SystemTableContainer.cs

Go to the documentation of this file.

// 
//  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 Deveel.Data.Sql;
using Deveel.Data.Sql.Tables;
using Deveel.Data.Transactions;

namespace Deveel.Data {
    abstract class SystemTableContainer : ITableContainer {
        protected SystemTableContainer(ITransaction transaction, ObjectName tableName) {
            Transaction = transaction;
            TableName = tableName;
        }

        public ITransaction Transaction { get; private set; }

        public ObjectName TableName { get; private set; }

        public int TableCount {
            get { return Transaction.TableExists(TableName) ? Transaction.GetTable(TableName).RowCount : 0; }
        }

        public int FindByName(ObjectName name) {
            if (Transaction.RealTableExists(TableName)) {
                // Search the table.  We assume that the schema and name of the object
                // are in columns 0 and 1 respectively.
                var table = Transaction.GetTable(TableName);
                var rowE = table.GetEnumerator();
                int p = 0;
                while (rowE.MoveNext()) {
                    int rowIndex = rowE.Current.RowId.RowNumber;
                    var obName = table.GetValue(rowIndex, 1);
                    if (obName.Value.ToString().Equals(name.Name)) {
                        var obSchema = table.GetValue(rowIndex, 0);
                        if (obSchema.Value.ToString().Equals(name.ParentName)) {
                            // Match so return this
                            return p;
                        }
                    }
                    ++p;
                }
            }

            return -1;
        }

        public ObjectName GetTableName(int offset) {
            if (Transaction.RealTableExists(TableName)) {
                // Search the table.  We assume that the schema and name of the object
                // are in columns 0 and 1 respectively.
                var table = Transaction.GetTable(TableName);
                var rowE = table.GetEnumerator();
                int p = 0;
                while (rowE.MoveNext()) {
                    int rowIndex = rowE.Current.RowId.RowNumber;
                    if (offset == p) {
                        var obSchema = table.GetValue(rowIndex, 0);
                        var obName = table.GetValue(rowIndex, 1);
                        return new ObjectName(new ObjectName(obSchema.Value.ToString()), obName.Value.ToString());
                    }
                    ++p;
                }
            }

            throw new Exception("Out of bounds.");
        }

        public abstract TableInfo GetTableInfo(int offset);

        public abstract string GetTableType(int offset);

        public bool ContainsTable(ObjectName name) {
            // This set can not contain the table that is backing it, so we always
            // return false for that.  This check stops an annoying recursive
            // situation for table name resolution.
            if (name.Equals(TableName))
                return false;

            return FindByName(name) != -1;
        }

        public abstract ITable GetTable(int offset);
    }
}