Use system properties to track the current transport
This change retools the transport selection mechanism a fair bit. Transports
are now specified by name rather than by numeric ID, and the name of the
currently selected transport is stored in a persistent system property under the
name "persist.service.bkup.trans".
The name -> IBackupTransport translation is now handled by maintaining a map
from the names to the live IBackupTransport objects that correspond. The Google
transport service observer now registers and unregisters the transport as the
service goes up and down.
The bmgr command has been expanded to include real transport interrogation and
selection by name, and some documentation has been written for it.
diff --git a/services/java/com/android/server/BackupManagerService.java b/services/java/com/android/server/BackupManagerService.java
index c0f0d74..2b9ac4d 100644
--- a/services/java/com/android/server/BackupManagerService.java
+++ b/services/java/com/android/server/BackupManagerService.java
@@ -42,13 +42,13 @@
import android.os.ParcelFileDescriptor;
import android.os.Process;
import android.os.RemoteException;
+import android.os.SystemProperties;
import android.util.Log;
import android.util.SparseArray;
import android.backup.IBackupManager;
import android.backup.IRestoreObserver;
import android.backup.IRestoreSession;
-import android.backup.BackupManager;
import android.backup.RestoreSet;
import com.android.internal.backup.LocalTransport;
@@ -68,6 +68,7 @@
import java.util.HashMap;
import java.util.HashSet;
import java.util.List;
+import java.util.Map;
class BackupManagerService extends IBackupManager.Stub {
private static final String TAG = "BackupManagerService";
@@ -79,7 +80,6 @@
private static final int MSG_RUN_BACKUP = 1;
private static final int MSG_RUN_FULL_BACKUP = 2;
private static final int MSG_RUN_RESTORE = 3;
- private static final String RESTORE_OBSERVER_KEY = "_resOb";
// Timeout interval for deciding that a bind or clear-data has taken too long
static final long TIMEOUT_INTERVAL = 10 * 1000;
@@ -127,8 +127,11 @@
private final Object mClearDataLock = new Object();
private volatile boolean mClearingData;
- // Current active transport & restore session
- private int mTransportId;
+ // Transport bookkeeping
+ static private final String BACKUP_TRANSPORT_PROPERTY = "persist.service.bkup.trans";
+ private final HashMap<String,IBackupTransport> mTransports
+ = new HashMap<String,IBackupTransport>();
+ private String mCurrentTransport;
private IBackupTransport mLocalTransport, mGoogleTransport;
private RestoreSession mActiveRestoreSession;
@@ -175,11 +178,19 @@
// Set up our transport options and initialize the default transport
// TODO: Have transports register themselves somehow?
// TODO: Don't create transports that we don't need to?
- mTransportId = BackupManager.TRANSPORT_GOOGLE;
mLocalTransport = new LocalTransport(context); // This is actually pretty cheap
- mGoogleTransport = null;
+ ComponentName localName = new ComponentName(context, LocalTransport.class);
+ registerTransport(localName.flattenToShortString(), mLocalTransport);
- // Attach to the Google backup transport.
+ mGoogleTransport = null;
+ // !!! TODO: set up the default transport name "the right way"
+ mCurrentTransport = SystemProperties.get(BACKUP_TRANSPORT_PROPERTY,
+ "com.google.android.backup/.BackupTransportService");
+ if (DEBUG) Log.v(TAG, "Starting with transport " + mCurrentTransport);
+
+ // Attach to the Google backup transport. When this comes up, it will set
+ // itself as the current transport because we explicitly reset mCurrentTransport
+ // to null.
Intent intent = new Intent().setComponent(new ComponentName(
"com.google.android.backup",
"com.google.android.backup.BackupTransportService"));
@@ -238,6 +249,13 @@
}
}
+ // Add a transport to our set of available backends
+ private void registerTransport(String name, IBackupTransport transport) {
+ synchronized (mTransports) {
+ mTransports.put(name, transport);
+ }
+ }
+
// ----- Track installation/removal of packages -----
BroadcastReceiver mBroadcastReceiver = new BroadcastReceiver() {
public void onReceive(Context context, Intent intent) {
@@ -283,11 +301,13 @@
public void onServiceConnected(ComponentName name, IBinder service) {
if (DEBUG) Log.v(TAG, "Connected to Google transport");
mGoogleTransport = IBackupTransport.Stub.asInterface(service);
+ registerTransport(name.flattenToShortString(), mGoogleTransport);
}
public void onServiceDisconnected(ComponentName name) {
if (DEBUG) Log.v(TAG, "Disconnected from Google transport");
mGoogleTransport = null;
+ registerTransport(name.flattenToShortString(), null);
}
};
@@ -299,7 +319,7 @@
switch (msg.what) {
case MSG_RUN_BACKUP:
{
- IBackupTransport transport = getTransport(mTransportId);
+ IBackupTransport transport = getTransport(mCurrentTransport);
if (transport == null) {
Log.v(TAG, "Backup requested but no transport available");
break;
@@ -474,19 +494,13 @@
}
// Return the given transport
- private IBackupTransport getTransport(int transportID) {
- switch (transportID) {
- case BackupManager.TRANSPORT_LOCAL:
- Log.v(TAG, "Supplying local transport");
- return mLocalTransport;
-
- case BackupManager.TRANSPORT_GOOGLE:
- Log.v(TAG, "Supplying Google transport");
- return mGoogleTransport;
-
- default:
- Log.e(TAG, "Asked for unknown transport " + transportID);
- return null;
+ private IBackupTransport getTransport(String transportName) {
+ synchronized (mTransports) {
+ IBackupTransport transport = mTransports.get(transportName);
+ if (transport == null) {
+ Log.w(TAG, "Requested unavailable transport: " + transportName);
+ }
+ return transport;
}
}
@@ -1111,21 +1125,51 @@
}
}
- // Report the currently active transport
- public int getCurrentTransport() {
+ // Report the name of the currently active transport
+ public String getCurrentTransport() {
mContext.enforceCallingPermission("android.permission.BACKUP", "selectBackupTransport");
- Log.v(TAG, "getCurrentTransport() returning " + mTransportId);
- return mTransportId;
+ Log.v(TAG, "getCurrentTransport() returning " + mCurrentTransport);
+ return mCurrentTransport;
}
- // Select which transport to use for the next backup operation
- public int selectBackupTransport(int transportId) {
+ // Report all known, available backup transports
+ public String[] listAllTransports() {
mContext.enforceCallingPermission("android.permission.BACKUP", "selectBackupTransport");
- int prevTransport = mTransportId;
- mTransportId = transportId;
- Log.v(TAG, "selectBackupTransport() set " + mTransportId + " returning " + prevTransport);
- return prevTransport;
+ String[] list = null;
+ ArrayList<String> known = new ArrayList<String>();
+ for (Map.Entry<String, IBackupTransport> entry : mTransports.entrySet()) {
+ if (entry.getValue() != null) {
+ known.add(entry.getKey());
+ }
+ }
+
+ if (known.size() > 0) {
+ list = new String[known.size()];
+ known.toArray(list);
+ }
+ return list;
+ }
+
+ // Select which transport to use for the next backup operation. If the given
+ // name is not one of the available transports, no action is taken and the method
+ // returns null.
+ public String selectBackupTransport(String transport) {
+ mContext.enforceCallingPermission("android.permission.BACKUP", "selectBackupTransport");
+
+ synchronized (mTransports) {
+ String prevTransport = null;
+ if (mTransports.get(transport) != null) {
+ prevTransport = mCurrentTransport;
+ mCurrentTransport = transport;
+ SystemProperties.set(BACKUP_TRANSPORT_PROPERTY, transport);
+ Log.v(TAG, "selectBackupTransport() set " + mCurrentTransport
+ + " returning " + prevTransport);
+ } else {
+ Log.w(TAG, "Attempt to select unavailable transport " + transport);
+ }
+ return prevTransport;
+ }
}
// Callback: a requested backup agent has been instantiated. This should only
@@ -1163,7 +1207,7 @@
}
// Hand off a restore session
- public IRestoreSession beginRestoreSession(int transportID) {
+ public IRestoreSession beginRestoreSession(String transport) {
mContext.enforceCallingPermission("android.permission.BACKUP", "beginRestoreSession");
synchronized(this) {
@@ -1171,7 +1215,7 @@
Log.d(TAG, "Restore session requested but one already active");
return null;
}
- mActiveRestoreSession = new RestoreSession(transportID);
+ mActiveRestoreSession = new RestoreSession(transport);
}
return mActiveRestoreSession;
}
@@ -1184,8 +1228,8 @@
private IBackupTransport mRestoreTransport = null;
RestoreSet[] mRestoreSets = null;
- RestoreSession(int transportID) {
- mRestoreTransport = getTransport(transportID);
+ RestoreSession(String transport) {
+ mRestoreTransport = getTransport(transport);
}
// --- Binder interface ---
@@ -1246,6 +1290,10 @@
@Override
public void dump(FileDescriptor fd, PrintWriter pw, String[] args) {
synchronized (mQueueLock) {
+ pw.println("Available transports:");
+ for (String t : listAllTransports()) {
+ pw.println(" " + t);
+ }
int N = mBackupParticipants.size();
pw.println("Participants:");
for (int i=0; i<N; i++) {