private DicomDirectoryRecord ParseDirectoryRecord(uint offset, List <uint> notFoundOffsets)
{
DicomDirectoryRecord record = null;
if (_lookup.TryGetValue(offset, out var dataset))
{
record = new DicomDirectoryRecord(dataset)
{
Offset = offset
};
_lookup.Remove(offset);
record.NextDirectoryRecord =
ParseDirectoryRecord(record.GetSingleValue <uint>(DicomTag.OffsetOfTheNextDirectoryRecord), notFoundOffsets);
record.LowerLevelDirectoryRecord =
ParseDirectoryRecord(record.GetSingleValue <uint>(DicomTag.OffsetOfReferencedLowerLevelDirectoryEntity), notFoundOffsets);
}
else
{
if (offset != 0)
{
notFoundOffsets.Add(offset);
}
}
return(record);
}
private DicomDirectoryRecord ParseDirectoryRecord(DicomDirectoryRecord record, uint offset, uint[] offsets)
{
if (record == null)
{
// Find the best matching existing offset for the given offset
// The given offset should be in offsets and the following entry in that sorted array gives
// us the next used offset. That's the upper bound for the search
var index = Array.BinarySearch(offsets, offset);
if (index < 0)
{
return(null);
}
uint maxOffset;
int maxIndex = offsets.Length - 1;
// Deal with the rare possibility that offsets can contain duplicates
while (true)
{
if (index >= maxIndex)
{
maxOffset = uint.MaxValue;
break;
}
maxOffset = offsets[++index];
if (maxOffset != offset)
{
break;
}
}
offset = _lookup.Keys.FirstOrDefault(key => key >= offset && key < maxOffset);
if (!_lookup.TryGetValue(offset, out var dataset))
{
return(null);
}
record = new DicomDirectoryRecord(dataset)
{
Offset = offset
};
_lookup.Remove(offset);
}
var nextOffset = record.GetSingleValue <uint>(DicomTag.OffsetOfTheNextDirectoryRecord);
if (nextOffset > 0)
{
record.NextDirectoryRecord = ParseDirectoryRecord(record.NextDirectoryRecord, nextOffset, offsets);
}
var lowerLevelOffset = record.GetSingleValue <uint>(DicomTag.OffsetOfReferencedLowerLevelDirectoryEntity);
if (lowerLevelOffset > 0)
{
record.LowerLevelDirectoryRecord = ParseDirectoryRecord(record.LowerLevelDirectoryRecord, lowerLevelOffset, offsets);
}
return(record);
}
private DicomDirectoryRecord ParseDirectoryRecordNotExact(DicomDirectoryRecord root, uint rootOffset, List <uint> offsets)
{
// Collect all used offsets, and sort them (they can contain duplicates)
foreach (var dataset in _lookup.Values)
{
var offset = dataset.GetSingleValue <uint>(DicomTag.OffsetOfTheNextDirectoryRecord);
if (offset > 0)
{
offsets.Add(offset);
}
offset = dataset.GetSingleValue <uint>(DicomTag.OffsetOfReferencedLowerLevelDirectoryEntity);
if (offset > 0)
{
offsets.Add(offset);
}
}
var offsetArray = offsets.ToArray();
Array.Sort(offsetArray);
return(ParseDirectoryRecord(root, rootOffset, offsetArray));
}
