DataContext.cs :  » Content-Management-Systems-CMS » Kooboo » Everest » Providers » Versioning » DB4O » C# / CSharp Open Source

/*
Kooboo is a content management system based on ASP.NET MVC framework. Copyright 2009 Yardi Technology Limited.

This program is free software: you can redistribute it and/or modify it under the terms of the
GNU General Public License version 3 as published by the Free Software Foundation.

This program 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 General Public License for more details.

You should have received a copy of the GNU General Public License along with this program.
If not, see http://www.kooboo.com/gpl3/.
*/
using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.IO;
using System.Collections;
using Db4objects.Db4o;
using Db4objects.Db4o.Query;
using Db4objects.Db4o.Config;
using Everest.Library.Versioning;
namespace Everest.Providers.Versioning.DB4O{
    public class DataContext : IDisposable
    {
        IObjectContainer versionDb;

        private string dbDirectory;
        public DataContext(string dbDirectory)
        {
            this.dbDirectory = dbDirectory;

            IConfiguration objConfig = Db4oFactory.NewConfiguration();
            objConfig.ObjectClass(typeof(VersionItem)).ObjectField("<UUID>k__BackingField").Indexed(true);
            objConfig.ObjectClass(typeof(VersionItem)).ObjectField("<Revision>k__BackingField").Indexed(true);
            versionDb = Db4objects.Db4o.Db4oFactory.OpenFile(objConfig, Path.Combine(Path.Combine(AppDomain.CurrentDomain.BaseDirectory, dbDirectory), "Versioning.config"));
        }

        public IEnumerable<IVersionItem> GetVersions(Guid uuid)
        {
            IQuery query = QueryVersions(uuid);
            IObjectSet result = query.Execute();
            IList<IVersionItem> list = new List<IVersionItem>();
            foreach (var item in result)
            {
                list.Add((VersionItem)item);
            }
            return list;
        }

        private IQuery QueryVersions(Guid uuid)
        {
            IQuery query = versionDb.Query();
            query.Constrain(typeof(VersionItem));
            query.Descend("<UUID>k__BackingField").Constrain(uuid).Equal();
            query.Descend("<Revision>k__BackingField").OrderDescending();
            return query;
        }
        public VersionItem GetLastestVersion(Guid uuid)
        {
            IQuery query = QueryVersions(uuid);
            IObjectSet result = query.Execute();
            if (result.Count > 0)
            {
                return (VersionItem)result[0];
            }
            return null;
        }
        public VersionItem GetVersion(Guid uuid, int revision)
        {
            IQuery query = versionDb.Query();
            query.Constrain(typeof(VersionItem));
            query.Descend("<UUID>k__BackingField").Constrain(uuid).Equal();
            query.Descend("<Revision>k__BackingField").Constrain(revision).Equal();
            IObjectSet result = query.Execute();
            if (result.Count > 0)
            {
                return (VersionItem)result[0];
            }
            return null;
        }
        public void SaveVersion(VersionItem versionItem)
        {
            versionDb.Store(versionItem);
            versionDb.Commit();
        }
        public void DeleteVersions(Guid uuid)
        {
            IQuery query = QueryVersions(uuid);
            IObjectSet result = query.Execute();
            foreach (var item in result)
            {
                versionDb.Delete(item);
            }
            versionDb.Commit();
        }

        #region IDisposable Members

        public void Dispose()
        {
            versionDb.Close();
        }

        #endregion
    }
}