introduce InitWalkerContextCustomNode macro, new comments

funbringer · funbringer · commit c79b3f7e85ce · 2016-06-02T16:13:29.000+03:00
diff --git a/src/nodes_common.c b/src/nodes_common.c
@@ -481,6 +481,7 @@ end_append_common(CustomScanState *node)
 {
 	RuntimeAppendState *scan_state = (RuntimeAppendState *) node;
 
+	clear_walker_context(&scan_state->wcxt);
 	clear_plan_states(&scan_state->css);
 	hash_destroy(scan_state->children_table);
 }
@@ -498,21 +499,8 @@ rescan_append_common(CustomScanState *node)
 
 	ranges = list_make1_irange(make_irange(0, prel->children_count - 1, false));
 
-	/*
-	 * We'd like to persist RangeEntry array
-	 * in case of range partitioning, so 'wcxt'
-	 * is stored inside of RuntimeAppendState
-	 */
-	if (!scan_state->wcxt_cached)
-	{
-		scan_state->wcxt.prel = prel;
-		scan_state->wcxt.econtext = econtext;
-		scan_state->wcxt.ranges = NULL;
-
-		scan_state->wcxt_cached = true;
-	}
-	scan_state->wcxt.hasLeast = false;		/* refresh runtime values */
-	scan_state->wcxt.hasGreatest = false;
+	InitWalkerContextCustomNode(&scan_state->wcxt, scan_state->prel,
+								econtext, &scan_state->wcxt_cached);
 
 	foreach (lc, scan_state->custom_exprs)
 	{
diff --git a/src/partition_filter.c b/src/partition_filter.c
@@ -159,21 +159,8 @@ partition_filter_exec(CustomScanState *node)
 		CopyToTempConst(constlen,    attlen);
 		CopyToTempConst(constbyval,  attbyval);
 
-		/*
-		 * We'd like to persist RangeEntry array
-		 * in case of range partitioning, so 'wcxt'
-		 * is stored inside of PartitionFilterState
-		 */
-		if (!state->wcxt_cached)
-		{
-			state->wcxt.prel = state->prel;
-			state->wcxt.econtext = econtext;
-			state->wcxt.ranges = NULL;
-
-			state->wcxt_cached = true;
-		}
-		state->wcxt.hasLeast = false;		/* refresh runtime values */
-		state->wcxt.hasGreatest = false;
+		InitWalkerContextCustomNode(&state->wcxt, state->prel,
+									econtext, &state->wcxt_cached);
 
 		ranges = walk_expr_tree((Expr *) &state->temp_const, &state->wcxt)->rangeset;
 		parts = get_partition_oids(ranges, &nparts, state->prel);
@@ -215,11 +202,12 @@ partition_filter_end(CustomScanState *node)
 		heap_close(rri_handle->resultRelInfo->ri_RelationDesc,
 				   RowExclusiveLock);
 	}
-
 	hash_destroy(state->result_rels_table);
 
 	Assert(list_length(node->custom_ps) == 1);
 	ExecEndNode((PlanState *) linitial(node->custom_ps));
+
+	clear_walker_context(&state->wcxt);
 }
 
 void
diff --git a/src/partition_filter.h b/src/partition_filter.h
@@ -23,13 +23,14 @@ typedef struct
 	ResultRelInfo	   *savedRelInfo;
 
 	Plan			   *subplan;
-	Const				temp_const; /* temporary const for expr walker */
+	Const				temp_const;		/* temporary const for expr walker */
 
 	HTAB			   *result_rels_table;
 	HASHCTL				result_rels_table_config;
 
 	WalkerContext		wcxt;
-	bool				wcxt_cached;
+	bool				wcxt_cached;	/* does wcxt contain cached data,
+										   e.g. RangeEntry array? */
 } PartitionFilterState;
 
 
diff --git a/src/pathman.h b/src/pathman.h
@@ -78,7 +78,6 @@ typedef struct PartRelationInfo
 	PartType		parttype;
 	Index			attnum;
 	Oid				atttype;
-
 } PartRelationInfo;
 
 /*
@@ -256,12 +255,12 @@ typedef struct
 typedef struct
 {
 	/* Main partitioning structure */
-	PartRelationInfo	   *prel;
+	const PartRelationInfo *prel;
 
 	/* Cached values */
-	RangeEntry			   *ranges;		/*cached RangeEntry array */
-	size_t					nranges;
-	ExprContext			   *econtext;
+	const RangeEntry	   *ranges;		/* cached RangeEntry array (copy) */
+	size_t					nranges;	/* number of RangeEntries */
+	ExprContext			   *econtext;	/* for ExecEvalExpr() */
 
 	/* Runtime values */
 	bool					hasLeast,
@@ -270,6 +269,9 @@ typedef struct
 							greatest;
 } WalkerContext;
 
+/*
+ * Usual initialization procedure for WalkerContext
+ */
 #define InitWalkerContext(context, prel_info, ecxt) \
 	do { \
 		(context)->prel = (prel_info); \
@@ -279,6 +281,24 @@ typedef struct
 		(context)->hasGreatest = false; \
 	} while (0)
 
+/*
+ * We'd like to persist RangeEntry (ranges) array
+ * in case of range partitioning, so 'wcxt' is stored
+ * inside of Custom Node
+ */
+#define InitWalkerContextCustomNode(context, prel_info, ecxt, isCached) \
+	do { \
+		if (!*isCached) \
+		{ \
+			(context)->prel = prel_info; \
+			(context)->econtext = ecxt; \
+			(context)->ranges = NULL; \
+			*isCached = true; \
+		} \
+		(context)->hasLeast = false; \
+		(context)->hasGreatest = false; \
+	} while (0)
+
 void select_range_partitions(const Datum value,
 							 const bool byVal,
 							 FmgrInfo *cmp_func,
diff --git a/src/pg_pathman.c b/src/pg_pathman.c
@@ -313,6 +313,7 @@ handle_modification_query(Query *parse)
 	InitWalkerContext(&context, prel, NULL);
 	wrap = walk_expr_tree(expr, &context);
 	finish_least_greatest(wrap, &context);
+	clear_walker_context(&context);
 
 	ranges = irange_list_intersect(ranges, wrap->rangeset);
 
@@ -710,6 +711,12 @@ change_varnos_in_restrinct_info(RestrictInfo *rinfo, change_varno_context *conte
 	}
 }
 
+/*
+ * Refresh cached RangeEntry array within WalkerContext
+ *
+ * This is essential when we add new partitions
+ * while executing INSERT query on partitioned table.
+ */
 void
 refresh_walker_context_ranges(WalkerContext *context)
 {
@@ -721,12 +728,15 @@ refresh_walker_context_ranges(WalkerContext *context)
 	context->nranges = rangerel->ranges.elem_count;
 }
 
+/*
+ * Free all temporary data cached by WalkerContext
+ */
 void
 clear_walker_context(WalkerContext *context)
 {
 	if (context->ranges)
 	{
-		pfree(context->ranges);
+		pfree((void *) context->ranges);
 		context->ranges = NULL;
 	}
 }
@@ -1023,14 +1033,14 @@ static void
 handle_binary_opexpr(WalkerContext *context, WrapperNode *result,
 					 const Var *v, const Const *c)
 {
-	HashRelationKey		key;
-	int					int_value,
-						strategy;
-	FmgrInfo		    cmp_func;
-	Oid					cmp_proc_oid;
-	const OpExpr	   *expr = (const OpExpr *)result->orig;
-	TypeCacheEntry	   *tce;
-	PartRelationInfo   *prel = context->prel;
+	HashRelationKey			key;
+	int						int_value,
+							strategy;
+	TypeCacheEntry		   *tce;
+	FmgrInfo				cmp_func;
+	Oid						cmp_proc_oid;
+	const OpExpr		   *expr = (const OpExpr *) result->orig;
+	const PartRelationInfo *prel = context->prel;
 
 	/* Determine operator type */
 	tce = lookup_type_cache(v->vartype,
diff --git a/src/pl_funcs.c b/src/pl_funcs.c
@@ -381,4 +381,3 @@ release_partitions_lock(PG_FUNCTION_ARGS)
 	LWLockRelease(pmstate->edit_partitions_lock);
 	PG_RETURN_NULL();
 }
-
diff --git a/src/utils.c b/src/utils.c
@@ -21,6 +21,10 @@
 
 static bool clause_contains_params_walker(Node *node, void *context);
 
+
+/*
+ * Check whether clause contains PARAMs or not
+ */
 bool
 clause_contains_params(Node *clause)
 {
@@ -59,6 +63,11 @@ bms_print(Bitmapset *bms)
   return str.data;
 }
 
+/*
+ * Copied from util/plancat.c
+ *
+ * Build a targetlist representing the columns of the specified index.
+ */
 List *
 build_index_tlist(PlannerInfo *root, IndexOptInfo *index,
 				  Relation heapRelation)
@@ -143,6 +152,12 @@ check_rinfo_for_partitioned_attr(List *rinfo, Index varno, AttrNumber varattno)
 	return false;
 }
 
+/*
+ * Append trigger info contained in 'more' to 'src'.
+ *
+ * This allows us to execute some of main table's triggers on children.
+ * See ExecInsert() for more details.
+ */
 TriggerDesc *
 append_trigger_descs(TriggerDesc *src, TriggerDesc *more, bool *grown_up)
 {
@@ -234,6 +249,9 @@ add_missing_partition(Oid partitioned_table, Const *value)
 	return result;
 }
 
+/*
+ * Get BTORDER_PROC for two types described by Oids
+ */
 void
 fill_type_cmp_fmgr_info(FmgrInfo *finfo, Oid type1, Oid type2)
 {

Original file line number	Diff line number	Diff line change
`@@ -381,4 +381,3 @@ release_partitions_lock(PG_FUNCTION_ARGS)`
`381`	`381`	`LWLockRelease(pmstate->edit_partitions_lock);`
`382`	`382`	`PG_RETURN_NULL();`
`383`	`383`	`}`
`384`		`-`