internal static IAggregate <TInput, TState, TResult> TransformOutput <TInput, TState, TAggregateResult, TResult>(
this IAggregate <TInput, TState, TAggregateResult> aggregate,
Expression <Func <TAggregateResult, TResult> > transform)
{
Contract.Requires(aggregate != null);
Contract.Requires(transform != null);
return(GeneratedAggregate.Create(
initialState: aggregate.InitialState(),
accumulate: aggregate.Accumulate(),
deaccumulate: aggregate.Deaccumulate(),
difference: aggregate.Difference(),
computeResult: aggregate.ComputeResult().TransformOutput(transform)));
}
public static IAggregate <TInput?, TState, TResult> MakeInputNullableAndSkipNulls <TInput, TState, TResult>(
this IAggregate <TInput, TState, TResult> aggregate) where TInput : struct
{
Contract.Requires(aggregate != null);
Expression <Func <TState, long, TInput?, TState> > newAccumulate = (oldState, timestamp, input) =>
input.HasValue ? CallInliner.Call(aggregate.Accumulate(), oldState, timestamp, input.Value) : oldState;
Expression <Func <TState, long, TInput?, TState> > newDeaccumulate = (oldState, timestamp, input) =>
input.HasValue ? CallInliner.Call(aggregate.Deaccumulate(), oldState, timestamp, input.Value) : oldState;
return(GeneratedAggregate.Create(
initialState: aggregate.InitialState(),
accumulate: newAccumulate.InlineCalls(),
deaccumulate: newDeaccumulate.InlineCalls(),
difference: aggregate.Difference(),
computeResult: aggregate.ComputeResult()));
}
public static IAggregate <TInput, NullOutputWrapper <TState>, TResult> OutputDefaultWhenEmpty <TInput, TState, TResult>(
this IAggregate <TInput, TState, TResult> aggregate)
{
Contract.Requires(aggregate != null);
Expression <Func <NullOutputWrapper <TState> > > newInitialState =
() => new NullOutputWrapper <TState>
{
Count = 0,
State = CallInliner.Call(aggregate.InitialState())
};
Expression <Func <NullOutputWrapper <TState>, long, TInput, NullOutputWrapper <TState> > > newAccumulate =
(oldState, timestamp, input) => new NullOutputWrapper <TState>
{
Count = oldState.Count + 1,
State = CallInliner.Call(aggregate.Accumulate(), oldState.State, timestamp, input)
};
Expression <Func <NullOutputWrapper <TState>, long, TInput, NullOutputWrapper <TState> > > newDeaccumulate =
(oldState, timestamp, input) => new NullOutputWrapper <TState>
{
Count = oldState.Count - 1,
State = CallInliner.Call(aggregate.Deaccumulate(), oldState.State, timestamp, input)
};
Expression <Func <NullOutputWrapper <TState>, NullOutputWrapper <TState>, NullOutputWrapper <TState> > > newDifference =
(leftState, rightState) => new NullOutputWrapper <TState>
{
Count = leftState.Count - rightState.Count,
State = CallInliner.Call(aggregate.Difference(), leftState.State, rightState.State)
};
Expression <Func <NullOutputWrapper <TState>, TResult> > newComputeResult =
state => state.Count == 0 ? default : CallInliner.Call(aggregate.ComputeResult(), state.State);
return(GeneratedAggregate.Create(
initialState: newInitialState.InlineCalls(),
accumulate: newAccumulate.InlineCalls(),
deaccumulate: newDeaccumulate.InlineCalls(),
difference: newDifference.InlineCalls(),
computeResult: newComputeResult.InlineCalls()));
}
public static IAggregate <TInput, TState, TResult> SkipNulls <TInput, TState, TResult>(
this IAggregate <TInput, TState, TResult> aggregate)
{
Contract.Requires(aggregate != null);
var inputType = typeof(TInput).GetTypeInfo();
return(inputType.IsClass
? GeneratedAggregate.Create(
initialState: aggregate.InitialState(),
accumulate: AddSkipNullClassLogic(aggregate.Accumulate()),
deaccumulate: AddSkipNullClassLogic(aggregate.Deaccumulate()),
difference: aggregate.Difference(),
computeResult: aggregate.ComputeResult())
: inputType.IsGenericType && inputType.GetGenericTypeDefinition() == typeof(Nullable <>)
? GeneratedAggregate.Create(
initialState: aggregate.InitialState(),
accumulate: AddSkipNullValueLogic(aggregate.Accumulate()),
deaccumulate: AddSkipNullValueLogic(aggregate.Deaccumulate()),
difference: aggregate.Difference(),
computeResult: aggregate.ComputeResult())
: aggregate);
}
public static IAggregate <TInput, TState, TResult> ApplyFilter <TInput, TState, TResult>(
this IAggregate <TInput, TState, TResult> aggregate,
Expression <Func <TInput, bool> > filter)
{
Contract.Requires(aggregate != null);
if (filter == null || filter.Body.ExpressionEquals(Expression.Constant(true)))
{
return(aggregate);
}
Expression <Func <TState, long, TInput, TState> > newAccumulate = (oldState, timestamp, input) =>
CallInliner.Call(filter, input) ? CallInliner.Call(aggregate.Accumulate(), oldState, timestamp, input) : oldState;
Expression <Func <TState, long, TInput, TState> > newDeaccumulate = (oldState, timestamp, input) =>
CallInliner.Call(filter, input) ? CallInliner.Call(aggregate.Deaccumulate(), oldState, timestamp, input) : oldState;
return(GeneratedAggregate.Create(
initialState: aggregate.InitialState(),
accumulate: newAccumulate.InlineCalls(),
deaccumulate: newDeaccumulate.InlineCalls(),
difference: aggregate.Difference(),
computeResult: aggregate.ComputeResult()));
}
