private Result <int, ErrorCodes?> MultyThreadedDecompression(Stream inputStream, Stream outputStream)
{
using (var writerFinished = new ManualResetEvent(false))
using (var workersPool = new WorkersPool.WorkersPool(settings.ThreadsCount, log))
using (var tasksQueue = new BlockingTasksQueue(settings.CompressingQueueSize, workersPool, log))
{
var outputFile = new OutputFileWithoutOffsetStore(outputStream);
var blockId = 0;
var writeDecompressedTask =
RunDequeueingOutputWriteDecompressedBlocks(writerFinished, outputFile, tasksQueue);
workersPool.PushTask(writeDecompressedTask);
var needWaitTasksFinished = false;
var needEndTasks = true;
StreamingGzipBlock streamingGzipBlock = null;
try
{
foreach (var block in gzipBlockSplitter.SplitBlocks(inputStream))
{
if (block is StreamingGzipBlock gzipBlock)
{
tasksQueue.EndTasks();
needEndTasks = false;
if (needWaitTasksFinished)
{
writerFinished.WaitOne();
needWaitTasksFinished = false;
}
streamingGzipBlock = gzipBlock;
break;
}
tasksQueue.EnqueueTask(
new DelegateTask(
blockId++.ToString(),
() => ((IndependentGzipBlock)block).Decompress())
);
needWaitTasksFinished = true;
}
}
finally
{
if (needEndTasks)
{
tasksQueue.EndTasks();
}
}
if (needWaitTasksFinished)
{
writerFinished.WaitOne();
}
streamingGzipBlock?.WriteDecompressedDataTo(outputStream);
return(outputFile.CompressionRatio(inputStream.Length));
}
}
private static IWorkerTask RunDequeueingOutputWriteDecompressedBlocks(
ManualResetEvent writerFinished,
OutputFileWithoutOffsetStore outputFile,
BlockingTasksQueue tasksQueue)
{
return(new DelegateWorkerTask(
"Writer",
() =>
{
var error = WriteCompressedBlocks();
if (error != null)
{
throw new CompressorException(error.Value);
}
}));
ErrorCodes?WriteCompressedBlocks()
{
try
{
foreach (var result in tasksQueue.ConsumeTaskResults())
{
if (result.IsFailed)
{
if (result.Exception is CompressorException fileSystemException)
{
return(fileSystemException.Error);
}
throw result.Exception;
}
var decompressedBlock = (byte[])result.Result;
var error = outputFile.Append(decompressedBlock.ToSegment());
if (error != null)
{
return(error.Value);
}
}
return(null);
}
finally
{
writerFinished.Set();
}
}
}
