Add new sysconf and pg information functions

- Add function pg_page_size()
- Add function pg_segment_size()
- Add function vm_available_pages()
- Add function vm_page_size()
- Add function vm_physical_pages()

Also some README edition and preparing release 1.4.0

ChangeLog

@@ -1,10 +1,22 @@
+15/12/2024 Cédric Villemain <[email protected]>
+  * 1.4.0 - Add GHA test for PostgreSQL 17
+		  - Drop support for PostgreSQL < 12
+		  - Add function pg_page_size()
+          - Add function pg_segment_size()
+          - Add function vm_available_pages()
+          - Add function vm_page_size()
+          - Add function vm_physical_pages()
+
 21/09/2023 Cédric Villemain <[email protected]>
   * 1.3.1 - drop support for upgrading from "unpackaged"
+
 21/09/2023 Cédric Villemain <[email protected]>
   * 1.3   - added support for PostgreSQL 16
           - drop support for PostgreSQL < 9.4
-2019-10-29 Cédric Villemain <[email protected]>
+
+29/10/2019 Cédric Villemain <[email protected]>
   * 1.2.2 - Fix bad errno usage
+
 22/09/2017 Cédric Villemain <[email protected]>
   * 1.2.1 - Fix check on NULL input for drawer function
 

Makefile

@@ -1,11 +1,11 @@
 EXTENSION    = pgfincore
-EXTVERSION   = 1.3.1
+EXTVERSION   = 1.4.0
 
 MODULES      = $(EXTENSION)
 MODULEDIR    = $(EXTENSION)
 DOCS         = README.md
-DATA         = $(EXTENSION)--1.2--1.3.1.sql \
-               $(EXTENSION)--$(EXTVERSION).sql
+DATA         = $(EXTENSION)--1.3.1.sql \
+	       $(EXTENSION)--1.3.1--1.4.0.sql
 
 REGRESS      = $(EXTENSION)
 

README.md

@@ -35,41 +35,34 @@ You can grab the latest code with git:
 
     git clone git://git.postgresql.org/git/pgfincore.git
     or
+    git://github.com/pgfincore/pgfincore.git
+    or
     git://github.com/klando/pgfincore.git
 
-And the project is on pgfoundry : http://pgfoundry.org/projects/pgfincore
-
 ## INSTALL
 
+* PgFincore is packaged for *RPM* at http://yum.postgresql.org/
+* PgFincore is packaged for *debian* at http://pgapt.debian.net/
+* PgFincore extension is available on some large SQL cloud providers.
+
 From source code:
 
     make clean
     make
     su
     make install
 
-For PostgreSQL >= 9.1, log in your database and:
+Log in your database and:
 
     mydb=# CREATE EXTENSION pgfincore;
 
-For other release, create the functions from the sql script (it should be in
-your contrib directory):
-
-    psql mydb -f pgfincore.sql
-
 PgFincore is also shipped with Debian scripts to build your own package:
 
     aptitude install debhelper postgresql-server-dev-all postgresql-server-dev-9.1
-    # or postgresql-server-dev-8.4|postgresql-server-dev-9.0
+    # or postgresql-server-dev-8.4|postgresql-server-dev-9.0
     make deb
     dpkg -i ../postgresql-9.1-pgfincore_1.1.1-1_amd64.deb
 
-PgFincore is packaged for *RPM* at http://yum.postgresql.org/
-PgFincore is packaged for *debian* at http://pgapt.debian.net/
-
-
-
-
 ## EXAMPLES
 
 Here are some examples of usage. If you want more details go to Documentation_
@@ -217,6 +210,26 @@ Executing a snapshot and a restore is very simple:
               OUT group_dirty bigint)
       RETURNS setof record
 
+:: pg_page_size() RETURNS bigint
+
+    Returns PostgreSQL page size in bytes
+
+:: pg_segment_size() RETURNS int
+
+    Returns PostgreSQL segment size in blocks
+
+:: vm_available_pages() RETURNS bigint
+
+    Returns current number of available pages in system memory
+
+:: vm_page_size() RETURNS bigint
+
+    Returns system page size in bytes
+
+:: vm_physical_pages() RETURNS bigint
+
+    Returns total number of physical pages in system memory
+
 ## DOCUMENTATION
 
 ### pgsysconf
@@ -338,14 +351,12 @@ For example:
 
 ## REQUIREMENTS
 
- * PgFincore needs mincore() or fincore() and POSIX_FADVISE
+ * PgFincore requires sysconf(), mincore() or fincore(), and POSIX_FADVISE.
+ * PostgreSQL >= 9.3
 
 ## LIMITATIONS
 
  * PgFincore has a limited mode when POSIX_FADVISE is not provided by the platform.
-
- * PgFincore needs PostgreSQL >= 8.3
-
  * PgFincore does not work on windows.
 
 ## SEE ALSO

expected/pgfincore.out

@@ -92,3 +92,36 @@ select NULL || pgfincore_drawer(databit) from pgfincore('test','main',true);
 
 (1 row)
 
+--
+-- System/PostgreSQL info
+--
+-- assume most systems have same defaults
+-- it's possible to add another output file
+-- to manage larger PostgreSQL and or system page size.
+SELECT pg_page_size();
+ pg_page_size 
+--------------
+         8192
+(1 row)
+
+SELECT pg_segment_size();
+ pg_segment_size 
+-----------------
+          131072
+(1 row)
+
+SELECT vm_page_size();
+ vm_page_size 
+--------------
+         4096
+(1 row)
+
+-- no output for the following:
+SELECT FROM vm_physical_pages();
+--
+(1 row)
+
+SELECT FROM vm_available_pages();
+--
+(1 row)
+

pgfincore--1.3.1--1.4.0.sql

@@ -0,0 +1,24 @@
+CREATE FUNCTION pg_page_size() RETURNS bigint
+AS '$libdir/pgfincore' LANGUAGE C STABLE;
+COMMENT ON FUNCTION pg_page_size()
+IS 'Returns PostgreSQL page size in bytes';
+
+CREATE FUNCTION pg_segment_size() RETURNS bigint
+AS '$libdir/pgfincore' LANGUAGE C STABLE;
+COMMENT ON FUNCTION pg_segment_size()
+IS 'Returns PostgreSQL segment size in blocks';
+
+CREATE FUNCTION vm_available_pages() RETURNS bigint
+AS '$libdir/pgfincore' LANGUAGE C STABLE;
+COMMENT ON FUNCTION vm_available_pages()
+IS 'Returns current number of free pages in system memory';
+
+CREATE FUNCTION vm_page_size() RETURNS bigint
+AS '$libdir/pgfincore' LANGUAGE C STABLE;
+COMMENT ON FUNCTION vm_page_size()
+IS 'Returns system page size in bytes';
+
+CREATE FUNCTION vm_physical_pages(OUT sys_pages_free bigint)
+AS '$libdir/pgfincore' LANGUAGE C STABLE;
+COMMENT ON FUNCTION vm_physical_pages()
+IS 'Returns number of pages in system memory';

pgfincore.c

@@ -1111,3 +1111,74 @@ pgfincore_drawer(PG_FUNCTION_ARGS)
 	*r = '\0';
 	PG_RETURN_CSTRING(result);
 }
+
+/*
+ * sysconf and PostgreSQL informations
+ */
+PG_FUNCTION_INFO_V1(pg_page_size);
+PG_FUNCTION_INFO_V1(pg_segment_size);
+PG_FUNCTION_INFO_V1(vm_available_pages);
+PG_FUNCTION_INFO_V1(vm_page_size);
+PG_FUNCTION_INFO_V1(vm_physical_pages);
+
+/* PostgreSQL Page size */
+static inline size_t pg_PageSize()
+{
+        return BLCKSZ;
+}
+Datum
+pg_page_size(PG_FUNCTION_ARGS)
+{
+	PG_RETURN_UINT64(pg_PageSize());
+}
+
+/* PostgreSQL Segment size */
+static inline uint32 pg_SegmentSize()
+{
+	return RELSEG_SIZE;
+}
+Datum
+pg_segment_size(PG_FUNCTION_ARGS)
+{
+        PG_RETURN_UINT32(pg_SegmentSize());
+}
+
+/* System Page size */
+static size_t     _sc_pagesize    = 0;
+static inline size_t vm_PageSize()
+{
+	if (_sc_pagesize == 0)
+		_sc_pagesize = sysconf(_SC_PAGESIZE);
+	return ((size_t) _sc_pagesize);
+}
+Datum
+vm_page_size(PG_FUNCTION_ARGS)
+{
+	PG_RETURN_UINT64(vm_PageSize());
+}
+
+/* System number of available pages */
+static inline size_t vm_AvPhysPages()
+{
+	return (size_t) sysconf(_SC_AVPHYS_PAGES);
+}
+Datum
+vm_available_pages(PG_FUNCTION_ARGS)
+{
+	PG_RETURN_UINT64(vm_AvPhysPages());
+}
+
+/* System number of physical pages */
+static size_t 		_sc_phys_pages  = 0;
+static inline size_t vm_PhysPages()
+{
+	if (_sc_phys_pages == 0)
+		_sc_phys_pages = sysconf(_SC_PHYS_PAGES);
+	return _sc_phys_pages;
+}
+Datum
+vm_physical_pages(PG_FUNCTION_ARGS)
+{
+	PG_RETURN_UINT64(vm_PhysPages());
+}
+

pgfincore.control

@@ -1,6 +1,6 @@
 # pgfincore extension
 comment = 'examine and manage the os buffer cache'
-default_version = '1.3.1'
+default_version = '1.4.0'
 module_pathname = '$libdir/pgfincore'
 directory = pgfincore
 relocatable = true

sql/pgfincore.sql

@@ -51,3 +51,17 @@ select from pgfadvise_normal('test');
 -- tests drawers
 --
 select NULL || pgfincore_drawer(databit) from pgfincore('test','main',true);
+
+--
+-- System/PostgreSQL info
+--
+-- assume most systems have same defaults
+-- it's possible to add another output file
+-- to manage larger PostgreSQL and or system page size.
+SELECT pg_page_size();
+SELECT pg_segment_size();
+SELECT vm_page_size();
+-- no output for the following:
+SELECT FROM vm_physical_pages();
+SELECT FROM vm_available_pages();
+