/// <summary>
/// Reserved for private static ValueCheckpointFile.OpenAsync().
/// </summary>
private ValueCheckpointFile(string filename, Kernel32Types.PRIORITY_HINT priorityHint = Kernel32Types.PRIORITY_HINT.IoPriorityHintNormal)
{
// Open the file for read with asynchronous flag and 4096 cache size (C# default).
this.ReaderPool = new StreamPool(
() => FabricFile.Open(filename, FileMode.Open, FileAccess.Read, FileShare.Read, 4096, FileOptions.Asynchronous | FileOptions.RandomAccess));
this.priorityHint = priorityHint;
}
/// <summary>
/// Reserved for private static KeyCheckpointFile.OpenAsync().
/// </summary>
private KeyCheckpointFile(string filename, bool isValueAReferenceType)
{
// Open the file for read with asynchronous flag and 4096 cache size (C# default).
// MCoskun: Used for recovery and merge. Hence the Io Priority is set at AcquireStream time.
this.ReaderPool = new StreamPool(
() => FabricFile.Open(filename, FileMode.Open, FileAccess.Read, FileShare.Read, 4096, FileOptions.Asynchronous | FileOptions.RandomAccess));
this.isValueAReferenceType = isValueAReferenceType;
}
/// <summary>
/// Reserved for private static ValueCheckpointFile.OpenAsync().
/// </summary>
private ValueCheckpointFile(string filename, Kernel32Types.PRIORITY_HINT priorityHint = Kernel32Types.PRIORITY_HINT.IoPriorityHintNormal)
{
// Open the file for read with asynchronous flag and 4096 cache size (C# default).
// Because of the issue at https://github.com/dotnet/corefx/issues/6007
// where asynchonous reads can internally be synchronous reads with wait calls, we can be
// bottlenecked by the limited number of I/O completion ports in overlapped I/O
// causing a lot of blocked threads and extreme slowdown when met with a large number
// of concurrent reads. Due to this, we chose to disable the FileOptions.Asynchronous option.
this.ReaderPool = new StreamPool(
() => FabricFile.Open(filename, FileMode.Open, FileAccess.Read, FileShare.Read, 4096, FileOptions.RandomAccess));
this.priorityHint = priorityHint;
}
