public void Parse(IBinaryStream index)
{
index.Position = 16;
int segment_count = Binary.BigEndian(index.ReadInt32());
m_segments = new List <BundleSegment> (segment_count);
long packed_offset = m_data_offset;
long unpacked_offset = 0;
for (int i = 0; i < segment_count; ++i)
{
var segment = new BundleSegment();
segment.Offset = packed_offset;
segment.UnpackedOffset = unpacked_offset;
segment.UnpackedSize = Binary.BigEndian(index.ReadUInt32());
segment.PackedSize = Binary.BigEndian(index.ReadUInt32());
segment.Compression = Binary.BigEndian(index.ReadUInt16());
m_segments.Add(segment);
packed_offset += segment.PackedSize;
unpacked_offset += segment.UnpackedSize;
}
int count = Binary.BigEndian(index.ReadInt32());
m_bundles = new List <BundleEntry> (count);
for (int i = 0; i < count; ++i)
{
var entry = new BundleEntry();
entry.Offset = Binary.BigEndian(index.ReadInt64());
entry.Size = (uint)Binary.BigEndian(index.ReadInt64());
entry.Flags = Binary.BigEndian(index.ReadUInt32());
entry.Name = index.ReadCString(Encoding.UTF8);
m_bundles.Add(entry);
}
}
void ReadCompressedSegment(BundleSegment segment)
{
m_input.Position = segment.Offset;
int method = segment.Compression & 0x3F;
if (1 == method)
{
m_buffer_len = LzmaDecompressBlock(segment.PackedSize, segment.UnpackedSize);
return;
}
if (null == m_packed || segment.PackedSize > m_packed.Length)
{
m_packed = new byte[segment.PackedSize];
}
int packed_size = m_input.Read(m_packed, 0, (int)segment.PackedSize);
var output = PrepareBuffer(segment.UnpackedSize);
if (3 == method || 2 == method)
{
m_buffer_len = Lz4Compressor.DecompressBlock(m_packed, packed_size, output, (int)segment.UnpackedSize);
}
else
{
throw new NotImplementedException("Not supported Unity asset bundle compression.");
}
}
int ReadFromSegment(BundleSegment segment, byte[] buffer, int offset, int count)
{
Debug.Assert(m_position >= segment.UnpackedOffset && m_position <= segment.UnpackedOffset + segment.UnpackedSize);
if (!segment.IsCompressed)
{
int available = (int)Math.Min(count, (segment.UnpackedOffset + segment.UnpackedSize) - m_position);
return(m_input.Read(buffer, offset, available));
}
else
{
if (0 == m_buffer_len)
{
ReadCompressedSegment(segment);
}
int available = Math.Min(count, m_buffer_len - m_buffer_pos);
Buffer.BlockCopy(m_buffer, m_buffer_pos, buffer, offset, available);
m_buffer_pos += available;
return(available);
}
}
void ReadCompressedSegment(BundleSegment segment)
{
m_input.Position = segment.Offset;
if (null == m_packed || segment.PackedSize > m_packed.Length)
{
m_packed = new byte[segment.PackedSize];
}
int packed_size = m_input.Read(m_packed, 0, (int)segment.PackedSize);
if (null == m_buffer || segment.UnpackedSize > m_buffer.Length)
{
m_buffer = new byte[segment.UnpackedSize];
}
if (3 == segment.Compression)
{
m_buffer_len = Lz4Compressor.DecompressBlock(m_packed, packed_size, m_buffer, (int)segment.UnpackedSize);
}
else
{
throw new NotImplementedException("Not supported Unity asset bundle compression.");
}
}