private void BuildProjector(LambdaExpression projectionLambda, LambdaExpression aggregator, out Delegate projector, out Delegate asyncProjector) { var sqlQueryProviderParam = Expression.Parameter(typeof(SqlQueryProvider)); var formatResultsParam = Expression.Parameter(typeof(SqlQueryFormatResult)); var placeholderValuesParam = Expression.Parameter(typeof(object[])); var elementType = projectionLambda.ReturnType; Expression executor; if (elementType.IsDataAccessObjectType()) { var concreteElementType = this.DataAccessModel.GetConcreteTypeFromDefinitionType(elementType); var constructor = typeof(DataAccessObjectProjector <,>).MakeGenericType(elementType, concreteElementType).GetConstructors(BindingFlags.Public | BindingFlags.Instance).Single(); executor = Expression.New ( constructor, sqlQueryProviderParam, Expression.Constant(this.DataAccessModel), Expression.Constant(this.SqlDatabaseContext), formatResultsParam, placeholderValuesParam, projectionLambda ); } else { if ((aggregator?.Body as MethodCallExpression)?.Method.GetGenericMethodOrRegular() == MethodInfoFastRef.EnumerableExtensionsAlwaysReadFirstMethod) { var constructor = typeof(AlwaysReadFirstObjectProjector <,>).MakeGenericType(projectionLambda.ReturnType, projectionLambda.ReturnType).GetConstructors(BindingFlags.Public | BindingFlags.Instance).Single(); executor = Expression.New ( constructor, sqlQueryProviderParam, Expression.Constant(this.DataAccessModel), Expression.Constant(this.SqlDatabaseContext), formatResultsParam, placeholderValuesParam, projectionLambda ); } else { var projectorType = !DataAccessObjectAwareResultTypeComparerBuilder.NeedsComparer(projectionLambda.ReturnType) ? typeof(ObjectProjector <,>) : typeof(DataAccessObjectContainerProjector <,>); var constructor = projectorType.MakeGenericType(projectionLambda.ReturnType, projectionLambda.ReturnType).GetConstructors(BindingFlags.Public | BindingFlags.Instance).Single(); executor = Expression.New ( constructor, sqlQueryProviderParam, Expression.Constant(this.DataAccessModel), Expression.Constant(this.SqlDatabaseContext), formatResultsParam, placeholderValuesParam, projectionLambda ); } } var asyncExecutor = executor; var cancellationToken = Expression.Parameter(typeof(CancellationToken)); if (aggregator != null) { var originalExecutor = executor; var aggr = aggregator; var newBody = SqlConstantPlaceholderReplacer.Replace(aggr.Body, placeholderValuesParam); executor = SqlExpressionReplacer.Replace(newBody, aggr.Parameters[0], originalExecutor); newBody = ProjectionAsyncRewriter.Rewrite(newBody, cancellationToken); asyncExecutor = SqlExpressionReplacer.Replace(newBody, aggr.Parameters[0], originalExecutor); } projectionLambda = Expression.Lambda(executor, sqlQueryProviderParam, formatResultsParam, placeholderValuesParam); var asyncProjectorLambda = Expression.Lambda(asyncExecutor, sqlQueryProviderParam, formatResultsParam, placeholderValuesParam, cancellationToken); ProjectorCacheInfo cacheInfo; var key = new ProjectorCacheKey(projectionLambda); var oldCache = this.SqlDatabaseContext.projectorCache; if (!oldCache.TryGetValue(key, out cacheInfo)) { cacheInfo.projector = projectionLambda.Compile(); cacheInfo.asyncProjector = asyncProjectorLambda.Compile(); if (this.SqlDatabaseContext.projectorCache.Count >= ProjectorCacheMaxLimit) { ProjectionExpressionCacheLogger.Info(() => $"Projector has been flushed because it overflowed with a size of {ProjectionExpressionCacheMaxLimit}\n\nProjector: {projectionLambda}\n\nAt: {new StackTrace()}"); var newCache = new Dictionary <ProjectorCacheKey, ProjectorCacheInfo>(ProjectorCacheMaxLimit, ProjectorCacheEqualityComparer.Default); foreach (var value in oldCache.Take(oldCache.Count / 3)) { newCache[value.Key] = value.Value; } newCache[key] = cacheInfo; this.SqlDatabaseContext.projectorCache = newCache; } else { var newCache = new Dictionary <ProjectorCacheKey, ProjectorCacheInfo>(oldCache, ProjectorCacheEqualityComparer.Default) { [key] = cacheInfo }; this.SqlDatabaseContext.projectorCache = newCache; } ProjectionCacheLogger.Info(() => $"Cached projector:\n{cacheInfo.projector}"); ProjectionCacheLogger.Debug(() => $"Projector Cache Size: {this.SqlDatabaseContext.projectionExpressionCache.Count}"); } projector = cacheInfo.projector; asyncProjector = cacheInfo.asyncProjector; }
public DataAccessObjectContainerProjector(SqlQueryProvider provider, DataAccessModel dataAccessModel, SqlDatabaseContext sqlDatabaseContext, SqlQueryFormatResult formatResult, object[] placeholderValues, Func <ObjectProjector, IDataReader, int, object[], Func <DataAccessObject, DataAccessObject>, U> objectReader) : base(provider, dataAccessModel, sqlDatabaseContext, formatResult, placeholderValues, objectReader) { outputComparer = DataAccessObjectAwareResultTypeComparerBuilder.CreateComparer <T>(); }