public void Dispose()
{
HasEndOfStream = true;
if (_container != null)
{
_container.DisposePacketReader(this);
}
_container = null;
_current = null;
if (_first != null)
{
var node = _first;
_first = null;
while (node.Next != null)
{
var tmp = node.Next;
node.Next = null;
node = tmp;
node.Prev = null;
}
}
_last = null;
}
public DataPacket FindPacket(long granulePos, Func <DataPacket, DataPacket, int> packetGranuleCountCallback)
{
// This will find which packet contains the granule position being requested. It is basically a linear search.
// Please note, the spec actually calls for a bisection search, but the result here should be the same.
// don't look for any position before 0!
if (granulePos < 0)
{
throw new ArgumentOutOfRangeException(nameof(granulePos));
}
OggPacket foundPacket = null;
// determine which direction to search from...
var packet = _current ?? _first;
if (granulePos > packet.PageGranulePosition)
{
// forward search
// find the first packet in the page the requested granule is on
while (granulePos > packet.PageGranulePosition)
{
if ((packet.Next == null || packet.IsContinued) && !HasEndOfStream)
{
_container.GatherNextPage(StreamSerial);
if (HasEndOfStream)
{
packet = null;
break;
}
}
packet = packet.Next;
}
foundPacket = FindPacketInPage(packet, granulePos, packetGranuleCountCallback);
}
else
{
// reverse search (or we're looking at the same page)
while (packet.Prev != null && (granulePos <= packet.Prev.PageGranulePosition || packet.Prev.PageGranulePosition == -1))
{
packet = packet.Prev;
}
foundPacket = FindPacketInPage(packet, granulePos, packetGranuleCountCallback);
}
return(foundPacket);
}
public static void Return(OggPacket packet)
{
if (packet == null)
{
return;
}
lock (_mutex)
{
if (_pool.Count < MaxPackets)
{
_pool.Push(packet);
}
}
}
private OggPacket GetLastPacketInPage(OggPacket packet)
{
if (packet != null)
{
int pageSeqNumber = packet.PageSequenceNumber;
while (packet.Next != null && packet.Next.PageSequenceNumber == pageSeqNumber)
{
packet = packet.Next;
}
if (packet != null && packet.IsContinued)
{
// move to the *actual* last packet of the page...
// If .Prev is null, something is wrong and we can't seek anyway
packet = packet.Prev;
}
}
return(packet);
}
internal void AddPacket(OggPacket packet)
{
lock (_packetLock)
{
// if we've already found the end of the stream, don't accept any more packets
if (HasEndOfStream)
{
return;
}
// if the packet is a resync, it cannot be a continuation...
if (packet.IsResync)
{
packet.IsContinuation = false;
if (_last != null)
{
_last.IsContinued = false;
}
}
if (packet.IsContinuation)
{
// if we get here, the stream is invalid if there isn't a previous packet
if (_last == null)
{
throw new InvalidDataException();
}
// if the last packet isn't continued, something is wrong
if (!_last.IsContinued)
{
throw new InvalidDataException();
}
_last.MergeWith(packet);
_last.IsContinued = packet.IsContinued;
}
else
{
if (!(packet is OggPacket p))
{
throw new ArgumentException("Wrong packet datatype.");
}
if (_first == null)
{
// this is the first packet to add, so just set first & last to point at it
_first = p;
_last = p;
}
else
{
// swap the new packet in to the last position (remember, we're doubly-linked)
_last = (p.Prev = _last).Next = p;
}
}
if (packet.IsEndOfStream)
{
SetEndOfStream();
}
}
}
private OggPacket FindPacketInPage(
OggPacket pagePacket,
long targetGranulePos,
Func <DataPacket, DataPacket, int> packetGranuleCountCallback)
{
OggPacket lastPacketInPage = GetLastPacketInPage(pagePacket);
if (lastPacketInPage == null)
{
return(null);
}
// return the packet the granule position is in
OggPacket packet = lastPacketInPage;
do
{
if (!packet.GranuleCount.HasValue)
{
// we don't know its length or position...
// if it's the last packet in the page, it gets the page's granule position. Otherwise, calc it.
if (packet == lastPacketInPage)
{
packet.GranulePosition = packet.PageGranulePosition;
}
else
{
packet.GranulePosition = packet.Next.GranulePosition - packet.Next.GranuleCount.Value;
}
// if it's the last packet in the stream, it might be a partial. The spec says the last packet has to be on its own page, so if it is not assume the stream was truncated.
if (packet == _last && HasEndOfStream && packet.Prev.PageSequenceNumber < packet.PageSequenceNumber)
{
packet.GranuleCount = (int)(packet.GranulePosition - packet.Prev.PageGranulePosition);
}
else if (packet.Prev != null)
{
packet.Prev.Reset();
packet.Reset();
packet.GranuleCount = packetGranuleCountCallback(packet, packet.Prev);
}
else
{
// probably the first data packet...
if (packet.GranulePosition > packet.Next.GranulePosition - packet.Next.GranuleCount)
{
throw new InvalidOperationException("First data packet size mismatch.");
}
packet.GranuleCount = (int)packet.GranulePosition;
}
}
// we now know the granule position and count of the packet... is the target within that range?
if (targetGranulePos <= packet.GranulePosition && targetGranulePos > packet.GranulePosition - packet.GranuleCount)
{
// make sure the previous packet has a position too
if (packet.Prev != null && !packet.Prev.GranuleCount.HasValue)
{
packet.Prev.GranulePosition = packet.GranulePosition - packet.GranuleCount.Value;
}
return(packet);
}
packet = packet.Prev;
} while (packet != null && packet.PageSequenceNumber == lastPacketInPage.PageSequenceNumber);
// couldn't find it, but maybe that's because something glitched in the file...
// we're doing this in case there's a dicontinuity in the file... It's not perfect, but it'll work
if (packet != null && packet.PageGranulePosition < targetGranulePos)
{
packet.GranulePosition = packet.PageGranulePosition;
return(packet.Next);
}
return(null);
}