/*
* Licensed to the Apache Software Foundation (ASF) under one
* or more contributor license agreements. See the NOTICE file
* distributed with this work for additional information
* regarding copyright ownership. The ASF licenses this file
* to you 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 org.apache.shindig.gadgets.http;
import org.apache.shindig.common.util.Utf8UrlCoder;
import org.apache.shindig.gadgets.GadgetException;
import org.apache.shindig.gadgets.oauth.OAuthRequest;
import org.apache.shindig.gadgets.rewrite.image.ImageRewriter;
import com.google.inject.Inject;
import com.google.inject.Provider;
import com.google.inject.Singleton;
/**
* A standard implementation of a request pipeline. Performs request caching and
* signing on top of standard HTTP requests.
*/
@Singleton
public class DefaultRequestPipeline implements RequestPipeline {
private final HttpFetcher httpFetcher;
private final HttpCache httpCache;
private final Provider<OAuthRequest> oauthRequestProvider;
private final ImageRewriter imageRewriter;
private final InvalidationService invalidationService;
@Inject
public DefaultRequestPipeline(HttpFetcher httpFetcher,
HttpCache httpCache,
Provider<OAuthRequest> oauthRequestProvider,
ImageRewriter imageRewriter,
InvalidationService invalidationService) {
this.httpFetcher = httpFetcher;
this.httpCache = httpCache;
this.oauthRequestProvider = oauthRequestProvider;
this.imageRewriter = imageRewriter;
this.invalidationService = invalidationService;
}
public HttpResponse execute(HttpRequest request) throws GadgetException {
normalizeProtocol(request);
HttpResponse invalidatedResponse = null;
if (!request.getIgnoreCache()) {
HttpResponse cachedResponse = httpCache.getResponse(request);
// Note that we don't remove invalidated entries from the cache as we want them to be
// available in the event of a backend fetch failure
if (cachedResponse != null) {
if (!cachedResponse.isStale()) {
if(invalidationService.isValid(request, cachedResponse)) {
return cachedResponse;
} else {
invalidatedResponse = cachedResponse;
}
}
}
}
HttpResponse fetchedResponse = null;
switch (request.getAuthType()) {
case NONE:
fetchedResponse = httpFetcher.fetch(request);
break;
case SIGNED:
case OAUTH:
fetchedResponse = oauthRequestProvider.get().fetch(request);
break;
default:
return HttpResponse.error();
}
if (fetchedResponse.isError() && invalidatedResponse != null) {
// Use the invalidated cached response if it is not stale. We don't update its
// mark so it remains invalidated
return invalidatedResponse;
}
if (!fetchedResponse.isError() && !request.getIgnoreCache() && request.getCacheTtl() != 0) {
fetchedResponse = imageRewriter.rewrite(request, fetchedResponse);
}
if (!request.getIgnoreCache() ) {
// Mark the response with invalidation information prior to caching
if (fetchedResponse.getCacheTtl() > 0) {
fetchedResponse = invalidationService.markResponse(request, fetchedResponse);
}
httpCache.addResponse(request, fetchedResponse);
}
return fetchedResponse;
}
public void normalizeProtocol(HttpRequest request) throws GadgetException {
// Normalize the protocol part of the URI
if (request.getUri().getScheme()== null) {
throw new GadgetException(GadgetException.Code.INVALID_PARAMETER,
"Url " + request.getUri().toString() + " does not include scheme");
} else if (!"http".equals(request.getUri().getScheme()) &&
!"https".equals(request.getUri().getScheme())) {
throw new GadgetException(GadgetException.Code.INVALID_PARAMETER,
"Invalid request url scheme in url: " + Utf8UrlCoder.encode(request.getUri().toString()) +
"; only \"http\" and \"https\" supported.");
}
}
}