package android.content;
import android.database.SQLException;
import android.os.Bundle;
import android.os.Debug;
import android.os.NetStat;
import android.os.Parcelable;
import android.os.Process;
import android.os.SystemProperties;
import android.text.TextUtils;
import android.util.Config;
import android.util.EventLog;
import android.util.Log;
import android.util.TimingLogger;
/**
* @hide
*/
public abstract class TempProviderSyncAdapter extends SyncAdapter {
private static final String TAG = "Sync";
private static final int MAX_GET_SERVER_DIFFS_LOOP_COUNT = 20;
private static final int MAX_UPLOAD_CHANGES_LOOP_COUNT = 10;
private static final int NUM_ALLOWED_SIMULTANEOUS_DELETIONS = 5;
private static final long PERCENT_ALLOWED_SIMULTANEOUS_DELETIONS = 20;
private volatile SyncableContentProvider mProvider;
private volatile SyncThread mSyncThread = null;
private volatile boolean mProviderSyncStarted;
private volatile boolean mAdapterSyncStarted;
public TempProviderSyncAdapter(SyncableContentProvider provider) {
super();
mProvider = provider;
}
/**
* Used by getServerDiffs() to track the sync progress for a given
* sync adapter. Implementations of SyncAdapter generally specialize
* this class in order to track specific data about that SyncAdapter's
* sync. If an implementation of SyncAdapter doesn't need to store
* any data for a sync it may use TrivialSyncData.
*/
public static abstract class SyncData implements Parcelable {
}
public final void setContext(Context context) {
mContext = context;
}
/**
* Retrieve the Context this adapter is running in. Only available
* once onSyncStarting() is called (not available from constructor).
*/
final public Context getContext() {
return mContext;
}
/**
* Called right before a sync is started.
*
* @param context allows you to publish status and interact with the
* @param account the account to sync
* @param forced if true then the sync was forced
* @param result information to track what happened during this sync attempt
* @return true, if the sync was successfully started. One reason it can
* fail to start is if there is no user configured on the device.
*/
public abstract void onSyncStarting(SyncContext context, String account, boolean forced,
SyncResult result);
/**
* Called right after a sync is completed
*
* @param context allows you to publish status and interact with the
* user during interactive syncs.
* @param success true if the sync suceeded, false if an error occured
*/
public abstract void onSyncEnding(SyncContext context, boolean success);
/**
* Implement this to return true if the data in your content provider
* is read only.
*/
public abstract boolean isReadOnly();
/**
* Get diffs from the server since the last completed sync and put them
* into a temporary provider.
*
* @param context allows you to publish status and interact with the
* user during interactive syncs.
* @param syncData used to track the progress this client has made in syncing data
* from the server
* @param tempProvider this is where the diffs should be stored
* @param extras any extra data describing the sync that is desired
* @param syncInfo sync adapter-specific data that is used during a single sync operation
* @param syncResult information to track what happened during this sync attempt
*/
public abstract void getServerDiffs(SyncContext context,
SyncData syncData, SyncableContentProvider tempProvider,
Bundle extras, Object syncInfo, SyncResult syncResult);
/**
* Send client diffs to the server, optionally receiving more diffs from the server
*
* @param context allows you to publish status and interact with the
* user during interactive syncs.
* @param clientDiffs the diffs from the client
* @param serverDiffs the SyncableContentProvider that should be populated with
* the entries that were returned in response to an insert/update/delete request
* to the server
* @param syncResult information to track what happened during this sync attempt
* @param dontActuallySendDeletes
*/
public abstract void sendClientDiffs(SyncContext context,
SyncableContentProvider clientDiffs,
SyncableContentProvider serverDiffs, SyncResult syncResult,
boolean dontActuallySendDeletes);
/**
* Reads the sync data from the ContentProvider
* @param contentProvider the ContentProvider to read from
* @return the SyncData for the provider. This may be null.
*/
public SyncData readSyncData(SyncableContentProvider contentProvider) {
return null;
}
/**
* Create and return a new, empty SyncData object
*/
public SyncData newSyncData() {
return null;
}
/**
* Stores the sync data in the Sync Stats database, keying it by
* the account that was set in the last call to onSyncStarting()
*/
public void writeSyncData(SyncData syncData, SyncableContentProvider contentProvider) {}
/**
* Indicate to the SyncAdapter that the last sync that was started has
* been cancelled.
*/
public abstract void onSyncCanceled();
/**
* Initializes the temporary content providers used during
* {@link TempProviderSyncAdapter#sendClientDiffs}.
* May copy relevant data from the underlying db into this provider so
* joins, etc., can work.
*
* @param cp The ContentProvider to initialize.
*/
protected void initTempProvider(SyncableContentProvider cp) {}
protected Object createSyncInfo() {
return null;
}
/**
* Called when the accounts list possibly changed, to give the
* SyncAdapter a chance to do any necessary bookkeeping, e.g.
* to make sure that any required SubscribedFeeds subscriptions
* exist.
* @param accounts the list of accounts
*/
public abstract void onAccountsChanged(String[] accounts);
private Context mContext;
private class SyncThread extends Thread {
private final String mAccount;
private final Bundle mExtras;
private final SyncContext mSyncContext;
private volatile boolean mIsCanceled = false;
private long mInitialTxBytes;
private long mInitialRxBytes;
private final SyncResult mResult;
SyncThread(SyncContext syncContext, String account, Bundle extras) {
super("SyncThread");
mAccount = account;
mExtras = extras;
mSyncContext = syncContext;
mResult = new SyncResult();
}
void cancelSync() {
mIsCanceled = true;
if (mAdapterSyncStarted) onSyncCanceled();
if (mProviderSyncStarted) mProvider.onSyncCanceled();
// We may lose the last few sync events when canceling. Oh well.
int uid = Process.myUid();
logSyncDetails(NetStat.getUidTxBytes(uid) - mInitialTxBytes,
NetStat.getUidRxBytes(uid) - mInitialRxBytes, mResult);
}
@Override
public void run() {
Process.setThreadPriority(Process.myTid(),
Process.THREAD_PRIORITY_BACKGROUND);
int uid = Process.myUid();
mInitialTxBytes = NetStat.getUidTxBytes(uid);
mInitialRxBytes = NetStat.getUidRxBytes(uid);
try {
sync(mSyncContext, mAccount, mExtras);
} catch (SQLException e) {
Log.e(TAG, "Sync failed", e);
mResult.databaseError = true;
} finally {
mSyncThread = null;
if (!mIsCanceled) {
logSyncDetails(NetStat.getUidTxBytes(uid) - mInitialTxBytes,
NetStat.getUidRxBytes(uid) - mInitialRxBytes, mResult);
mSyncContext.onFinished(mResult);
}
}
}
private void sync(SyncContext syncContext, String account, Bundle extras) {
mIsCanceled = false;
mProviderSyncStarted = false;
mAdapterSyncStarted = false;
String message = null;
boolean syncForced = extras.getBoolean(ContentResolver.SYNC_EXTRAS_FORCE, false);
try {
mProvider.onSyncStart(syncContext, account);
mProviderSyncStarted = true;
onSyncStarting(syncContext, account, syncForced, mResult);
if (mResult.hasError()) {
message = "SyncAdapter failed while trying to start sync";
return;
}
mAdapterSyncStarted = true;
if (mIsCanceled) {
return;
}
final String syncTracingEnabledValue = SystemProperties.get(TAG + "Tracing");
final boolean syncTracingEnabled = !TextUtils.isEmpty(syncTracingEnabledValue);
try {
if (syncTracingEnabled) {
System.gc();
System.gc();
Debug.startMethodTracing("synctrace." + System.currentTimeMillis());
}
runSyncLoop(syncContext, account, extras);
} finally {
if (syncTracingEnabled) Debug.stopMethodTracing();
}
onSyncEnding(syncContext, !mResult.hasError());
mAdapterSyncStarted = false;
mProvider.onSyncStop(syncContext, true);
mProviderSyncStarted = false;
} finally {
if (mAdapterSyncStarted) {
mAdapterSyncStarted = false;
onSyncEnding(syncContext, false);
}
if (mProviderSyncStarted) {
mProviderSyncStarted = false;
mProvider.onSyncStop(syncContext, false);
}
if (!mIsCanceled) {
if (message != null) syncContext.setStatusText(message);
}
}
}
private void runSyncLoop(SyncContext syncContext, String account, Bundle extras) {
TimingLogger syncTimer = new TimingLogger(TAG + "Profiling", "sync");
syncTimer.addSplit("start");
int loopCount = 0;
boolean tooManyGetServerDiffsAttempts = false;
final boolean overrideTooManyDeletions =
extras.getBoolean(ContentResolver.SYNC_EXTRAS_OVERRIDE_TOO_MANY_DELETIONS,
false);
final boolean discardLocalDeletions =
extras.getBoolean(ContentResolver.SYNC_EXTRAS_DISCARD_LOCAL_DELETIONS, false);
boolean uploadOnly = extras.getBoolean(ContentResolver.SYNC_EXTRAS_UPLOAD,
false /* default this flag to false */);
SyncableContentProvider serverDiffs = null;
TempProviderSyncResult result = new TempProviderSyncResult();
try {
if (!uploadOnly) {
/**
* This loop repeatedly calls SyncAdapter.getServerDiffs()
* (to get changes from the feed) followed by
* ContentProvider.merge() (to incorporate these changes
* into the provider), stopping when the SyncData returned
* from getServerDiffs() indicates that all the data was
* fetched.
*/
while (!mIsCanceled) {
// Don't let a bad sync go forever
if (loopCount++ == MAX_GET_SERVER_DIFFS_LOOP_COUNT) {
Log.e(TAG, "runSyncLoop: Hit max loop count while getting server diffs "
+ getClass().getName());
// TODO: change the structure here to schedule a new sync
// with a backoff time, keeping track to be sure
// we don't keep doing this forever (due to some bug or
// mismatch between the client and the server)
tooManyGetServerDiffsAttempts = true;
break;
}
// Get an empty content provider to put the diffs into
if (serverDiffs != null) serverDiffs.close();
serverDiffs = mProvider.getTemporaryInstance();
// Get records from the server which will be put into the serverDiffs
initTempProvider(serverDiffs);
Object syncInfo = createSyncInfo();
SyncData syncData = readSyncData(serverDiffs);
// syncData will only be null if there was a demarshalling error
// while reading the sync data.
if (syncData == null) {
mProvider.wipeAccount(account);
syncData = newSyncData();
}
mResult.clear();
if (Log.isLoggable(TAG, Log.VERBOSE)) {
Log.v(TAG, "runSyncLoop: running getServerDiffs using syncData "
+ syncData.toString());
}
getServerDiffs(syncContext, syncData, serverDiffs, extras, syncInfo,
mResult);
if (mIsCanceled) return;
if (Log.isLoggable(TAG, Log.VERBOSE)) {
Log.v(TAG, "runSyncLoop: result: " + mResult);
}
if (mResult.hasError()) return;
if (mResult.partialSyncUnavailable) {
if (Config.LOGD) {
Log.d(TAG, "partialSyncUnavailable is set, setting "
+ "ignoreSyncData and retrying");
}
mProvider.wipeAccount(account);
continue;
}
// write the updated syncData back into the temp provider
writeSyncData(syncData, serverDiffs);
// apply the downloaded changes to the provider
if (Log.isLoggable(TAG, Log.VERBOSE)) {
Log.v(TAG, "runSyncLoop: running merge");
}
mProvider.merge(syncContext, serverDiffs,
null /* don't return client diffs */, mResult);
if (mIsCanceled) return;
if (Log.isLoggable(TAG, Log.VERBOSE)) {
Log.v(TAG, "runSyncLoop: result: " + mResult);
}
// if the server has no more changes then break out of the loop
if (!mResult.moreRecordsToGet) {
if (Log.isLoggable(TAG, Log.VERBOSE)) {
Log.v(TAG, "runSyncLoop: fetched all data, moving on");
}
break;
}
if (Log.isLoggable(TAG, Log.VERBOSE)) {
Log.v(TAG, "runSyncLoop: more data to fetch, looping");
}
}
}
/**
* This loop repeatedly calls ContentProvider.merge() followed
* by SyncAdapter.merge() until either indicate that there is
* no more work to do by returning null.
* <p>
* The initial ContentProvider.merge() returns a temporary
* ContentProvider that contains any local changes that need
* to be committed to the server.
* <p>
* The SyncAdapter.merge() calls upload the changes to the server
* and populates temporary provider (the serverDiffs) with the
* result.
* <p>
* Subsequent calls to ContentProvider.merge() incoporate the
* result of previous SyncAdapter.merge() calls into the
* real ContentProvider and again return a temporary
* ContentProvider that contains any local changes that need
* to be committed to the server.
*/
loopCount = 0;
boolean readOnly = isReadOnly();
long previousNumModifications = 0;
if (serverDiffs != null) {
serverDiffs.close();
serverDiffs = null;
}
// If we are discarding local deletions then we need to redownload all the items
// again (since some of them might have been deleted). We do this by deleting the
// sync data for the current account by writing in a null one.
if (discardLocalDeletions) {
serverDiffs = mProvider.getTemporaryInstance();
initTempProvider(serverDiffs);
writeSyncData(null, serverDiffs);
}
while (!mIsCanceled) {
if (Config.LOGV) {
Log.v(TAG, "runSyncLoop: Merging diffs from server to client");
}
if (result.tempContentProvider != null) {
result.tempContentProvider.close();
result.tempContentProvider = null;
}
mResult.clear();
mProvider.merge(syncContext, serverDiffs, readOnly ? null : result,
mResult);
if (mIsCanceled) return;
if (Log.isLoggable(TAG, Log.VERBOSE)) {
Log.v(TAG, "runSyncLoop: result: " + mResult);
}
SyncableContentProvider clientDiffs =
readOnly ? null : result.tempContentProvider;
if (clientDiffs == null) {
// Nothing to commit back to the server
if (Config.LOGV) Log.v(TAG, "runSyncLoop: No client diffs");
break;
}
long numModifications = mResult.stats.numUpdates
+ mResult.stats.numDeletes
+ mResult.stats.numInserts;
// as long as we are making progress keep resetting the loop count
if (numModifications < previousNumModifications) {
loopCount = 0;
}
previousNumModifications = numModifications;
// Don't let a bad sync go forever
if (loopCount++ >= MAX_UPLOAD_CHANGES_LOOP_COUNT) {
Log.e(TAG, "runSyncLoop: Hit max loop count while syncing "
+ getClass().getName());
mResult.tooManyRetries = true;
break;
}
if (!overrideTooManyDeletions && !discardLocalDeletions
&& hasTooManyDeletions(mResult.stats)) {
if (Config.LOGD) {
Log.d(TAG, "runSyncLoop: Too many deletions were found in provider "
+ getClass().getName() + ", not doing any more updates");
}
long numDeletes = mResult.stats.numDeletes;
mResult.stats.clear();
mResult.tooManyDeletions = true;
mResult.stats.numDeletes = numDeletes;
break;
}
if (Config.LOGV) Log.v(TAG, "runSyncLoop: Merging diffs from client to server");
if (serverDiffs != null) serverDiffs.close();
serverDiffs = clientDiffs.getTemporaryInstance();
initTempProvider(serverDiffs);
mResult.clear();
sendClientDiffs(syncContext, clientDiffs, serverDiffs, mResult,
discardLocalDeletions);
if (Log.isLoggable(TAG, Log.VERBOSE)) {
Log.v(TAG, "runSyncLoop: result: " + mResult);
}
if (!mResult.madeSomeProgress()) {
if (Log.isLoggable(TAG, Log.VERBOSE)) {
Log.v(TAG, "runSyncLoop: No data from client diffs merge");
}
break;
}
if (Log.isLoggable(TAG, Log.VERBOSE)) {
Log.v(TAG, "runSyncLoop: made some progress, looping");
}
}
// add in any status codes that we saved from earlier
mResult.tooManyRetries |= tooManyGetServerDiffsAttempts;
if (Log.isLoggable(TAG, Log.VERBOSE)) {
Log.v(TAG, "runSyncLoop: final result: " + mResult);
}
} finally {
// do this in the finally block to guarantee that is is set and not overwritten
if (discardLocalDeletions) {
mResult.fullSyncRequested = true;
}
if (serverDiffs != null) serverDiffs.close();
if (result.tempContentProvider != null) result.tempContentProvider.close();
syncTimer.addSplit("stop");
syncTimer.dumpToLog();
}
}
}
/**
* Logs details on the sync.
* Normally this will be overridden by a subclass that will provide
* provider-specific details.
*
* @param bytesSent number of bytes the sync sent over the network
* @param bytesReceived number of bytes the sync received over the network
* @param result The SyncResult object holding info on the sync
*/
protected void logSyncDetails(long bytesSent, long bytesReceived, SyncResult result) {
EventLog.writeEvent(SyncAdapter.LOG_SYNC_DETAILS, TAG, bytesSent, bytesReceived, "");
}
public void startSync(SyncContext syncContext, String account, Bundle extras) {
if (mSyncThread != null) {
syncContext.onFinished(SyncResult.ALREADY_IN_PROGRESS);
return;
}
mSyncThread = new SyncThread(syncContext, account, extras);
mSyncThread.start();
}
public void cancelSync() {
if (mSyncThread != null) {
mSyncThread.cancelSync();
}
}
protected boolean hasTooManyDeletions(SyncStats stats) {
long numEntries = stats.numEntries;
long numDeletedEntries = stats.numDeletes;
long percentDeleted = (numDeletedEntries == 0)
? 0
: (100 * numDeletedEntries /
(numEntries + numDeletedEntries));
boolean tooManyDeletions =
(numDeletedEntries > NUM_ALLOWED_SIMULTANEOUS_DELETIONS)
&& (percentDeleted > PERCENT_ALLOWED_SIMULTANEOUS_DELETIONS);
return tooManyDeletions;
}
}