public bool Compress(Stream inputUncompressed, Stream outputCompressed, int compressionBlockSize = DefaultBlockSize)
{
var workBlocksCount = (int)(inputUncompressed.Length / compressionBlockSize);
workBlocksCount += (inputUncompressed.Length % compressionBlockSize > 0) ? 1 : 0;
var compressionWorkThreads = new List <Thread>();
for (int i = 0; i < Environment.ProcessorCount; i += 1)
{
_buffers.Push(new byte[compressionBlockSize]);
}
using (var outputWriter = new BinaryWriter(outputCompressed))
{
outputWriter.Write(ArchiveMagic);
outputWriter.Write(compressionBlockSize);
outputWriter.Write(workBlocksCount);
_runningThreads = 0;
var currentWorkBlock = 0;
byte[] buf = null;
while (currentWorkBlock <= workBlocksCount)
{
if (_runningThreads >= Environment.ProcessorCount)
{
MaxReasonableThreadsIdle();
continue;
}
lock (_threadLock)
{
buf = _buffers.Pop();
}
var actualRead = inputUncompressed.Read(buf, 0, compressionBlockSize);
var compressionWork = new Thread(ThreadCompressWork);
compressionWorkThreads.Add(compressionWork);
var compressionWorkData = new ThreadCompressWorkData(currentWorkBlock, buf, actualRead, outputWriter);
_runningThreads += 1;
compressionWork.Start(compressionWorkData);
currentWorkBlock += 1;
}
AwaitRemainingRunningThreads(compressionWorkThreads);
}
_buffers.Clear();
return(true);
}
private void GetCompressedBlockData(ThreadCompressWorkData workData, MemoryStream compressedBlockOutput)
{
using (MemoryStream compressedOutput = new MemoryStream())
{
using (GZipStream compressionStream = new GZipStream(compressedOutput, CompressionLevel.Optimal, leaveOpen: true))
{
compressionStream.Write(workData.DataForCompression, 0, workData.DataSize);
}
int compressedDataLength = (int)compressedOutput.Length;
using (var binaryWriter = new BinaryWriter(compressedBlockOutput, System.Text.Encoding.Default, leaveOpen: true))
{
binaryWriter.Write(workData.BlockIndex);
binaryWriter.Write(compressedDataLength);
compressedOutput.Seek(0, SeekOrigin.Begin);
compressedOutput.CopyTo(binaryWriter.BaseStream);
}
}
}
