public static void Main()
{
var test = "Test";
Expression <Func <Cat, string> > expression = cat => cat.SayMew(test);
var list = new List <string>();
var stopwatch = Stopwatch.StartNew();
for (int i = 0; i < 10000; i++)
{
var body = expression.Body as MethodCallExpression;
var argument = body.Arguments[0];
// () => (object)test;
var converted = Expression.Convert(argument, typeof(object));
var lambda = Expression.Lambda <Func <object> >(converted);
var func = lambda.Compile();
list.Add(func() as string);
}
Console.WriteLine($"{stopwatch.Elapsed} - Extracting with normal expression and convert");
Console.WriteLine(list.Count);
list = new List <string>();
stopwatch = Stopwatch.StartNew();
for (int i = 0; i < 10000; i++)
{
var body = expression.Body as MethodCallExpression;
var argument = body.Arguments[0];
// () => (object)test;
var converted = Expression.Convert(argument, typeof(object));
var lambda = Expression.Lambda <Func <object> >(converted);
var func = lambda.CompileFast();
list.Add(func() as string);
}
Console.WriteLine($"{stopwatch.Elapsed} - Extracting with fast compiled expression and convert");
Console.WriteLine(list.Count);
list = new List <string>();
stopwatch = Stopwatch.StartNew();
for (int i = 0; i < 10000; i++)
{
var body = expression.Body as MethodCallExpression;
var argument = body.Arguments[0];
var argumentMember = argument as MemberExpression;
var closureClass = argumentMember.Expression as ConstantExpression;
var closureClassValue = closureClass.Value;
var fieldInfo = argumentMember.Member as FieldInfo;
var value = fieldInfo.GetValue(closureClassValue);
list.Add(value as string);
}
Console.WriteLine($"{stopwatch.Elapsed} - Extracting with reflection");
Console.WriteLine(list.Count);
list = new List <string>();
var bodyCold = expression.Body as MethodCallExpression;
var argumentCold = bodyCold.Arguments[0];
var argumentMemberCold = argumentCold as MemberExpression;
var closureClassCold = argumentMemberCold.Expression as ConstantExpression;
var closureClassValueCold = closureClassCold.Value;
MemberHelper.GetMembers(closureClassValueCold.GetType());
stopwatch = Stopwatch.StartNew();
for (int i = 0; i < 10000; i++)
{
var body = expression.Body as MethodCallExpression;
var argument = body.Arguments[0];
var argumentMember = argument as MemberExpression;
var closureClass = argumentMember.Expression as ConstantExpression;
var closureClassValue = closureClass.Value;
var members = MemberHelper.GetMembers(closureClassValue.GetType());
var value = members[0].Getter(closureClassValue);
list.Add(value as string);
}
Console.WriteLine($"{stopwatch.Elapsed} - Extracting with reflection and compiled delegates");
Console.WriteLine(list.Count);
list = new List <string>();
stopwatch = Stopwatch.StartNew();
for (int i = 0; i < 10000; i++)
{
var slowExpression = new SlowExpression();
var value = slowExpression.BuildSlowExpression();
list.Add(value);
}
Console.WriteLine($"{stopwatch.Elapsed} - Building with slow expression");
Console.WriteLine(list.Count);
list = new List <string>();
stopwatch = Stopwatch.StartNew();
for (int i = 0; i < 10000; i++)
{
var slowExpression = new SlowExpressionWithFastCompile();
var value = slowExpression.BuildSlowExpression();
list.Add(value);
}
Console.WriteLine($"{stopwatch.Elapsed} - Building with slow expression and fast compile");
Console.WriteLine(list.Count);
list = new List <string>();
stopwatch = Stopwatch.StartNew();
for (int i = 0; i < 10000; i++)
{
var slowExpression = new FastExpression();
var value = slowExpression.BuildFastExpression();
list.Add(value);
}
Console.WriteLine($"{stopwatch.Elapsed} - Building with fast expression");
Console.WriteLine(list.Count);
}
