap_fetch(scan_state->outer, SnapshotSelf,
+								   &htup_outer, &buf1, false, NULL))
+					{
+						return FetchTidPairInvalid;
+					}
 				}
 
 				values[col_index] = heap_getattr(&htup_outer, var->varattno,
@@ -588,8 +597,11 @@ fetch_next_pair(CrossmatchScanState *scan_state)
 				if (!htup_inner_ready)
 				{
 					htup_inner_ready = true;
-					heap_fetch(scan_state->inner, SnapshotSelf,
-								&htup_inner, &buf2, false, NULL);
+					if(!heap_fetch(scan_state->inner, SnapshotSelf,
+								   &htup_inner, &buf2, false, NULL))
+					{
+						return FetchTidPairInvalid;
+					}
 				}
 
 				values[col_index] = heap_getattr(&htup_inner, var->varattno,
@@ -611,7 +623,7 @@ fetch_next_pair(CrossmatchScanState *scan_state)
 		ExecStoreTuple(htup, slot, InvalidBuffer, false);
 	}
 
-	return true;
+	return FetchTidPairReady;
 }
 
 static TupleTableSlot *
@@ -620,12 +632,19 @@ crossmatch_exec(CustomScanState *node)
 	CrossmatchScanState	   *scan_state = (CrossmatchScanState *) node;
 	TupleTableSlot		   *scanSlot = node->ss.ss_ScanTupleSlot;
 
-	for(;;)
+	for (;;)
 	{
 		if (!node->ss.ps.ps_TupFromTlist)
 		{
-			/* Fetch next tid pair if we're done with the SRF function */
-			if (!fetch_next_pair(scan_state))
+			FetchTidPairState fetch_state;
+
+			do
+			{
+				fetch_state = fetch_next_pair(scan_state);
+			}
+			while (fetch_state == FetchTidPairInvalid);
+
+			if (fetch_state == FetchTidPairFinished)
 				return NULL;
 		}
 

Original file line number	Diff line number	Diff line change
`@@ -28,6 +28,13 @@ extern void _PG_init(void);`
`28`	`28`
`29`	`29`	`static set_join_pathlist_hook_type set_join_pathlist_next;`
`30`	`30`
	`31`	`+typedef enum`
	`32`	`+{`
	`33`	`+ FetchTidPairFinished = 0,`
	`34`	`+ FetchTidPairInvalid,`
	`35`	`+ FetchTidPairReady`
	`36`	`+} FetchTidPairState;`
	`37`	`+`
`31`	`38`	`typedef struct`
`32`	`39`	`{`
`33`	`40`	`CustomPath cpath;`
`@@ -528,7 +535,7 @@ crossmatch_begin(CustomScanState node, EState estate, int eflags)`
`528`	`535`	`}`
`529`	`536`	`}`
`530`	`537`
`531`		`-static bool`
	`538`	`+static FetchTidPairState`
`532`	`539`	`fetch_next_pair(CrossmatchScanState *scan_state)`
`533`	`540`	`{`
`534`	`541`	`ScanState *ss = &scan_state->css.ss;`
`@@ -549,7 +556,7 @@ fetch_next_pair(CrossmatchScanState *scan_state)`
`549`	`556`
`550`	`557`	`if (!ItemPointerIsValid(&p_tids[0]) \|\| !ItemPointerIsValid(&p_tids[1]))`
`551`	`558`	`{`
`552`		`- return false;`
	`559`	`+ return FetchTidPairFinished;`
`553`	`560`	`}`
`554`	`561`
`555`	`562`	`/* We don't have to fetch tuples if scan tlist is empty */`
`@@ -573,9 +580,11 @@ fetch_next_pair(CrossmatchScanState *scan_state)`
`573`	`580`	`if (!htup_outer_ready)`
`574`	`581`	`{`
`575`	`582`	`htup_outer_ready = true;`
`576`		`- /* TODO: check result */`
`577`		`- heap_fetch(scan_state->outer, SnapshotSelf,`
`578`		`- &htup_outer, &buf1, false, NULL);`
	`583`	`+ if(!heap_fetch(scan_state->outer, SnapshotSelf,`
	`584`	`+ &htup_outer, &buf1, false, NULL))`
	`585`	`+ {`
	`586`	`+ return FetchTidPairInvalid;`
	`587`	`+ }`
`579`	`588`	`}`
`580`	`589`
`581`	`590`	`values[col_index] = heap_getattr(&htup_outer, var->varattno,`
`@@ -588,8 +597,11 @@ fetch_next_pair(CrossmatchScanState *scan_state)`
`588`	`597`	`if (!htup_inner_ready)`
`589`	`598`	`{`
`590`	`599`	`htup_inner_ready = true;`
`591`		`- heap_fetch(scan_state->inner, SnapshotSelf,`
`592`		`- &htup_inner, &buf2, false, NULL);`
	`600`	`+ if(!heap_fetch(scan_state->inner, SnapshotSelf,`
	`601`	`+ &htup_inner, &buf2, false, NULL))`
	`602`	`+ {`
	`603`	`+ return FetchTidPairInvalid;`
	`604`	`+ }`
`593`	`605`	`}`
`594`	`606`
`595`	`607`	`values[col_index] = heap_getattr(&htup_inner, var->varattno,`
`@@ -611,7 +623,7 @@ fetch_next_pair(CrossmatchScanState *scan_state)`
`611`	`623`	`ExecStoreTuple(htup, slot, InvalidBuffer, false);`
`612`	`624`	`}`
`613`	`625`
`614`		`- return true;`
	`626`	`+ return FetchTidPairReady;`
`615`	`627`	`}`
`616`	`628`
`617`	`629`	`static TupleTableSlot *`
`@@ -620,12 +632,19 @@ crossmatch_exec(CustomScanState *node)`
`620`	`632`	`CrossmatchScanState scan_state = (CrossmatchScanState ) node;`
`621`	`633`	`TupleTableSlot *scanSlot = node->ss.ss_ScanTupleSlot;`
`622`	`634`
`623`		`- for(;;)`
	`635`	`+ for (;;)`
`624`	`636`	`{`
`625`	`637`	`if (!node->ss.ps.ps_TupFromTlist)`
`626`	`638`	`{`
`627`		`- /* Fetch next tid pair if we're done with the SRF function */`
`628`		`- if (!fetch_next_pair(scan_state))`
	`639`	`+ FetchTidPairState fetch_state;`
	`640`	`+`
	`641`	`+ do`
	`642`	`+ {`
	`643`	`+ fetch_state = fetch_next_pair(scan_state);`
	`644`	`+ }`
	`645`	`+ while (fetch_state == FetchTidPairInvalid);`
	`646`	`+`
	`647`	`+ if (fetch_state == FetchTidPairFinished)`
`629`	`648`	`return NULL;`
`630`	`649`	`}`
`631`	`650`