Stream HTTP content directly to Azure blob storage

AzureBlobContentDisposition.cs

namespace Azure
{
    using System.Net.Http.Headers;

    public class AzureBlobContentDisposition
    {
        public AzureBlobContentDisposition(ContentDispositionHeaderValue headerValue)
        {
            this.FileName = headerValue?.FileName;
        }

        public string FileName { get; }

        public static implicit operator string(AzureBlobContentDisposition disposition)
        {
            return disposition.ToString();
        }

        public static AzureBlobContentDisposition Parse(string disposition)
        {
            ContentDispositionHeaderValue headerValue;
            ContentDispositionHeaderValue.TryParse(disposition, out headerValue);
            return new AzureBlobContentDisposition(headerValue);
        }

        public override string ToString()
        {
            if (!string.IsNullOrWhiteSpace(this.FileName))
            {
                return new ContentDispositionHeaderValue("attachment")
                           {
                               FileName = this.FileName
                           }.ToString();
            }

            return string.Empty;
        }
    }
}

AzureTemporaryStorage.cs

namespace Azure
{
    using System;
    using System.IO;
    using System.Linq;
    using System.Net.Http;
    using System.Net.Http.Headers;
    using System.Threading;
    using System.Threading.Tasks;

    using Microsoft.WindowsAzure.Storage.Blob;

    public class AzureTemporaryStorage
    {
        private readonly CloudBlobContainer container;

        public AzureTemporaryStorage(CloudBlobContainer container)
        {
            this.container = container;
        }

        public async Task<Guid> UploadAsync(HttpContent content, CancellationToken cancellationToken = default(CancellationToken))
        {
            content.EnsureIsMimeMultipartContent();

            var blobId = Guid.NewGuid();

            var writeStream = this.GetWriteStream(assetId);
            var provider = new DelegateMultipartStreamProvider(writeStream);
            await content.ReadAsMultipartAsync(provider, cancellationToken).ConfigureAwait(false);

            return blobId;
        }

        private Func<HttpContent, HttpContentHeaders, Stream> GetWriteStream(Guid blobId)
        {
            return (content, headers) =>
                {
                    var block = this.container.GetBlockBlobReference(blobId.ToString("N"));
                    block.Properties.ContentDisposition = new AzureBlobContentDisposition(headers.ContentDisposition);
                    block.Properties.ContentType = headers.ContentType.MediaType;
                    return block.OpenWrite();
                };
        }
    }
}

DelegateMultipartStreamProvider.cs

namespace Azure
{
    using System;
    using System.IO;
    using System.Net.Http;
    using System.Net.Http.Headers;

    public class DelegateMultipartStreamProvider : MultipartStreamProvider
    {
        private readonly Func<HttpContent, HttpContentHeaders, Stream> getWriteStream;

        public DelegateMultipartStreamProvider(Func<HttpContent, HttpContentHeaders, Stream> getWriteStream)
        {
            this.getWriteStream = getWriteStream;
        }

        public override Stream GetStream(HttpContent parent, HttpContentHeaders headers)
        {
            return this.getWriteStream(parent, headers);
        }
    }
}