/* This Source Code Form is subject to the terms of the Mozilla Public
* License, v. 2.0. If a copy of the MPL was not distributed with this
* file, You can obtain one at http://mozilla.org/MPL/2.0/. */
package org.mozilla.gecko.sync.stage;
import java.net.URISyntaxException;
import org.mozilla.gecko.sync.CredentialsSource;
import org.mozilla.gecko.sync.InfoCounts;
import org.mozilla.gecko.sync.JSONRecordFetcher;
import org.mozilla.gecko.sync.Logger;
import org.mozilla.gecko.sync.repositories.ConstrainedServer11Repository;
import org.mozilla.gecko.sync.repositories.Repository;
import org.mozilla.gecko.sync.repositories.Server11RepositorySession;
import org.mozilla.gecko.sync.repositories.delegates.RepositorySessionCreationDelegate;
import android.content.Context;
/**
* This is a constrained repository -- one which fetches a limited number
* of records -- that additionally refuses to sync if the limit will
* be exceeded on a first sync by the number of records on the server.
*
* You must pass an {@link InfoCounts} instance, which will be interrogated
* in the event of a first sync.
*
* "First sync" means that our sync timestamp is not greater than zero.
*/
public class SafeConstrainedServer11Repository extends ConstrainedServer11Repository {
// This can be lazily evaluated if we need it.
private JSONRecordFetcher countFetcher;
public SafeConstrainedServer11Repository(String serverURI,
String username,
String collection,
CredentialsSource credentialsSource,
long limit,
String sort,
JSONRecordFetcher countFetcher)
throws URISyntaxException {
super(serverURI, username, collection, credentialsSource, limit, sort);
this.countFetcher = countFetcher;
}
@Override
public void createSession(RepositorySessionCreationDelegate delegate,
Context context) {
delegate.onSessionCreated(new CountCheckingServer11RepositorySession(this, this.getDefaultFetchLimit()));
}
public class CountCheckingServer11RepositorySession extends Server11RepositorySession {
/**
* The session will report no data available if this is a first sync
* and the server has more data available than this limit.
*/
private long fetchLimit;
public CountCheckingServer11RepositorySession(Repository repository, long fetchLimit) {
super(repository);
this.fetchLimit = fetchLimit;
}
@Override
public boolean shouldSkip() {
// If this is a first sync, verify that we aren't going to blow through our limit.
if (this.lastSyncTimestamp <= 0) {
final InfoCounts counts;
try {
// This'll probably be the same object, but best to obey the API.
counts = new InfoCounts(countFetcher.fetchBlocking());
} catch (Exception e) {
Logger.warn(LOG_TAG, "Skipping " + collection + " until we can fetch counts.", e);
return true;
}
Integer c = counts.getCount(collection);
if (c == null) {
return false;
}
Logger.info(LOG_TAG, "First sync for " + collection + ": " + c.intValue() + " items.");
if (c.intValue() > fetchLimit) {
Logger.warn(LOG_TAG, "Too many items to sync safely. Skipping.");
return true;
}
}
return super.shouldSkip();
}
}
}