public static byte[] RA_ApplyStream(long pos, long size, Stream origin, Stream delta)
{
uint origin_ofst = (uint)origin.Position;
uint base_delta_ofst = (uint)delta.Position;
uint limit, total = 0;
uint lenSrc = (uint)origin.Length;
uint lenDelta = (uint)delta.Length;
Fossil.StreamReader zDelta = new Fossil.StreamReader(delta);
limit = zDelta.GetInt();
if (zDelta.GetChar() != '\n')
{
throw new Exception("size integer not terminated by \'\\n\'");
}
//Fossil.StreamWriter zOut = new Fossil.StreamWriter();
List <byte> zOut = new List <byte>();
while (zDelta.HaveBytes())
{
uint cnt, ofst, real_ofst, delta_ofst;
cnt = zDelta.GetInt();
switch (zDelta.GetChar())
{
case '@':
real_ofst = zDelta.GetInt();
ofst = real_ofst + origin_ofst;
if (zDelta.HaveBytes() && zDelta.GetChar() != ',')
{
throw new Exception("copy command not terminated by \',\'");
}
total += cnt;
if (total > limit)
{
throw new Exception("copy exceeds output file size");
}
if (ofst + cnt > lenSrc)
{
throw new Exception("copy extends past end of input");
}
if ((pos <= real_ofst && real_ofst < pos + size) || pos <= +cnt && real_ofst < pos + cnt + size)
{
origin.Seek(Math.Max((int)ofst, (int)pos + origin_ofst), SeekOrigin.Begin);
for (int i = Math.Max((int)real_ofst, (int)pos); i < Math.Min((int)(real_ofst + cnt), pos + size); i++)
{
zOut.Add((byte)origin.ReadByte());
}
}
break;
case ':':
total += cnt;
if (total > limit)
{
throw new Exception("insert command gives an output larger than predicted");
}
if (cnt > lenDelta)
{
throw new Exception("insert count exceeds size of delta");
}
delta_ofst = (uint)zDelta.BaseStream.Position - base_delta_ofst;
if ((pos <= delta_ofst && delta_ofst < pos + size) || pos <= +cnt && delta_ofst < pos + cnt + size)
{
zDelta.BaseStream.Seek(Math.Max((int)pos - delta_ofst, 0), SeekOrigin.Current);
for (int i = Math.Max((int)delta_ofst, (int)pos); i < Math.Min((int)(delta_ofst + cnt), pos + size); i++)
{
zOut.Add((byte)origin.ReadByte());
}
}
//zOut.PutArray(zDelta.BaseStream, (int)zDelta.BaseStream.Position, (int)(zDelta.BaseStream.Position + cnt));
//zDelta.BaseStream.Position += cnt;
break;
case ';':
/*byte[] output = zOut.ToArray();
* if (cnt != Checksum(output))
* throw new Exception("bad checksum");
* if (total != limit)
* throw new Exception("generated size does not match predicted size");*/
return(zOut.ToArray());
default:
throw new Exception("unknown delta operator");
}
}
throw new Exception("unterminated delta");
}
public static MemoryStream ApplyStream(Stream origin, Stream delta)
{
uint origin_ofst = (uint)origin.Position;
uint limit, total = 0;
uint lenSrc = (uint)origin.Length;
uint lenDelta = (uint)delta.Length;
Fossil.StreamReader zDelta = new Fossil.StreamReader(delta);
limit = zDelta.GetInt();
if (zDelta.GetChar() != '\n')
{
throw new Exception("size integer not terminated by \'\\n\'");
}
Fossil.StreamWriter zOut = new Fossil.StreamWriter();
while (zDelta.HaveBytes())
{
uint cnt, ofst;
cnt = zDelta.GetInt();
switch (zDelta.GetChar())
{
case '@':
ofst = zDelta.GetInt() + origin_ofst;
if (zDelta.HaveBytes() && zDelta.GetChar() != ',')
{
throw new Exception("copy command not terminated by \',\'");
}
total += cnt;
if (total > limit)
{
throw new Exception("copy exceeds output file size");
}
if (ofst + cnt > lenSrc)
{
throw new Exception("copy extends past end of input");
}
zOut.PutArray(origin, (int)ofst, (int)(ofst + cnt));
break;
case ':':
total += cnt;
if (total > limit)
{
throw new Exception("insert command gives an output larger than predicted");
}
if (cnt > lenDelta)
{
throw new Exception("insert count exceeds size of delta");
}
zOut.PutArray(zDelta.BaseStream, (int)zDelta.BaseStream.Position, (int)(zDelta.BaseStream.Position + cnt));
//zDelta.BaseStream.Position += cnt;
break;
case ';':
byte[] output = zOut.ToArray();
if (cnt != Checksum(output))
{
throw new Exception("bad checksum");
}
if (total != limit)
{
throw new Exception("generated size does not match predicted size");
}
return(zOut.BaseStream);
default:
throw new Exception("unknown delta operator");
}
}
throw new Exception("unterminated delta");
}
