public async Task WriteAsync_AfterMemoryThresholdIsReached_BuffersToMemory()
{
// Arrange
var input = new byte[] { 1, 2, 3, 4, 5, 6, 7 };
using var bufferingStream = new FileBufferingWriteStream(memoryThreshold: 4, tempFileDirectoryAccessor: () => TempDirectory);
// Act
await bufferingStream.WriteAsync(input, 0, 5);
await bufferingStream.WriteAsync(input, 5, 2);
// Assert
var pageBuffer = bufferingStream.PagedByteBuffer;
var fileStream = bufferingStream.FileStream;
// File should have been created.
Assert.NotNull(fileStream);
var fileBytes = ReadFileContent(fileStream);
Assert.Equal(input.Length, bufferingStream.Length);
Assert.Equal(new byte[] { 1, 2, 3, 4, 5, }, fileBytes);
Assert.Equal(new byte[] { 6, 7 }, ReadBufferedContent(pageBuffer));
}
public async Task WriteAsync_DoesNotThrow_IfBufferLimitIsReached()
{
// Arrange
var input = new byte[5];
using var bufferingStream = new FileBufferingWriteStream(memoryThreshold: 2, bufferLimit: 10, tempFileDirectoryAccessor: () => TempDirectory);
// Act
await bufferingStream.WriteAsync(input, 0, input.Length);
await bufferingStream.WriteAsync(input, 0, input.Length); // Should get to exactly the buffer limit, which is fine
// If we got here, the test succeeded.
}
public async Task WriteAsync_Throws_IfWriteCumulativeWritesExceedsBuffersLimit()
{
// Arrange
var input = new byte[6];
var bufferingStream = new FileBufferingWriteStream(memoryThreshold: 2, bufferLimit: 10, tempFileDirectoryAccessor: () => TempDirectory);
// Act
await bufferingStream.WriteAsync(input, 0, input.Length);
var exception = await Assert.ThrowsAsync <IOException>(() => bufferingStream.WriteAsync(input, 0, input.Length));
Assert.Equal("Buffer limit exceeded.", exception.Message);
// Verify we return the buffer.
Assert.True(bufferingStream.Disposed);
}
public async Task WriteAsync_BuffersContentToMemory()
{
// Arrange
using var bufferingStream = new FileBufferingWriteStream(tempFileDirectoryAccessor: () => TempDirectory);
var input = Encoding.UTF8.GetBytes("Hello world");
// Act
await bufferingStream.WriteAsync(input, 0, input.Length);
// Assert
// We should have written content to memory
var pagedByteBuffer = bufferingStream.PagedByteBuffer;
Assert.Equal(input, ReadBufferedContent(pagedByteBuffer));
// No files should not have been created.
Assert.Null(bufferingStream.FileStream);
}
public async Task WriteAsync_BeforeMemoryThresholdIsReached_WritesToMemory()
{
// Arrange
var input = new byte[] { 1, 2, };
using var bufferingStream = new FileBufferingWriteStream(memoryThreshold: 2, tempFileDirectoryAccessor: () => TempDirectory);
// Act
await bufferingStream.WriteAsync(input, 0, 2);
// Assert
var pageBuffer = bufferingStream.PagedByteBuffer;
var fileStream = bufferingStream.FileStream;
// File should have been created.
Assert.Null(fileStream);
// No content should be in the memory stream
Assert.Equal(2, pageBuffer.Length);
Assert.Equal(input, ReadBufferedContent(pageBuffer));
}
public async Task WriteAsync_BuffersContentToDisk_WhenWriteWillOverflowMemoryThreshold()
{
// Arrange
var input = new byte[] { 1, 2, 3, };
using var bufferingStream = new FileBufferingWriteStream(memoryThreshold: 2, tempFileDirectoryAccessor: () => TempDirectory);
// Act
await bufferingStream.WriteAsync(input, 0, input.Length);
// Assert
var pageBuffer = bufferingStream.PagedByteBuffer;
var fileStream = bufferingStream.FileStream;
// File should have been created.
Assert.NotNull(fileStream);
var fileBytes = ReadFileContent(fileStream);
Assert.Equal(input, fileBytes);
// No content should be in the memory stream
Assert.Equal(0, pageBuffer.Length);
}