modules/platforms/dotnet/Apache.Ignite.Linq/Impl/CacheQueryableBase.cs

/*
 * Licensed to the Apache Software Foundation (ASF) under one or more
 * contributor license agreements.  See the NOTICE file distributed with
 * this work for additional information regarding copyright ownership.
 * The ASF licenses this file to You 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.
 */

namespace Apache.Ignite.Linq.Impl
{
    using System;
    using System.Linq;
    using System.Linq.Expressions;
    using Apache.Ignite.Core;
    using Apache.Ignite.Core.Cache.Configuration;
    using Apache.Ignite.Core.Cache.Query;
    using Remotion.Linq;

    /// <summary>
    /// Base class for cache queryables.
    /// </summary>
    internal abstract class CacheQueryableBase<T> : QueryableBase<T>, ICacheQueryableInternal
    {
        /** <inheritdoc /> */
        protected CacheQueryableBase(IQueryProvider provider) : base(provider)
        {
            // No-op.
        }

        /** <inheritdoc /> */
        protected CacheQueryableBase(IQueryProvider provider, Expression expression) : base(provider, expression)
        {
            // No-op.
        }

        /** <inheritdoc /> */
        public CacheConfiguration CacheConfiguration
        {
            get { return CacheQueryProvider.CacheConfiguration; }
        }

        /** <inheritdoc /> */
        public string CacheName
        {
            get { return CacheConfiguration.Name; }
        }

        /** <inheritdoc /> */
        [Obsolete("Deprecated, null for thin client.")]
        public IIgnite Ignite
        {
            get { return CacheQueryProvider.Ignite; }
        }

        /** <inheritdoc /> */
        public SqlFieldsQuery GetFieldsQuery()
        {
            var data = GetQueryData();
            var executor = CacheQueryProvider.Executor;

            return executor.GetFieldsQuery(data.QueryText, data.Parameters.ToArray());
        }

        /** <inheritdoc /> */
        public QueryModel GetQueryModel()
        {
            return CacheQueryProvider.GenerateQueryModel(Expression);
        }

        /** <inheritdoc /> */
        public string TableName
        {
            get { return CacheQueryProvider.TableName; }
        }

        /** <inheritdoc /> */
        public Func<object[], IQueryCursor<TQ>> CompileQuery<TQ>(LambdaExpression queryExpression)
        {
            var executor = CacheQueryProvider.Executor;

            // Generate two models: from current expression, and from provided lambda.
            // Lambda expression provides a way to identify argument mapping.
            // Comparing two models allows to check whether whole query is within lambda.
            var model = GetQueryModel();
            var lambdaModel = CacheQueryProvider.GenerateQueryModel(queryExpression.Body);

            return executor.CompileQuery<TQ>(model, lambdaModel, queryExpression);
        }

        /** <inheritdoc /> */
        public Func<object[], IQueryCursor<TQ>> CompileQuery<TQ>()
        {
            var executor = CacheQueryProvider.Executor;

            return executor.CompileQuery<TQ>(GetQueryModel());
        }

        /// <summary>
        /// Gets the cache query provider.
        /// </summary>
        private CacheFieldsQueryProvider CacheQueryProvider
        {
            get { return (CacheFieldsQueryProvider)Provider; }
        }

        /// <summary>
        /// Gets the query data.
        /// </summary>
        /// <returns></returns>
        private QueryData GetQueryData()
        {
            var model = GetQueryModel();

            return CacheFieldsQueryExecutor.GetQueryData(model);
        }

        /// <summary>
        /// Returns a <see cref="string" /> that represents this instance.
        /// </summary>
        /// <returns>
        /// A <see cref="string" /> that represents this instance.
        /// </returns>
        public override string ToString()
        {
            return string.Format("CacheQueryable [CacheName={0}, TableName={1}, Query={2}]", 
                CacheName, TableName, GetFieldsQuery());
        }
    }
}