Update of contrib stuff from massimo.

contrib/sequence/Makefile

@@ -0,0 +1,62 @@
+#-------------------------------------------------------------------------
+#
+# Makefile--
+#    Makefile for new sequence functions.
+#
+#-------------------------------------------------------------------------
+
+PGDIR = ../..
+SRCDIR = $(PGDIR)/src
+
+include $(SRCDIR)/Makefile.global
+
+INCLUDE_OPT =	-I ./ \
+		-I $(SRCDIR)/ \
+		-I $(SRCDIR)/include \
+		-I $(SRCDIR)/port/$(PORTNAME)
+
+CFLAGS += $(INCLUDE_OPT)
+
+ifeq ($(PORTNAME), linux)
+  ifdef LINUX_ELF
+    ifeq ($(CC), gcc)
+      CFLAGS += -fPIC
+    endif
+  endif
+endif
+
+ifeq ($(PORTNAME), i386_solaris)
+  CFLAGS+= -fPIC
+endif
+
+MODNAME =	set_sequence
+
+MODULE =	$(MODNAME)$(DLSUFFIX)
+
+all:		module sql
+
+module:		$(MODULE)
+
+sql:		$(MODNAME).sql
+
+install:	$(MODULE)
+		cp -p $(MODULE) $(LIBDIR)
+		cd $(LIBDIR); strip $(MODULE)
+
+%.sql: %.sql.in
+		sed "s|MODULE_PATHNAME|$(LIBDIR)/$(MODULE)|" < $< > $@
+
+.SUFFIXES: $(DLSUFFIX)
+
+%$(DLSUFFIX): %.c
+		cc $(CFLAGS) -shared -o $@ $<
+
+depend dep:
+		$(CC) -MM $(INCLUDE_OPT) *.c >depend
+
+clean:
+		rm -f $(MODULE) $(MODNAME).sql
+
+ifeq (depend,$(wildcard depend))
+include depend
+endif

contrib/sequence/set_sequence.c

@@ -0,0 +1,41 @@
+/*
+ * set_sequence.c --
+ *
+ * Set a new sequence value.
+ *
+ * Copyright (c) 1996, Massimo Dal Zotto <dz@cs.unitn.it>
+ */
+
+#include "postgres.h"
+#include "nodes/parsenodes.h"
+#include "commands/sequence.h"
+
+#include "set_sequence.h"
+
+extern int setval(struct varlena *seqin, int4 val);
+
+int
+set_currval(struct varlena *sequence, int4 nextval)
+{
+    return setval(sequence, nextval);
+}
+
+int
+next_id(struct varlena *sequence)
+{
+    return nextval(sequence);
+}
+
+int
+last_id(struct varlena *sequence)
+{
+    return currval(sequence);
+}
+
+int
+set_last_id(struct varlena *sequence, int4 nextval)
+{
+    return setval(sequence, nextval);
+}
+
+/* end of file */

contrib/sequence/set_sequence.h

@@ -0,0 +1,9 @@
+#ifndef SET_SEQUENCE_H
+#define SET_SEQUENCE_H
+
+int set_currval(struct varlena *sequence, int4 nextval);
+int next_id(struct varlena *sequence);
+int last_id(struct varlena *sequence);
+int set_last_id(struct varlena *sequence, int4 nextval);
+
+#endif

contrib/sequence/set_sequence.sql.in

@@ -0,0 +1,33 @@
+-- SQL code to define new sequence utilities
+
+-- Set a new sequence value
+--
+create function set_currval(text, int4) returns int4
+  as 'MODULE_PATHNAME'
+  language 'C';
+
+-- Increment the value of sequence
+--
+--	select next_id('sequence_name');
+--
+create function next_id(text) returns int4
+  as 'MODULE_PATHNAME'
+  language 'C';
+
+-- Return the last value set for a sequence
+--
+--	select last_id('sequence_name');
+--
+create function last_id(text) returns int4
+  as 'MODULE_PATHNAME'
+  language 'C';
+
+-- Set the current value of a sequence
+--
+--	select set_last_id('sequence_name', 1);
+--
+create function set_last_id(text,int4) returns int4
+  as 'MODULE_PATHNAME'
+  language 'C';
+
+-- end of file