Allow remote query execution (dblink)

Joe Conway

contrib/dblink/dblink.h

@@ -0,0 +1,70 @@
+/*
+ * dblink.h
+ *
+ * Functions returning results from a remote database
+ *
+ * Copyright (c) Joseph Conway <joe.conway@mail.com>, 2001;
+ * 
+ * Permission to use, copy, modify, and distribute this software and its
+ * documentation for any purpose, without fee, and without a written agreement
+ * is hereby granted, provided that the above copyright notice and this
+ * paragraph and the following two paragraphs appear in all copies.
+ * 
+ * IN NO EVENT SHALL THE AUTHOR OR DISTRIBUTORS BE LIABLE TO ANY PARTY FOR
+ * DIRECT, INDIRECT, SPECIAL, INCIDENTAL, OR CONSEQUENTIAL DAMAGES, INCLUDING
+ * LOST PROFITS, ARISING OUT OF THE USE OF THIS SOFTWARE AND ITS
+ * DOCUMENTATION, EVEN IF THE AUTHOR OR DISTRIBUTORS HAVE BEEN ADVISED OF THE
+ * POSSIBILITY OF SUCH DAMAGE.
+ * 
+ * THE AUTHOR AND DISTRIBUTORS SPECIFICALLY DISCLAIMS ANY WARRANTIES,
+ * INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY
+ * AND FITNESS FOR A PARTICULAR PURPOSE.  THE SOFTWARE PROVIDED HEREUNDER IS
+ * ON AN "AS IS" BASIS, AND THE AUTHOR AND DISTRIBUTORS HAS NO OBLIGATIONS TO
+ * PROVIDE MAINTENANCE, SUPPORT, UPDATES, ENHANCEMENTS, OR MODIFICATIONS.
+ *
+ */
+
+#ifndef DBLINK_H
+#define DBLINK_H
+
+#include <string.h>
+#include "postgres.h"
+#include "libpq-fe.h"
+#include "libpq-int.h"
+#include "fmgr.h"
+#include "access/tupdesc.h"
+#include "executor/executor.h"
+#include "nodes/nodes.h"
+#include "nodes/execnodes.h"
+#include "utils/builtins.h"
+
+/*
+ * This struct holds the results of the remote query.
+ * Use fn_extra to hold a pointer to it across calls
+ */
+typedef struct
+{
+	/*
+	 * last tuple number accessed
+	 */
+	int			tup_num;
+
+	/*
+	 * the actual query results
+	 */
+	PGresult	*res;
+
+} dblink_results;
+
+/*
+ * External declarations
+ */
+extern Datum dblink(PG_FUNCTION_ARGS);
+extern Datum dblink_tok(PG_FUNCTION_ARGS);
+
+/*
+ * Internal declarations
+ */
+dblink_results *init_dblink_results(MemoryContext fn_mcxt);
+
+#endif	 /* DBLINK_H */