public override void Ingress <T>(DryadLinqContext context,
IEnumerable <T> source,
Uri dataSetUri,
DryadLinqMetaData metaData,
CompressionScheme compressionScheme,
bool isTemp = false)
{
string account, key, container, blob;
AzureUtils.FromAzureUri(dataSetUri, out account, out key, out container, out blob);
if (compressionScheme != CompressionScheme.None)
{
throw new DryadLinqException("Not implemented: writing to Azure temporary storage with compression enabled");
}
AzureDfsClient client = new AzureDfsClient(account, key, container);
DryadLinqFactory <T> factory = (DryadLinqFactory <T>)DryadLinqCodeGen.GetFactory(context, typeof(T));
using (Stream stream = client.GetFileStreamWriterAsync(blob).Result)
{
DryadLinqBlockStream nativeStream = new DryadLinqBlockStream(stream);
DryadLinqRecordWriter <T> writer = factory.MakeWriter(nativeStream);
foreach (T rec in source)
{
writer.WriteRecordSync(rec);
}
writer.Close();
}
}
protected override async Task Open()
{
Log.LogInformation("Opening read for " + source.AbsoluteUri);
string account, key, container, blobName;
AzureUtils.FromAzureUri(source, out account, out key, out container, out blobName);
client = new AzureDfsClient(account, key, container, false, new PeloponneseLogger(Log.Logger));
client.SetParallelThreadCount(4);
NameValueCollection query = System.Web.HttpUtility.ParseQueryString(source.Query);
if (query["blobs"] == null)
{
blobIndex = -1;
}
else
{
blobIndex = 0;
}
await OpenBlob();
}
public override Uri RewriteUri <T>(DryadLinqContext context, Uri dataSetUri, FileAccess access)
{
string account, key, container, blob;
AzureUtils.FromAzureUri(dataSetUri, out account, out key, out container, out blob);
UriBuilder builder = new UriBuilder(dataSetUri);
NameValueCollection query = System.Web.HttpUtility.ParseQueryString(builder.Query);
if (key == null)
{
query["key"] = context.AzureAccountKey(account);
}
if (access != FileAccess.Write &&
typeof(T) == typeof(Microsoft.Research.DryadLinq.LineRecord))
{
query["seekBoundaries"] = "Microsoft.Research.DryadLinq.LineRecord";
}
builder.Query = query.ToString();
return(builder.Uri);
}
private async Task OpenBlob()
{
string account, key, container, blobName;
AzureUtils.FromAzureUri(source, out account, out key, out container, out blobName);
NameValueCollection query = System.Web.HttpUtility.ParseQueryString(source.Query);
if (blobIndex >= 0)
{
string[] blobs = query["blobs"].Split(',');
blobName += blobs[blobIndex];
++blobIndex;
}
Log.LogInformation("Opening read for blob " + blobName);
readStream = (await client.GetDfsFileStreamAsync(blobName, ExecutionTimeout, new PeloponneseLogger(Log.Logger))).Stream;
long offset = -1;
if (query["offset"] != null)
{
offset = Int64.Parse(query["offset"]);
readStream.Seek(offset, SeekOrigin.Begin);
}
bytesToRead = Int64.MaxValue;
if (query["length"] != null)
{
bytesToRead = Int64.Parse(query["length"]);
}
if (query["seekboundaries"] != null)
{
if (offset == -1 || bytesToRead == Int64.MaxValue)
{
throw new ApplicationException("Reading " + source.AbsoluteUri + ": Can't look for line endings without block start and end metadata");
}
if (query["seekboundaries"] != "Microsoft.Research.DryadLinq.LineRecord")
{
throw new ApplicationException("Reading " + source.AbsoluteUri + ": Don't know how to seek for record boundaries of type " + query["seekboundaries"]);
}
// SeekLineRecordBoundaries updates bytesToRead
offset = await SeekLineRecordBoundaries(offset);
readStream.Seek(offset, SeekOrigin.Begin);
}
long thisLength;
if (bytesToRead == Int64.MaxValue)
{
thisLength = readStream.Length;
}
else
{
thisLength = bytesToRead;
}
long currentLength = TotalLength;
if (currentLength == -1)
{
currentLength = thisLength;
Log.LogInformation("Setting Azure read total length to " + currentLength);
}
else
{
currentLength += thisLength;
Log.LogInformation("Increasing Azure read total length to " + thisLength);
}
TotalLength = currentLength;
}
