public static void ParallelDownloadToFile(this CloudBlockBlob blob, string fileName, int maxBlockSize)
{
// refresh the values
blob.FetchAttributes();
long fileSize = blob.Attributes.Properties.Length;
var filePath = Path.GetDirectoryName(fileName);
var fileNameWithoutPath = Path.GetFileNameWithoutExtension(fileName);
// let's figure out how big the file is here
long leftToRead = fileSize;
int startPosition = 0;
// have 1 block for every maxBlockSize bytes plus 1 for the remainder
var blockCount =
((int)Math.Floor((double)(fileSize / maxBlockSize))) + 1;
// setup the control array
BlockTransferDetail[] transferDetails = new BlockTransferDetail[blockCount];
// create an array of block keys
string[] blockKeys = new string[blockCount];
var blockIds = new List<string>();
// populate the control array...
for (int j = 0; j < transferDetails.Length; j++)
{
int toRead = (int)(maxBlockSize < leftToRead ?
maxBlockSize :
leftToRead);
string blockId = Path.Combine(filePath,
string.Format("{0}_{1}.dat",
fileNameWithoutPath,
j.ToString("00000000000")));
transferDetails[j] = new BlockTransferDetail()
{
StartPosition = startPosition,
BytesToRead = toRead,
BlockId = blockId
};
if (toRead > 0)
{
blockIds.Add(blockId);
}
// increment the starting position
startPosition += toRead;
leftToRead -= toRead;
}
// now we do a || download of the file.
var result = Parallel.For(0, transferDetails.Length, j =>
{
// get the blob as a stream
using (BlobStream stream = blob.OpenRead())
{
// move to the proper location
stream.Seek(transferDetails[j].StartPosition, SeekOrigin.Begin);
// setup a buffer with the proper size
byte[] buff = new byte[transferDetails[j].BytesToRead];
// read into the buffer
stream.Read(buff, 0, transferDetails[j].BytesToRead);
// flush the buffer to disk
using (Stream fileStream = new FileStream(transferDetails[j].BlockId, FileMode.Create, FileAccess.Write, FileShare.None))
{
using (BinaryWriter bw = new BinaryWriter(fileStream))
{
bw.Write(buff);
bw.Close();
}
}
buff = null;
}
});
// assemble the file into one now...
using (Stream fileStream = new FileStream(fileName, FileMode.Append, FileAccess.Write, FileShare.None))
{
using (BinaryWriter bw = new BinaryWriter(fileStream))
{
// loop through each of the files on the disk
for (int j = 0; j < transferDetails.Length; j++)
{
// read them into the file (append)
bw.Write(File.ReadAllBytes(transferDetails[j].BlockId));
// and then delete them
File.Delete(transferDetails[j].BlockId);
}
}
}
transferDetails = null;
}
/// <summary>
/// Uploads a file from the file system to a blob. Parallel implementation of
/// UploadFile().
/// </summary>
/// <param name="blob">Blob object that is extended by this method</param>
/// <param name="fileName">The file to be uploaded.</param>
/// <param name="options">A Microsoft.WindowsAzure.StorageClient.BlobRequestOptions object indicating any addtional options to be specified on the request</param>
/// <param name="maxBlockSize">The maximum size of an individual block transferred</param>
public static void ParallelUploadFile(this CloudBlockBlob blob, string fileName, BlobRequestOptions options, int maxBlockSize)
{
var file = new FileInfo(fileName);
long fileSize = file.Length;
// let's figure out how big the file is here
long leftToRead = fileSize;
int startPosition = 0;
// have 1 block for every maxBlockSize bytes plus 1 for the remainder
var blockCount =
((int)Math.Floor((double)(fileSize / maxBlockSize))) + 1;
// setup the control array
BlockTransferDetail[] transferDetails = new BlockTransferDetail[blockCount];
// create an array of block keys
string[] blockKeys = new string[blockCount];
var blockIds = new List<string>();
// populate the control array...
for (int j = 0; j < transferDetails.Length; j++)
{
int toRead = (int)(maxBlockSize < leftToRead ?
maxBlockSize :
leftToRead);
string blockId = Convert.ToBase64String(
ASCIIEncoding.ASCII.GetBytes(
string.Format("Block{0}Stop", j.ToString("00000000000"))));
//Console.WriteLine(blockId);
transferDetails[j] = new BlockTransferDetail()
{
StartPosition = startPosition,
BytesToRead = toRead,
BlockId = blockId
};
if (toRead > 0)
{
blockIds.Add(blockId);
}
// increment the starting position
startPosition += toRead;
leftToRead -= toRead;
}
// now we do a || upload of the file.
var result = Parallel.For(0, transferDetails.Length, j =>
{
using (FileStream fs = new FileStream(file.FullName,
FileMode.Open, FileAccess.Read))
{
byte[] buff = new byte[transferDetails[j].BytesToRead];
BinaryReader br = new BinaryReader(fs);
// move the file system reader to the proper position
fs.Seek(transferDetails[j].StartPosition, SeekOrigin.Begin);
br.Read(buff, 0, transferDetails[j].BytesToRead);
if (buff.Length > 0)
{
// calculate the block-level hash
string blockHash = Helpers.GetMD5HashFromStream(buff);
//blob.PutBlock(transferDetails[j].BlockId, new MemoryStream(buff), blockHash, options);
blob.PutBlock(transferDetails[j].BlockId, new MemoryStream(buff), null, options);
}
}
});
// commit the file
blob.PutBlockList(blockIds);
}
