public SelectManyKeyPipeWithStartEdge(SelectManyStreamable <TKey, TSource, TResult> stream, IStreamObserver <TKey, TResult> observer)
: base(stream, observer)
{
this.selector = (Expression <Func <long, TKey, TSource, IEnumerable <TResult> > >)stream.Selector;
this.selectorFunc = this.selector.Compile();
this.pool = MemoryManager.GetMemoryPool <TKey, TResult>(stream.Properties.IsColumnar);
this.pool.Get(out this.batch);
this.batch.Allocate();
this.iter = 0;
this.errorMessages = stream.ErrorMessages;
}
public static Tuple <Type, string> Generate <TKey, TPayload, TResult>(SelectManyStreamable <TKey, TPayload, TResult> stream)
{
Contract.Ensures(Contract.Result <Tuple <Type, string> >() == null || typeof(UnaryPipe <TKey, TPayload, TResult>).GetTypeInfo().IsAssignableFrom(Contract.Result <Tuple <Type, string> >().Item1));
string generatedClassName;
string expandedCode;
string errorMessages = null;
try
{
generatedClassName = $"SelectMany_{sequenceNumber++}";
var keyType = typeof(TKey);
var payloadType = typeof(TPayload);
var resultType = typeof(TResult);
var template = new SelectManyTemplate(generatedClassName, keyType, payloadType, resultType);
var tm = new TypeMapper(keyType, payloadType, resultType);
var gps = tm.GenericTypeVariables(keyType, payloadType, resultType);
template.genericParameters = gps.BracketedCommaSeparatedString();
template.numberOfGenericParameters = gps.Count();
template.TKeyTResultGenericParameters = tm.GenericTypeVariables(keyType, resultType).BracketedCommaSeparatedString();
template.MemoryPoolGenericParameters = $"<{template.TKey}, {template.TResult}>";
if (resultType == typeof(int) || resultType == typeof(long) || resultType == typeof(string))
{
template.MemoryPoolGenericParameters = string.Empty;
}
var payloadParameterIndex = 0;
if (stream.HasKey && stream.HasStartEdge)
{
payloadParameterIndex = 2;
}
else if (stream.HasKey || stream.HasStartEdge)
{
payloadParameterIndex = 1;
}
var selector = stream.Selector;
var payloadParameter = selector.Parameters.ElementAt(payloadParameterIndex);
template.PARAMETER = payloadParameter.Name;
template.resultPayloadRepresentation = new ColumnarRepresentation(resultType);
template.resultFields = template.resultPayloadRepresentation.AllFields;
if (template.numberOfGenericParameters > 0)
{
generatedClassName = generatedClassName + "`" + template.numberOfGenericParameters.ToString(CultureInfo.InvariantCulture);
}
expandedCode = string.Empty;
Expression transformedSelector = selector;
// No substitutions are made for the start edge parameter or key parameter. Both just remain in the
// body of the result selector and are set as local variables in the generated code.
var keyParameterIndex = stream.HasStartEdge ? 1 : 0;
var tuple = OptimizeSelectMany(selector.Body);
if (tuple != null)
{
template.enumerableRepeatSelector = true;
var resultSelector = stream.Selector;
var sourceMessageType = StreamMessageManager.GetStreamMessageType <TKey, TPayload>();
var pseudoLambdaParameters = new ParameterExpression[stream.HasKey ? 2 : 1];
var pseudoLambdaIndex = 0;
if (stream.HasKey)
{
pseudoLambdaParameters[pseudoLambdaIndex++] = selector.Parameters[keyParameterIndex];
}
pseudoLambdaParameters[pseudoLambdaIndex] = payloadParameter;
var pseudoLambda = Expression.Lambda(tuple.Item1, pseudoLambdaParameters);
var parameterSubstitutions = new List <Tuple <ParameterExpression, SelectParameterInformation> >
{
Tuple.Create(payloadParameter, new SelectParameterInformation()
{
BatchName = "batch", BatchType = sourceMessageType, IndexVariableName = "i", parameterRepresentation = new ColumnarRepresentation(payloadType)
})
};
var projectionResult = SelectTransformer.Transform(pseudoLambda, parameterSubstitutions, template.resultPayloadRepresentation, true, stream.HasStartEdge);
template.computedFields = projectionResult.ComputedFields;
template.useEnumerator = false;
var loopCounter = tuple.Item2;
var newParameters = new ParameterExpression[stream.HasKey ? 2 : 1];
newParameters[0] = payloadParameter;
if (stream.HasKey)
{
newParameters[1] = selector.Parameters[keyParameterIndex];
}
var loopCounterLambda = Expression.Lambda(loopCounter, payloadParameter);
var transformedLoopCounter = Extensions.TransformFunction <TKey, TPayload>(loopCounterLambda, 0);
template.loopCounter = transformedLoopCounter.Body.ExpressionToCSharp();
// REVIEW: Alternative: use Inline to replace occurrences of the key parameter
// with "batch.key.col[i]".
if (stream.HasKey)
{
template.keyParameterName = selector.Parameters[keyParameterIndex].Name;
}
}
else
{
transformedSelector = Extensions.TransformFunction <TKey, TPayload>(stream.Selector, payloadParameterIndex).Body;
if (transformedSelector == null)
{
template.useEnumerator = true;
template.transformedSelectorAsSource = stream.Selector.ExpressionToCSharp();
}
else
{
var tuple2 = OptimizeSelectMany(transformedSelector);
if (tuple2 != null)
{
template.useEnumerator = false;
template.loopCounter = tuple2.Item2.ExpressionToCSharp();
template.transformedSelectorAsSource = tuple2.Item1.ExpressionToCSharp();
}
else
{
template.useEnumerator = true;
template.transformedSelectorAsSource = transformedSelector.ExpressionToCSharp();
}
}
}
template.StartEdgeParameterName = stream.HasStartEdge ? selector.Parameters.ElementAt(0).Name : null;
template.hasKey = stream.HasKey;
expandedCode = template.TransformText();
var assemblyReferences = Transformer.AssemblyReferencesNeededFor(typeof(TKey), typeof(TPayload), typeof(TResult));
assemblyReferences.Add(typeof(IStreamable <,>).GetTypeInfo().Assembly);
assemblyReferences.Add(Transformer.GeneratedStreamMessageAssembly <TKey, TPayload>());
assemblyReferences.Add(Transformer.GeneratedStreamMessageAssembly <TKey, TResult>());
assemblyReferences.Add(Transformer.GeneratedMemoryPoolAssembly <TKey, TResult>());
assemblyReferences.AddRange(Transformer.AssemblyReferencesNeededFor(stream.Selector));
var a = Transformer.CompileSourceCode(expandedCode, assemblyReferences, out errorMessages);
var t = a.GetType(generatedClassName);
t = t.InstantiateAsNecessary(typeof(TKey), typeof(TPayload), typeof(TResult));
return(Tuple.Create(t, errorMessages));
}
catch
{
if (Config.CodegenOptions.DontFallBackToRowBasedExecution)
{
throw new InvalidOperationException("Code Generation failed when it wasn't supposed to!");
}
return(Tuple.Create((Type)null, errorMessages));
}
}
