/// <inheritdoc/>
public async Task <UInt32> TransformChunkAsync(
Stream input,
UInt32 inputChunkSize,
Stream output,
NefsDataTransform transform,
NefsProgress p)
{
using (var transformedStream = new MemoryStream())
{
// Copy raw chunk to temp stream
await input.CopyPartialAsync(transformedStream, inputChunkSize, p.CancellationToken);
transformedStream.Seek(0, SeekOrigin.Begin);
// Compress
if (transform.IsZlibCompressed)
{
using (var tempStream = new MemoryStream())
{
await DeflateHelper.DeflateAsync(transformedStream, (int)inputChunkSize, tempStream);
tempStream.Seek(0, SeekOrigin.Begin);
transformedStream.Seek(0, SeekOrigin.Begin);
await tempStream.CopyPartialAsync(transformedStream, tempStream.Length, p.CancellationToken);
transformedStream.Seek(0, SeekOrigin.Begin);
transformedStream.SetLength(tempStream.Length);
}
}
// Encrypt
if (transform.IsAesEncrypted)
{
using (var aesManager = this.CreateAesManager(transform.Aes256Key))
using (var cryptoStream = new CryptoStream(transformedStream, aesManager.CreateEncryptor(), CryptoStreamMode.Read, leaveOpen: true))
using (var tempStream = new MemoryStream())
{
await cryptoStream.CopyToAsync(tempStream, p.CancellationToken);
tempStream.Seek(0, SeekOrigin.Begin);
transformedStream.Seek(0, SeekOrigin.Begin);
await tempStream.CopyPartialAsync(transformedStream, tempStream.Length, p.CancellationToken);
transformedStream.Seek(0, SeekOrigin.Begin);
transformedStream.SetLength(tempStream.Length);
}
}
// Copy transformed chunk to output stream
await transformedStream.CopyToAsync(output, p.CancellationToken);
// Return size of transformed chunk
return((uint)transformedStream.Length);
}
}
/// <inheritdoc/>
public async Task <NefsItemSize> CompressAsync(
Stream input,
Int64 inputOffset,
UInt32 inputLength,
Stream output,
Int64 outputOffset,
UInt32 chunkSize,
NefsProgress p)
{
var chunkSizes = new List <UInt32>();
input.Seek(inputOffset, SeekOrigin.Begin);
output.Seek(outputOffset, SeekOrigin.Begin);
// Split file into chunks and compress them
using (var t = p.BeginTask(1.0f, $"Compressing stream"))
{
var lastChunkSize = 0;
var totalChunkSize = 0;
var lastBytesRead = 0;
var bytesRemaining = (int)inputLength;
// Determine how many chunks to split file into
var numChunks = (int)Math.Ceiling(inputLength / (double)chunkSize);
for (var i = 0; i < numChunks; ++i)
{
using (var st = p.BeginSubTask(1.0f / numChunks, $"Compressing chunk {i + 1}/{numChunks}"))
{
var nextBytes = Math.Min(chunkSize, bytesRemaining);
// Compress this chunk and write it to the output file
(lastBytesRead, lastChunkSize) = await DeflateHelper.DeflateAsync(input, (int)nextBytes, output, p.CancellationToken);
totalChunkSize += lastChunkSize;
bytesRemaining -= lastBytesRead;
// Record the total compressed size after this chunk
chunkSizes.Add((UInt32)totalChunkSize);
}
}
}
// Return item size
return(new NefsItemSize(inputLength, chunkSizes));
}