Allow extracting and parsing of reloptions from a bare pg_class tuple, and

refactor the relcache code that used to do that.  This allows other callers
(particularly autovacuum) to do the same without necessarily having to open
and lock a table.

diff --git a/src/backend/access/common/reloptions.c b/src/backend/access/common/reloptions.c
index 01876ff90d92a05501f30e54a12b754929bbb3e9..f9d36ee92b9ab7df4a8c1312fe5a8faf96fe9b7a 100644 (file)
--- a/src/backend/access/common/reloptions.c
+++ b/src/backend/access/common/reloptions.c
@@ -558,6 +558,53 @@ untransformRelOptions(Datum options)
        return result;
 }
 
+/*
+ * Extract and parse reloptions from a pg_class tuple.
+ *
+ * This is a low-level routine, expected to be used by relcache code and
+ * callers that do not have a table's relcache entry (e.g. autovacuum).  For
+ * other uses, consider grabbing the rd_options pointer from the relcache entry
+ * instead.
+ *
+ * tupdesc is pg_class' tuple descriptor.  amoptions is the amoptions regproc
+ * in the case of the tuple corresponding to an index, or InvalidOid otherwise.
+ */
+bytea *
+extractRelOptions(HeapTuple tuple, TupleDesc tupdesc, Oid amoptions)
+{
+       bytea  *options;
+       bool    isnull;
+       Datum   datum;
+       Form_pg_class   classForm;
+
+       datum = fastgetattr(tuple,
+                                               Anum_pg_class_reloptions,
+                                               tupdesc,
+                                               &isnull);
+       if (isnull)
+               return NULL;
+
+       classForm = (Form_pg_class) GETSTRUCT(tuple);
+
+       /* Parse into appropriate format; don't error out here */
+       switch (classForm->relkind)
+       {
+               case RELKIND_RELATION:
+               case RELKIND_TOASTVALUE:
+               case RELKIND_UNCATALOGED:
+                       options = heap_reloptions(classForm->relkind, datum, false);
+                       break;
+               case RELKIND_INDEX:
+                       options = index_reloptions(amoptions, datum, false);
+                       break;
+               default:
+                       Assert(false);          /* can't get here */
+                       options = NULL;         /* keep compiler quiet */
+                       break;
+       }
+       
+       return options;
+}
 
 /*
  * Interpret reloptions that are given in text-array format.

diff --git a/src/backend/utils/cache/relcache.c b/src/backend/utils/cache/relcache.c
index e9021de332f700722571ff68c5d6dfee28c882c6..970063586fadc9ae48a541e8c1b698f035cc9d81 100644 (file)
--- a/src/backend/utils/cache/relcache.c
+++ b/src/backend/utils/cache/relcache.c
@@ -351,8 +351,6 @@ AllocateRelationDesc(Relation relation, Form_pg_class relp)
 static void
 RelationParseRelOptions(Relation relation, HeapTuple tuple)
 {
-       Datum           datum;
-       bool            isnull;
        bytea      *options;
 
        relation->rd_options = NULL;
@@ -374,31 +372,10 @@ RelationParseRelOptions(Relation relation, HeapTuple tuple)
         * we might not have any other for pg_class yet (consider executing this
         * code for pg_class itself)
         */
-       datum = fastgetattr(tuple,
-                                               Anum_pg_class_reloptions,
-                                               GetPgClassDescriptor(),
-                                               &isnull);
-       if (isnull)
-               return;
-
-       /* Parse into appropriate format; don't error out here */
-       switch (relation->rd_rel->relkind)
-       {
-               case RELKIND_RELATION:
-               case RELKIND_TOASTVALUE:
-               case RELKIND_UNCATALOGED:
-                       options = heap_reloptions(relation->rd_rel->relkind, datum,
-                                                                         false);
-                       break;
-               case RELKIND_INDEX:
-                       options = index_reloptions(relation->rd_am->amoptions, datum,
-                                                                          false);
-                       break;
-               default:
-                       Assert(false);          /* can't get here */
-                       options = NULL;         /* keep compiler quiet */
-                       break;
-       }
+       options = extractRelOptions(tuple,
+                                                               GetPgClassDescriptor(),
+                                                               relation->rd_rel->relkind == RELKIND_INDEX ?
+                                                               relation->rd_am->amoptions : InvalidOid);
 
        /* Copy parsed data into CacheMemoryContext */
        if (options)

diff --git a/src/include/access/reloptions.h b/src/include/access/reloptions.h
index 393d0bb5d3faab5edbb23bda91f392a5a3b4755d..8fc10d636d3f392d4219d404d25571d33238528c 100644 (file)
--- a/src/include/access/reloptions.h
+++ b/src/include/access/reloptions.h
@@ -18,6 +18,7 @@
 #ifndef RELOPTIONS_H
 #define RELOPTIONS_H
 
+#include "access/htup.h"
 #include "nodes/pg_list.h"
 
 /* types supported by reloptions */
@@ -241,6 +242,8 @@ extern void add_string_reloption(int kind, char *name, char *desc,
 extern Datum transformRelOptions(Datum oldOptions, List *defList,
                                        bool ignoreOids, bool isReset);
 extern List *untransformRelOptions(Datum options);
+extern bytea *extractRelOptions(HeapTuple tuple, TupleDesc tupdesc,
+                                 Oid amoptions);
 extern relopt_value *parseRelOptions(Datum options, bool validate,
                                relopt_kind kind, int *numrelopts);
 extern void *allocateReloptStruct(Size base, relopt_value *options,