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Commit b49ceb3b authored by Christopher Tate's avatar Christopher Tate
Browse files

Remember which apps have available restore info in the ancestral dataset 

When we perform a full-system restore, remember the set of applications which
have data available in our ancestral dataset.  This is a key filter for not
having to do a round trip to the [remote] storage backend at app-install time
unless it is likely to be fruitful.

Change-Id: I7c77b490c560c581888d84f02f258b2e2d73bc69
parent ec5df83c

services/java/com/android/server/BackupManagerService.java

+49 −6
Original line number Diff line number Diff line
@@ -76,6 +76,7 @@ import java.util.HashSet; 
import java.util.List;

import java.util.Map;

import java.util.Random;

import java.util.Set;



class BackupManagerService extends IBackupManager.Stub {

    private static final String TAG = "BackupManagerService";
@@ -226,7 +227,9 @@ class BackupManagerService extends IBackupManager.Stub { 
    private File mEverStored;

    HashSet<String> mEverStoredApps = new HashSet<String>();



    static final int CURRENT_ANCESTRAL_RECORD_VERSION = 1;  // increment when the schema changes

    File mTokenFile;

    Set<String> mAncestralPackages = null;

    long mAncestralToken = 0;

    long mCurrentToken = 0;
@@ -500,8 +503,20 @@ class BackupManagerService extends IBackupManager.Stub { 
        mTokenFile = new File(mBaseStateDir, "ancestral");

        try {

            RandomAccessFile tf = new RandomAccessFile(mTokenFile, "r");

            int version = tf.readInt();

            if (version == CURRENT_ANCESTRAL_RECORD_VERSION) {

                mAncestralToken = tf.readLong();

                mCurrentToken = tf.readLong();



                int numPackages = tf.readInt();

                if (numPackages >= 0) {

                    mAncestralPackages = new HashSet<String>();

                    for (int i = 0; i < numPackages; i++) {

                        String pkgName = tf.readUTF();

                        mAncestralPackages.add(pkgName);

                    }

                }

            }

        } catch (IOException e) {

            Log.w(TAG, "Unable to read token file", e);

        }
@@ -972,12 +987,31 @@ class BackupManagerService extends IBackupManager.Stub { 
        }

    }



    // Record the current and ancestral backup tokens persistently

    // Persistently record the current and ancestral backup tokens as well

    // as the set of packages with data [supposedly] available in the

    // ancestral dataset.

    void writeRestoreTokens() {

        try {

            RandomAccessFile af = new RandomAccessFile(mTokenFile, "rwd");



            // First, the version number of this record, for futureproofing

            af.writeInt(CURRENT_ANCESTRAL_RECORD_VERSION);



            // Write the ancestral and current tokens

            af.writeLong(mAncestralToken);

            af.writeLong(mCurrentToken);



            // Now write the set of ancestral packages

            if (mAncestralPackages == null) {

                af.writeInt(-1);

            } else {

                af.writeInt(mAncestralPackages.size());

                if (DEBUG) Log.v(TAG, "Ancestral packages:  " + mAncestralPackages.size());

                for (String pkgName : mAncestralPackages) {

                    af.writeUTF(pkgName);

                    if (DEBUG) Log.v(TAG, "   " + pkgName);

                }

            }

            af.close();

        } catch (IOException e) {

            Log.w(TAG, "Unable to write token file:", e);
@@ -1502,6 +1536,7 @@ class BackupManagerService extends IBackupManager.Stub { 
             * the user is waiting, after all.

             */



            PackageManagerBackupAgent pmAgent = null;

            int error = -1; // assume error



            // build the set of apps to restore
@@ -1562,7 +1597,7 @@ class BackupManagerService extends IBackupManager.Stub { 
                }



                // Pull the Package Manager metadata from the restore set first

                PackageManagerBackupAgent pmAgent = new PackageManagerBackupAgent(

                pmAgent = new PackageManagerBackupAgent(

                        mPackageManager, agentPackages);

                processOneRestore(omPackage, 0, IBackupAgent.Stub.asInterface(pmAgent.onBind()));
@@ -1705,8 +1740,10 @@ class BackupManagerService extends IBackupManager.Stub { 
                }



                // If this was a restoreAll operation, record that this was our

                // ancestral dataset

                if (mTargetPackage == null) {

                // ancestral dataset, as well as the set of apps that are possibly

                // restoreable from the dataset

                if (mTargetPackage == null && pmAgent != null) {

                    mAncestralPackages = pmAgent.getRestoredPackages();

                    mAncestralToken = mToken;

                    writeRestoreTokens();

                }
@@ -2436,6 +2473,12 @@ class BackupManagerService extends IBackupManager.Stub { 
                }

            }



            pw.println("Ancestral packages: "

                    + (mAncestralPackages == null ? "none" : mAncestralPackages.size()));

            for (String pkg : mAncestralPackages) {

                pw.println("    " + pkg);

            }



            pw.println("Ever backed up: " + mEverStoredApps.size());

            for (String pkg : mEverStoredApps) {

                pw.println("    " + pkg);

services/java/com/android/server/PackageManagerBackupAgent.java

+15 −0
Original line number Diff line number Diff line
@@ -40,6 +40,7 @@ import java.util.ArrayList; 
import java.util.HashMap;

import java.util.HashSet;

import java.util.List;

import java.util.Set;



/**

 * We back up the signatures of each package so that during a system restore,
@@ -101,6 +102,20 @@ public class PackageManagerBackupAgent extends BackupAgent { 
        return mRestoredSignatures.get(packageName);

    }



    public Set<String> getRestoredPackages() {

        if (mRestoredSignatures == null) {

            Log.w(TAG, "getRestoredPackages() before metadata read!");

            return null;

        }



        // This is technically the set of packages on the originating handset

        // that had backup agents at all, not limited to the set of packages

        // that had actually contributed a restore dataset, but it's a

        // close enough approximation for our purposes and does not require any

        // additional involvement by the transport to obtain.

        return mRestoredSignatures.keySet();

    }

    

    // The backed up data is the signature block for each app, keyed by

    // the package name.

    public void onBackup(ParcelFileDescriptor oldState, BackupDataOutput data,