/// <summary>
/// Function to assemble a file from delta and original and output it to the "output" file
/// </summary>
/// <param name="delta">Path to delta file</param>
/// <param name="original">Path to original file</param>
/// <param name="output">Path to output file</param>
private static void DoDecode(string delta, string original, string output)
{
using (FileStream outputS = new FileStream(output, FileMode.Create, FileAccess.Write))
using (FileStream dictS = new FileStream(original, FileMode.Open, FileAccess.Read))
using (FileStream targetS = new FileStream(delta, FileMode.Open, FileAccess.Read))
{
VCDecoder decoder = new VCDecoder(dictS, targetS, outputS);
//You must call decoder.Start() first. The header of the delta file must be available before calling decoder.Start()
VCDiffResult result = decoder.Start();
if (result != VCDiffResult.SUCCESS)
{
//error abort
}
result = decoder.Decode(out long bytesWritten);
if (result != VCDiffResult.SUCCESS)
{
//error decoding
}
//if success bytesWritten will contain the number of bytes that were decoded
}
}
void DoDecode(string outputFile, string oldFile, string patchFile)
{
using (FileStream target = new FileStream(patchFile, FileMode.Open, FileAccess.Read))
{
byte[] oldHash = new byte[20];
byte[] newHash = new byte[20];
target.Read(oldHash, 0, oldHash.Length);
target.Read(newHash, 0, newHash.Length);
byte[] realHash = GetSha1FromFile(oldFile);
bool oldHashMatches = CompareHashes(oldHash, realHash);
if (!oldHashMatches)
{
if (CompareHashes(realHash, newHash))
{
File.Copy(oldFile, outputFile);
return;
}
else
{
throw new Exception("file hash mismatch");
}
}
using (FileStream dict = new FileStream(oldFile, FileMode.Open, FileAccess.Read))
using (FileStream output = new FileStream(outputFile, FileMode.Create, FileAccess.Write))
{
VCDecoder decoder = new VCDecoder(dict, target, output);
//You must call decoder.Start() first. The header of the delta file must be available before calling decoder.Start()
VCDiffResult result = decoder.Start();
if (result != VCDiffResult.SUCCESS)
{
//error abort
throw new Exception("abort while decoding");
}
long bytesWritten = 0;
result = decoder.Decode(out bytesWritten);
if (result != VCDiffResult.SUCCESS)
{
//error decoding
throw new Exception("Error decoding");
}
//if success bytesWritten will contain the number of bytes that were decoded
}
}
}
private static VCDiffResult Decode(Stream sold, Stream sdelta, Stream sout)
{
VCDecoder decoder = new VCDecoder(sold, sdelta, sout);
var result = decoder.Start();
if (result != VCDiffResult.Succes)
{
return(result);
}
return(decoder.Decode(out _));
}
/// <summary>
/// Do not run on main thread
/// </summary>
/// <param name="id"></param>
/// <param name="region"></param>
public static bool Merge(int id, string region)
{
if (!HasLocalData(id, region) || !HasLocalDataDiff(id, region))
{
return(false);
}
byte[] dictData = GetLocalData(id, region);
byte[] deltaData = GetLocalDataDiff(id, region);
if (dictData == null || deltaData == null)
{
return(false);
}
try
{
using (ByteBuffer dictBuffer = new ByteBuffer(dictData))
using (ByteBuffer deltaBuffer = new ByteBuffer(deltaData))
using (MemoryStream ms = new MemoryStream())
{
VCDecoder decoder = new VCDecoder(dictBuffer, deltaBuffer, ms);
VCDiffResult result = decoder.Start();
if (result != VCDiffResult.SUCCESS)
{
return(false);
}
long bytesWritten = 0;
result = decoder.Decode(out bytesWritten);
if (result != VCDiffResult.SUCCESS)
{
return(false);
}
string fname = string.Format(id >= 0 ? DB_FILE : DB_REGION_FILE, region, id);
string fpath = Path.Combine(DirectoryPath, fname);
File.WriteAllBytes(fpath, ms.ToArray());
return(true);
}
}
catch (Exception e)
{
Debug.WriteLine(e.ToString());
}
return(false);
}
internal static void MergeDiffToDat(Stream origStream, Stream modifiedStream, Stream mergedStream)
{
VCDecoder decoder = new VCDecoder(origStream, modifiedStream, mergedStream);
VCDiffResult result = decoder.Start(); //encodes with no checksum and not interleaved
if (result != VCDiffResult.SUCCESS)
{
//error was not able to encode properly
}
else
{
long bytesWritten = 0;
result = decoder.Decode(out bytesWritten);
if (result != VCDiffResult.SUCCESS)
{
}
}
}
public void TestEncodeAndDecodeShouldBeTheSame()
{
int size = 20 * 1024 * 1024; // 20 MB
byte[] oldData = CreateRandomByteArray(size);
byte[] newData = new byte[size];
oldData.CopyTo(newData, 0);
AddRandomPiecesIn(oldData);
var sOld = new MemoryStream(oldData);
var sNew = new MemoryStream(newData);
var sDelta = new MemoryStream(new byte[size], true);
var coder = new VCCoder(sOld, sNew, sDelta);
Assert.AreEqual(VCDiffResult.Succes, coder.Encode());
TestContext.Out.WriteLine($"Delta is {sDelta.Position / 1024 / 1024} MB's");
sDelta.SetLength(sDelta.Position);
sDelta.Position = 0;
sOld.Position = 0;
sNew.Position = 0;
var sPatched = new MemoryStream(new byte[size], true);
var decoder = new VCDecoder(sOld, sDelta, sPatched);
Assert.AreEqual(VCDiffResult.Succes, decoder.Start());
Assert.AreEqual(VCDiffResult.Succes, decoder.Decode(out long bytesWritten));
TestContext.Out.WriteLine($"Written {bytesWritten / 1024 / 1024} MB's");
Assert.AreEqual(sNew.ToArray(), sPatched.ToArray());
}
