From 27512e1fe271ec8efdb120a25be1a0333c727751 Mon Sep 17 00:00:00 2001
From: Dan Goodliffe <dan@randomdan.homeip.net>
Date: Thu, 19 Nov 2015 21:32:03 +0000
Subject: Add a database connection pool.

---
 libdbpp/Jamfile.jam                      |  2 ++
 libdbpp/connectionPool.cpp               | 27 +++++++++++++++++++++
 libdbpp/connectionPool.h                 | 32 +++++++++++++++++++++++++
 libdbpp/unittests/Jamfile.jam            | 13 ++++++++++
 libdbpp/unittests/testConnectionPool.cpp | 41 ++++++++++++++++++++++++++++++++
 5 files changed, 115 insertions(+)
 create mode 100644 libdbpp/connectionPool.cpp
 create mode 100644 libdbpp/connectionPool.h
 create mode 100644 libdbpp/unittests/testConnectionPool.cpp

diff --git a/libdbpp/Jamfile.jam b/libdbpp/Jamfile.jam
index 1e09e94..ff52020 100644
--- a/libdbpp/Jamfile.jam
+++ b/libdbpp/Jamfile.jam
@@ -8,6 +8,7 @@ alias glibmm : : : :
 lib boost_date_time : : <name>boost_date_time ;
 lib boost_filesystem ;
 lib boost_system ;
+lib boost_thread ;
 lib adhocutil : : : : <include>/usr/include/adhocutil ;
 lib boost_utf : : <name>boost_unit_test_framework ;
 
@@ -16,6 +17,7 @@ lib dbppcore :
 	<library>glibmm
 	<library>adhocutil
 	<library>boost_system
+	<library>boost_thread
 	<library>boost_filesystem
 	<cflags>-fvisibility=hidden
 	<variant>release:<cflags>-flto
diff --git a/libdbpp/connectionPool.cpp b/libdbpp/connectionPool.cpp
new file mode 100644
index 0000000..24a78fa
--- /dev/null
+++ b/libdbpp/connectionPool.cpp
@@ -0,0 +1,27 @@
+#include "connectionPool.h"
+#include <resourcePool.impl.h>
+
+template class AdHoc::ResourcePool<DB::Connection>;
+template class AdHoc::ResourceHandle<DB::Connection>;
+
+namespace DB {
+	ConnectionPool::ConnectionPool(unsigned int m, unsigned int k, const std::string & t, const std::string & cs) :
+		ResourcePool<Connection>(m, k),
+		factory(ConnectionFactory::get(t)),
+		connectionString(cs)
+	{
+	}
+
+	Connection *
+	ConnectionPool::createResource() const
+	{
+		return factory->create(connectionString);
+	}
+
+	void
+	ConnectionPool::testResource(const Connection * c) const
+	{
+		c->ping();
+	}
+}
+
diff --git a/libdbpp/connectionPool.h b/libdbpp/connectionPool.h
new file mode 100644
index 0000000..c2ce950
--- /dev/null
+++ b/libdbpp/connectionPool.h
@@ -0,0 +1,32 @@
+#ifndef DB_CONNECTIONPOOL_H
+#define DB_CONNECTIONPOOL_H
+
+#include <resourcePool.h>
+#include <visibility.h>
+#include "connection.h"
+
+namespace DB {
+	/// Specialisation of AdHoc::ResourcePool for database connections.
+	class DLL_PUBLIC ConnectionPool : public AdHoc::ResourcePool<Connection> {
+		public:
+			/// Create a new connection pool.
+			/// @param max Maximum number of concurrent database connections.
+			/// @param keep Number of connections to keep open after use.
+			/// @param type Database connection factory name.
+			/// @param connectionString Connection string to pass to the connection factory.
+			ConnectionPool(unsigned int max, unsigned int keep, const std::string & type, const std::string & connectionString);
+
+		protected:
+			/// Create a new connection.
+			Connection * createResource() const override;
+			/// Ping a connection.
+			void testResource(const Connection *) const override;
+
+		private:
+			const ConnectionFactory * factory;
+			const std::string connectionString;
+	};
+}
+
+#endif
+
diff --git a/libdbpp/unittests/Jamfile.jam b/libdbpp/unittests/Jamfile.jam
index b7b2170..aa6c195 100644
--- a/libdbpp/unittests/Jamfile.jam
+++ b/libdbpp/unittests/Jamfile.jam
@@ -23,6 +23,19 @@ run
 	testConnection
 	;
 
+run
+	testConnectionPool.cpp
+	: : :
+	<define>ROOT=\"$(me)\"
+	<define>BOOST_TEST_DYN_LINK
+	<library>..//dbppcore
+	<library>..//adhocutil
+	<library>../../libpqpp//dbpp-postgresql
+	<library>boost_utf
+	:
+	testConnectionPool
+	;
+
 run
 	testUtils.cpp
 	: : :
diff --git a/libdbpp/unittests/testConnectionPool.cpp b/libdbpp/unittests/testConnectionPool.cpp
new file mode 100644
index 0000000..ebe22d1
--- /dev/null
+++ b/libdbpp/unittests/testConnectionPool.cpp
@@ -0,0 +1,41 @@
+#define BOOST_TEST_MODULE DbConnectionPool
+#include <boost/test/unit_test.hpp>
+
+#include <connectionPool.h>
+#include <mock.h>
+#include <buffer.h>
+
+class MockPool : public PQ::Mock, public DB::ConnectionPool {
+	public:
+		MockPool() :
+			PQ::Mock("user=postgres dbname=postgres", "pqmock", { }),
+			DB::ConnectionPool(4, 2, "postgresql", stringbf("user=postgres dbname=%s", databaseName()))
+		{
+		}
+};
+
+BOOST_AUTO_TEST_CASE( basic )
+{
+	MockPool pool;
+	DB::Connection * cr;
+	{
+		auto c = pool.get();
+		c->beginTx();
+		c->commitTx();
+		cr = c.get();
+	}
+	{
+		auto c = pool.get();
+		BOOST_REQUIRE_EQUAL(cr, c.get());
+	}
+	{
+		auto c1 = pool.get();
+		auto c2 = pool.get();
+		auto c3 = pool.get();
+		auto c4 = pool.get();
+		BOOST_REQUIRE_EQUAL(4, pool.inUseCount());
+	}
+	BOOST_REQUIRE_EQUAL(0, pool.inUseCount());
+	BOOST_REQUIRE_EQUAL(2, pool.availableCount());
+}
+
-- 
cgit v1.2.3