public Expression ProcessResultOperator(ResultOperatorBase resultOperator, QueryModel queryModel,
IGeneratedQueryCode gc, ICodeContext cc,
CompositionContainer container)
{
if (resultOperator == null)
{
throw new ArgumentNullException("resultOperator");
}
if (cc == null)
{
throw new ArgumentNullException("CodeContext can't be null");
}
// Determine the type of the result operator we are processing and
// anything we need to know about it.
Type sumType;
sumType = cc.LoopVariable.Type;
bool doAverage = false;
if (resultOperator is SumResultOperator)
{
doAverage = false;
}
else
{
doAverage = true;
}
// We only know how to sum basic types
if (!sumType.IsNumberType())
{
throw new InvalidOperationException(string.Format("Do not know how to generate C++ to sum type {0}.", sumType.Name));
}
var accumulator = DeclarableParameter.CreateDeclarableParameterExpression(sumType);
accumulator.SetInitialValue("0");
// Sum and average are a alike in that we are going to add everything we see up.
var add = Expression.Add(accumulator, cc.LoopVariable);
var addResolved = ExpressionToCPP.GetExpression(add, gc, cc, container);
gc.Add(new StatementAggregate(accumulator, addResolved));
// If this is a sum no further work needs to happen.
if (!doAverage)
{
return(accumulator);
}
// If this is a average then we need to add a simple count.
var counter = DeclarableParameter.CreateDeclarableParameterExpression(typeof(int));
counter.SetInitialValue("0");
var incbyone = Expression.Add(counter, Expression.Constant(1));
gc.Add(new StatementAggregate(counter, ExpressionToCPP.GetExpression(incbyone, gc, cc, container)));
// Next, we have to delcare the counter and the accumulator. These are now both temprorary variables.
if (cc.LoopIndexVariable == null)
{
throw new AverageNotAllowedAtTopLevelException("Attempt to use Average at top level, accross events. Not currently implemented.");
}
gc.AddOutsideLoop(counter);
gc.AddOutsideLoop(accumulator);
// It is an error to average a sequence with no elements. So we need to throw a C++ exception. We need to pop up out of the loop in order
// to do this.
// http://msdn.microsoft.com/en-us/library/bb354760.aspx (for specs on Average on this).
var testForSomething = Expression.Equal(counter, Expression.Constant(0));
gc.AddAtResultScope(new StatementThrowIfTrue(ExpressionToCPP.GetExpression(testForSomething, gc, cc, container), "Can't take an average of a null sequence"));
var returnType = DetermineAverageReturnType(sumType);
var faccumulator = Expression.Convert(accumulator, returnType);
var fcount = Expression.Convert(counter, returnType);
var divide = Expression.Divide(faccumulator, fcount);
// We are done with this calculation, so pop up and out.
gc.Pop();
return(divide);
}
/// <summary>
/// Process the First/last. This means adding a pointer (or not if we are looking at a plane type) and
/// then filling it till it is full or filling it till the loop is done. Bomb out if we are asked to at the end!!
/// </summary>
/// <param name="resultOperator"></param>
/// <param name="queryModel"></param>
/// <param name="_codeEnv"></param>
/// <returns></returns>
public Expression ProcessResultOperator(ResultOperatorBase resultOperator, QueryModel queryModel,
IGeneratedQueryCode gc, ICodeContext cc, CompositionContainer container)
{
///
/// First, do data normalization
///
var asFirst = resultOperator as FirstResultOperator;
var asLast = resultOperator as LastResultOperator;
if (asFirst == null && asLast == null)
{
throw new ArgumentNullException("First/Last operator must be either first or last, and not null!");
}
bool isFirst = asFirst != null;
bool bombIfNothing = true;
if (isFirst)
{
bombIfNothing = !asFirst.ReturnDefaultWhenEmpty;
}
else
{
bombIfNothing = !asLast.ReturnDefaultWhenEmpty;
}
//
// Figure out if we need to cache the result:
// - simple variable which has a default value which can be used later on.
// like a double, etc.
// - We actually allow for a default variable.
//
bool cacheResult = cc.LoopVariable.Type.IsNumberType();
cacheResult = cacheResult && !bombIfNothing;
//
// Next, make sure we are looping over something. This had better be an array we are looking at!
//
if (cc.LoopIndexVariable == null)
{
throw new InvalidOperationException(string.Format("Can't apply First operator when we aren't looping over some well formed array '{0}'", cc.LoopVariable.ToString()));
}
var indexExpr = cc.LoopIndexVariable;
//
// We need to hold onto either the first or the last item here, so we create a statement that holds nnto the
// first or the last time. It also has to mark the thing as valid! It will break when it is done.
// While the bool can be used later on to get at the exception we might be throwing, the actual
// result may be used much further on down. To protect against that, we set the array index to be -1,
// and then hope there is a crash later on! :-)
//
// It is possible that this is part of a dual selection. For example, if you are interested in the jet that has the closest track, and the
// loop is constructed over the jets first, and then the tracks. This First will likely be for a track index, but we will be looking up the
// track later. So we need to record both the jet and track index. To get the other indicies, we just look for all loop variables between here and
// the result scope.
//
var valueWasSeen = DeclarableParameter.CreateDeclarableParameterExpression(typeof(bool));
var indexSeen = DeclarableParameter.CreateDeclarableParameterExpression(indexExpr.Type);
if (indexSeen.Type.IsNumberType())
indexSeen.SetInitialValue("-1");
gc.AddAtResultScope(valueWasSeen);
gc.AddAtResultScope(indexSeen);
var rv = new Statements.StatementRecordValue(indexSeen, indexExpr, valueWasSeen, isFirst);
gc.Add(rv);
foreach (var v in gc.GetUsedQuerySourceVariables(rv, indexExpr))
{
var saver = DeclarableParameter.CreateDeclarableParameterExpression(v.Type);
gc.AddAtResultScope(saver);
rv.AddNewSaver(saver, v);
cc.Add(v.RawValue, saver);
}
gc.Pop(true);
if (bombIfNothing)
{
var test = ExpressionToCPP.GetExpression(Expression.Not(valueWasSeen), gc, cc, container);
gc.Add(new Statements.StatementThrowIfTrue(test, string.Format("First/Last predicate executed on a null sequence: {0}", queryModel.ToString())));
}
//
// Finally, we need the new expression. For this we basically just ask for the translated expression. We
// also add a substitution for later on for more complex expressions.
//
var firstlastValue = cc.LoopVariable;
cc.Add(indexExpr.RawValue, indexSeen);
Debug.WriteLine("First/Last: {0} for QM {1}", indexSeen.ToString(), queryModel.ToString());
// Reset the expression we are looking at in the loop.
var newIndexExpr = firstlastValue.ReplaceSubExpression(indexExpr.AsExpression(), indexSeen);
cc.SetLoopVariable(newIndexExpr, indexSeen);
if (cacheResult)
{
//
// Set the default value
//
var actualValue = DeclarableParameter.CreateDeclarableParameterExpression(cc.LoopVariable.Type);
actualValue.SetInitialValue("0");
//
// If everything went well, then we can do the assignment. Otherwise, we leave
// it as above (having the default value).
//
gc.Add(new Statements.StatementFilter(valueWasSeen));
gc.Add(new Statements.StatementAssign(actualValue,
ExpressionToCPP.GetExpression(firstlastValue, gc, cc, container)));
gc.Pop();
return actualValue;
}
else
{
// No need to cache the result - so no need to add extra code.
return newIndexExpr;
}
}
/// <summary>
/// Process the First/last. This means adding a pointer (or not if we are looking at a plane type) and
/// then filling it till it is full or filling it till the loop is done. Bomb out if we are asked to at the end!!
/// </summary>
/// <param name="resultOperator"></param>
/// <param name="queryModel"></param>
/// <param name="_codeEnv"></param>
/// <returns></returns>
public Expression ProcessResultOperator(ResultOperatorBase resultOperator, QueryModel queryModel,
IGeneratedQueryCode gc, ICodeContext cc, CompositionContainer container)
{
///
/// First, do data normalization
///
var asFirst = resultOperator as FirstResultOperator;
var asLast = resultOperator as LastResultOperator;
if (asFirst == null && asLast == null)
{
throw new ArgumentNullException("First/Last operator must be either first or last, and not null!");
}
bool isFirst = asFirst != null;
bool bombIfNothing = true;
if (isFirst)
{
bombIfNothing = !asFirst.ReturnDefaultWhenEmpty;
}
else
{
bombIfNothing = !asLast.ReturnDefaultWhenEmpty;
}
//
// Figure out if we need to cache the result:
// - simple variable which has a default value which can be used later on.
// like a double, etc.
// - We actually allow for a default variable.
//
bool cacheResult = cc.LoopVariable.Type.IsNumberType();
cacheResult = cacheResult && !bombIfNothing;
//
// Next, make sure we are looping over something. This had better be an array we are looking at!
//
if (cc.LoopIndexVariable == null)
{
throw new InvalidOperationException(string.Format("Can't apply First operator when we aren't looping over some well formed array '{0}'", cc.LoopVariable.ToString()));
}
var indexExpr = cc.LoopIndexVariable;
//
// We need to hold onto either the first or the last item here, so we create a statement that holds nnto the
// first or the last time. It also has to mark the thing as valid! It will break when it is done.
// While the bool can be used later on to get at the exception we might be throwing, the actual
// result may be used much further on down. To protect against that, we set the array index to be -1,
// and then hope there is a crash later on! :-)
//
// It is possible that this is part of a dual selection. For example, if you are interested in the jet that has the closest track, and the
// loop is constructed over the jets first, and then the tracks. This First will likely be for a track index, but we will be looking up the
// track later. So we need to record both the jet and track index. To get the other indicies, we just look for all loop variables between here and
// the result scope.
//
var valueWasSeen = DeclarableParameter.CreateDeclarableParameterExpression(typeof(bool));
var indexSeen = DeclarableParameter.CreateDeclarableParameterExpression(indexExpr.Type);
if (indexSeen.Type.IsNumberType())
{
indexSeen.SetInitialValue("-1");
}
gc.AddAtResultScope(valueWasSeen);
gc.AddAtResultScope(indexSeen);
var rv = new Statements.StatementRecordValue(indexSeen, indexExpr, valueWasSeen, isFirst);
gc.Add(rv);
foreach (var v in gc.GetUsedQuerySourceVariables(rv, indexExpr))
{
var saver = DeclarableParameter.CreateDeclarableParameterExpression(v.Type);
gc.AddAtResultScope(saver);
rv.AddNewSaver(saver, v);
cc.Add(v.RawValue, saver);
}
gc.Pop(true);
if (bombIfNothing)
{
var test = ExpressionToCPP.GetExpression(Expression.Not(valueWasSeen), gc, cc, container);
gc.Add(new Statements.StatementThrowIfTrue(test, string.Format("First/Last predicate executed on a null sequence: {0}", queryModel.ToString())));
}
//
// Finally, we need the new expression. For this we basically just ask for the translated expression. We
// also add a substitution for later on for more complex expressions.
//
var firstlastValue = cc.LoopVariable;
cc.Add(indexExpr.RawValue, indexSeen);
Debug.WriteLine("First/Last: {0} for QM {1}", indexSeen.ToString(), queryModel.ToString());
// Reset the expression we are looking at in the loop.
var newIndexExpr = firstlastValue.ReplaceSubExpression(indexExpr.AsExpression(), indexSeen);
cc.SetLoopVariable(newIndexExpr, indexSeen);
if (cacheResult)
{
//
// Set the default value
//
var actualValue = DeclarableParameter.CreateDeclarableParameterExpression(cc.LoopVariable.Type);
actualValue.SetInitialValue("0");
//
// If everything went well, then we can do the assignment. Otherwise, we leave
// it as above (having the default value).
//
gc.Add(new Statements.StatementFilter(valueWasSeen));
gc.Add(new Statements.StatementAssign(actualValue,
ExpressionToCPP.GetExpression(firstlastValue, gc, cc, container)));
gc.Pop();
return(actualValue);
}
else
{
// No need to cache the result - so no need to add extra code.
return(newIndexExpr);
}
}
public Expression ProcessResultOperator(ResultOperatorBase resultOperator, QueryModel queryModel,
IGeneratedQueryCode gc, ICodeContext cc,
CompositionContainer container)
{
if (resultOperator == null)
throw new ArgumentNullException("resultOperator");
if (cc == null)
throw new ArgumentNullException("CodeContext can't be null");
//
// Determine the type of the result operator we are processing and
// anything we need to know about it.
//
Type sumType;
sumType = cc.LoopVariable.Type;
bool doAverage = false;
if (resultOperator is SumResultOperator)
{
doAverage = false;
}
else
{
doAverage = true;
}
//
// We only know how to sum basic types
//
if (!sumType.IsNumberType())
{
throw new InvalidOperationException(string.Format("Do not know how to generate C++ to sum type {0}.", sumType.Name));
}
var accumulator = DeclarableParameter.CreateDeclarableParameterExpression(sumType);
accumulator.SetInitialValue("0");
//
// Now, in the loop we are currently in, we do the "add".
//
var add = Expression.Add(accumulator, cc.LoopVariable);
var addResolved = ExpressionToCPP.GetExpression(add, gc, cc, container);
gc.Add(new StatementAggregate(accumulator, addResolved));
//
// The sum will just be this accumulator - so return it.
//
if (!doAverage)
return accumulator;
//
// If this is a average then we need to add a simple count on. Further, we need to declare
// everything we are going to need for later.
//
var counter = DeclarableParameter.CreateDeclarableParameterExpression(typeof(int));
counter.SetInitialValue("0");
gc.AddOutsideLoop(counter);
gc.AddOutsideLoop(accumulator);
var incbyone = Expression.Add(counter, Expression.Constant(1));
gc.Add(new StatementAggregate(counter, ExpressionToCPP.GetExpression(incbyone, gc, cc, container)));
// It is an error to average a sequence with no elements. So we need to throw a C++ exception. We need to pop up out of the loop in order
// to do this.
// http://msdn.microsoft.com/en-us/library/bb354760.aspx (for specs on Average on this).
var testForSomething = Expression.Equal(counter, Expression.Constant(0));
gc.AddAtResultScope(new StatementThrowIfTrue(ExpressionToCPP.GetExpression(testForSomething, gc, cc, container), "Can't take an average of a null sequence"));
var returnType = DetermineAverageReturnType(sumType);
var faccumulator = Expression.Convert(accumulator, returnType);
var fcount = Expression.Convert(counter, returnType);
var divide = Expression.Divide(faccumulator, fcount);
// We are done with this calculation, so pop up and out.
gc.Pop();
return divide;
}
