public PackObject GetObjectWithOffset(GitPackReader reader)
{
Debug.WriteLine("Fetching object with offset: {0}".FormatWith(reader.Position));
// Read first byte, it contains the type and 4 bits of object length
byte buffer = reader.ReadByte();
ObjectType type = (ObjectType)((buffer >> 4) & 7);
long size = buffer & 0xf;
// Read byte while 8th bit is 1.
int bitCount = 4;
while ((buffer & 0x80) != 0) // >> 7 == 1);
{
buffer = reader.ReadByte();
size |= ((long)buffer & 0x7f) << bitCount;
bitCount += 7;
}
if (type == ObjectType.RefDelta)
{
return new REFDelta(size, type, reader);
}
else if (type == ObjectType.OFSDelta)
{
return new OFSDelta(size, type, reader);
}
else
{
using (MemoryStream inflated = reader.UncompressToLength(size))
{
return new Undeltified(size, type, inflated.ToArray());
}
}
}
public PackObject GetObjectWithOffset(long offset)
{
using (GitPackReader reader = new GitPackReader(File.OpenRead(Path)))
{
// Set stream position to offset
reader.Position = offset;
// Read first byte, it contains the type and 4 bits of object length
byte buffer = reader.ReadByte();
ObjectType type = (ObjectType)((buffer >> 4) & 7);
long size = buffer & 0xf;
// Read byte while 8th bit is 1.
int bitCount = 4;
do
{
buffer = reader.ReadByte();
size |= ((long)buffer & 0x7f) << bitCount;
bitCount += 7;
} while (buffer >> 7 == 1);
if (type == ObjectType.RefDelta)
{
return(new REFDelta(size, type, reader));
}
else if (type == ObjectType.OFSDelta)
{
return(new OFSDelta(size, type, reader));
}
else
{
using (MemoryStream inflated = reader.UncompressToLength(size))
{
return(new Undeltified(size, type, inflated.ToArray()));
}
}
}
}
public PackObject GetObjectWithOffset(long offset)
{
using (GitPackReader reader = new GitPackReader(File.OpenRead(Path)))
{
// Set stream position to offset
reader.Position = offset;
// Read first byte, it contains the type and 4 bits of object length
byte buffer = reader.ReadByte();
ObjectType type = (ObjectType)((buffer >> 4) & 7);
long size = buffer & 0xf;
// Read byte while 8th bit is 1.
int bitCount = 4;
do
{
buffer = reader.ReadByte();
size |= ((long)buffer & 0x7f) << bitCount;
bitCount += 7;
} while (buffer >> 7 == 1);
if (type == ObjectType.RefDelta)
{
return new REFDelta(size, type, reader);
}
else if (type == ObjectType.OFSDelta)
{
return new OFSDelta(size, type, reader);
}
else
{
using (MemoryStream inflated = reader.UncompressToLength(size))
{
return new Undeltified(size, type, inflated.ToArray());
}
}
}
}
private void VerifyPack()
{
using (GitPackReader reader = new GitPackReader(File.OpenRead(Path)))
{
string header;
int version, numberOfObjects;
header = reader.ReadBytes(4).GetString();
version = reader.ReadBytes(4).Sum(b => b);
numberOfObjects = reader.ReadBytes(4).Sum(b => b);
if (Version != version)
{
throw new PackFileException(String.Format("Bad version number {0}. Was expecting {1}", version, Version), Path);
}
if (HEADER != header)
{
throw new PackFileException("Invalid header for pack-file. Needs to be: 'PACK'", Path);
}
}
}
private void Load()
{
string magicNumber;
int version;
using (GitPackReader reader = new GitPackReader(File.OpenRead(Path)))
{
magicNumber = reader.ReadBytes(4).GetString();
version = reader.ReadBytes(4).Sum(b => b);
if (Version != version)
{
throw new PackFileException(String.Format("Bad version number {0}. Was expecting {1}", version, Version), Path);
}
if (MAGIC_NUMBER != magicNumber)
{
throw new PackFileException("Invalid header for pack-file. Needs to be: 'PACK'", Path);
}
#region Fanout Table
fanout = new int[FANOUT];
shas = new int[FANOUT][];
offsets = new byte[FANOUT][];
crcs = new byte[FANOUT][];
// one big read, faster as 256 small 4 byte read statements ?
byte[] fanoutRaw = new byte[FANOUT * 4];
fanoutRaw = reader.ReadBytes(FANOUT * 4);
for (int idx = 0; idx < FANOUT; idx++)
{
fanout[idx] = System.Net.IPAddress.HostToNetworkOrder(BitConverter.ToInt32(fanoutRaw, idx * 4));
}
#endregion
NumberOfObjects = fanout[FANOUT - 1];
#region SHA's
for (int idx = 0; idx < FANOUT; idx++)
{
int bucketCount;
if (idx == 0)
{
bucketCount = fanout[idx];
}
else
{
bucketCount = fanout[idx] - fanout[idx - 1];
}
if (bucketCount == 0)
{
shas[idx] = new int[] { };
crcs[idx] = new byte[] { };
offsets[idx] = new byte[] { };
continue;
}
int recordLength = bucketCount * 20;
int[] bin = new int[recordLength >> 2];
byte[] rawRecord = reader.ReadBytes(recordLength);
for (int i = 0; i < bin.Length; i++)
{
bin[i] = System.Net.IPAddress.HostToNetworkOrder(BitConverter.ToInt32(rawRecord, i << 2));
}
shas[idx] = bin;
offsets[idx] = new byte[bucketCount * 4];
crcs[idx] = new byte[bucketCount * 4];
}
#endregion
#region CRC32
for (int idx = 0; idx < FANOUT; idx++)
{
crcs[idx] = reader.ReadBytes(crcs[idx].Length);
}
#endregion
#region 32 bit offset table
for (int idx = 0; idx < FANOUT; idx++)
{
offsets[idx] = reader.ReadBytes(offsets[idx].Length);
}
#endregion
// TODO: Support 64 bit tables
string packChecksum = reader.ReadBytes(20).GetString();
string idxChecksum = reader.ReadBytes(20).GetString();
}
}
private void Load()
{
string magicNumber;
int version;
using (GitPackReader reader = new GitPackReader(File.OpenRead(Path)))
{
magicNumber = reader.ReadBytes(4).GetString();
version = reader.ReadBytes(4).Sum(b => b);
if (Version != version)
throw new PackFileException(String.Format("Bad version number {0}. Was expecting {1}", version, Version), Path);
if (MAGIC_NUMBER != magicNumber)
throw new PackFileException("Invalid header for pack-file. Needs to be: 'PACK'", Path);
#region Fanout Table
fanout = new int[FANOUT];
shas = new int[FANOUT][];
offsets = new byte[FANOUT][];
crcs = new byte[FANOUT][];
// one big read, faster as 256 small 4 byte read statements ?
byte[] fanoutRaw = new byte[FANOUT * 4];
fanoutRaw = reader.ReadBytes(FANOUT * 4);
for (int idx = 0; idx < FANOUT; idx++)
fanout[idx] = System.Net.IPAddress.HostToNetworkOrder(BitConverter.ToInt32(fanoutRaw, idx * 4));
#endregion
NumberOfObjects = fanout[FANOUT - 1];
#region SHA's
for (int idx = 0; idx < FANOUT; idx++)
{
int bucketCount;
if (idx == 0)
bucketCount = fanout[idx];
else
bucketCount = fanout[idx] - fanout[idx - 1];
if (bucketCount == 0)
{
shas[idx] = new int[] { };
crcs[idx] = new byte[] { };
offsets[idx] = new byte[] { };
continue;
}
int recordLength = bucketCount * 20;
int[] bin = new int[recordLength >> 2];
byte[] rawRecord = reader.ReadBytes(recordLength);
for (int i = 0; i < bin.Length; i++)
{
bin[i] = System.Net.IPAddress.HostToNetworkOrder(BitConverter.ToInt32(rawRecord, i << 2));
}
shas[idx] = bin;
offsets[idx] = new byte[bucketCount * 4];
crcs[idx] = new byte[bucketCount * 4];
}
#endregion
#region CRC32
for (int idx = 0; idx < FANOUT; idx++)
crcs[idx] = reader.ReadBytes(crcs[idx].Length);
#endregion
#region 32 bit offset table
for (int idx = 0; idx < FANOUT; idx++)
offsets[idx] = reader.ReadBytes(offsets[idx].Length);
#endregion
// TODO: Support 64 bit tables
string packChecksum = reader.ReadBytes(20).GetString();
string idxChecksum = reader.ReadBytes(20).GetString();
}
}
public override IStorableObject GetObject(string sha)
{
Debug.WriteLine("Fetching object with sha: {0}".FormatWith(sha));
try
{
if (Index != null)
{
long packFileOffset = Index.GetPackFileOffset(new Sha(sha));
using (GitPackReader reader = new GitPackReader(File.OpenRead(PackFilePath)))
{
reader.Position = packFileOffset;
PackObject obj = Pack.GetObjectWithOffset(reader);
if (obj is Undeltified)
{
return ((Undeltified)obj).ToGitObject(Repo, sha);
}
else if (obj is Deltified)
{
List<Deltified> deltas = new List<Deltified>();
deltas.Add((Deltified)obj);
while (obj is Deltified)
{
if (obj is REFDelta)
{
string baseSha = ((REFDelta)obj).BaseSHA;
packFileOffset = Index.GetPackFileOffset(new Sha(baseSha));
}
else
{
packFileOffset -= ((OFSDelta)obj).BackwardsBaseOffset;
}
reader.Position = packFileOffset;
obj = Pack.GetObjectWithOffset(reader);
if (obj is Deltified)
deltas.Add((Deltified)obj);
}
for (int i = deltas.Count - 1; i >= 0; i--)
{
((Undeltified)obj).ApplyDelta(deltas[i]);
}
return ((Undeltified)obj).ToGitObject(Repo, sha);
}
else
{
throw new ApplicationException("Don't know what to do with: {0}".FormatWith(obj.GetType().FullName));
}
}
}
else
{
return Pack.GetObject(sha);
}
}
catch (Exception ex)
{
throw new PackFileException("Something went wrong while fetching object: {0}".FormatWith(sha), PackFilePath, ex);
}
}
private void VerifyPack()
{
using (GitPackReader reader = new GitPackReader(File.OpenRead(Path)))
{
string header;
int version, numberOfObjects;
header = reader.ReadBytes(4).GetString();
version = reader.ReadBytes(4).Sum(b => b);
numberOfObjects = reader.ReadBytes(4).Sum(b => b);
if (Version != version)
throw new PackFileException(String.Format("Bad version number {0}. Was expecting {1}", version, Version), Path);
if (HEADER != header)
throw new PackFileException("Invalid header for pack-file. Needs to be: 'PACK'", Path);
}
}
