tf_idf_source GUC and its validation

Author: Alexander Korotkov

Makefile

@@ -5,7 +5,7 @@ OBJS = src/rumsort.o src/rum_ts_utils.o src/rumtsquery.o \
 	src/rumbtree.o src/rumbulk.o src/rumdatapage.o \
 	src/rumentrypage.o src/rumget.o src/ruminsert.o \
 	src/rumscan.o src/rumutil.o src/rumvacuum.o src/rumvalidate.o \
-	src/btree_rum.o $(WIN32RES)
+	src/btree_rum.o src/tf_idf.o $(WIN32RES)
 
 EXTENSION = rum
 DATA = rum--1.0.sql rum--1.0--1.1.sql rum--1.1.sql

src/rum.h

@@ -19,6 +19,7 @@
 #include "access/sdir.h"
 #include "lib/rbtree.h"
 #include "storage/bufmgr.h"
+#include "utils/guc.h"
 
 #include "rumsort.h"
 
@@ -1008,4 +1009,9 @@ extern Datum FunctionCall10Coll(FmgrInfo *flinfo, Oid collation,
 				   Datum arg6, Datum arg7, Datum arg8,
 				   Datum arg9, Datum arg10);
 
+/* tf_idf.c */
+extern char *TFIDFSource;
+extern bool check_tf_idf_source(char **newval, void **extra, GucSource source);
+extern void assign_tf_idf_source(const char *newval, void *extra);
+
 #endif   /* __RUM_H__ */

src/rumutil.c

@@ -49,6 +49,17 @@ _PG_init(void)
 							PGC_USERSET, 0,
 							NULL, NULL, NULL);
 
+	DefineCustomStringVariable("tf_tdf_source",
+							   "Source statistics for TD/IFD calculation.",
+							   "",
+							   &TFIDFSource,
+							   "",
+							   PGC_USERSET,
+							   0,
+							   check_tf_idf_source,
+							   assign_tf_idf_source,
+							   NULL);
+
 	rum_relopt_kind = add_reloption_kind();
 
 	add_string_reloption(rum_relopt_kind, "attach",

src/tf_idf.c

@@ -0,0 +1,121 @@
+/*-------------------------------------------------------------------------
+ *
+ * tf_idf.c
+ *		Implementation of TD/IDF statistics calculation.
+ *
+ * Portions Copyright (c) 2017, Postgres Professional
+ *
+ *-------------------------------------------------------------------------
+ */
+#include "postgres.h"
+
+#include "catalog/namespace.h"
+#include "catalog/pg_type.h"
+#include "utils/builtins.h"
+#include "utils/lsyscache.h"
+#include "utils/varlena.h"
+
+#include "rum.h"
+
+char *TFIDFSource;
+
+#define EXIT_CHECK_TF_IDF_SOURCE(error) \
+	do { \
+		GUC_check_errdetail(error); \
+		pfree(rawname); \
+		list_free(namelist); \
+		if (rel) \
+			RelationClose(rel); \
+		return false; \
+	} while (false);
+
+bool
+check_tf_idf_source(char **newval, void **extra, GucSource source)
+{
+	char	   *rawname;
+	char	   *attname;
+	List	   *namelist;
+	Oid			namespaceId;
+	Oid			relId;
+	Relation	rel = NULL;
+	TupleDesc	tupDesc;
+	AttrNumber	attrno;
+	int			i;
+
+	/* Need a modifiable copy of string */
+	rawname = pstrdup(*newval);
+
+	/* Parse string into list of identifiers */
+	if (!SplitIdentifierString(rawname, '.', &namelist))
+	{
+		/* syntax error in name list */
+		EXIT_CHECK_TF_IDF_SOURCE("List syntax is invalid.");
+	}
+
+	switch (list_length(namelist))
+	{
+		case 0:
+			return true;
+		case 1:
+			EXIT_CHECK_TF_IDF_SOURCE("improper column name (there should be at least 2 dotted names)");
+		case 2:
+			relId = RelnameGetRelid(linitial(namelist));
+			attname = lsecond(namelist);
+			break;
+		case 3:
+			/* use exact schema given */
+			namespaceId = LookupExplicitNamespace(linitial(namelist), true);
+			if (!OidIsValid(namespaceId))
+				relId = InvalidOid;
+			else
+				relId = get_relname_relid(lsecond(namelist), namespaceId);
+			attname = lthird(namelist);
+			break;
+		default:
+			EXIT_CHECK_TF_IDF_SOURCE("improper column name (too many dotted names)");
+	}
+
+	if (!OidIsValid(relId))
+		EXIT_CHECK_TF_IDF_SOURCE("relation not found");
+
+	rel = RelationIdGetRelation(relId);
+	tupDesc = rel->rd_att;
+	if (rel->rd_rel->relkind == RELKIND_INDEX)
+	{
+		attrno = pg_atoi(attname, sizeof(attrno), 10);
+		if (attrno <= 0 || attrno > rel->rd_index->indnatts)
+			EXIT_CHECK_TF_IDF_SOURCE("wrong index attribute number");
+		if (rel->rd_index->indkey.values[attrno - 1] != InvalidAttrNumber)
+			EXIT_CHECK_TF_IDF_SOURCE("regular indexed column is specified");
+	}
+	else
+	{
+		attrno = InvalidAttrNumber;
+		for (i = 0; i < tupDesc->natts; i++)
+		{
+			if (namestrcmp(&(tupDesc->attrs[i]->attname), attname) == 0)
+			{
+				attrno = tupDesc->attrs[i]->attnum;
+				break;
+			}
+		}
+
+		if (attrno == InvalidAttrNumber)
+			EXIT_CHECK_TF_IDF_SOURCE("attribute not found");
+	}
+
+	if (tupDesc->attrs[attrno - 1]->atttypid != TSVECTOROID)
+		EXIT_CHECK_TF_IDF_SOURCE("attribute should be of tsvector type");
+
+	pfree(rawname);
+	list_free(namelist);
+	RelationClose(rel);
+	return true;
+}
+
+
+void
+assign_tf_idf_source(const char *newval, void *extra)
+{
+
+}