public static async Task <string> FindNode(Stream stream, ReadOnlyMemory <byte> name, CancellationToken cancellationToken)
{
var reader = PipeReader.Create(stream);
byte[] hash = null;
while (true)
{
var result = await reader.ReadAsync(cancellationToken).ConfigureAwait(false);
var buffer = result.Buffer;
var position = TryFindNode(buffer, name.Span, result.IsCompleted, out hash);
if (hash != null)
{
break;
}
if (result.IsCompleted)
{
break;
}
reader.AdvanceTo(position, buffer.End);
}
reader.Complete();
return(CharUtils.ToHex(hash));
}
public int?GetOffset(byte[] objectId)
{
if (this.offsets.TryGetValue(CharUtils.ToHex(objectId), out int cachedOffset))
{
return(cachedOffset);
}
var indexReader = this.indexReader.Value;
var offset = indexReader.GetOffset(objectId);
if (offset != null)
{
this.offsets.TryAdd(CharUtils.ToHex(objectId), offset.Value);
}
return(offset);
}
public static string FindNode(Stream stream, ReadOnlySpan <byte> name)
{
byte[] buffer = ArrayPool <byte> .Shared.Rent((int)stream.Length);
Span <byte> contents = new Span <byte>(buffer, 0, (int)stream.Length);
stream.ReadAll(contents);
string value = null;
while (contents.Length > 0)
{
// Format: [mode] [file/ folder name]\0[SHA - 1 of referencing blob or tree]
// Mode is either 6-bytes long (directory) or 7-bytes long (file).
// If the entry is a file, the first byte is '1'
var fileNameEnds = contents.IndexOf((byte)0);
bool isFile = contents[0] == (byte)'1';
var modeLength = isFile ? 7 : 6;
var currentName = contents.Slice(modeLength, fileNameEnds - modeLength);
if (currentName.SequenceEqual(name))
{
value = CharUtils.ToHex(contents.Slice(fileNameEnds + 1, 20));
break;
}
else
{
contents = contents.Slice(fileNameEnds + 1 + 20);
}
}
ArrayPool <byte> .Shared.Return(buffer);
return(value);
}
public static Stream GetObject(GitPack pack, Stream stream, int offset, string objectType, GitPackObjectType packObjectType)
{
if (pack == null)
{
throw new ArgumentNullException(nameof(pack));
}
if (stream == null)
{
throw new ArgumentNullException(nameof(stream));
}
// Read the signature
stream.Seek(0, SeekOrigin.Begin);
Span <byte> buffer = stackalloc byte[4];
stream.ReadAll(buffer);
Debug.Assert(buffer.SequenceEqual(Signature));
stream.ReadAll(buffer);
var versionNumber = BinaryPrimitives.ReadInt32BigEndian(buffer);
Debug.Assert(versionNumber == 2);
stream.ReadAll(buffer);
var numberOfObjects = BinaryPrimitives.ReadInt32BigEndian(buffer);
stream.Seek(offset, SeekOrigin.Begin);
var(type, decompressedSize) = ReadObjectHeader(stream);
if (type == GitPackObjectType.OBJ_OFS_DELTA)
{
var baseObjectRelativeOffset = ReadVariableLengthInteger(stream);
var baseObjectOffset = (int)(offset - baseObjectRelativeOffset);
var deltaStream = GitObjectStream.Create(stream, decompressedSize);
int baseObjectlength = ReadMbsInt(deltaStream);
int targetLength = ReadMbsInt(deltaStream);
var baseObjectStream = pack.GetObject(baseObjectOffset, objectType);
return(new GitPackDeltafiedStream(baseObjectStream, deltaStream, targetLength));
}
else if (type == GitPackObjectType.OBJ_REF_DELTA)
{
Span <byte> baseObjectId = stackalloc byte[20];
stream.ReadAll(baseObjectId);
Stream baseObject = pack.Repository.GetObjectBySha(CharUtils.ToHex(baseObjectId), objectType);
throw new NotImplementedException();
}
// Tips for handling deltas: https://github.com/choffmeister/gitnet/blob/4d907623d5ce2d79a8875aee82e718c12a8aad0b/src/GitNet/GitPack.cs
if (type != packObjectType)
{
throw new GitException();
}
return(GitObjectStream.Create(stream, decompressedSize));
}