/// <summary>
/// Creates the alias to this entry and returnes data which can be used to aliasing the target.
/// </summary>
/// <param name="snapshot">The snapshot.</param>
/// <returns>
/// Alias data fro the newly created aliases.
/// </returns>
public AliasData CreateAliasToEntry(Snapshot snapshot)
{
//Collect alias indexes
AssignCollector indexesCollector = new AssignCollector(snapshot);
indexesCollector.ProcessPath(path);
//Memory locations where to get data from
ReadCollector valueCollector = new ReadCollector(snapshot);
valueCollector.ProcessPath(path);
//Get data from locations
ReadWorker worker = new ReadWorker(snapshot);
MemoryEntry value = worker.ReadValue(valueCollector);
//Makes deep copy of data to prevent changes after assign alias
TemporaryIndex temporaryIndex = snapshot.CreateTemporary();
MergeWithinSnapshotWorker mergeWorker = new MergeWithinSnapshotWorker(snapshot);
mergeWorker.MergeMemoryEntry(temporaryIndex, value);
AliasData data = new AliasData(indexesCollector.MustIndexes, indexesCollector.MayIndexes, temporaryIndex);
data.TemporaryIndexToRealease(temporaryIndex);
return(data);
}
/// <summary>
/// Determine that memory represented by current snapshot entry Is already defined.
/// If not, reading memory returns UndefinedValue. But UndefinedValue can be returned
/// even for defined memory entries - this can be used to distinct
/// between null/undefined semantic of PHP.
/// </summary>
/// <param name="context">Context snapshot where operation is proceeded</param>
/// <returns>True whether memory represented by current snapshot entry Is already defined.</returns>
protected override bool isDefined(SnapshotBase context)
{
Snapshot snapshot = ToSnapshot(context);
SnapshotLogger.append(context, "is defined:" + this.ToString());
ReadCollector collector = new ReadCollector(snapshot);
collector.ProcessPath(path);
return(collector.IsDefined);
}
/// <summary>
/// Resolve method on current snapshot entry with given methodName
/// </summary>
/// <param name="context">Context where methods are resolved</param>
/// <param name="methodName">Name of resolved method</param>
/// <returns>
/// Resolved methods
/// </returns>
protected override IEnumerable <FunctionValue> resolveMethod(SnapshotBase context, QualifiedName methodName)
{
Snapshot snapshot = ToSnapshot(context);
SnapshotLogger.append(context, "resolve method - path: " + this.ToString() + " method: " + methodName);
ReadCollector collector = new ReadCollector(snapshot);
collector.ProcessPath(path);
ReadWorker worker = new ReadWorker(snapshot);
MemoryEntry memory = worker.ReadValue(collector);
return(snapshot.resolveMethod(memory, methodName));
}
/// <summary>
/// Read memory represented by current snapshot entry
/// </summary>
/// <param name="context">Context snapshot where operation is proceeded</param>
/// <returns>
/// Memory represented by current snapshot entry
/// </returns>
protected override MemoryEntry readMemory(SnapshotBase context)
{
Snapshot snapshot = ToSnapshot(context);
SnapshotLogger.append(context, "read: " + this.ToString());
ReadCollector collector = new ReadCollector(snapshot);
collector.ProcessPath(path);
ReadWorker worker = new ReadWorker(snapshot);
MemoryEntry entry = worker.ReadValue(collector);
SnapshotLogger.appendToSameLine(" value: " + entry.ToString());
return(entry);
}
/// <summary>
/// Initializes a new instance of the <see cref="FieldLocationVisitor"/> class.
/// </summary>
/// <param name="fieldSegment">The field segment.</param>
/// <param name="collector">The collector.</param>
public FieldLocationVisitor(FieldPathSegment fieldSegment, ReadCollector collector)
: base(collector.snapshot.MemoryAssistant)
{
this.fieldSegment = fieldSegment;
this.collector = collector;
}
/// <summary>
/// Initializes a new instance of the <see cref="IndexLocationVisitor"/> class.
/// </summary>
/// <param name="indexSegment">The index segment.</param>
/// <param name="collector">The collector.</param>
public IndexLocationVisitor(IndexPathSegment indexSegment, ReadCollector collector)
: base(collector.snapshot.MemoryAssistant)
{
this.indexSegment = indexSegment;
this.collector = collector;
}