Fix several oversights in previous commit - attribute options patch.

I failed to 'cvs add' the new files and also neglected to bump catversion.

src/backend/utils/cache/attoptcache.c

@@ -0,0 +1,181 @@
+/*-------------------------------------------------------------------------
+ *
+ * attoptcache.c
+ *	  Attribute options cache management.
+ *
+ * Attribute options are cached separately from the fixed-size portion of
+ * pg_attribute entries, which are handled by the relcache.
+ *
+ * Portions Copyright (c) 1996-2010, PostgreSQL Global Development Group
+ * Portions Copyright (c) 1994, Regents of the University of California
+ *
+ * IDENTIFICATION
+ *	  $PostgreSQL: pgsql/src/backend/utils/cache/attoptcache.c,v 1.1 2010/01/22 16:42:31 rhaas Exp $
+ *
+ *-------------------------------------------------------------------------
+ */
+#include "postgres.h"
+
+#include "access/reloptions.h"
+#include "catalog/pg_attribute.h"
+#include "utils/attoptcache.h"
+#include "utils/catcache.h"
+#include "utils/hsearch.h"
+#include "utils/inval.h"
+#include "utils/rel.h"
+#include "utils/syscache.h"
+
+
+/* Hash table for informations about each attribute's options */
+static HTAB *AttoptCacheHash = NULL;
+
+/* attrelid and attnum form the lookup key, and must appear first */
+typedef struct
+{
+	Oid			attrelid;
+	int			attnum;
+} AttoptCacheKey;
+
+typedef struct
+{
+	AttoptCacheKey key;			/* lookup key - must be first */
+	AttributeOpts *opts;		/* options, or NULL if none */
+} AttoptCacheEntry;
+
+
+/*
+ * InvalidateAttoptCacheCallback
+ *		Flush all cache entries when pg_attribute is updated.
+ *
+ * When pg_attribute is updated, we must flush the cache entry at least
+ * for that attribute.  Currently, we just flush them all.  Since attribute
+ * options are not currently used in performance-critical paths (such as
+ * query execution), this seems OK.
+ */
+static void
+InvalidateAttoptCacheCallback(Datum arg, int cacheid, ItemPointer tuplePtr)
+{
+	HASH_SEQ_STATUS status;
+	AttoptCacheEntry *attopt;
+
+	hash_seq_init(&status, AttoptCacheHash);
+	while ((attopt = (AttoptCacheEntry *) hash_seq_search(&status)) != NULL)
+	{
+		if (attopt->opts)
+			pfree(attopt->opts);
+		if (hash_search(AttoptCacheHash,
+						(void *) &attopt->key,
+						HASH_REMOVE,
+						NULL) == NULL)
+			elog(ERROR, "hash table corrupted");
+	}
+}
+
+/*
+ * InitializeAttoptCache
+ *		Initialize the tablespace cache.
+ */
+static void
+InitializeAttoptCache(void)
+{
+	HASHCTL ctl;
+
+	/* Initialize the hash table. */
+	MemSet(&ctl, 0, sizeof(ctl));
+	ctl.keysize = sizeof(AttoptCacheKey);
+	ctl.entrysize = sizeof(AttoptCacheEntry);
+	ctl.hash = tag_hash;
+	AttoptCacheHash =
+		hash_create("Attopt cache", 256, &ctl,
+				    HASH_ELEM | HASH_FUNCTION);
+
+	/* Make sure we've initialized CacheMemoryContext. */
+	if (!CacheMemoryContext)
+		CreateCacheMemoryContext();
+
+	/* Watch for invalidation events. */
+	CacheRegisterSyscacheCallback(ATTNUM,
+								  InvalidateAttoptCacheCallback,
+								  (Datum) 0);
+}
+
+/*
+ * get_attribute_options
+ *		Fetch attribute options for a specified table OID.
+ */
+AttributeOpts *
+get_attribute_options(Oid attrelid, int attnum)
+{
+	AttoptCacheKey key;
+	AttoptCacheEntry *attopt;
+	AttributeOpts  *result;
+	HeapTuple	tp;
+
+	/* Find existing cache entry, if any. */
+	if (!AttoptCacheHash)
+		InitializeAttoptCache();
+	memset(&key, 0, sizeof(key));	/* make sure any padding bits are unset */
+	key.attrelid = attrelid;
+	key.attnum = attnum;
+	attopt =
+		(AttoptCacheEntry *) hash_search(AttoptCacheHash,
+								         (void *) &key,
+										 HASH_FIND,
+										 NULL);
+
+	/* Not found in Attopt cache.  Construct new cache entry. */
+	if (!attopt)
+	{
+		AttributeOpts *opts;
+
+		tp = SearchSysCache(ATTNUM,
+							ObjectIdGetDatum(attrelid),
+							Int16GetDatum(attnum),
+							0, 0);
+
+		/*
+		 * If we don't find a valid HeapTuple, it must mean someone has
+		 * managed to request attribute details for a non-existent attribute.
+		 * We treat that case as if no options were specified.
+		 */
+		if (!HeapTupleIsValid(tp))
+			opts = NULL;
+		else
+		{
+			Datum	datum;
+			bool	isNull;
+
+			datum = SysCacheGetAttr(ATTNUM,
+									tp,
+									Anum_pg_attribute_attoptions,
+									&isNull);
+			if (isNull)
+				opts = NULL;
+			else
+			{
+				bytea *bytea_opts = attribute_reloptions(datum, false);
+				opts = MemoryContextAlloc(CacheMemoryContext,
+										  VARSIZE(bytea_opts));
+				memcpy(opts, bytea_opts, VARSIZE(bytea_opts));
+			}
+			ReleaseSysCache(tp);
+		}
+
+		/*
+		 * It's important to create the actual cache entry only after
+		 * reading pg_attribute, since the read could cause a cache flush.
+		 */
+		attopt = (AttoptCacheEntry *) hash_search(AttoptCacheHash,
+												   (void *) &key,
+												   HASH_ENTER,
+												   NULL);
+		attopt->opts = opts;
+	}
+
+	/* Return results in caller's memory context. */
+	if (attopt->opts == NULL)
+		return NULL;
+	result = palloc(VARSIZE(attopt->opts));
+	memcpy(result, attopt->opts, VARSIZE(attopt->opts));
+	return result;
+}

src/include/catalog/catversion.h

@@ -37,7 +37,7 @@
  * Portions Copyright (c) 1996-2010, PostgreSQL Global Development Group
  * Portions Copyright (c) 1994, Regents of the University of California
  *
- * $PostgreSQL: pgsql/src/include/catalog/catversion.h,v 1.577 2010/01/22 15:45:15 petere Exp $
+ * $PostgreSQL: pgsql/src/include/catalog/catversion.h,v 1.578 2010/01/22 16:42:31 rhaas Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -53,6 +53,6 @@
  */
 
 /*							yyyymmddN */
-#define CATALOG_VERSION_NO	201001221
+#define CATALOG_VERSION_NO	201001222
 
 #endif

src/include/utils/attoptcache.h

@@ -0,0 +1,28 @@
+/*-------------------------------------------------------------------------
+ *
+ * attoptcache.h
+ *	  Attribute options cache.
+ *
+ * Portions Copyright (c) 1996-2010, PostgreSQL Global Development Group
+ * Portions Copyright (c) 1994, Regents of the University of California
+ *
+ * $PostgreSQL: pgsql/src/include/utils/attoptcache.h,v 1.1 2010/01/22 16:42:31 rhaas Exp $
+ *
+ *-------------------------------------------------------------------------
+ */
+#ifndef SPCCACHE_H
+#define SPCCACHE_H
+
+/*
+ * Attribute options.
+ */
+typedef struct AttributeOpts
+{
+	int32		vl_len_;		/* varlena header (do not touch directly!) */
+	float8		n_distinct;
+	float8		n_distinct_inherited;
+} AttributeOpts;
+
+AttributeOpts *get_attribute_options(Oid spcid, int attnum);
+
+#endif   /* SPCCACHE_H */