/// <summary>
/// Returns true iff the equality and hashcode functions defined in
/// <paramref name="payloadEqualityComparer"/> can be used in columnar codegen.
/// </summary>
/// <typeparam name="T">The type of the payload</typeparam>
/// <param name="payloadEqualityComparer">The equality and hashcode functions
/// represented as lambda expressions.</param>
/// <returns>True iff both the equality and hashcode functions can be used in columnar
/// codegen operators.</returns>
public static bool CanUsePayloadEquality <T>(this IEqualityComparerExpression <T> payloadEqualityComparer)
{
var typeofT = typeof(T);
// If T is a struct, then even if the user defined equality function calls a method on the struct,
// it can still be used because the active events will have a field of type T.
if (typeofT.GetTypeInfo().IsValueType)
{
return(true);
}
// If T is a type for which the columnar representation is just a pseudo-field, e.g., string,
// then the payload is not really represented as a set of its fields, but is an instance of T
if (new ColumnarRepresentation(typeofT).noFields)
{
return(true);
}
// If T is a reference type, then codegen is going to define a structurally-equivalent type T'
// and the active events will have a field of type T'. So if the equality or hash functions ever
// use a value of type T (other than to dereference it for a field/property) then it cannot be used.
var equalsIsBad = ParameterInstanceFinder.FoundInstance(payloadEqualityComparer.GetEqualsExpr());
var hashIsBad = ParameterInstanceFinder.FoundInstance(payloadEqualityComparer.GetGetHashCodeExpr());
return(!equalsIsBad && !hashIsBad);
}
public static IEqualityComparerExpression <T> GetCompoundEqualityComparerExpression <T, T1, T2, T3>(Expression <Func <T, T1> > lambda1, IEqualityComparerExpression <T1> iece1, Expression <Func <T, T2> > lambda2, IEqualityComparerExpression <T2> iece2, Expression <Func <T, T3> > lambda3, IEqualityComparerExpression <T3> iece3)
{
var iece1EqualsExpr = iece1.GetEqualsExpr();
var iece2EqualsExpr = iece2.GetEqualsExpr();
var iece3EqualsExpr = iece3.GetEqualsExpr();
Expression <Func <T, T, bool> > equalsTemplate =
(left, right) =>
CallInliner.Call(iece1EqualsExpr, CallInliner.Call(lambda1, left), CallInliner.Call(lambda1, right)) &&
CallInliner.Call(iece2EqualsExpr, CallInliner.Call(lambda2, left), CallInliner.Call(lambda2, right)) &&
CallInliner.Call(iece3EqualsExpr, CallInliner.Call(lambda3, left), CallInliner.Call(lambda3, right))
;
var iece1HashExpr = iece1.GetGetHashCodeExpr();
var iece2HashExpr = iece2.GetGetHashCodeExpr();
var iece3HashExpr = iece3.GetGetHashCodeExpr();
Expression <Func <T, int> > hashTemplate =
value =>
CallInliner.Call(iece1HashExpr, CallInliner.Call(lambda1, value)) ^
CallInliner.Call(iece2HashExpr, CallInliner.Call(lambda2, value)) ^
CallInliner.Call(iece3HashExpr, CallInliner.Call(lambda3, value))
;
return(new EqualityComparerExpression <T>(equalsTemplate.InlineCalls(), hashTemplate.InlineCalls()));
}
public static Func <FastDictionary2 <TKey, TValue> > CreateFastDictionary2Generator <TKey, TValue>(
this IEqualityComparerExpression <TKey> comparerExp, int capacity, Func <TKey, TKey, bool> equalsFunc, Func <TKey, int> getHashCodeFunc, QueryContainer container)
{
if (EqualityComparerExpression <TKey> .IsSimpleDefault(comparerExp))
{
return(() => new FastDictionary2 <TKey, TValue>());
}
if (container == null)
{
return(() => new FastDictionary2 <TKey, TValue>(capacity, equalsFunc, getHashCodeFunc));
}
var equalsExp = comparerExp.GetEqualsExpr();
var getHashCodeExp = comparerExp.GetGetHashCodeExpr();
var vars = VariableFinder.Find(equalsExp).Select(o => o.GetHashCode()).ToList();
if (!vars.Any())
{
vars.Add(string.Empty.StableHash());
}
var hashvars = VariableFinder.Find(getHashCodeExp).Select(o => o.GetHashCode()).ToList();
if (!hashvars.Any())
{
hashvars.Add(string.Empty.StableHash());
}
var key =
Tuple.Create(
equalsExp.ToString() + getHashCodeExp.ToString() + string.Concat(vars.Aggregate((a, i) => a ^ i)) + string.Concat(hashvars.Aggregate((a, i) => a ^ i)),
typeof(TKey), typeof(TValue));
Type temp;
lock (sentinel)
{
if (!generatorCache.TryGetValue(key, out temp))
{
string typeName = Prefix + classCounter++;
var builderCode = new GeneratedFastDictionary(typeName, "2").TransformText();
var a = Transformer.CompileSourceCode(builderCode, Array.Empty <Assembly>(), out string errorMessages);
temp = a.GetType(typeName + "`2");
temp = temp.MakeGenericType(typeof(TKey), typeof(TValue));
MethodInfo init = temp.GetTypeInfo().GetMethod("Initialize", BindingFlags.Static | BindingFlags.Public);
init.Invoke(null, new object[] { equalsFunc, getHashCodeFunc, capacity });
generatorCache.Add(key, temp);
}
if (!container.TryGetFastDictionary2Type(key, out Type other))
{
container.RegisterFastDictionary2Type(key, temp);
}
}
return(() => (FastDictionary2 <TKey, TValue>)Activator.CreateInstance(temp));
}
public static IEqualityComparerExpression <T> GetEqualityComparerExpression <T, T1>(
Expression <Func <T, T1> > lambda1, IEqualityComparerExpression <T1> iece1)
{
var iece1EqualsExpr = iece1.GetEqualsExpr();
Expression <Func <T, T, bool> > equalsTemplate =
(left, right) =>
CallInliner.Call(iece1EqualsExpr, CallInliner.Call(lambda1, left),
CallInliner.Call(lambda1, right));
var iece1HashExpr = iece1.GetGetHashCodeExpr();
Expression <Func <T, int> > hashTemplate =
value =>
CallInliner.Call(iece1HashExpr, CallInliner.Call(lambda1, value));
return(new EqualityComparerExpression <T>(equalsTemplate.InlineCalls(), hashTemplate.InlineCalls()));
}
public static bool ExpressionEquals <T>(this IEqualityComparerExpression <T> source, IEqualityComparerExpression <T> other)
{
return(EqualityComparer.IsEqual(source.GetEqualsExpr(), other.GetEqualsExpr()) &&
EqualityComparer.IsEqual(source.GetGetHashCodeExpr(), other.GetGetHashCodeExpr()));
}
private static bool IsEqualIECE <T>(IEqualityComparerExpression <T> o1, IEqualityComparerExpression <T> o2)
{
return(EqualityComparer.IsEqual(o1.GetEqualsExpr(), o2.GetEqualsExpr()) &&
EqualityComparer.IsEqual(o1.GetGetHashCodeExpr(), o2.GetGetHashCodeExpr()));
}
