Don't persist description res ids as they are subject to change.

Instead persist the resource name and update the javadoc to suggest
that apps should re-acquire the lease if the description resource
changes.

Bug: 150829640
Test: atest --test-mapping apex/blobstore
Change-Id: Ibeabffe7de046ed74cbbcaed6c69c9d25028799d

5 files changed, 113 insertions, 30 deletions

diff --git a/apex/blobstore/framework/java/android/app/blob/BlobStoreManager.java b/apex/blobstore/framework/java/android/app/blob/BlobStoreManager.java
index f53f1f19aea7..d1e28e99b6d6 100644
--- a/apex/blobstore/framework/java/android/app/blob/BlobStoreManager.java
+++ b/apex/blobstore/framework/java/android/app/blob/BlobStoreManager.java
@@ -145,6 +145,9 @@ public class BlobStoreManager {
     /** @hide */
     public static final int INVALID_RES_ID = -1;
 
+    /** @hide */
+    public static final String DESC_RES_TYPE_STRING = "string";
+
     private final Context mContext;
     private final IBlobStoreManager mService;
 
@@ -269,6 +272,9 @@ public class BlobStoreManager {
      * <p> When an app acquires a lease on a blob, the System will try to keep this
      * blob around but note that it can still be deleted if it was requested by the user.
      *
+     * <p> In case the resource name for the {@code descriptionResId} is modified as part of
+     * an app update, apps should re-acquire the lease with the new resource id.
+     *
      * @param blobHandle the {@link BlobHandle} representing the blob that the caller wants to
      *                   acquire a lease for.
      * @param descriptionResId the resource id for a short description string that can be surfaced
@@ -380,6 +386,9 @@ public class BlobStoreManager {
      * <p> When an app acquires a lease on a blob, the System will try to keep this
      * blob around but note that it can still be deleted if it was requested by the user.
      *
+     * <p> In case the resource name for the {@code descriptionResId} is modified as part of
+     * an app update, apps should re-acquire the lease with the new resource id.
+     *
      * @param blobHandle the {@link BlobHandle} representing the blob that the caller wants to
      *                   acquire a lease for.
      * @param descriptionResId the resource id for a short description string that can be surfaced
diff --git a/apex/blobstore/framework/java/android/app/blob/XmlTags.java b/apex/blobstore/framework/java/android/app/blob/XmlTags.java
index 9834d7477838..e64edc393769 100644
--- a/apex/blobstore/framework/java/android/app/blob/XmlTags.java
+++ b/apex/blobstore/framework/java/android/app/blob/XmlTags.java
@@ -51,6 +51,6 @@ public final class XmlTags {
 
     // For leasee
     public static final String TAG_LEASEE = "l";
-    public static final String ATTR_DESCRIPTION_RES_ID = "rid";
+    public static final String ATTR_DESCRIPTION_RES_NAME = "rn";
     public static final String ATTR_DESCRIPTION = "d";
 }
diff --git a/apex/blobstore/service/java/com/android/server/blob/BlobMetadata.java b/apex/blobstore/service/java/com/android/server/blob/BlobMetadata.java
index 4a85a69b82d3..888c3af8bbf7 100644
--- a/apex/blobstore/service/java/com/android/server/blob/BlobMetadata.java
+++ b/apex/blobstore/service/java/com/android/server/blob/BlobMetadata.java
@@ -15,8 +15,9 @@
  */
 package com.android.server.blob;
 
+import static android.app.blob.BlobStoreManager.DESC_RES_TYPE_STRING;
 import static android.app.blob.XmlTags.ATTR_DESCRIPTION;
-import static android.app.blob.XmlTags.ATTR_DESCRIPTION_RES_ID;
+import static android.app.blob.XmlTags.ATTR_DESCRIPTION_RES_NAME;
 import static android.app.blob.XmlTags.ATTR_EXPIRY_TIME;
 import static android.app.blob.XmlTags.ATTR_ID;
 import static android.app.blob.XmlTags.ATTR_PACKAGE;
@@ -29,7 +30,9 @@ import static android.app.blob.XmlTags.TAG_LEASEE;
 import static android.os.Process.INVALID_UID;
 import static android.system.OsConstants.O_RDONLY;
 
+import static com.android.server.blob.BlobStoreConfig.LOGV;
 import static com.android.server.blob.BlobStoreConfig.TAG;
+import static com.android.server.blob.BlobStoreConfig.XML_VERSION_ADD_DESC_RES_NAME;
 import static com.android.server.blob.BlobStoreConfig.XML_VERSION_ADD_STRING_DESC;
 
 import android.annotation.NonNull;
@@ -154,7 +157,7 @@ class BlobMetadata {
         synchronized (mMetadataLock) {
             // We need to override the leasee data, so first remove any existing
             // leasee before adding the new one.
-            final Leasee leasee = new Leasee(callingPackage, callingUid,
+            final Leasee leasee = new Leasee(mContext, callingPackage, callingUid,
                     descriptionResId, description, leaseExpiryTimeMillis);
             mLeasees.remove(leasee);
             mLeasees.add(leasee);
@@ -459,59 +462,123 @@ class BlobMetadata {
     }
 
     static final class Leasee extends Accessor {
-        public final int descriptionResId;
+        public final String descriptionResEntryName;
         public final CharSequence description;
         public final long expiryTimeMillis;
 
-        Leasee(String packageName, int uid, int descriptionResId, CharSequence description,
-                long expiryTimeMillis) {
+        Leasee(@NonNull Context context, @NonNull String packageName,
+                int uid, int descriptionResId,
+                @Nullable CharSequence description, long expiryTimeMillis) {
             super(packageName, uid);
-            this.descriptionResId = descriptionResId;
+            final Resources packageResources = getPackageResources(context, packageName,
+                    UserHandle.getUserId(uid));
+            this.descriptionResEntryName = getResourceEntryName(packageResources, descriptionResId);
+            this.expiryTimeMillis = expiryTimeMillis;
+            this.description = description == null
+                    ? getDescription(packageResources, descriptionResId)
+                    : description;
+        }
+
+        Leasee(String packageName, int uid, @Nullable String descriptionResEntryName,
+                @Nullable CharSequence description, long expiryTimeMillis) {
+            super(packageName, uid);
+            this.descriptionResEntryName = descriptionResEntryName;
             this.expiryTimeMillis = expiryTimeMillis;
             this.description = description;
         }
 
+        @Nullable
+        private static String getResourceEntryName(@Nullable Resources packageResources,
+                int resId) {
+            if (!ResourceId.isValid(resId) || packageResources == null) {
+                return null;
+            }
+            return packageResources.getResourceEntryName(resId);
+        }
+
+        @Nullable
+        private static String getDescription(@NonNull Context context,
+                @NonNull String descriptionResEntryName, @NonNull String packageName, int userId) {
+            if (descriptionResEntryName == null || descriptionResEntryName.isEmpty()) {
+                return null;
+            }
+            final Resources resources = getPackageResources(context, packageName, userId);
+            if (resources == null) {
+                return null;
+            }
+            try {
+                final int resId = resources.getIdentifier(descriptionResEntryName,
+                        DESC_RES_TYPE_STRING, packageName);
+                return resId <= 0 ? null : resources.getString(resId);
+            } catch (Resources.NotFoundException e) {
+                if (LOGV) {
+                    Slog.w(TAG, "Description resource not found", e);
+                }
+                return null;
+            }
+        }
+
+        @Nullable
+        private static String getDescription(@Nullable Resources packageResources,
+                int descriptionResId) {
+            if (!ResourceId.isValid(descriptionResId) || packageResources == null) {
+                return null;
+            }
+            return packageResources.getString(descriptionResId);
+        }
+
         boolean isStillValid() {
             return expiryTimeMillis == 0 || expiryTimeMillis <= System.currentTimeMillis();
         }
 
-        void dump(Context context, IndentingPrintWriter fout) {
+        void dump(@NonNull Context context, @NonNull IndentingPrintWriter fout) {
             fout.println("desc: " + getDescriptionToDump(context));
             fout.println("expiryMs: " + expiryTimeMillis);
         }
 
-        private String getDescriptionToDump(Context context) {
-            String desc = null;
-            if (ResourceId.isValid(descriptionResId)) {
-                try {
-                    final Resources leaseeRes = context.getPackageManager()
-                            .getResourcesForApplicationAsUser(
-                                    packageName, UserHandle.getUserId(uid));
-                    desc = leaseeRes.getString(descriptionResId);
-                } catch (PackageManager.NameNotFoundException e) {
-                    Slog.d(TAG, "Unknown package in user " + UserHandle.getUserId(uid) + ": "
-                            + packageName, e);
-                    desc = "<none>";
-                }
-            } else {
+        @NonNull
+        private String getDescriptionToDump(@NonNull Context context) {
+            String desc = getDescription(context, descriptionResEntryName, packageName,
+                    UserHandle.getUserId(uid));
+            if (desc == null) {
                 desc = description.toString();
             }
-            return desc;
+            return desc == null ? "<none>" : desc;
+        }
+
+        @Nullable
+        private static Resources getPackageResources(@NonNull Context context,
+                @NonNull String packageName, int userId) {
+            try {
+                return context.getPackageManager()
+                        .getResourcesForApplicationAsUser(packageName, userId);
+            } catch (PackageManager.NameNotFoundException e) {
+                Slog.d(TAG, "Unknown package in user " + userId + ": "
+                        + packageName, e);
+                return null;
+            }
         }
 
         void writeToXml(@NonNull XmlSerializer out) throws IOException {
             XmlUtils.writeStringAttribute(out, ATTR_PACKAGE, packageName);
             XmlUtils.writeIntAttribute(out, ATTR_UID, uid);
-            XmlUtils.writeIntAttribute(out, ATTR_DESCRIPTION_RES_ID, descriptionResId);
+            XmlUtils.writeStringAttribute(out, ATTR_DESCRIPTION_RES_NAME, descriptionResEntryName);
             XmlUtils.writeLongAttribute(out, ATTR_EXPIRY_TIME, expiryTimeMillis);
             XmlUtils.writeStringAttribute(out, ATTR_DESCRIPTION, description);
         }
 
         @NonNull
-        static Leasee createFromXml(@NonNull XmlPullParser in, int version) throws IOException {
+        static Leasee createFromXml(@NonNull XmlPullParser in, int version)
+                throws IOException {
             final String packageName = XmlUtils.readStringAttribute(in, ATTR_PACKAGE);
             final int uid = XmlUtils.readIntAttribute(in, ATTR_UID);
-            final int descriptionResId = XmlUtils.readIntAttribute(in, ATTR_DESCRIPTION_RES_ID);
+            final String descriptionResEntryName;
+            if (version >= XML_VERSION_ADD_DESC_RES_NAME) {
+                descriptionResEntryName = XmlUtils.readStringAttribute(
+                        in, ATTR_DESCRIPTION_RES_NAME);
+            } else {
+                descriptionResEntryName = null;
+            }
             final long expiryTimeMillis = XmlUtils.readLongAttribute(in, ATTR_EXPIRY_TIME);
             final CharSequence description;
             if (version >= XML_VERSION_ADD_STRING_DESC) {
@@ -520,7 +587,8 @@ class BlobMetadata {
                 description = null;
             }
 
-            return new Leasee(packageName, uid, descriptionResId, description, expiryTimeMillis);
+            return new Leasee(packageName, uid, descriptionResEntryName,
+                    description, expiryTimeMillis);
         }
     }
 
diff --git a/apex/blobstore/service/java/com/android/server/blob/BlobStoreConfig.java b/apex/blobstore/service/java/com/android/server/blob/BlobStoreConfig.java
index bcc1610435d9..6d31b2c30067 100644
--- a/apex/blobstore/service/java/com/android/server/blob/BlobStoreConfig.java
+++ b/apex/blobstore/service/java/com/android/server/blob/BlobStoreConfig.java
@@ -32,8 +32,9 @@ class BlobStoreConfig {
     public static final int XML_VERSION_INIT = 1;
     // Added a string variant of lease description.
     public static final int XML_VERSION_ADD_STRING_DESC = 2;
+    public static final int XML_VERSION_ADD_DESC_RES_NAME = 3;
 
-    public static final int XML_VERSION_CURRENT = XML_VERSION_ADD_STRING_DESC;
+    public static final int XML_VERSION_CURRENT = XML_VERSION_ADD_DESC_RES_NAME;
 
     private static final String ROOT_DIR_NAME = "blobstore";
     private static final String BLOBS_DIR_NAME = "blobs";
diff --git a/apex/blobstore/service/java/com/android/server/blob/BlobStoreManagerService.java b/apex/blobstore/service/java/com/android/server/blob/BlobStoreManagerService.java
index 05c661127eab..b202e95ed211 100644
--- a/apex/blobstore/service/java/com/android/server/blob/BlobStoreManagerService.java
+++ b/apex/blobstore/service/java/com/android/server/blob/BlobStoreManagerService.java
@@ -54,6 +54,7 @@ import android.content.pm.ApplicationInfo;
 import android.content.pm.PackageManagerInternal;
 import android.content.pm.PackageStats;
 import android.content.res.ResourceId;
+import android.content.res.Resources;
 import android.os.Binder;
 import android.os.Handler;
 import android.os.HandlerThread;
@@ -1181,8 +1182,12 @@ public class BlobStoreManagerService extends SystemService {
             final int callingUid = Binder.getCallingUid();
             verifyCallingPackage(callingUid, packageName);
 
-            acquireLeaseInternal(blobHandle, descriptionResId, description, leaseExpiryTimeMillis,
-                    callingUid, packageName);
+            try {
+                acquireLeaseInternal(blobHandle, descriptionResId, description,
+                        leaseExpiryTimeMillis, callingUid, packageName);
+            } catch (Resources.NotFoundException e) {
+                throw new IllegalArgumentException(e);
+            }
         }
 
         @Override