/// <summary>
/// Optimizes the filter; but does not try to combine nested filter (etc.)
/// </summary>
QueryNode OptimizeFilter(Filter filter)
{
QueryNode target = Visit(filter.Target);
List <LambdaExpression> newConditions = new List <LambdaExpression>();
OptimizeQueryExpressionVisitor optimizer = new OptimizeQueryExpressionVisitor();
foreach (LambdaExpression expr in filter.Conditions)
{
Expression optimizedExpr = optimizer.Visit(expr.Body);
if (optimizedExpr.NodeType == ExpressionType.Constant && optimizedExpr.Type == typeof(bool))
{
bool val = (bool)((ConstantExpression)optimizedExpr).Value;
if (val)
{
continue;
}
}
newConditions.Add(Expression.Lambda(optimizedExpr, expr.Parameters));
}
if (newConditions.Count == 0)
{
return(target);
}
else
{
return(new Filter(target, newConditions.ToArray()));
}
}
public override object Execute(Expression inputExpression)
{
Stopwatch watch = Stopwatch.StartNew();
Expression partiallyEvaluatedExpression = PartialEvaluator.Eval(inputExpression, CanBeEvaluatedStatically);
QueryExecutionOptions options = new QueryExecutionOptions();
Expression expression = new ConvertToQueryAstVisitor(options).Visit(partiallyEvaluatedExpression);
// options have been initialized by ConvertToQueryAstVisitor, start logging:
if (options.HasLoggers)
{
options.WriteLogLine("Input expression: " + inputExpression);
options.WriteLogLine("Partially evaluated expression: " + partiallyEvaluatedExpression);
options.WriteLogLine("Converted to Query AST: " + expression);
}
expression = new OptimizeQueryExpressionVisitor().Visit(expression);
if (options.HasLoggers)
{
options.WriteLogLine("Optimized Query AST: " + expression);
options.WriteLogLine("Query preparation time: " + watch.Elapsed);
}
object result;
// If the whole query was converted, execute it:
QueryNode query = expression as QueryNode;
if (query != null)
{
result = query.Execute(this, options);
}
else
{
// Query not converted completely: we have to use a LINQ-To-Objects / LINQ-To-Profiler mix
expression = new ExecuteAllQueriesVisitor(this, options).Visit(expression);
if (expression.Type.IsValueType)
{
expression = Expression.Convert(expression, typeof(object));
}
var lambdaExpression = Expression.Lambda <Func <object> >(expression);
result = lambdaExpression.Compile()();
}
watch.Stop();
options.WriteLogLine("Total query execution time: " + watch.Elapsed);
return(result);
}
/// <summary>
/// Optimizes the filter; but does not try to combine nested filter (etc.)
/// </summary>
QueryNode OptimizeFilter(Filter filter)
{
QueryNode target = Visit(filter.Target);
List<LambdaExpression> newConditions = new List<LambdaExpression>();
OptimizeQueryExpressionVisitor optimizer = new OptimizeQueryExpressionVisitor();
foreach (LambdaExpression expr in filter.Conditions) {
Expression optimizedExpr = optimizer.Visit(expr.Body);
if (optimizedExpr.NodeType == ExpressionType.Constant && optimizedExpr.Type == typeof(bool)) {
bool val = (bool)((ConstantExpression)optimizedExpr).Value;
if (val)
continue;
}
newConditions.Add(Expression.Lambda(optimizedExpr, expr.Parameters));
}
if (newConditions.Count == 0)
return target;
else
return new Filter(target, newConditions.ToArray());
}
public override object Execute(Expression inputExpression)
{
Stopwatch watch = Stopwatch.StartNew();
Expression partiallyEvaluatedExpression = PartialEvaluator.Eval(inputExpression, CanBeEvaluatedStatically);
QueryExecutionOptions options = new QueryExecutionOptions();
Expression expression = new ConvertToQueryAstVisitor(options).Visit(partiallyEvaluatedExpression);
// options have been initialized by ConvertToQueryAstVisitor, start logging:
if (options.HasLoggers) {
options.WriteLogLine("Input expression: " + inputExpression);
options.WriteLogLine("Partially evaluated expression: " + partiallyEvaluatedExpression);
options.WriteLogLine("Converted to Query AST: " + expression);
}
expression = new OptimizeQueryExpressionVisitor().Visit(expression);
if (options.HasLoggers) {
options.WriteLogLine("Optimized Query AST: " + expression);
options.WriteLogLine("Query preparation time: " + watch.Elapsed);
}
object result;
// If the whole query was converted, execute it:
QueryNode query = expression as QueryNode;
if (query != null) {
result = query.Execute(this, options);
} else {
// Query not converted completely: we have to use a LINQ-To-Objects / LINQ-To-Profiler mix
expression = new ExecuteAllQueriesVisitor(this, options).Visit(expression);
if (expression.Type.IsValueType) {
expression = Expression.Convert(expression, typeof(object));
}
var lambdaExpression = Expression.Lambda<Func<object>>(expression);
result = lambdaExpression.Compile()();
}
watch.Stop();
options.WriteLogLine("Total query execution time: " + watch.Elapsed);
return result;
}
