Resolve issue#1: add ptrack_get_change_stat().

Also bump extversion to 2.2

Author: ololobus

.gitignore

@@ -1,6 +1,4 @@
 .deps
 *.so
 *.o
-ptrack--2.0.sql
 Dockerfile
-

Makefile

@@ -2,13 +2,11 @@
 
 MODULE_big = ptrack
 OBJS = ptrack.o datapagemap.o engine.o $(WIN32RES)
-EXTENSION = ptrack
-EXTVERSION = 2.1
-DATA = ptrack.sql ptrack--2.0--2.1.sql
-DATA_built = $(EXTENSION)--$(EXTVERSION).sql
 PGFILEDESC = "ptrack - block-level incremental backup engine"
 
-EXTRA_CLEAN = $(EXTENSION)--$(EXTVERSION).sql
+EXTENSION = ptrack
+EXTVERSION = 2.2
+DATA = ptrack--2.1.sql ptrack--2.0--2.1.sql ptrack--2.1--2.2.sql
 
 TAP_TESTS = 1
 
@@ -22,13 +20,3 @@ top_builddir = ../..
 include $(top_builddir)/src/Makefile.global
 include $(top_srcdir)/contrib/contrib-global.mk
 endif
-
-$(EXTENSION)--$(EXTVERSION).sql: ptrack.sql
-	cat $^ > $@
-
-# temp-install: EXTRA_INSTALL=contrib/ptrack
-
-# check-tap: temp-install
-# 	$(prove_check)
-
-# check: check-tap

ptrack--2.1--2.2.sql

@@ -0,0 +1,29 @@
+/* ptrack/ptrack--2.1--2.2.sql */
+
+-- Complain if script is sourced in psql, rather than via ALTER EXTENSION
+\echo Use "ALTER EXTENSION ptrack UPDATE;" to load this file.\ quit
+
+CREATE FUNCTION ptrack_get_change_stat(start_lsn pg_lsn)
+	RETURNS TABLE (
+		files bigint,
+		pages bigint,
+		"size, MB" numeric
+	) AS
+$func$
+DECLARE
+block_size bigint;
+BEGIN
+	block_size := (SELECT setting FROM pg_settings WHERE name = 'block_size');
+
+	RETURN QUERY
+	SELECT changed_files,
+		   changed_pages,
+		   block_size*changed_pages/(1024.0*1024)
+	FROM
+		(SELECT count(path) AS changed_files,
+				sum(
+					length(replace(right((pagemap)::text, -1)::varbit::text, '0', ''))
+				) AS changed_pages
+		 FROM ptrack_get_pagemapset(start_lsn)) s;
+END
+$func$ LANGUAGE plpgsql;

ptrack.sql ptrack--2.1.sql

@@ -1,3 +1,5 @@
+/* ptrack/ptrack--2.1.sql */
+
 -- Complain if script is sourced in psql, rather than via CREATE EXTENSION
 \echo Use "CREATE EXTENSION ptrack" to load this file. \quit
 

ptrack.control

@@ -1,5 +1,5 @@
 # ptrack extension
 comment = 'block-level incremental backup engine'
-default_version = '2.1'
+default_version = '2.2'
 module_pathname = '$libdir/ptrack'
 relocatable = true

ptrack.h

@@ -22,7 +22,7 @@
 #include "utils/relcache.h"
 
 /* Ptrack version as a string */
-#define PTRACK_VERSION "2.1"
+#define PTRACK_VERSION "2.2"
 /* Ptrack version as a number */
 #define PTRACK_VERSION_NUM 220
 

t/001_basic.pl

@@ -10,7 +10,7 @@
 use TestLib;
 use Test::More;
 
-plan tests => 23;
+plan tests => 24;
 
 my $node;
 my $res;
@@ -115,6 +115,10 @@
 	qr/$rel_oid/,
 	'ptrack pagemapset should contain new relation oid');
 
+# Check change stats
+$res_stdout = $node->safe_psql("postgres", "SELECT pages FROM ptrack_get_change_stat('$flush_lsn')");
+is($res_stdout > 0, 1, 'should be able to get aggregated stats of changes');
+
 # We should be able to change ptrack map size (but loose all changes)
 $node->append_conf(
 	'postgresql.conf', q{