private async Task BuildFilePatchAction(FilePatchInstruction instruction, string targetFilePath, Action <IFilePatchAction> callback)
{
string installedHash = await SHA256.GetFileHashAsync(targetFilePath);
bool isOld = installedHash == instruction.OldHash;
bool isNew = installedHash == instruction.NewHash;
if (!isNew)
{
bool needsBackup = !isOld && installedHash != null;
if (instruction.NewHash == null)
{
callback(new RemoveAction(this, instruction.Path, needsBackup));
}
else if (isOld && instruction.HasDelta)
{
string deltaFileName = Path.Combine("delta", instruction.NewHash + "_from_" + instruction.OldHash);
callback(new DeltaPatchAction(this, instruction.Path, deltaFileName, instruction.DeltaSize, instruction.DeltaHash));
}
else
{
string fullFileName = Path.Combine("full", instruction.NewHash);
callback(new FullReplaceAction(this, instruction.Path, fullFileName, needsBackup, instruction.FullReplaceSize, instruction.CompressedHash));
}
}
if (instruction.NewHash != null)
{
callback(new ModifiedTimeReplaceAction(this, instruction.Path, instruction.NewLastWriteTime));
}
}
private async Task BuildFilePatchAction(FilePatchInstruction instruction, string targetFilePath, Action <IFilePatchAction> callback)
{
string installedHash = await Sha256.GetFileHashAsync(targetFilePath);
bool isOld = installedHash == instruction.OldHash;
instruction.isActive = true;
// Patch file only if it is different from the new version
if (installedHash != instruction.NewHash)
{
// Backup any existing files that don't match the old hash
bool needsBackup = !isOld && installedHash != null;
if (instruction.NewHash == null)
{
// File deleted
callback(new RemoveAction(this, instruction.Path, needsBackup));
}
else if (isOld && instruction.HasDelta)
{
// Incremental update
string deltaFileName = Path.Combine("delta", instruction.NewHash + "_from_" + instruction.OldHash);
callback(new DeltaPatchAction(this, instruction.Path, deltaFileName, instruction.DeltaSize, instruction.DeltaHash));
}
else
{
// Full download
string fullFileName = Path.Combine("full", instruction.NewHash);
callback(new FullReplaceAction(this, instruction.Path, fullFileName, needsBackup, instruction.FullReplaceSize, instruction.CompressedHash));
}
}
// Update LastWriteTime
if (instruction.NewHash != null)
{
callback(new ModifiedTimeReplaceAction(this, instruction.Path, instruction.NewLastWriteTime));
}
}
