/// <summary>
/// Implementation method for the ClearPage methods.
/// </summary>
/// <param name="startOffset">The start offset. Must be multiples of 512.</param>
/// <param name="length">Length of the data range to be cleared. Must be multiples of 512.</param>
/// <param name="options">An object that specifies any additional options for the request.</param>
/// <returns>A <see cref="TaskSequence"/> that writes the pages.</returns>
private TaskSequence ClearPageImpl(long startOffset, long length, BlobRequestOptions options)
{
CommonUtils.AssertNotNull("options", options);
if (startOffset < 0 || startOffset % Protocol.Constants.PageSize != 0)
{
CommonUtils.ArgumentOutOfRange("startOffset", startOffset);
}
if (length <= 0 || length % Protocol.Constants.PageSize != 0)
{
CommonUtils.ArgumentOutOfRange("length", length);
}
PutPageProperties properties = new PutPageProperties()
{
Range = new PageRange(startOffset, startOffset + length - 1),
PageWrite = PageWrite.Clear,
};
var webRequest = ProtocolHelper.GetWebRequest(
this.ServiceClient,
options,
(timeout) => BlobRequest.PutPage(this.TransformedAddress, timeout, properties, null));
webRequest.ContentLength = 0;
// signing request needs Size to be set
this.ServiceClient.Credentials.SignRequest(webRequest);
// Get the response
var responseTask = webRequest.GetResponseAsyncWithTimeout(this.ServiceClient, options.Timeout);
yield return(responseTask);
// Parse the response
using (HttpWebResponse webResponse = responseTask.Result as HttpWebResponse)
{
this.ParseSizeAndLastModified(webResponse);
}
}
/// <summary>
/// Implementation method for the WritePage methods.
/// </summary>
/// <param name="pageData">The page data.</param>
/// <param name="startOffset">The start offset.</param>
/// <param name="sourceStreamPosition">The beginning position of the source stream prior to execution, negative if stream is unseekable.</param>
/// <param name="options">An object that specifies any additional options for the request.</param>
/// <returns>A <see cref="TaskSequence"/> that writes the pages.</returns>
private TaskSequence WritePageImpl(Stream pageData, long startOffset, long sourceStreamPosition, BlobRequestOptions options)
{
CommonUtils.AssertNotNull("options", options);
long length = pageData.Length;
// Logic to rewind stream on a retry
// For non seekable streams we need a way to detect the retry iteration so as to only attempt to execute once.
// The first attempt will have SourceStreamPosition = -1, which means the first iteration on a non seekable stream.
// The second attempt will have SourceStreamPosition = -2, anything below -1 is considered an abort. Since the Impl method
// does not have an execution context to be aware of what iteration is used the SourceStreamPosition is utilized as counter to
// differentiate between the first attempt and a retry.
if (sourceStreamPosition >= 0 && pageData.CanSeek)
{
if (sourceStreamPosition != pageData.Position)
{
pageData.Seek(sourceStreamPosition, 0);
}
}
else if (sourceStreamPosition < -1)
{
throw new NotSupportedException(string.Format(CultureInfo.CurrentCulture, SR.CannotRetryNonSeekableStreamError));
}
if (startOffset % Protocol.Constants.PageSize != 0)
{
CommonUtils.ArgumentOutOfRange("startOffset", startOffset);
}
long rangeStreamOffset = pageData.CanSeek ? pageData.Position : 0;
PutPageProperties properties = new PutPageProperties()
{
Range = new PageRange(startOffset, startOffset + length - rangeStreamOffset - 1),
PageWrite = PageWrite.Update,
};
if ((1 + properties.Range.EndOffset - properties.Range.StartOffset) % Protocol.Constants.PageSize != 0 ||
(1 + properties.Range.EndOffset - properties.Range.StartOffset) == 0)
{
CommonUtils.ArgumentOutOfRange("pageData", pageData);
}
var webRequest = ProtocolHelper.GetWebRequest(
this.ServiceClient,
options,
(timeout) => BlobRequest.PutPage(this.TransformedAddress, timeout, properties, null));
////BlobRequest.AddMetadata(webRequest, this.Metadata);
// Retrieve the stream
var requestStreamTask = webRequest.GetRequestStreamAsync();
yield return(requestStreamTask);
// Copy the data
using (var outputStream = requestStreamTask.Result)
{
var copyTask = new InvokeTaskSequenceTask(() => { return(pageData.WriteTo(outputStream)); });
yield return(copyTask);
// Materialize any exceptions
var scratch = copyTask.Result;
}
// signing request needs Size to be set
this.ServiceClient.Credentials.SignRequest(webRequest);
// Get the response
var responseTask = webRequest.GetResponseAsyncWithTimeout(this.ServiceClient, options.Timeout);
yield return(responseTask);
// Parse the response
using (HttpWebResponse webResponse = responseTask.Result as HttpWebResponse)
{
this.ParseSizeAndLastModified(webResponse);
}
}