public async Task WritesBytesFromGivenBufferToGivenFileAtGivenOffsetAsync()
{
const int fileSize = 4_001;
string filePath = GetTestFilePath();
byte[] content = RandomNumberGenerator.GetBytes(fileSize);
using (SafeFileHandle handle = File.OpenHandle(filePath, FileMode.CreateNew, FileAccess.Write, FileShare.None, FileOptions.Asynchronous))
{
int total = 0;
int current = 0;
while (total != fileSize)
{
Memory <byte> buffer = content.AsMemory(total, Math.Min(content.Length - total, fileSize / 4));
current = await RandomAccess.WriteAsync(handle, buffer, fileOffset : total);
Assert.InRange(current, 0, buffer.Length);
total += current;
}
}
Assert.Equal(content, File.ReadAllBytes(filePath));
}
public async Task WriteAsyncUsingMultipleBuffers(bool async)
{
string filePath = GetTestFilePath();
int bufferSize = Environment.SystemPageSize;
int fileSize = bufferSize * 10;
byte[] content = RandomNumberGenerator.GetBytes(fileSize);
using (SafeFileHandle handle = File.OpenHandle(filePath, FileMode.CreateNew, FileAccess.Write, FileShare.None, FileOptions.Asynchronous | NoBuffering))
using (SectorAlignedMemory <byte> buffer_1 = SectorAlignedMemory <byte> .Allocate(bufferSize))
using (SectorAlignedMemory <byte> buffer_2 = SectorAlignedMemory <byte> .Allocate(bufferSize))
{
long total = 0;
IReadOnlyList <ReadOnlyMemory <byte> > buffers = new ReadOnlyMemory <byte>[]
{
buffer_1.Memory,
buffer_2.Memory,
};
while (total != fileSize)
{
content.AsSpan((int)total, bufferSize).CopyTo(buffer_1.GetSpan());
content.AsSpan((int)total + bufferSize, bufferSize).CopyTo(buffer_2.GetSpan());
total += async
? await RandomAccess.WriteAsync(handle, buffers, fileOffset : total)
: RandomAccess.Write(handle, buffers, fileOffset: total);
}
}
Assert.Equal(content, File.ReadAllBytes(filePath));
}
public async Task WriteUsingEmptyBufferReturnsZeroAsync()
{
using (SafeFileHandle handle = File.OpenHandle(GetTestFilePath(), FileMode.Create, FileAccess.Write, options: FileOptions.Asynchronous))
{
Assert.Equal(0, await RandomAccess.WriteAsync(handle, Array.Empty <byte>(), fileOffset: 0));
}
}
static async Task Validate(SafeFileHandle handle, FileOptions options, bool[] syncWrites, bool[] syncReads)
{
byte[] writeBuffer = new byte[1];
byte[] readBuffer = new byte[2];
long fileOffset = 0;
foreach (bool syncWrite in syncWrites)
{
foreach (bool syncRead in syncReads)
{
writeBuffer[0] = (byte)fileOffset;
if (syncWrite)
{
RandomAccess.Write(handle, writeBuffer, fileOffset);
}
else
{
await RandomAccess.WriteAsync(handle, writeBuffer, fileOffset);
}
Assert.Equal(writeBuffer.Length, syncRead ? RandomAccess.Read(handle, readBuffer, fileOffset) : await RandomAccess.ReadAsync(handle, readBuffer, fileOffset));
Assert.Equal(writeBuffer[0], readBuffer[0]);
fileOffset += 1;
}
}
}
public async Task WritesBytesFromGivenBufferToGivenFileAtGivenOffsetAsync(FileOptions options)
{
const int fileSize = 4_001;
string filePath = GetTestFilePath();
byte[] content = RandomNumberGenerator.GetBytes(fileSize);
using (SafeFileHandle handle = File.OpenHandle(filePath, FileMode.CreateNew, FileAccess.Write, FileShare.None, options))
{
long total = 0;
while (total != fileSize)
{
int firstBufferLength = (int)Math.Min(content.Length - total, fileSize / 4);
Memory <byte> buffer_1 = content.AsMemory((int)total, firstBufferLength);
Memory <byte> buffer_2 = content.AsMemory((int)total + firstBufferLength);
await RandomAccess.WriteAsync(
handle,
new ReadOnlyMemory <byte>[]
{
buffer_1,
Array.Empty <byte>(),
buffer_2
},
fileOffset : total);
total += buffer_1.Length + buffer_2.Length;
}
}
Assert.Equal(content, File.ReadAllBytes(filePath));
}
public async Task ReadWriteAsyncUsingNonPageSizedMultipleBuffers()
{
string filePath = GetTestFilePath();
// The Windows scatter/gather APIs accept segments that are exactly one page long.
// Combined with the FILE_FLAG_NO_BUFFERING's requirements, the segments must also
// be aligned at page size boundaries and have a size of a multiple of the page size.
// Using segments with a length of twice the page size adheres to the second requirement
// but not the first. The RandomAccess implementation will see it and issue sequential
// read/write syscalls per segment, instead of one scatter/gather syscall.
// This test verifies that fallback behavior.
int bufferSize = Environment.SystemPageSize * 2;
int fileSize = bufferSize * 2;
byte[] content = RandomNumberGenerator.GetBytes(fileSize);
using (SafeFileHandle handle = File.OpenHandle(filePath, FileMode.CreateNew, FileAccess.ReadWrite, FileShare.None, FileOptions.Asynchronous | NoBuffering))
using (SectorAlignedMemory <byte> buffer = SectorAlignedMemory <byte> .Allocate(fileSize))
{
Memory <byte> firstHalf = buffer.Memory.Slice(0, bufferSize);
Memory <byte> secondHalf = buffer.Memory.Slice(bufferSize);
content.AsSpan().CopyTo(buffer.GetSpan());
await RandomAccess.WriteAsync(handle, new ReadOnlyMemory <byte>[] { firstHalf, secondHalf }, 0);
buffer.GetSpan().Clear();
await RandomAccess.ReadAsync(handle, new Memory <byte>[] { firstHalf, secondHalf }, 0);
}
Assert.Equal(content, await File.ReadAllBytesAsync(filePath));
}
public async Task WriteUsingEmptyBufferReturnsZeroAsync(FileOptions options)
{
using (SafeFileHandle handle = File.OpenHandle(GetTestFilePath(), FileMode.Create, FileAccess.Write, options: options))
{
Assert.Equal(0, await RandomAccess.WriteAsync(handle, new ReadOnlyMemory <byte>[] { Array.Empty <byte>() }, fileOffset: 0));
}
}
public async Task WriteUsingSingleBuffer(bool asyncOperation, bool asyncHandle)
{
string filePath = GetTestFilePath();
int bufferSize = Environment.SystemPageSize;
int fileSize = bufferSize * 10;
byte[] content = RandomNumberGenerator.GetBytes(fileSize);
using (SafeFileHandle handle = File.OpenHandle(filePath, FileMode.CreateNew, FileAccess.Write, FileShare.None, GetFileOptions(asyncHandle)))
using (SectorAlignedMemory <byte> buffer = SectorAlignedMemory <byte> .Allocate(bufferSize))
{
int total = 0;
while (total != fileSize)
{
int take = Math.Min(content.Length - total, bufferSize);
content.AsSpan(total, take).CopyTo(buffer.GetSpan());
if (asyncOperation)
{
await RandomAccess.WriteAsync(handle, buffer.Memory, fileOffset : total);
}
else
{
RandomAccess.Write(handle, buffer.GetSpan(), fileOffset: total);
}
total += buffer.Memory.Length;
}
}
Assert.Equal(content, File.ReadAllBytes(filePath));
}
public async Task ReadWriteAsyncUsingMultipleBuffers(bool memoryPageSized)
{
string filePath = GetTestFilePath();
// We test with buffers both one and two memory pages long. In the former case,
// the I/O operations will issue one scatter/gather API call, and in the latter
// case they will issue multiple calls; one per buffer. The buffers must still
// be aligned to comply with FILE_FLAG_NO_BUFFERING's requirements.
int bufferSize = Environment.SystemPageSize * (memoryPageSized ? 1 : 2);
int fileSize = bufferSize * 2;
byte[] content = RandomNumberGenerator.GetBytes(fileSize);
using (SafeFileHandle handle = File.OpenHandle(filePath, FileMode.CreateNew, FileAccess.ReadWrite, FileShare.None, FileOptions.Asynchronous | NoBuffering))
using (SectorAlignedMemory <byte> buffer = SectorAlignedMemory <byte> .Allocate(fileSize))
{
Memory <byte> firstHalf = buffer.Memory.Slice(0, bufferSize);
Memory <byte> secondHalf = buffer.Memory.Slice(bufferSize);
content.AsSpan().CopyTo(buffer.GetSpan());
await RandomAccess.WriteAsync(handle, new ReadOnlyMemory <byte>[] { firstHalf, secondHalf }, 0);
buffer.GetSpan().Clear();
long nRead = await RandomAccess.ReadAsync(handle, new Memory <byte>[] { firstHalf, secondHalf }, 0);
Assert.Equal(buffer.GetSpan().Length, nRead);
AssertExtensions.SequenceEqual(buffer.GetSpan(), content.AsSpan());
}
}
public void ThrowsArgumentNullExceptionForNullBuffers(FileOptions options)
{
using (SafeFileHandle handle = File.OpenHandle(GetTestFilePath(), FileMode.CreateNew, FileAccess.Write, FileShare.None, options))
{
AssertExtensions.Throws <ArgumentNullException>("buffers", () => RandomAccess.WriteAsync(handle, buffers: null, 0));
}
}
public async Task WriteUsingEmptyBufferReturnsAsync(FileOptions options)
{
using (SafeFileHandle handle = File.OpenHandle(GetTestFilePath(), FileMode.Create, FileAccess.Write, options: options))
{
await RandomAccess.WriteAsync(handle, Array.Empty <byte>(), fileOffset : 0);
}
}
/// <summary>
/// Writes the bucket to <paramref name="stream"/> and then closes <paramref name="bucket"/>
/// </summary>
/// <param name="stream"></param>
/// <param name="bucket"></param>
/// <param name="cancellationToken">Token for <see cref="Stream.WriteAsync(byte[], int, int, CancellationToken)"/></param>
/// <returns></returns>
/// <exception cref="ArgumentNullException"></exception>
public static async ValueTask WriteToAsync(this Bucket bucket, Stream stream, CancellationToken cancellationToken = default)
{
if (bucket is null)
{
throw new ArgumentNullException(nameof(bucket));
}
else if (stream is null)
{
throw new ArgumentNullException(nameof(stream));
}
using (bucket)
{
#if NET6_0_OR_GREATER
if (stream is FileStream fs && fs.CanSeek && bucket is IBucketReadBuffers rb)
{
var handle = fs.SafeFileHandle;
long pos = fs.Position;
while (true)
{
cancellationToken.ThrowIfCancellationRequested();
var(buffers, done) = await bucket.ReadBuffersAsync().ConfigureAwait(false);
if (buffers.Length > 0)
{
var len = buffers.Sum(x => (long)x.Length);
await RandomAccess.WriteAsync(handle, buffers, pos, cancellationToken).ConfigureAwait(false);
pos += len;
}
if (done)
{
fs.Position = pos;
return;
}
}
}
#endif
while (true)
{
cancellationToken.ThrowIfCancellationRequested();
var bb = await bucket.ReadAsync().ConfigureAwait(false);
if (bb.IsEof)
{
break;
}
await stream.WriteAsync(bb, cancellationToken).ConfigureAwait(false);
}
}
}
public async Task ReadWriteAsyncUsingEmptyBuffers()
{
string filePath = GetTestFilePath();
using SafeFileHandle handle = File.OpenHandle(filePath, FileMode.CreateNew, FileAccess.ReadWrite, FileShare.None, FileOptions.Asynchronous | NoBuffering);
long nRead = await RandomAccess.ReadAsync(handle, Array.Empty <Memory <byte> >(), 0);
Assert.Equal(0, nRead);
await RandomAccess.WriteAsync(handle, Array.Empty <ReadOnlyMemory <byte> >(), 0);
}
public async Task TaskAlreadyCanceledAsync(FileOptions options)
{
using (SafeFileHandle handle = File.OpenHandle(GetTestFilePath(), FileMode.CreateNew, FileAccess.ReadWrite, options: options))
{
CancellationTokenSource cts = GetCancelledTokenSource();
CancellationToken token = cts.Token;
Assert.True(RandomAccess.WriteAsync(handle, new ReadOnlyMemory <byte>[] { new byte[1] }, 0, token).IsCanceled);
TaskCanceledException ex = await Assert.ThrowsAsync <TaskCanceledException>(() => RandomAccess.WriteAsync(handle, new ReadOnlyMemory <byte>[] { new byte[1] }, 0, token).AsTask());
Assert.Equal(token, ex.CancellationToken);
}
}
public async Task WriteBeyondEndOfFileExtendsTheFileAsync(FileOptions options)
{
string filePath = GetTestFilePath();
using (SafeFileHandle handle = File.OpenHandle(filePath, FileMode.CreateNew, FileAccess.Write, options: options))
{
Assert.Equal(0, RandomAccess.GetLength(handle));
await RandomAccess.WriteAsync(handle, new byte[1] {
1
}, fileOffset : 1);
Assert.Equal(2, RandomAccess.GetLength(handle));
}
Assert.Equal(new byte[] { 0, 1 }, await File.ReadAllBytesAsync(filePath));
}
public async Task DuplicatedBufferDuplicatesContentAsync(FileOptions options)
{
const byte value = 1;
const int repeatCount = 2;
string filePath = GetTestFilePath();
ReadOnlyMemory <byte> buffer = new byte[1] {
value
};
List <ReadOnlyMemory <byte> > buffers = Enumerable.Repeat(buffer, repeatCount).ToList();
using (SafeFileHandle handle = File.OpenHandle(filePath, FileMode.Create, FileAccess.Write, options: options))
{
Assert.Equal(repeatCount, await RandomAccess.WriteAsync(handle, buffers, fileOffset: 0));
}
byte[] actualContent = File.ReadAllBytes(filePath);
Assert.Equal(repeatCount, actualContent.Length);
Assert.All(actualContent, actual => Assert.Equal(value, actual));
}
public async Task ThrowsOnReadAccess(FileOptions options)
{
using (SafeFileHandle handle = GetHandleToExistingFile(FileAccess.Read, options))
{
await Assert.ThrowsAsync <UnauthorizedAccessException>(async() => await RandomAccess.WriteAsync(handle, new ReadOnlyMemory <byte>[] { new byte[1] }, 0));
}
}
protected override ValueTask <long> MethodUnderTest(SafeFileHandle handle, byte[] bytes, long fileOffset)
=> RandomAccess.WriteAsync(handle, new ReadOnlyMemory <byte>[] { bytes }, fileOffset);
public async Task ThrowsOnReadAccess()
{
using (SafeFileHandle handle = GetHandleToExistingFile(FileAccess.Read))
{
await Assert.ThrowsAsync <UnauthorizedAccessException>(async() => await RandomAccess.WriteAsync(handle, new byte[1], 0));
}
}
protected override ValueTask MethodUnderTest(SafeFileHandle handle, byte[] bytes, long fileOffset) => RandomAccess.WriteAsync(handle, bytes, fileOffset);
