From fe787aa87b250e8baefb275424b6e2fffa8c38f9 Mon Sep 17 00:00:00 2001
From: =?utf8?q?C=C3=A9dric=20Villemain?= <cedric.villemain.debian@gmail.com>
Date: Thu, 10 Dec 2009 03:20:22 +0100
Subject: [PATCH] add pgsysconf()

---
 ChangeLog        |  1 +
 pgfincore.c      | 36 ++++++++++++++++++++++++++++++++++++
 pgfincore.sql.in |  8 ++++++++
 3 files changed, 45 insertions(+)

diff --git a/ChangeLog b/ChangeLog
index 04f7a86..44095b2 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -9,6 +9,7 @@
 		  - add posix_fadvise_random flag
 		  - rewrite main SRF
 		  - improve output (more informations)
+		  - add pgsysconf()
 
 26/10/2009 Cédric Villemain <cedric.villemain@dalibo.com>
 
diff --git a/pgfincore.c b/pgfincore.c
index d8ad3a6..1b5220a 100644
--- a/pgfincore.c
+++ b/pgfincore.c
@@ -39,6 +39,7 @@ typedef struct
   char *relationpath;		/* the relation path */
 } pgfincore_fctx;
 
+Datum pgsysconf(PG_FUNCTION_ARGS);
 Datum pgfincore(PG_FUNCTION_ARGS);
 static Datum pgmincore_file(char *filename,
 							FunctionCallInfo fcinfo);
@@ -46,6 +47,41 @@ static Datum pgfadvise_file(char *filename,
 							int action,
 							FunctionCallInfo fcinfo);
 
+							/*
+ * pgsysconf
+ */
+PG_FUNCTION_INFO_V1(pgsysconf);
+Datum
+pgsysconf(PG_FUNCTION_ARGS) {
+  HeapTuple	tuple;
+  TupleDesc tupdesc;
+  Datum		values[3];
+  bool		nulls[3];
+
+  // OS things
+  int64 pageSize  = sysconf(_SC_PAGESIZE); /* Page size */
+  int64 pageCache = sysconf(_SC_PHYS_PAGES); /* total page cache */
+  int64 pageFree  = sysconf(_SC_AVPHYS_PAGES); /* free page cache */
+
+  tupdesc = CreateTemplateTupleDesc(3, false);
+  TupleDescInitEntry(tupdesc, (AttrNumber) 1, "block_size",
+									  INT8OID, -1, 0);
+  TupleDescInitEntry(tupdesc, (AttrNumber) 2, "block_cache",
+									  INT8OID, -1, 0);
+  TupleDescInitEntry(tupdesc, (AttrNumber) 3, "block_free",
+									  INT8OID, -1, 0);
+
+  tupdesc = BlessTupleDesc(tupdesc);
+
+  values[0] = Int64GetDatum(pageSize);
+  values[1] = Int64GetDatum(pageCache);
+  values[2] = Int64GetDatum(pageFree);
+
+  tuple = heap_form_tuple(tupdesc, values, nulls);
+
+  PG_RETURN_DATUM( HeapTupleGetDatum(tuple) );
+}
+
 /* fincore -
  */
 PG_FUNCTION_INFO_V1(pgfincore);
diff --git a/pgfincore.sql.in b/pgfincore.sql.in
index 5311359..fd60df2 100644
--- a/pgfincore.sql.in
+++ b/pgfincore.sql.in
@@ -1,5 +1,13 @@
 SET search_path = public;
 
+CREATE OR REPLACE FUNCTION
+pgsysconf(OUT block_size bigint,
+		  OUT block_cache bigint,
+		  OUT block_free bigint)
+RETURNS record
+AS 'MODULE_PATHNAME'
+LANGUAGE C;
+
 CREATE OR REPLACE FUNCTION
 pgfincore(IN regclass,
 		  IN text,
-- 
2.39.5