/**
* Copyright 2011 Google 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 org.waveprotocol.box.server.rpc;
import com.google.common.annotations.VisibleForTesting;
import com.google.inject.Inject;
import com.google.inject.Singleton;
import com.google.inject.name.Named;
import com.google.protobuf.MessageLite;
import com.google.wave.api.SearchResult;
import com.google.wave.api.SearchResult.Digest;
import com.google.wave.api.data.converter.EventDataConverterManager;
import org.waveprotocol.box.search.SearchProto.SearchRequest;
import org.waveprotocol.box.search.SearchProto.SearchResponse;
import org.waveprotocol.box.search.SearchProto.SearchResponse.Builder;
import org.waveprotocol.box.server.authentication.SessionManager;
import org.waveprotocol.box.server.robots.OperationServiceRegistry;
import org.waveprotocol.box.server.robots.util.ConversationUtil;
import org.waveprotocol.box.server.rpc.ProtoSerializer.SerializationException;
import org.waveprotocol.box.server.waveserver.WaveletProvider;
import org.waveprotocol.box.webclient.search.SearchService;
import org.waveprotocol.wave.model.wave.ParticipantId;
import org.waveprotocol.wave.util.logging.Log;
import java.io.IOException;
import java.util.List;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
/**
* A servlet to provide search functionality by using Data API. Typically will
* be hosted on /search.
*
* Valid request format is: GET /search/?query=in:inbox&index=0&numResults=50.
* The format of the returned information is the protobuf-JSON format used by
* the websocket interface.
*
* @author vega113@gmail.com (Yuri Z.)
*/
@SuppressWarnings("serial")
@Singleton
public final class SearchServlet extends AbstractSearchServlet {
private static final Log LOG = Log.get(SearchServlet.class);
private final ProtoSerializer serializer;
/**
* Constructs SearchResponse which is a protobuf generated class from the
* output of Data API search service. SearchResponse contains the same
* information as searchResult.
*
* @param searchResult the search results with digests.
* @return SearchResponse
*/
public static SearchResponse serializeSearchResult(SearchResult searchResult, int total) {
Builder searchBuilder = SearchResponse.newBuilder();
searchBuilder.setQuery(searchResult.getQuery()).setTotalResults(total);
for (SearchResult.Digest searchResultDigest : searchResult.getDigests()) {
SearchResponse.Digest digest = serializeDigest(searchResultDigest);
searchBuilder.addDigests(digest);
}
SearchResponse searchResponse = searchBuilder.build();
return searchResponse;
}
/**
* Copies data from {@link Digest} into {@link SearchResponse.Digest}.
*/
private static SearchResponse.Digest serializeDigest(Digest searchResultDigest) {
SearchResponse.Digest.Builder digestBuilder = SearchResponse.Digest.newBuilder();
digestBuilder.setBlipCount(searchResultDigest.getBlipCount());
digestBuilder.setLastModified(searchResultDigest.getLastModified());
digestBuilder.setSnippet(searchResultDigest.getSnippet());
digestBuilder.setTitle(searchResultDigest.getTitle());
digestBuilder.setUnreadCount(searchResultDigest.getUnreadCount());
digestBuilder.setWaveId(searchResultDigest.getWaveId());
List<String> participants = searchResultDigest.getParticipants();
if (participants.isEmpty()) {
// This shouldn't be possible.
digestBuilder.setAuthor("nobody@example.com");
} else {
digestBuilder.setAuthor(participants.get(0));
for (int i = 1; i < participants.size(); i++) {
digestBuilder.addParticipants(participants.get(i));
}
}
SearchResponse.Digest digest = digestBuilder.build();
return digest;
}
@Inject
public SearchServlet(SessionManager sessionManager, EventDataConverterManager converterManager,
@Named("DataApiRegistry") OperationServiceRegistry operationRegistry,
WaveletProvider waveletProvider, ConversationUtil conversationUtil, ProtoSerializer serializer) {
super(conversationUtil, converterManager, waveletProvider, sessionManager, operationRegistry);
this.serializer = serializer;
}
/**
* Creates HTTP response to the search query. Main entrypoint for this class.
*/
@Override
@VisibleForTesting
protected void doGet(HttpServletRequest req, HttpServletResponse response) throws IOException {
ParticipantId user = sessionManager.getLoggedInUser(req.getSession(false));
if (user == null) {
response.setStatus(HttpServletResponse.SC_FORBIDDEN);
return;
}
SearchRequest searchRequest = parseSearchRequest(req, response);
SearchResult searchResult = performSearch(searchRequest, user);
int totalGuess = computeTotalResultsNumberGuess(searchRequest, searchResult);
LOG.fine("Results: " + searchResult.getNumResults() + ", total: " + totalGuess);
SearchResponse searchResponse = serializeSearchResult(searchResult, totalGuess);
serializeObjectToServlet(searchResponse, response);
}
private int computeTotalResultsNumberGuess(SearchRequest searchRequest, SearchResult searchResult) {
// The Data API does not return the total size of the search result, even
// though the searcher knows it. The only approximate knowledge that can be
// gleaned from the Data API is whether there are more search results beyond
// those returned. If the searcher returns as many (or more) results as
// requested, then assume that more results exist, but the total is unknown.
// Otherwise, the total has been reached.
int totalGuess;
if (searchResult.getNumResults() >= searchRequest.getNumResults()) {
totalGuess = SearchService.UNKNOWN_SIZE;
} else {
totalGuess = searchRequest.getIndex() + searchResult.getNumResults();
}
return totalGuess;
}
/**
* Writes the json with search results to Response.
*/
private void serializeObjectToServlet(MessageLite message, HttpServletResponse resp)
throws IOException {
if (message == null) {
resp.sendError(HttpServletResponse.SC_FORBIDDEN);
} else {
resp.setStatus(HttpServletResponse.SC_OK);
resp.setContentType("application/json; charset=utf8");
// This is to make sure the fetched data is fresh - since the w3c spec
// is rarely respected.
resp.setHeader("Cache-Control", "no-store");
try {
resp.getWriter().append(serializer.toJson(message).toString());
} catch (SerializationException e) {
throw new IOException(e);
}
}
}
}