/*
* Copyright 2010 Proofpoint, Inc.
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package com.proofpoint.discovery.client.announce;
import com.google.common.base.Charsets;
import com.google.common.io.CharStreams;
import com.google.common.net.HttpHeaders;
import com.google.common.net.MediaType;
import com.google.common.util.concurrent.ListenableFuture;
import com.google.inject.Inject;
import com.proofpoint.discovery.client.DiscoveryException;
import com.proofpoint.discovery.client.ForDiscoveryClient;
import com.proofpoint.http.client.CacheControl;
import com.proofpoint.http.client.HttpClient;
import com.proofpoint.http.client.Request;
import com.proofpoint.http.client.Request.Builder;
import com.proofpoint.http.client.Response;
import com.proofpoint.http.client.ResponseHandler;
import com.proofpoint.json.JsonCodec;
import com.proofpoint.node.NodeInfo;
import com.proofpoint.units.Duration;
import java.io.IOException;
import java.io.InputStreamReader;
import java.net.URI;
import java.util.Set;
import java.util.concurrent.CancellationException;
import java.util.concurrent.TimeUnit;
import static com.google.common.base.Preconditions.checkNotNull;
import static com.proofpoint.http.client.JsonBodyGenerator.jsonBodyGenerator;
import static com.proofpoint.http.client.Request.Builder.prepareDelete;
import static com.proofpoint.http.client.Request.Builder.preparePut;
public class HttpDiscoveryAnnouncementClient implements DiscoveryAnnouncementClient
{
private static final MediaType MEDIA_TYPE_JSON = MediaType.create("application", "json");
private final NodeInfo nodeInfo;
private final JsonCodec<Announcement> announcementCodec;
private final HttpClient httpClient;
@Inject
public HttpDiscoveryAnnouncementClient(NodeInfo nodeInfo,
JsonCodec<Announcement> announcementCodec,
@ForDiscoveryClient HttpClient httpClient)
{
checkNotNull(nodeInfo, "nodeInfo is null");
checkNotNull(announcementCodec, "announcementCodec is null");
checkNotNull(httpClient, "httpClient is null");
this.nodeInfo = nodeInfo;
this.announcementCodec = announcementCodec;
this.httpClient = httpClient;
}
@Override
public ListenableFuture<Duration> announce(Set<ServiceAnnouncement> services)
{
checkNotNull(services, "services is null");
Builder builder;
final boolean servicesEmpty = services.isEmpty();
if (servicesEmpty) {
builder = prepareDelete();
}
else {
Announcement announcement = new Announcement(nodeInfo.getEnvironment(), nodeInfo.getNodeId(), nodeInfo.getPool(), nodeInfo.getLocation(), services);
builder = preparePut()
.setHeader("Content-Type", MEDIA_TYPE_JSON.toString())
.setBodyGenerator(jsonBodyGenerator(announcementCodec, announcement));
}
Request request = builder
.setUri(URI.create("v1/announcement/" + nodeInfo.getNodeId()))
.setHeader("User-Agent", nodeInfo.getNodeId())
.build();
return httpClient.executeAsync(request, new DiscoveryResponseHandler<Duration>("Announcement")
{
@Override
public Duration handle(Request request, Response response)
throws DiscoveryException
{
int statusCode = response.getStatusCode();
if (statusCode == 404 && servicesEmpty) {
statusCode = 200;
}
if (!isSuccess(statusCode)) {
throw new DiscoveryException(String.format("Announcement failed with status code %s: %s", statusCode, getBodyForError(response)));
}
return extractMaxAge(response);
}
});
}
private boolean isSuccess(int statusCode)
{
return statusCode / 100 == 2;
}
private static String getBodyForError(Response response)
{
try {
return CharStreams.toString(new InputStreamReader(response.getInputStream(), Charsets.UTF_8));
}
catch (IOException e) {
return "(error getting body)";
}
}
@Override
public ListenableFuture<Void> unannounce()
{
Request request = prepareDelete()
.setUri(URI.create("v1/announcement/" + nodeInfo.getNodeId()))
.setHeader("User-Agent", nodeInfo.getNodeId())
.build();
return httpClient.executeAsync(request, new DiscoveryResponseHandler<Void>("Unannouncement"));
}
private Duration extractMaxAge(Response response)
{
String header = response.getHeader(HttpHeaders.CACHE_CONTROL);
if (header != null) {
CacheControl cacheControl = CacheControl.valueOf(header);
if (cacheControl.getMaxAge() > 0) {
return new Duration(cacheControl.getMaxAge(), TimeUnit.SECONDS);
}
}
return DEFAULT_DELAY;
}
private static class DiscoveryResponseHandler<T>
implements ResponseHandler<T, DiscoveryException>
{
private final String name;
protected DiscoveryResponseHandler(String name)
{
this.name = name;
}
@Override
public T handle(Request request, Response response)
{
return null;
}
@Override
public final T handleException(Request request, Exception exception)
{
if (exception instanceof InterruptedException) {
throw new DiscoveryException(name + " was interrupted");
}
if (exception instanceof CancellationException) {
throw new DiscoveryException(name + " was canceled");
}
if (exception instanceof DiscoveryException) {
throw (DiscoveryException) exception;
}
throw new DiscoveryException(name + " failed", exception);
}
}
}