Merge "Add BlobStoreManager.getRemainingLeaseQuotaBytes." into rvc-dev am: add060f917

Change-Id: I2789b7afab45a2545f17054157e3eb9628f31c21

apex/blobstore/framework/java/android/app/blob/BlobStoreManager.java

@@ -25,6 +25,7 @@ import android.annotation.Nullable;
 import android.annotation.SystemService;
 import android.annotation.TestApi;
 import android.content.Context;
+import android.os.LimitExceededException;
 import android.os.ParcelFileDescriptor;
 import android.os.ParcelableException;
 import android.os.RemoteCallback;
@@ -167,6 +168,12 @@ public class BlobStoreManager {
      * finalized (either committed or abandoned) within a reasonable period of
      * time, typically about a week.
      *
+     * <p> If an app is planning to acquire a lease on this data (using
+     * {@link #acquireLease(BlobHandle, int)} or one of it's other variants) after committing
+     * this data (using {@link Session#commit(Executor, Consumer)}), it is recommended that
+     * the app checks the remaining quota for acquiring a lease first using
+     * {@link #getRemainingLeaseQuotaBytes()} and can skip contributing this data if needed.
+     *
      * @param blobHandle the {@link BlobHandle} identifier for which a new session
      *                   needs to be created.
      * @return positive, non-zero unique id that represents the created session.
@@ -294,8 +301,11 @@ public class BlobStoreManager {
      * @throws IllegalArgumentException when {@code blobHandle} is invalid or
      *                                  if the {@code leaseExpiryTimeMillis} is greater than the
      *                                  {@link BlobHandle#getExpiryTimeMillis()}.
-     * @throws IllegalStateException when a lease could not be acquired, such as when the
+     * @throws LimitExceededException when a lease could not be acquired, such as when the
-     *                               caller is trying to acquire too many leases.
+     *                                caller is trying to acquire leases on too much data. Apps
+     *                                can avoid this by checking the remaining quota using
+     *                                {@link #getRemainingLeaseQuotaBytes()} before trying to
+     *                                acquire a lease.
      *
      * @see {@link #acquireLease(BlobHandle, int)}
      * @see {@link #acquireLease(BlobHandle, CharSequence)}
@@ -307,6 +317,7 @@ public class BlobStoreManager {
                     mContext.getOpPackageName());
         } catch (ParcelableException e) {
             e.maybeRethrow(IOException.class);
+            e.maybeRethrow(LimitExceededException.class);
             throw new RuntimeException(e);
         } catch (RemoteException e) {
             throw e.rethrowFromSystemServer();
@@ -350,8 +361,11 @@ public class BlobStoreManager {
      * @throws IllegalArgumentException when {@code blobHandle} is invalid or
      *                                  if the {@code leaseExpiryTimeMillis} is greater than the
      *                                  {@link BlobHandle#getExpiryTimeMillis()}.
-     * @throws IllegalStateException when a lease could not be acquired, such as when the
+     * @throws LimitExceededException when a lease could not be acquired, such as when the
-     *                               caller is trying to acquire too many leases.
+     *                                caller is trying to acquire leases on too much data. Apps
+     *                                can avoid this by checking the remaining quota using
+     *                                {@link #getRemainingLeaseQuotaBytes()} before trying to
+     *                                acquire a lease.
      *
      * @see {@link #acquireLease(BlobHandle, int, long)}
      * @see {@link #acquireLease(BlobHandle, CharSequence)}
@@ -363,6 +377,7 @@ public class BlobStoreManager {
                     mContext.getOpPackageName());
         } catch (ParcelableException e) {
             e.maybeRethrow(IOException.class);
+            e.maybeRethrow(LimitExceededException.class);
             throw new RuntimeException(e);
         } catch (RemoteException e) {
             throw e.rethrowFromSystemServer();
@@ -399,8 +414,11 @@ public class BlobStoreManager {
      * @throws SecurityException when the blob represented by the {@code blobHandle} does not
      *                           exist or the caller does not have access to it.
      * @throws IllegalArgumentException when {@code blobHandle} is invalid.
-     * @throws IllegalStateException when a lease could not be acquired, such as when the
+     * @throws LimitExceededException when a lease could not be acquired, such as when the
-     *                               caller is trying to acquire too many leases.
+     *                                caller is trying to acquire leases on too much data. Apps
+     *                                can avoid this by checking the remaining quota using
+     *                                {@link #getRemainingLeaseQuotaBytes()} before trying to
+     *                                acquire a lease.
      *
      * @see {@link #acquireLease(BlobHandle, int, long)}
      * @see {@link #acquireLease(BlobHandle, CharSequence, long)}
@@ -443,8 +461,11 @@ public class BlobStoreManager {
      * @throws SecurityException when the blob represented by the {@code blobHandle} does not
      *                           exist or the caller does not have access to it.
      * @throws IllegalArgumentException when {@code blobHandle} is invalid.
-     * @throws IllegalStateException when a lease could not be acquired, such as when the
+     * @throws LimitExceededException when a lease could not be acquired, such as when the
-     *                               caller is trying to acquire too many leases.
+     *                                caller is trying to acquire leases on too much data. Apps
+     *                                can avoid this by checking the remaining quota using
+     *                                {@link #getRemainingLeaseQuotaBytes()} before trying to
+     *                                acquire a lease.
      *
      * @see {@link #acquireLease(BlobHandle, int)}
      * @see {@link #acquireLease(BlobHandle, CharSequence, long)}
@@ -477,6 +498,24 @@ public class BlobStoreManager {
         }
     }
 
+    /**
+     * Return the remaining quota size for acquiring a lease (in bytes) which indicates the
+     * remaining amount of data that an app can acquire a lease on before the System starts
+     * rejecting lease requests.
+     *
+     * If an app wants to acquire a lease on a blob but the remaining quota size is not sufficient,
+     * then it can try releasing leases on any older blobs which are not needed anymore.
+     *
+     * @return the remaining quota size for acquiring a lease.
+     */
+    public @IntRange(from = 0) long getRemainingLeaseQuotaBytes() {
+        try {
+            return mService.getRemainingLeaseQuotaBytes(mContext.getOpPackageName());
+        } catch (RemoteException e) {
+            throw e.rethrowFromSystemServer();
+        }
+    }
+
     /**
      * Wait until any pending tasks (like persisting data to disk) have finished.
      *

apex/blobstore/framework/java/android/app/blob/IBlobStoreManager.aidl

@@ -31,6 +31,7 @@ interface IBlobStoreManager {
     void acquireLease(in BlobHandle handle, int descriptionResId, in CharSequence description,
             long leaseTimeoutMillis, in String packageName);
     void releaseLease(in BlobHandle handle, in String packageName);
+    long getRemainingLeaseQuotaBytes(String packageName);
 
     void waitForIdle(in RemoteCallback callback);
 

apex/blobstore/service/java/com/android/server/blob/BlobStoreManagerService.java

@@ -62,7 +62,9 @@ import android.content.res.Resources;
 import android.os.Binder;
 import android.os.Handler;
 import android.os.HandlerThread;
+import android.os.LimitExceededException;
 import android.os.ParcelFileDescriptor;
+import android.os.ParcelableException;
 import android.os.Process;
 import android.os.RemoteCallback;
 import android.os.SystemClock;
@@ -394,9 +396,9 @@ public class BlobStoreManagerService extends SystemService {
                 throw new IllegalArgumentException(
                         "Lease expiry cannot be later than blobs expiry time");
             }
-            if (getTotalUsageBytesLocked(callingUid, callingPackage)
+            if (blobMetadata.getSize()
-                    + blobMetadata.getSize() > BlobStoreConfig.getAppDataBytesLimit()) {
+                    > getRemainingLeaseQuotaBytesInternal(callingUid, callingPackage)) {
-                throw new IllegalStateException("Total amount of data with an active lease"
+                throw new LimitExceededException("Total amount of data with an active lease"
                         + " is exceeding the max limit");
             }
             blobMetadata.addLeasee(callingPackage, callingUid,
@@ -445,6 +447,14 @@ public class BlobStoreManagerService extends SystemService {
         }
     }
 
+    private long getRemainingLeaseQuotaBytesInternal(int callingUid, String callingPackage) {
+        synchronized (mBlobsLock) {
+            final long remainingQuota = BlobStoreConfig.getAppDataBytesLimit()
+                    - getTotalUsageBytesLocked(callingUid, callingPackage);
+            return remainingQuota > 0 ? remainingQuota : 0;
+        }
+    }
+
     private List<BlobInfo> queryBlobsForUserInternal(int userId) {
         final ArrayList<BlobInfo> blobInfos = new ArrayList<>();
         synchronized (mBlobsLock) {
@@ -1302,6 +1312,8 @@ public class BlobStoreManagerService extends SystemService {
                         leaseExpiryTimeMillis, callingUid, packageName);
             } catch (Resources.NotFoundException e) {
                 throw new IllegalArgumentException(e);
+            } catch (LimitExceededException e) {
+                throw new ParcelableException(e);
             }
         }
 
@@ -1323,6 +1335,14 @@ public class BlobStoreManagerService extends SystemService {
             releaseLeaseInternal(blobHandle, callingUid, packageName);
         }
 
+        @Override
+        public long getRemainingLeaseQuotaBytes(@NonNull String packageName) {
+            final int callingUid = Binder.getCallingUid();
+            verifyCallingPackage(callingUid, packageName);
+
+            return getRemainingLeaseQuotaBytesInternal(callingUid, packageName);
+        }
+
         @Override
         public void waitForIdle(@NonNull RemoteCallback remoteCallback) {
             Objects.requireNonNull(remoteCallback, "remoteCallback must not be null");

api/current.txt

@@ -7605,6 +7605,7 @@ package android.app.blob {
     method public void acquireLease(@NonNull android.app.blob.BlobHandle, @IdRes int) throws java.io.IOException;
     method public void acquireLease(@NonNull android.app.blob.BlobHandle, @NonNull CharSequence) throws java.io.IOException;
     method @IntRange(from=1) public long createSession(@NonNull android.app.blob.BlobHandle) throws java.io.IOException;
+    method @IntRange(from=0) public long getRemainingLeaseQuotaBytes();
     method @NonNull public android.os.ParcelFileDescriptor openBlob(@NonNull android.app.blob.BlobHandle) throws java.io.IOException;
     method @NonNull public android.app.blob.BlobStoreManager.Session openSession(@IntRange(from=1) long) throws java.io.IOException;
     method public void releaseLease(@NonNull android.app.blob.BlobHandle) throws java.io.IOException;
@@ -36317,6 +36318,11 @@ package android.os {
     method public android.os.IBinder asBinder();
   }
 
+  public class LimitExceededException extends java.lang.IllegalStateException {
+    ctor public LimitExceededException();
+    ctor public LimitExceededException(@NonNull String);
+  }
+
   public final class LocaleList implements android.os.Parcelable {
     ctor public LocaleList(@NonNull java.util.Locale...);
     method public int describeContents();

core/java/android/os/LimitExceededException.java

@@ -0,0 +1,44 @@
+/*
+ * Copyright (C) 2020 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package android.os;
+
+import android.annotation.NonNull;
+
+/** Indicates that the app has exceeded a limit set by the System. */
+public class LimitExceededException extends IllegalStateException {
+
+    /**
+     * Constructs a new {@code LimitExceededException} with {@code null} as its
+     * detail message. The cause is not initialized, and may subsequently be
+     * initialized by a call to {@link #initCause}.
+     */
+    public LimitExceededException() {
+        super();
+    }
+
+    /**
+     * Constructs a new {@code LimitExceededException} with the specified detail message.
+     * The cause is not initialized, and may subsequently be initialized by a
+     * call to {@link #initCause}.
+     *
+     * @param message the detail message which is saved for later retrieval
+     *                by the {@link #getMessage()} method.
+     */
+    public LimitExceededException(@NonNull String message) {
+        super(message);
+    }
+}