lunchbox::PersistentMap Class Reference

Unified interface to save key-value pairs in a persistent store. More...

#include <persistentMap.h>

Inheritance diagram for lunchbox::PersistentMap:

Collaboration diagram for lunchbox::PersistentMap:

Public Member Functions
LUNCHBOX_API	PersistentMap (const std::string &uri=std::string())
	Construct a new persistent map. More...
LUNCHBOX_API	~PersistentMap ()
	Destruct the persistent map. More...
LUNCHBOX_API bool	insert (const std::string &key, const std::string &value)
	Insert or update a value in the database. More...
LUNCHBOX_API std::string	operator[] (const std::string &key) const
	Retrieve a value for a key. More...

Detailed Description

Unified interface to save key-value pairs in a persistent store.

Example:

/* Copyright (c) 2014 Stefan.Eilemann@epfl.ch
 *
 * This library is free software; you can redistribute it and/or modify it under
 * the terms of the GNU Lesser General Public License version 2.1 as published
 * by the Free Software Foundation.
 *
 * This library is distributed in the hope that it will be useful, but WITHOUT
 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS
 * FOR A PARTICULAR PURPOSE.  See the GNU Lesser General Public License for more
 * details.
 *
 * You should have received a copy of the GNU Lesser General Public License
 * along with this library; if not, write to the Free Software Foundation, Inc.,
 * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
 */

#include <test.h>
#include <lunchbox/persistentMap.h>
#ifdef LUNCHBOX_USE_LEVELDB
#  include <leveldb/db.h>
#endif
#include <stdexcept>

using lunchbox::PersistentMap;

void setup( const std::string& uri )
{
    PersistentMap map( uri );
    TEST( map.insert( "foo", "bar" ));
    TEST( map[ "foo" ] == "bar" );
    TEST( map[ "bar" ].empty( ));
}

void read( const std::string& uri )
{
    PersistentMap map( uri );
    TEST( map[ "foo" ] == "bar" );
    TEST( map[ "bar" ].empty( ));
}

void testGenericFailures()
{
    try
    {
        setup( "foobar://" );
    }
    catch( const std::runtime_error& )
    {
        return;
    }
    TESTINFO( false, "Missing exception" );
}

void testLevelDBFailures()
{
#ifdef LUNCHBOX_USE_LEVELDB
    try
    {
        setup( "leveldb:///doesnotexist/deadbeef/coffee" );
    }
    catch( const leveldb::Status& status )
    {
        return;
    }
    TESTINFO( false, "Missing exception" );
#endif
}

int main( int, char** )
{
    try
    {
#ifdef LUNCHBOX_USE_LEVELDB
        setup( "" );
        setup( "leveldb://" );
        setup( "leveldb://persistentMap2.leveldb" );
        read( "" );
        read( "leveldb://" );
        read( "leveldb://persistentMap2.leveldb" );
#endif
    }
#ifdef LUNCHBOX_USE_LEVELDB
    catch( const leveldb::Status& status )
    {
        TESTINFO( !"exception", status.ToString( ));
    }
#endif
    catch( const std::runtime_error& error )
    {
        TESTINFO( !"exception", error.what( ));
    }

    testGenericFailures();
    testLevelDBFailures();

    return EXIT_SUCCESS;
}

Definition at line 35 of file persistentMap.h.

Constructor & Destructor Documentation

LUNCHBOX_API lunchbox::PersistentMap::PersistentMap

(

const std::string &

uri = std::string()

)

Construct a new persistent map.

Depending on the URI scheme an implementation backend is chosen. If no URI is given, a default one is selected. Available implementations are:

• leveldb://path (if LUNCHBOX_USE_LEVELDB is defined)

Parameters

uri	the storage backend and destination.

Exceptions

std::runtime_error	if no suitable implementation is found.
leveldb::Status	if opening the leveldb database failed.

Version

1.9.2

LUNCHBOX_API lunchbox::PersistentMap::~PersistentMap

(

)

Destruct the persistent map.

Version

1.9.2

Member Function Documentation

LUNCHBOX_API bool lunchbox::PersistentMap::insert	(	const std::string &	key,
		const std::string &	value
	)

Insert or update a value in the database.

Parameters

key	the key to store the value.
value	the value stored at the key.

Returns

true on success, false otherwise

Version

1.9.2

LUNCHBOX_API std::string lunchbox::PersistentMap::operator[]

(

const std::string &

key

)

const

Retrieve a value for a key.

Parameters

key	the key to retreive.

Returns

the value, or an empty string if the key is not available.

Version

1.9.2

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The documentation for this class was generated from the following file:

• persistentMap.h