/// <summary>
/// Removes duplicate properties in the current object record.
/// </summary>
/// <remarks>
/// This method assumes that we are buffering and that the current buffered node is a StartObject.
/// It then goes, buffers the entire object record (and all its children) and removes duplicate properties (using the WCF DS Server algorithm).
/// It will remove duplicate properties on any objects in the subtree of the top-level object as well (behaves recursively).
/// The method also checks for in-stream errors and throws if it finds one.
/// </remarks>
private void RemoveDuplicateProperties()
{
Debug.Assert(this.removeDuplicateProperties, "The RemoveDuplicateProperties method should only be called if the removal of duplicate properties is turned on.");
Debug.Assert(this.currentBufferedNode.NodeType == JsonNodeType.StartObject, "this.currentBufferedNode.NodeType == JsonNodeType.StartObject");
Debug.Assert(this.parsingInStreamError, "this.parsingInStreamError");
this.AssertBuffering();
// Read ahead the entire object and create a map of properties.
// This will buffer the object record we are on and all its children (the entire subtree).
// We store a stack, which holds an item for each object record we find.
// Each item on this stack is a dictionary
// - key is the name of the property of a property in the object record
// - value is a List<PropertyDeduplicationRecord>, in this list we store a new record
// every time we find a property of a given name for the objet record.
// This stores pointer to the property node and pointer to the node after the property value.
Stack <ObjectRecordPropertyDeduplicationRecord> objectRecordStack = new Stack <ObjectRecordPropertyDeduplicationRecord>();
do
{
if (this.currentBufferedNode.NodeType == JsonNodeType.StartObject)
{
// New object record - add the node to our stack
objectRecordStack.Push(new ObjectRecordPropertyDeduplicationRecord());
// See if it's an in-stream error
BufferedNode startObjectPosition = this.currentBufferedNode;
this.TryReadErrorAndThrow();
this.currentBufferedNode = startObjectPosition;
}
else if (this.currentBufferedNode.NodeType == JsonNodeType.EndObject)
{
// End of object record
// Pop the node from our stack
ObjectRecordPropertyDeduplicationRecord currentObjectRecord = objectRecordStack.Pop();
// If there is a current property, mark its last value node.
if (currentObjectRecord.CurrentPropertyRecord != null)
{
currentObjectRecord.CurrentPropertyRecord.LastPropertyValueNode = this.currentBufferedNode.Previous;
}
// Now walk the list of properties for the object record and deduplicate them
foreach (List <PropertyDeduplicationRecord> propertyDeduplicationRecords in currentObjectRecord.Values)
{
// If there's just one property of this name - there's nothing to do.
if (propertyDeduplicationRecords.Count <= 1)
{
continue;
}
// Walk all the properties and each time remove the property we find from its current place and move it
// inplace of the first property. Note that since the property names are the same we can replace the property node itself
// without losing any information.
// Once we walk the entire list the outcome will be that we will have just one property of a given name,
// it will be in the position of the first property, but it will be the last property value.
// We could completely remove the property occurences which are not first or last, but it's easier to move them
// to the first one by one as it keeps the algorithm simple (and the performence difference is small enough).
PropertyDeduplicationRecord firstProperty = propertyDeduplicationRecords[0];
for (int propertyIndex = 1; propertyIndex < propertyDeduplicationRecords.Count; propertyIndex++)
{
PropertyDeduplicationRecord currentProperty = propertyDeduplicationRecords[propertyIndex];
Debug.Assert((string)firstProperty.PropertyNode.Value == (string)currentProperty.PropertyNode.Value, "The property names must be the same.");
// Note that property nodes must be preceded at least by the start object node and followed by the end object node
// so we don't have to check for end of list here.
// Remove the current property from the list
currentProperty.PropertyNode.Previous.Next = currentProperty.LastPropertyValueNode.Next;
currentProperty.LastPropertyValueNode.Next.Previous = currentProperty.PropertyNode.Previous;
// Now replace the first property with the current property
firstProperty.PropertyNode.Previous.Next = currentProperty.PropertyNode;
currentProperty.PropertyNode.Previous = firstProperty.PropertyNode.Previous;
firstProperty.LastPropertyValueNode.Next.Previous = currentProperty.LastPropertyValueNode;
currentProperty.LastPropertyValueNode.Next = firstProperty.LastPropertyValueNode.Next;
firstProperty = currentProperty;
}
}
if (objectRecordStack.Count == 0)
{
break;
}
}
else if (this.currentBufferedNode.NodeType == JsonNodeType.Property)
{
ObjectRecordPropertyDeduplicationRecord currentObjectRecord = objectRecordStack.Peek();
// If there is a previous property record, mark its last value node.
if (currentObjectRecord.CurrentPropertyRecord != null)
{
currentObjectRecord.CurrentPropertyRecord.LastPropertyValueNode = this.currentBufferedNode.Previous;
}
// Create a new property record for this property node and add it to the object record.
currentObjectRecord.CurrentPropertyRecord = new PropertyDeduplicationRecord(this.currentBufferedNode);
string propertyName = (string)this.currentBufferedNode.Value;
List <PropertyDeduplicationRecord> propertyDeduplicationRecords;
if (!currentObjectRecord.TryGetValue(propertyName, out propertyDeduplicationRecords))
{
propertyDeduplicationRecords = new List <PropertyDeduplicationRecord>();
currentObjectRecord.Add(propertyName, propertyDeduplicationRecords);
}
propertyDeduplicationRecords.Add(currentObjectRecord.CurrentPropertyRecord);
}
}while (this.ReadInternal());
}
private void RemoveDuplicateProperties()
{
Stack <ObjectRecordPropertyDeduplicationRecord> stack = new Stack <ObjectRecordPropertyDeduplicationRecord>();
do
{
if (this.currentBufferedNode.NodeType == JsonNodeType.StartObject)
{
stack.Push(new ObjectRecordPropertyDeduplicationRecord());
BufferedNode currentBufferedNode = this.currentBufferedNode;
this.TryReadErrorAndThrow();
this.currentBufferedNode = currentBufferedNode;
}
else if (this.currentBufferedNode.NodeType == JsonNodeType.EndObject)
{
ObjectRecordPropertyDeduplicationRecord record = stack.Pop();
if (record.CurrentPropertyRecord != null)
{
record.CurrentPropertyRecord.LastPropertyValueNode = this.currentBufferedNode.Previous;
}
foreach (List <PropertyDeduplicationRecord> list in record.Values)
{
if (list.Count > 1)
{
PropertyDeduplicationRecord record2 = list[0];
for (int i = 1; i < list.Count; i++)
{
PropertyDeduplicationRecord record3 = list[i];
record3.PropertyNode.Previous.Next = record3.LastPropertyValueNode.Next;
record3.LastPropertyValueNode.Next.Previous = record3.PropertyNode.Previous;
record2.PropertyNode.Previous.Next = record3.PropertyNode;
record3.PropertyNode.Previous = record2.PropertyNode.Previous;
record2.LastPropertyValueNode.Next.Previous = record3.LastPropertyValueNode;
record3.LastPropertyValueNode.Next = record2.LastPropertyValueNode.Next;
record2 = record3;
}
}
}
if (stack.Count == 0)
{
return;
}
}
else if (this.currentBufferedNode.NodeType == JsonNodeType.Property)
{
List <PropertyDeduplicationRecord> list2;
ObjectRecordPropertyDeduplicationRecord record4 = stack.Peek();
if (record4.CurrentPropertyRecord != null)
{
record4.CurrentPropertyRecord.LastPropertyValueNode = this.currentBufferedNode.Previous;
}
record4.CurrentPropertyRecord = new PropertyDeduplicationRecord(this.currentBufferedNode);
string key = (string)this.currentBufferedNode.Value;
if (!record4.TryGetValue(key, out list2))
{
list2 = new List <PropertyDeduplicationRecord>();
record4.Add(key, list2);
}
list2.Add(record4.CurrentPropertyRecord);
}
}while (this.ReadInternal());
}
