private T ReadPackFile <T>(FileStream fileStream, string hash, long offset, Func <Stream, long, bool, T> extractFunc)
{
byte[] lengthBuffer = new byte[1];
fileStream.Seek(offset, SeekOrigin.Begin);
fileStream.Read(lengthBuffer, 0, 1);
PackFileObjectType packFileObjectType = (PackFileObjectType)((lengthBuffer[0] & 0b0111_0000) >> 4);
long length = lengthBuffer[0] & 0b0000_1111; //First four bits are dropped as they are they are readNextByte indicator and packFileObjectType
int counter = 0;
while ((lengthBuffer[0] & 0b1000_0000) != 0)
{
counter++;
fileStream.Read(lengthBuffer, 0, 1);
length = length + ((lengthBuffer[0] & 0b0111_1111) << (4 + (7 * (counter - 1)))); //First bit is dropped as it is the readNextByte indicator
}
switch (packFileObjectType)
{
case PackFileObjectType.Commit:
return(extractFunc(fileStream, length, true));
case PackFileObjectType.Blob:
return(extractFunc(fileStream, length, true));
case PackFileObjectType.Tree:
return(extractFunc(fileStream, length, true));
case PackFileObjectType.ObjOfsDelta:
long baseObjOffset = ReadVariableLengthOffset(fileStream);
DeflateStream deflateStream = GetDeflateStreamForZlibData(fileStream);
int deltaDataLength = (int)length;
var sourceDataTuple = ReadVariableLengthSize(deflateStream);
deltaDataLength -= sourceDataTuple.bytesRead;
var targetLengthTuple = ReadVariableLengthSize(deflateStream);
deltaDataLength -= targetLengthTuple.bytesRead;
byte[] deltaBytes = new byte[deltaDataLength];
deflateStream.Read(deltaBytes, 0, deltaDataLength);
byte[] baseBytes = ReadPackFile(fileStream, null, offset - baseObjOffset, ReadBytes);
if (baseBytes.Length != sourceDataTuple.length)
{
throw new Exception("Base object did not match expected length");
}
byte[] undeltifiedData = Undeltify(baseBytes, deltaBytes, targetLengthTuple.length);
return(extractFunc(new MemoryStream(undeltifiedData), undeltifiedData.Length, false));
}
return(default(T));
}
private T ReadPackFile <T>(FileStream fileStream, string hash, long offset, Func <Stream, long, bool, T> extractFunc)
{
byte[] buffer = new byte[1];
fileStream.Seek(offset, (SeekOrigin)SeekOrigin.Begin);
fileStream.Read(buffer, 0, 1);
PackFileObjectType type = (PackFileObjectType)((byte)((buffer[0] & 0x70) >> 4));
long num = buffer[0] & 15;
int num2 = 0;
while ((buffer[0] & 0x80) != 0)
{
num2++;
fileStream.Read(buffer, 0, 1);
num += (buffer[0] & 0x7f) << ((4 + (7 * (num2 - 1))) & 0x1f);
}
switch (type)
{
case PackFileObjectType.Commit:
return(extractFunc(fileStream, num, true));
case PackFileObjectType.Tree:
return(extractFunc(fileStream, num, true));
case PackFileObjectType.Blob:
return(extractFunc(fileStream, num, true));
case PackFileObjectType.ObjOfsDelta:
{
long num3 = this.ReadVariableLengthOffset(fileStream);
DeflateStream deflateStreamForZlibData = this.GetDeflateStreamForZlibData(fileStream);
(int, long)tuple = this.ReadVariableLengthSize((Stream)deflateStreamForZlibData);
(int, long)tuple2 = this.ReadVariableLengthSize((Stream)deflateStreamForZlibData);
int count = (((int)num) - tuple.Item1) - tuple2.Item1;
byte[] buffer2 = new byte[count];
deflateStreamForZlibData.Read(buffer2, 0, count);
byte[] baseBytes = this.ReadPackFile <byte[]>(fileStream, null, offset - num3, new Func <Stream, long, bool, byte[]>(this.ReadBytes));
if (baseBytes.Length != tuple.Item2)
{
throw new Exception(______________________________("QmFzZSBvYmplY3QgZGlkIG5vdCBtYXRjaCBleHBlY3RlZCBsZW5ndGg="));
}
byte[] buffer4 = this.Undeltify(baseBytes, buffer2, tuple2.Item2);
return(extractFunc((Stream) new MemoryStream(buffer4), (long)buffer4.Length, false));
}
}
return(default(T));
}
