TODO marked as done:

[postgresql] / src / backend / catalog / namespace.c

diff --git a/src/backend/catalog/namespace.c b/src/backend/catalog/namespace.c
index e7fd1c1e5c016a221880fb0401bf7429b85bd0d6..fa0d20af307da781da711944fb9e5b6675a02888 100644 (file)
--- a/src/backend/catalog/namespace.c
+++ b/src/backend/catalog/namespace.c
@@ -13,7 +13,7 @@
  * Portions Copyright (c) 1994, Regents of the University of California
  *
  * IDENTIFICATION
- *       $Header: /cvsroot/pgsql/src/backend/catalog/namespace.c,v 1.41 2002/12/04 05:18:31 momjian Exp $
+ *       $Header: /cvsroot/pgsql/src/backend/catalog/namespace.c,v 1.42 2002/12/12 21:02:19 momjian Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -143,7 +143,7 @@ Datum               pg_type_is_visible(PG_FUNCTION_ARGS);
 Datum          pg_function_is_visible(PG_FUNCTION_ARGS);
 Datum          pg_operator_is_visible(PG_FUNCTION_ARGS);
 Datum          pg_opclass_is_visible(PG_FUNCTION_ARGS);
-
+Datum          pg_conversion_is_visible(PG_FUNCTION_ARGS);
 
 /*
  * RangeVarGetRelid
@@ -1035,6 +1035,87 @@ OpclassIsVisible(Oid opcid)
        return visible;
 }
 
+/*
+ * ConversionGetConid
+ *             Try to resolve an unqualified conversion name.
+ *             Returns OID if conversion found in search path, else InvalidOid.
+ *
+ * This is essentially the same as RelnameGetRelid.
+ */
+Oid
+ConversionGetConid(const char *conname)
+{
+       Oid             conid;
+       List       *lptr;
+
+       recomputeNamespacePath();
+
+       foreach(lptr, namespaceSearchPath)
+       {
+               Oid                     namespaceId = (Oid) lfirsti(lptr);
+
+               conid = GetSysCacheOid(CONNAMENSP,
+                                                          PointerGetDatum(conname),
+                                                          ObjectIdGetDatum(namespaceId),
+                                                          0, 0);
+               if (OidIsValid(conid))
+                       return conid;
+       }
+
+       /* Not found in path */
+       return InvalidOid;
+}
+
+/*
+ * ConversionIsVisible
+ *             Determine whether a conversion (identified by OID) is visible in the
+ *             current search path.  Visible means "would be found by searching
+ *             for the unqualified conversion name".
+ */
+bool
+ConversionIsVisible(Oid conid)
+{
+       HeapTuple       contup;
+       Form_pg_conversion conform;
+       Oid                     connamespace;
+       bool            visible;
+
+       contup = SearchSysCache(CONOID,
+                                                       ObjectIdGetDatum(conid),
+                                                       0, 0, 0);
+       if (!HeapTupleIsValid(contup))
+               elog(ERROR, "Cache lookup failed for converions %u", conid);
+       conform = (Form_pg_conversion) GETSTRUCT(contup);
+
+       recomputeNamespacePath();
+
+       /*
+        * Quick check: if it ain't in the path at all, it ain't visible.
+        * Items in the system namespace are surely in the path and so we
+        * needn't even do intMember() for them.
+        */
+       connamespace = conform->connamespace;
+       if (connamespace != PG_CATALOG_NAMESPACE &&
+               !intMember(connamespace, namespaceSearchPath))
+               visible = false;
+       else
+       {
+               /*
+                * If it is in the path, it might still not be visible; it could
+                * be hidden by another conversion of the same name earlier in the
+                * path. So we must do a slow check to see if this conversion would
+                * be found by ConvnameGetConid.
+                */
+               char       *conname = NameStr(conform->conname);
+               
+               visible = (ConversionGetConid(conname) == conid);
+       }
+
+       ReleaseSysCache(contup);
+
+       return visible;
+}
+
 /*
  * DeconstructQualifiedName
  *             Given a possibly-qualified name expressed as a list of String nodes,
@@ -1854,3 +1935,11 @@ pg_opclass_is_visible(PG_FUNCTION_ARGS)
 
        PG_RETURN_BOOL(OpclassIsVisible(oid));
 }
+
+Datum
+pg_conversion_is_visible(PG_FUNCTION_ARGS)
+{
+       Oid                     oid = PG_GETARG_OID(0);
+
+       PG_RETURN_BOOL(ConversionIsVisible(oid));
+}