SystemSession.cs

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// 
//  Copyright 2010-2015 Deveel
// 
//    Licensed under the Apache License, Version 2.0 (the "License");
//    you may not use this file except in compliance with the License.
//    You may obtain a copy of the License at
// 
//        http://www.apache.org/licenses/LICENSE-2.0
// 
//    Unless required by applicable law or agreed to in writing, software
//    distributed under the License is distributed on an "AS IS" BASIS,
//    WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
//    See the License for the specific language governing permissions and
//    limitations under the License.
//

using System;
using System.Collections.Generic;

using Deveel.Data.Diagnostics;
using Deveel.Data.Security;
using Deveel.Data.Services;
using Deveel.Data.Sql;
using Deveel.Data.Store;
using Deveel.Data.Transactions;

namespace Deveel.Data {
    class SystemSession : ISession {
        public SystemSession(ITransaction transaction) 
            : this(transaction, transaction.CurrentSchema()) {
        }

        public SystemSession(ITransaction transaction, string currentSchema) {
            if (String.IsNullOrEmpty(currentSchema))
                throw new ArgumentNullException("currentSchema");

            CurrentSchema =currentSchema;
            Transaction = transaction;
            Context = transaction.Context.CreateSessionContext();
            StartedOn = DateTimeOffset.UtcNow;
        }

        public void Dispose() {
            Transaction = null;
        }

        public string CurrentSchema { get; private set; }

        public DateTimeOffset StartedOn { get; private set; }

        public DateTimeOffset? LastCommandTime {
            get { return null; }
        }

        public User User {
            get { return User.System; }
        }

        public ITransaction Transaction { get; private set; }

        public ISessionContext Context { get; private set; }

        IEnumerable<KeyValuePair<string, object>> IEventSource.Metadata {
            get { return GetMetaData(); }
        }

        IEventSource IEventSource.ParentSource {
            get { return Transaction; }
        }

        IContext IEventSource.Context {
            get { return Context; }
        }

        private IEnumerable<KeyValuePair<string, object>> GetMetaData() {
            return new Dictionary<string, object> {
                { "session.user", User.SystemName }
            };
        } 

        public ILargeObject CreateLargeObject(long size, bool compressed) {
            throw new NotSupportedException();
        }

        public ILargeObject GetLargeObject(ObjectId objId) {
            throw new NotSupportedException();
        }

        public void Access(IEnumerable<IDbObject> objects, AccessType accessType) {
            // A system session bypasses any lock
        }

        public void Exit(IEnumerable<IDbObject> objects, AccessType accessType) {
            // A system session does not hold any lock
        }

        public void Lock(IEnumerable<IDbObject> objects, AccessType accessType, LockingMode mode) {
            // A system session does not hold any lock
        }

        public void Commit() {
            Transaction.Commit();
        }

        public void Rollback() {
            Transaction.Rollback();
        }

        public IQuery CreateQuery() {
            return new Query(this);
        }
    }
}