/// <summary>
/// Performs the chunking.
/// </summary>
/// <param name="stream">
/// The data source.
/// </param>
/// <param name="name">
/// A name for the data.
/// </param>
/// <param name="options">
/// The options when adding data to the IPFS file system.
/// </param>
/// <param name="blockService">
/// The destination for the chunked data block(s).
/// </param>
/// <param name="keyChain">
/// Used to protect the chunked data blocks(s).
/// </param>
/// <param name="cancel">
/// Is used to stop the task. When cancelled, the <see cref="TaskCanceledException"/> is raised.
/// </param>
/// <returns>
/// A task that represents the asynchronous operation. The task's value is
/// the sequence of file system nodes of the added data blocks.
/// </returns>
public async Task <IEnumerable <FileSystemNode> > ChunkAsync(
Stream stream,
string name,
AddFileOptions options,
IBlockApi blockService,
KeyChain keyChain,
CancellationToken cancel)
{
var protecting = !string.IsNullOrWhiteSpace(options.ProtectionKey);
var nodes = new List <FileSystemNode> ();
var chunkSize = options.ChunkSize;
var chunk = new byte[chunkSize];
var chunking = true;
var totalBytes = 0UL;
while (chunking)
{
// Get an entire chunk.
int length = 0;
while (length < chunkSize)
{
var n = await stream.ReadAsync(chunk, length, chunkSize - length, cancel);
if (n < 1)
{
chunking = false;
break;
}
length += n;
totalBytes += (uint)n;
}
// Only generate empty block, when the stream is empty.
if (length == 0 && nodes.Count > 0)
{
chunking = false;
break;
}
if (options.Progress != null)
{
options.Progress.Report(new TransferProgress
{
Name = name,
Bytes = totalBytes
});
}
// if protected data, then get CMS structure.
if (protecting)
{
// TODO: Inefficent to copy chunk, use ArraySegment in DataMessage.Data
var plain = new byte[length];
Array.Copy(chunk, plain, length);
var cipher = await keyChain.CreateProtectedData(options.ProtectionKey, plain, cancel);
var cid = await blockService.PutAsync(
data : cipher,
contentType : "cms",
multiHash : options.Hash,
encoding : options.Encoding,
pin : options.Pin,
cancel : cancel);
nodes.Add(new FileSystemNode
{
Id = cid,
Size = length,
DagSize = cipher.Length,
Links = FileSystemLink.None
});
}
else if (options.RawLeaves)
{
// TODO: Inefficent to copy chunk, use ArraySegment in DataMessage.Data
var data = new byte[length];
Array.Copy(chunk, data, length);
var cid = await blockService.PutAsync(
data : data,
contentType : "raw",
multiHash : options.Hash,
encoding : options.Encoding,
pin : options.Pin,
cancel : cancel);
nodes.Add(new FileSystemNode
{
Id = cid,
Size = length,
DagSize = length,
Links = FileSystemLink.None
});
}
else
{
// Build the DAG.
var dm = new DataMessage
{
Type = DataType.File,
FileSize = (ulong)length,
};
if (length > 0)
{
// TODO: Inefficent to copy chunk, use ArraySegment in DataMessage.Data
var data = new byte[length];
Array.Copy(chunk, data, length);
dm.Data = data;
}
var pb = new MemoryStream();
ProtoBuf.Serializer.Serialize <DataMessage>(pb, dm);
var dag = new DagNode(pb.ToArray(), null, options.Hash);
// Save it.
dag.Id = await blockService.PutAsync(
data : dag.ToArray(),
multiHash : options.Hash,
encoding : options.Encoding,
pin : options.Pin,
cancel : cancel);
var node = new FileSystemNode
{
Id = dag.Id,
Size = length,
DagSize = dag.Size,
Links = FileSystemLink.None
};
nodes.Add(node);
}
}
return(nodes);
}
