org.apache.druid.frame.file

Class FrameFileHttpResponseHandler

java.lang.Object

org.apache.druid.frame.file.FrameFileHttpResponseHandler

All Implemented Interfaces:

HttpResponseHandler<FrameFilePartialFetch,FrameFilePartialFetch>

public class FrameFileHttpResponseHandler
extends Object
implements HttpResponseHandler<FrameFilePartialFetch,FrameFilePartialFetch>

An HttpResponseHandler that streams data into a ReadableByteChunksFrameChannel. It is not required that the request actually fetches an entire frame file. The return object for this handler, FrameFilePartialFetch, allows callers to tell how much of the file was read in a particular request. This handler implements backpressure through FrameFilePartialFetch.backpressureFuture(). This allows callers to back off from issuing the next request, if appropriate. However: the handler does not implement backpressure through the HttpResponseHandler.TrafficCop mechanism. Therefore, it is important that each request retrieve a modest amount of data. The last fetch must be empty (zero content bytes) and must have the header HEADER_LAST_FETCH_NAME set to HEADER_LAST_FETCH_VALUE. Under these conditions, FrameFilePartialFetch.isLastFetch() returns true.

Nested Class Summary

Nested classes/interfaces inherited from interface org.apache.druid.java.util.http.client.response.HttpResponseHandler

HttpResponseHandler.TrafficCop

Field Summary

Fields

Modifier and Type	Field and Description
static String	HEADER_LAST_FETCH_NAME
static String	HEADER_LAST_FETCH_VALUE

Constructor Summary

Constructors

Constructor and Description
FrameFileHttpResponseHandler(ReadableByteChunksFrameChannel channel)

Method Summary

Modifier and Type	Method and Description
ClientResponse<FrameFilePartialFetch>	done(ClientResponse<FrameFilePartialFetch> clientResponse) Called after the final handleResponse() or handleChunk() call, signifying that no more data will arrive.
void	exceptionCaught(ClientResponse<FrameFilePartialFetch> clientResponse, Throwable e)
ClientResponse<FrameFilePartialFetch>	handleChunk(ClientResponse<FrameFilePartialFetch> clientResponse, org.jboss.netty.handler.codec.http.HttpChunk chunk, long chunkNum) Called for chunked responses, indicating another HttpChunk has arrived.
ClientResponse<FrameFilePartialFetch>	handleResponse(org.jboss.netty.handler.codec.http.HttpResponse response, HttpResponseHandler.TrafficCop trafficCop) Handles the initial HttpResponse object that comes back from Netty.

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Field Detail

HEADER_LAST_FETCH_NAME

public static final String HEADER_LAST_FETCH_NAME

See Also:

Constant Field Values

HEADER_LAST_FETCH_VALUE

public static final String HEADER_LAST_FETCH_VALUE

See Also:

Constant Field Values

Constructor Detail

FrameFileHttpResponseHandler

public FrameFileHttpResponseHandler(ReadableByteChunksFrameChannel channel)

Method Detail

handleResponse

public ClientResponse<FrameFilePartialFetch> handleResponse(org.jboss.netty.handler.codec.http.HttpResponse response,
                                                            HttpResponseHandler.TrafficCop trafficCop)

Description copied from interface: HttpResponseHandler

Handles the initial HttpResponse object that comes back from Netty.

Specified by:

handleResponse in interface HttpResponseHandler<FrameFilePartialFetch,FrameFilePartialFetch>

Parameters:

response - response from Netty

trafficCop - flow controller, allows resuming suspended reads

Returns:

response that may be "finished" or "unfinished".

handleChunk

public ClientResponse<FrameFilePartialFetch> handleChunk(ClientResponse<FrameFilePartialFetch> clientResponse,
                                                         org.jboss.netty.handler.codec.http.HttpChunk chunk,
                                                         long chunkNum)

Description copied from interface: HttpResponseHandler

Called for chunked responses, indicating another HttpChunk has arrived.

Specified by:

handleChunk in interface HttpResponseHandler<FrameFilePartialFetch,FrameFilePartialFetch>

Parameters:

clientResponse - last response returned by the prior handleResponse() or handleChunk()

chunk - the new chunk of data

chunkNum - the sequence number of this chunk (increases monotonically)

Returns:

response that may be "finished" or "unfinished".

done

public ClientResponse<FrameFilePartialFetch> done(ClientResponse<FrameFilePartialFetch> clientResponse)

Description copied from interface: HttpResponseHandler

Called after the final handleResponse() or handleChunk() call, signifying that no more data will arrive.

Specified by:

done in interface HttpResponseHandler<FrameFilePartialFetch,FrameFilePartialFetch>

Parameters:

clientResponse - last response returned by handleResponse() or handleChunk()

Returns:

response containing an object to hand back to the caller. It must be a "finished" response.

exceptionCaught

public void exceptionCaught(ClientResponse<FrameFilePartialFetch> clientResponse,
                            Throwable e)

Specified by:

exceptionCaught in interface HttpResponseHandler<FrameFilePartialFetch,FrameFilePartialFetch>