nl.topicus.jdbc.shaded.io.grpc.stub.MetadataUtils Maven / Gradle / Ivy
Go to download
Show more of this group Show more artifacts with this name
Show all versions of spanner-jdbc Show documentation
Show all versions of spanner-jdbc Show documentation
JDBC Driver for Google Cloud Spanner
/*
* Copyright 2014, Google Inc. All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions are
* met:
*
* * Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* * Redistributions in binary form must reproduce the above
* copyright notice, this list of conditions and the following disclaimer
* in the documentation and/or other materials provided with the
* distribution.
*
* * Neither the name of Google Inc. nor the names of its
* contributors may be used to endorse or promote products derived from
* this software without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
* "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
* LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
* A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
* OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
* SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
* LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
* DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
* THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
* OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*/
package nl.topicus.jdbc.shaded.io.grpc.stub;
import nl.topicus.jdbc.shaded.io.grpc.CallOptions;
import nl.topicus.jdbc.shaded.io.grpc.Channel;
import nl.topicus.jdbc.shaded.io.grpc.ClientCall;
import nl.topicus.jdbc.shaded.io.grpc.ClientInterceptor;
import nl.topicus.jdbc.shaded.io.grpc.ExperimentalApi;
import nl.topicus.jdbc.shaded.io.grpc.ForwardingClientCall.SimpleForwardingClientCall;
import nl.topicus.jdbc.shaded.io.grpc.ForwardingClientCallListener.SimpleForwardingClientCallListener;
import nl.topicus.jdbc.shaded.io.grpc.Metadata;
import nl.topicus.jdbc.shaded.io.grpc.MethodDescriptor;
import nl.topicus.jdbc.shaded.io.grpc.Status;
import java.util.concurrent.atomic.AtomicReference;
/**
* Utility functions for binding and receiving headers.
*/
public final class MetadataUtils {
// Prevent instantiation
private MetadataUtils() {}
/**
* Attaches a set of request headers to a stub.
*
* @param stub to bind the headers to.
* @param extraHeaders the headers to be passed by each call on the returned stub.
* @return an implementation of the stub with {@code extraHeaders} bound to each call.
*/
@ExperimentalApi("https://github.nl.topicus.jdbc.shaded.com.grpc/grpc-java/issues/1789")
public static > T attachHeaders(
T stub,
final Metadata extraHeaders) {
return stub.withInterceptors(newAttachHeadersInterceptor(extraHeaders));
}
/**
* Returns a client interceptor that attaches a set of headers to requests.
*
* @param extraHeaders the headers to be passed by each call that is processed by the returned
* interceptor
*/
public static ClientInterceptor newAttachHeadersInterceptor(final Metadata extraHeaders) {
return new ClientInterceptor() {
@Override
public ClientCall interceptCall(
MethodDescriptor method,
CallOptions callOptions,
Channel next) {
return new SimpleForwardingClientCall(next.newCall(method, callOptions)) {
@Override
public void start(Listener responseListener, Metadata headers) {
headers.merge(extraHeaders);
super.start(responseListener, headers);
}
};
}
};
}
/**
* Captures the last received metadata for a stub. Useful for testing
*
* @param stub to capture for
* @param headersCapture to record the last received headers
* @param trailersCapture to record the last received trailers
* @return an implementation of the stub that allows to access the last received call's
* headers and trailers via {@code headersCapture} and {@code trailersCapture}.
*/
@ExperimentalApi("https://github.nl.topicus.jdbc.shaded.com.grpc/grpc-java/issues/1789")
public static > T captureMetadata(
T stub,
AtomicReference headersCapture,
AtomicReference trailersCapture) {
return stub.withInterceptors(
newCaptureMetadataInterceptor(headersCapture, trailersCapture));
}
/**
* Captures the last received metadata on a channel. Useful for testing.
*
* @param headersCapture to record the last received headers
* @param trailersCapture to record the last received trailers
* @return an implementation of the channel with captures installed.
*/
public static ClientInterceptor newCaptureMetadataInterceptor(
final AtomicReference headersCapture,
final AtomicReference trailersCapture) {
return new ClientInterceptor() {
@Override
public ClientCall interceptCall(
MethodDescriptor method,
CallOptions callOptions,
Channel next) {
return new SimpleForwardingClientCall(next.newCall(method, callOptions)) {
@Override
public void start(Listener responseListener, Metadata headers) {
headersCapture.set(null);
trailersCapture.set(null);
super.start(new SimpleForwardingClientCallListener(responseListener) {
@Override
public void onHeaders(Metadata headers) {
headersCapture.set(headers);
super.onHeaders(headers);
}
@Override
public void onClose(Status status, Metadata trailers) {
trailersCapture.set(trailers);
super.onClose(status, trailers);
}
}, headers);
}
};
}
};
}
}