/// <summary>
/// Prepares operation for every descendant index of target array.
/// </summary>
/// <param name="operation">The operation.</param>
/// <returns>Array where the input arrays is merged into.</returns>
private void mergeArrays(MergeOperation operation)
{
AssociativeArray targetArray = Structure.GetArray(operation.TargetIndex);
ArrayDescriptor targetDescriptor = Structure.GetDescriptor(targetArray);
ContainerOperations collectIndexes = new ContainerOperations(this, targetDescriptor.Builder(), operation.TargetIndex, targetDescriptor.UnknownIndex);
foreach (var operationData in operation.Indexes)
{
MemoryIndex index = operationData.Item1;
Snapshot snapshot = operationData.Item2;
AssociativeArray arrayValue;
if (snapshot.Structure.TryGetArray(index, out arrayValue))
{
ArrayDescriptor descriptor = snapshot.Structure.GetDescriptor(arrayValue);
collectIndexes.AddContainer(descriptor, snapshot);
}
else
{
collectIndexes.SetUndefined();
}
}
collectIndexes.MergeContainers();
}
/// <summary>
/// Creates merge operations for all indexes in the target collection. Source indexes for the operation are
/// retreived from the source collections. When there is missing index in some collection the operation set
/// to undefined.
///
/// This method is for both phases of analysis.
/// </summary>
public void MergeContainers()
{
// Process all names which has unassociated index and creates one
foreach (string indexName in undefinedIndexes)
{
targetContainer.Indexes[indexName] = targetIndex.CreateIndex(indexName);
}
foreach (var index in targetContainer.Indexes)
{
MergeOperation operation = new MergeOperation(index.Value);
worker.addOperation(operation);
if (isUndefined)
{
operation.SetUndefined();
}
foreach (var source in sources)
{
ReadonlyIndexContainer container = source.Item1;
Snapshot snapshot = source.Item2;
MemoryIndex containerIndex;
if (container.Indexes.TryGetValue(index.Key, out containerIndex))
{
operation.Add(containerIndex, snapshot);
}
else
{
operation.Add(container.UnknownIndex, snapshot);
}
}
}
}
/// <summary>
/// Processes single merge operation - prepares all valid values and alias informations from the source indexes.
/// When the source indexes contains some array values prepares operation for every descendant index and merge the
/// array into one which will be stored in the target memory entry.
/// </summary>
/// <param name="operation">The operation.</param>
private void processMergeOperation(MergeOperation operation)
{
HashSet <Value> values = new HashSet <Value>();
foreach (var operationData in operation.Indexes)
{
MemoryIndex index = operationData.Item1;
Snapshot snapshot = operationData.Item2;
MemoryEntry entry = snapshot.Infos.GetMemoryEntry(index);
HashSetTools.AddAll(values, entry.PossibleValues);
}
if (Structure.HasArray(operation.TargetIndex))
{
mergeArrays(operation);
}
if (operation.IsUndefined)
{
values.Add(targetSnapshot.UndefinedValue);
}
Structure.SetMemoryEntry(operation.TargetIndex, new MemoryEntry(values));
}
private MergeOperation getOperation()
{
MergeOperation operation = operationStack.First.Value;
operationStack.RemoveFirst();
return(operation);
}
private void processMerge()
{
while (operationStack.Count > 0)
{
MergeOperation operation = getOperation();
processMergeOperation(operation);
}
}
/// <summary>
/// Initializes a new instance of the <see cref="ContainerOperations"/> class.
/// </summary>
/// <param name="worker">The worker.</param>
/// <param name="targetContainer">The target container.</param>
/// <param name="targetIndex">Index of the target.</param>
/// <param name="unknownIndex">Index of the unknown.</param>
public ContainerOperations(
IMergeWorker worker,
IWriteableIndexContainer targetContainer,
MemoryIndex targetIndex,
MemoryIndex unknownIndex)
{
this.targetContainer = targetContainer;
this.worker = worker;
this.targetIndex = targetIndex;
unknownOperation = new MergeOperation(unknownIndex);
worker.addOperation(unknownOperation);
}
/// <summary>
/// Prepares operation for every descendant index and merge the array into one which will be
/// stored in the target memory entry.
/// </summary>
/// <param name="operation">The operation.</param>
/// <returns>Array where the input arrays is merged into.</returns>
private Value mergeArrays(MergeOperation operation)
{
ArrayDescriptorBuilder builder = new ArrayDescriptorBuilder();
builder.SetParentVariable(operation.TargetIndex);
builder.SetUnknownField(operation.TargetIndex.CreateUnknownIndex());
ContainerOperations collectVariables = new ContainerOperations(this, builder, operation.TargetIndex, builder.UnknownIndex);
// Collecting possible indexes of merged array
AssociativeArray targetArray = null;
foreach (var operationData in operation.Indexes)
{
MemoryIndex index = operationData.Item1;
Snapshot snapshot = operationData.Item2;
AssociativeArray arrayValue;
if (snapshot.Structure.TryGetArray(index, out arrayValue))
{
// Target array value will be the firs one
if (targetArray == null)
{
if (index.Equals(operation.TargetIndex))
{
targetArray = arrayValue;
}
}
ArrayDescriptor descriptor = snapshot.Structure.GetDescriptor(arrayValue);
collectVariables.CollectIndexes(snapshot, index, descriptor);
}
else
{
collectVariables.SetUndefined();
}
}
if (targetArray == null)
{
targetArray = targetSnapshot.CreateArray();
}
builder.SetArrayValue(targetArray);
collectVariables.MergeContainers();
Structure.SetArray(operation.TargetIndex, targetArray);
Structure.SetDescriptor(targetArray, builder.Build());
return(targetArray);
}
public void MergeIndexes(MemoryIndex targetIndex, MemoryIndex sourceIndex)
{
if (!sourceIndex.IsPrefixOf(targetIndex) && !targetIndex.IsPrefixOf(sourceIndex))
{
MergeOperation operation = new MergeOperation(targetIndex);
operation.Add(targetIndex, targetSnapshot);
operation.Add(sourceIndex, targetSnapshot);
operation.IsRoot = true;
addOperation(operation);
arrayCount = 2;
processMerge();
}
}
/// <summary>
/// Main method of merge algorithm.
///
/// iI first phase prepares new empty data collection. Then collects all root memory locations and
/// prepares their operations. As the final step process all merge operations which traverses the
/// memory tree and merges data from all source indexes.
/// </summary>
internal void Merge()
{
ContainerOperations[] collectVariables = new ContainerOperations[targetSnapshot.CallLevel + 1];
ContainerOperations[] collectControl = new ContainerOperations[targetSnapshot.CallLevel + 1];
MergeOperation returnOperation = new MergeOperation();
for (int x = 0; x <= targetSnapshot.CallLevel; x++)
{
IndexContainer variables = Structure.Variables[x];
collectVariables[x] = new ContainerOperations(this, variables, variables.UnknownIndex, variables.UnknownIndex);
IndexContainer control = Structure.ContolVariables[x];
collectControl[x] = new ContainerOperations(this, control, control.UnknownIndex, control.UnknownIndex);
}
foreach (Snapshot snapshot in sourceSnapshots)
{
for (int sourceLevel = 0, targetLevel = 0; targetLevel <= targetSnapshot.CallLevel; sourceLevel++, targetLevel++)
{
if (sourceLevel == snapshot.CallLevel && snapshot.CallLevel != targetSnapshot.CallLevel)
{
if (isCallMerge)
{
break;
}
else
{
targetLevel = targetSnapshot.CallLevel;
}
}
collectVariables[targetLevel].AddContainer(snapshot.Structure.Variables[sourceLevel], snapshot);
collectControl[targetLevel].AddContainer(snapshot.Structure.ContolVariables[sourceLevel], snapshot);
}
}
mergeObjects();
for (int x = 0; x <= targetSnapshot.CallLevel; x++)
{
collectVariables[x].MergeContainers();
collectControl[x].MergeContainers();
mergeTemporary(x);
}
processMerge();
}
/// <summary>
/// Gets all values which can be in target memory entry. If sources contains some arrays merge this arrays together
/// and traverse their indexes.
/// </summary>
/// <param name="operation">The operation.</param>
/// <param name="visitor">The visitor.</param>
/// <returns>Values for the target memory entry.</returns>
private HashSet <Value> getValues(MergeOperation operation, CollectComposedValuesVisitor visitor)
{
HashSet <Value> values = visitor.Values;
bool noScalarValue = visitor.Values.Count == 0;
if (visitor.Arrays.Count > 0)
{
values.Add(mergeArrays(operation));
}
foreach (ObjectValue value in visitor.Objects)
{
values.Add(value);
}
return(values);
}
/// <summary>
/// Creates merge operations for all temporary indexes in the target structure.
/// </summary>
/// <param name="index">The index.</param>
private void mergeTemporary(int index)
{
foreach (var temp in Structure.Temporary[index])
{
MergeOperation operation = new MergeOperation(temp);
addOperation(operation);
foreach (Snapshot snapshot in sourceSnapshots)
{
if (snapshot.Structure.IsDefined(temp))
{
operation.Add(temp, snapshot);
}
else
{
operation.SetUndefined();
}
}
}
}
/// <summary>
/// Processes single merge operation - prepares all valid values and alias informations from the source indexes.
/// When the source indexes contains some array values prepares operation for every descendant index and merge the
/// array into one which will be stored in the target memory entry.
/// </summary>
/// <param name="operation">The operation.</param>
private void processMergeOperation(MergeOperation operation)
{
CollectComposedValuesVisitor visitor = new CollectComposedValuesVisitor();
ReferenceCollector references = new ReferenceCollector();
// Collect all data from source indexes
foreach (var operationData in operation.Indexes)
{
MemoryIndex index = operationData.Item1;
Snapshot snapshot = operationData.Item2;
MemoryEntry entry = snapshot.Structure.GetMemoryEntry(index);
visitor.VisitMemoryEntry(entry);
MemoryAlias aliases;
if (snapshot.Structure.TryGetAliases(index, out aliases))
{
references.CollectMust(aliases.MustAliasses, targetSnapshot.CallLevel);
references.CollectMay(aliases.MayAliasses, targetSnapshot.CallLevel);
}
else
{
references.InvalidateMust();
}
}
references.SetAliases(operation.TargetIndex, this, !operation.IsUndefined);
//repares the set of values - array values are traversed
HashSet <Value> values = getValues(operation, visitor);
// If some index in operation can be undefined add undefined value into result
if (operation.IsUndefined)
{
values.Add(targetSnapshot.UndefinedValue);
}
Structure.SetMemoryEntry(operation.TargetIndex, new MemoryEntry(values));
Structure.SetObjects(operation.TargetIndex, new ObjectValueContainer(visitor.Objects));
}
private void processMergeOperation(MergeOperation operation)
{
CollectComposedValuesVisitor visitor = new CollectComposedValuesVisitor();
ReferenceCollector references = new ReferenceCollector();
foreach (var item in operation.Indexes)
{
Snapshot snapshot = item.Item2;
MemoryIndex index = item.Item1;
MemoryEntry entry = snapshot.Structure.GetMemoryEntry(index);
visitor.VisitMemoryEntry(entry);
MemoryAlias aliases;
if (snapshot.Structure.TryGetAliases(index, out aliases))
{
references.CollectMust(aliases.MustAliasses, snapshot.CallLevel);
references.CollectMay(aliases.MayAliasses, snapshot.CallLevel);
}
else
{
references.InvalidateMust();
}
}
if (references.HasAliases && !operation.IsRoot)
{
if (!operation.IsUndefined && operation.Indexes.Count == 1 && references.HasMustAliases)
{
if (targetSnapshot == operation.Indexes.First().Item2)
{
references.AddMustAlias(operation.Indexes.First().Item1);
}
}
else
{
HashSet <MemoryIndex> referenceIndexes = new HashSet <MemoryIndex>();
foreach (var item in operation.Indexes)
{
MemoryIndex index = item.Item1;
Snapshot snapshot = item.Item2;
if (index != operation.TargetIndex && targetSnapshot == snapshot)
{
referenceIndexes.Add(index);
}
}
references.CollectMay(referenceIndexes, targetSnapshot.CallLevel);
}
}
references.SetAliases(operation.TargetIndex, targetSnapshot, !operation.IsUndefined);
HashSet <Value> values = getValues(operation.TargetIndex, visitor, operation.IsUndefined);
if (operation.IsUndefined)
{
values.Add(targetSnapshot.UndefinedValue);
}
targetSnapshot.Structure.SetMemoryEntry(operation.TargetIndex, new MemoryEntry(values));
}
/// <summary>
/// Main method of merge algorithm.
///
/// in first phase prepares new empty structure and data collections. Then collects all root memory locations
/// and prepares their operations. As the final step process all merge operations which traverses the memory tree
/// and creates new memory locations in target structure with the data from all source indexes.
/// </summary>
internal void Merge()
{
ContainerOperations[] collectVariables = new ContainerOperations[targetSnapshot.CallLevel + 1];
ContainerOperations[] collectControl = new ContainerOperations[targetSnapshot.CallLevel + 1];
MergeOperation returnOperation = new MergeOperation();
// Prepares empty structure for target snapshot
for (int x = 0; x <= targetSnapshot.CallLevel; x++)
{
IndexContainer variables = new IndexContainer(VariableIndex.CreateUnknown(x));
Structure.Variables[x] = variables;
collectVariables[x] = new ContainerOperations(this, variables, variables.UnknownIndex, variables.UnknownIndex);
IndexContainer control = new IndexContainer(ControlIndex.CreateUnknown(x));
Structure.ContolVariables[x] = control;
collectControl[x] = new ContainerOperations(this, control, control.UnknownIndex, control.UnknownIndex);
Structure.Temporary[x] = new IndexSet <TemporaryIndex>();
Structure.Arrays[x] = new IndexSet <AssociativeArray>();
}
// Collects all objects and root locations from the source objects
foreach (Snapshot snapshot in sourceSnapshots)
{
collectObjects(snapshot);
for (int sourceLevel = 0, targetLevel = 0; targetLevel <= targetSnapshot.CallLevel; sourceLevel++, targetLevel++)
{
// Local levels of snaphot has to be merged together no matter to call level of each snapshot.
if (sourceLevel == snapshot.CallLevel && snapshot.CallLevel != targetSnapshot.CallLevel)
{
if (isCallMerge)
{
// When this is the call merge the local level is forgotten
break;
}
else
{
targetLevel = targetSnapshot.CallLevel;
}
}
// Gets all root locations
collectVariables[targetLevel].CollectIndexes(snapshot, Structure.Variables[targetLevel].UnknownIndex, snapshot.Structure.Variables[sourceLevel]);
collectControl[targetLevel].CollectIndexes(snapshot, Structure.ContolVariables[targetLevel].UnknownIndex, snapshot.Structure.ContolVariables[sourceLevel]);
collectTemporary(snapshot, sourceLevel, targetLevel);
}
mergeDeclarations(Structure.FunctionDecl, snapshot.Structure.FunctionDecl);
mergeDeclarations(Structure.ClassDecl, snapshot.Structure.ClassDecl);
// When is it call merge remember which arrays was forgotten in order to support arrays in returns
if (isCallMerge)
{
foreach (AssociativeArray array in snapshot.Structure.Arrays.Local)
{
Structure.AddCallArray(array, snapshot);
}
}
}
mergeObjects();
// Prepares operations for all root locations
for (int x = 0; x <= targetSnapshot.CallLevel; x++)
{
collectVariables[x].MergeContainers();
collectControl[x].MergeContainers();
mergeTemporary(x);
}
processMerge();
// Build aliases
foreach (var alias in memoryAliases)
{
Structure.SetAlias(alias.Key, alias.Value.Build());
}
}
/// <summary>
/// Adds operation into stack of merge worker.
/// </summary>
/// <param name="operation">The operation.</param>
public void addOperation(MergeOperation operation)
{
operationStack.AddLast(operation);
}
private void addOperation(MergeOperation operation)
{
operationStack.AddLast(operation);
}
private AssociativeArray mergeArrays(
MemoryIndex targetIndex,
HashSet <AssociativeArray> arrays,
bool includeUndefined)
{
AssociativeArray arrayValue;
if (!targetSnapshot.Structure.TryGetArray(targetIndex, out arrayValue))
{
arrayValue = targetSnapshot.CreateArray(targetIndex);
}
ArrayDescriptor newDescriptor = targetSnapshot.Structure.GetDescriptor(arrayValue);
MergeOperation unknownMerge = new MergeOperation(newDescriptor.UnknownIndex);
unknownMerge.SetUndefined();
addOperation(unknownMerge);
HashSet <string> indexNames = new HashSet <string>();
foreach (AssociativeArray array in arrays)
{
foreach (Tuple <Snapshot, ArrayDescriptor> item in getArrayDescriptor(array))
{
Snapshot snapshot = item.Item1;
ArrayDescriptor descriptor = item.Item2;
unknownMerge.Add(descriptor.UnknownIndex, snapshot);
foreach (var index in descriptor.Indexes)
{
indexNames.Add(index.Key);
}
}
}
foreach (string indexName in indexNames)
{
MergeOperation operation = new MergeOperation();
if (includeUndefined)
{
operation.SetUndefined();
}
foreach (var array in arrays)
{
foreach (Tuple <Snapshot, ArrayDescriptor> item in getArrayDescriptor(array))
{
Snapshot snapshot = item.Item1;
ArrayDescriptor descriptor = item.Item2;
MemoryIndex sourceIndex;
if (descriptor.Indexes.TryGetValue(indexName, out sourceIndex))
{
operation.Add(sourceIndex, snapshot);
}
else
{
operation.Add(descriptor.UnknownIndex, snapshot);
}
}
}
MemoryIndex arrayIndex;
if (!newDescriptor.Indexes.TryGetValue(indexName, out arrayIndex))
{
arrayIndex = targetSnapshot.CreateIndex(indexName, arrayValue, true, false);
}
operation.SetTargetIndex(arrayIndex);
addOperation(operation);
}
return(arrayValue);
}
