The Tor Browser: comparison mobile/android/base/fxa/sync/FxAccountSchedulePolicy.java

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+:35b4ab0a55c1
+/* 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.fxa.sync;
+import org.mozilla.gecko.background.common.log.Logger;
+import org.mozilla.gecko.db.BrowserContract;
+import org.mozilla.gecko.fxa.authenticator.AndroidFxAccount;
+import org.mozilla.gecko.fxa.login.State.Action;
+import org.mozilla.gecko.sync.BackoffHandler;
+import android.accounts.Account;
+import android.content.ContentResolver;
+import android.content.Context;
+import android.os.Bundle;
+public class FxAccountSchedulePolicy implements SchedulePolicy {
+private static final String LOG_TAG = "FxAccountSchedulePolicy";
+// Our poll intervals are used to trigger automatic background syncs
+// in the absence of user activity.
+//
+// We also receive sync requests as a result of network tickles, so
+// these intervals are long, with the exception of the rapid polling
+// while we wait for verification: if we're waiting for the user to
+// click on a verification link, we sync very often in order to detect
+// a change in state.
+//
+// In the case of unverified -> unverified (no transition), this should be
+// very close to a single HTTP request (with the SyncAdapter overhead, of
+// course, but that's not wildly different from alarm manager overhead).
+//
+// The /account/status endpoint is HAWK authed by sessionToken, so we still
+// have to do some crypto no matter what.
+// TODO: only do this for a while...
+public static final long POLL_INTERVAL_PENDING_VERIFICATION = 60;         // 1 minute.
+// If we're in some kind of error state, there's no point trying often.
+// This is not the same as a server-imposed backoff, which will be
+// reflected dynamically.
+public static final long POLL_INTERVAL_ERROR_STATE_SEC = 24 * 60 * 60;    // 24 hours.
+// If we're the only device, just sync once or twice a day in case that
+// changes.
+public static final long POLL_INTERVAL_SINGLE_DEVICE_SEC = 18 * 60 * 60;  // 18 hours.
+// And if we know there are other devices, let's sync often enough that
+// we'll be more likely to be caught up (even if not completely) by the
+// time you next use this device. This is also achieved via Android's
+// network tickles.
+public static final long POLL_INTERVAL_MULTI_DEVICE_SEC = 12 * 60 * 60;   // 12 hours.
+// This is used solely as an optimization for backoff handling, so it's not
+// persisted.
+private static volatile long POLL_INTERVAL_CURRENT_SEC = POLL_INTERVAL_SINGLE_DEVICE_SEC;
+// Never sync more frequently than this, unless forced.
+// This is to avoid overly-frequent syncs during active browsing.
+public static final long RATE_LIMIT_FUNDAMENTAL_SEC = 90;                 // 90 seconds.
+/**
+* We are prompted to sync by several inputs:
+* * Periodic syncs that we schedule at long intervals. See the POLL constants.
+* * Network-tickle-based syncs that Android starts.
+* * Upload-only syncs that are caused by local database writes.
+*
+* We rate-limit periodic and network-sourced events with this constant.
+* We rate limit <b>both</b> with {@link FxAccountSchedulePolicy#RATE_LIMIT_FUNDAMENTAL_SEC}.
+*/
+public static final long RATE_LIMIT_BACKGROUND_SEC = 60 * 60;             // 1 hour.
+private final AndroidFxAccount account;
+private final Context context;
+public FxAccountSchedulePolicy(Context context, AndroidFxAccount account) {
+this.account = account;
+this.context = context;
+}
+/**
+* Return a millisecond timestamp in the future, offset from the current
+* time by the provided amount.
+* @param millis the duration by which to delay
+* @return a timestamp.
+*/
+private static long delay(long millis) {
+return System.currentTimeMillis() + millis;
+}
+/**
+* Updates the existing system periodic sync interval to the specified duration.
+*
+* @param intervalSeconds the requested period, which Android will vary by up to 4%.
+*/
+protected void requestPeriodicSync(final long intervalSeconds) {
+final String authority = BrowserContract.AUTHORITY;
+final Account account = this.account.getAndroidAccount();
+this.context.getContentResolver();
+Logger.info(LOG_TAG, "Scheduling periodic sync for " + intervalSeconds + ".");
+ContentResolver.addPeriodicSync(account, authority, Bundle.EMPTY, intervalSeconds);
+POLL_INTERVAL_CURRENT_SEC = intervalSeconds;
+}
+@Override
+public void onSuccessfulSync(int otherClientsCount) {
+// This undoes the change made in observeBackoffMillis -- once we hit backoff we'll
+// periodically sync at the backoff duration, but as soon as we succeed we'll switch
+// into the client-count-dependent interval.
+long interval = (otherClientsCount > 0) ? POLL_INTERVAL_MULTI_DEVICE_SEC : POLL_INTERVAL_SINGLE_DEVICE_SEC;
+requestPeriodicSync(interval);
+}
+@Override
+public void onHandleFinal(Action needed) {
+switch (needed) {
+case NeedsPassword:
+case NeedsUpgrade:
+requestPeriodicSync(POLL_INTERVAL_ERROR_STATE_SEC);
+break;
+case NeedsVerification:
+requestPeriodicSync(POLL_INTERVAL_PENDING_VERIFICATION);
+break;
+case None:
+// No action needed: we'll set the periodic sync interval
+// when the sync finishes, via the SessionCallback.
+break;
+}
+}
+@Override
+public void onUpgradeRequired() {
+// TODO: this shouldn't occur in FxA, but when we upgrade we
+// need to reduce the interval again.
+requestPeriodicSync(POLL_INTERVAL_ERROR_STATE_SEC);
+}
+@Override
+public void onUnauthorized() {
+// TODO: this shouldn't occur in FxA, but when we fix our credentials
+// we need to reduce the interval again.
+requestPeriodicSync(POLL_INTERVAL_ERROR_STATE_SEC);
+}
+@Override
+public void configureBackoffMillisOnBackoff(BackoffHandler backoffHandler, long backoffMillis, boolean onlyExtend) {
+if (onlyExtend) {
+backoffHandler.extendEarliestNextRequest(delay(backoffMillis));
+} else {
+backoffHandler.setEarliestNextRequest(delay(backoffMillis));
+}
+// Yes, we might be part-way through the interval, in which case the backoff
+// code will do its job. But we certainly don't want to reduce the interval
+// if we're given a small backoff instruction.
+// We'll reset the poll interval next time we sync without a backoff instruction.
+if (backoffMillis > (POLL_INTERVAL_CURRENT_SEC * 1000)) {
+// Slightly inflate the backoff duration to ensure that a fuzzed
+// periodic sync doesn't occur before our backoff has passed. Android
+// 19+ default to a 4% fuzz factor.
+requestPeriodicSync((long) Math.ceil((1.05 * backoffMillis) / 1000));
+}
+}
+/**
+* Accepts two {@link BackoffHandler} instances as input. These are used
+* respectively to track fundamental rate limiting, and to separately
+* rate-limit periodic and network-tickled syncs.
+*/
+@Override
+public void configureBackoffMillisBeforeSyncing(BackoffHandler fundamentalRateHandler, BackoffHandler backgroundRateHandler) {
+fundamentalRateHandler.setEarliestNextRequest(delay(RATE_LIMIT_FUNDAMENTAL_SEC * 1000));
+backgroundRateHandler.setEarliestNextRequest(delay(RATE_LIMIT_BACKGROUND_SEC * 1000));
+}
+}

The Tor Browser / file comparison

comparison: mobile/android/base/fxa/sync/FxAccountSchedulePolicy.java

mobile/android/base/fxa/sync/FxAccountSchedulePolicy.java