Use "real" free space; refresh on large changes.

For volumes where the OS manages cached data, use the "free space" as
reported by StorageStatsManager, which is the same value shown in
the Settings app and other UI elements.

Also, when the storage space changes significantly, invalidate anyone
who was holding a cached "free space" value.

Test: builds, boots
Bug: 38146029
Change-Id: I4b3a484a8bf32cd137a83f1ea441beca6dc6719a

1 files changed, 25 insertions, 2 deletions

diff --git a/packages/ExternalStorageProvider/src/com/android/externalstorage/ExternalStorageProvider.java b/packages/ExternalStorageProvider/src/com/android/externalstorage/ExternalStorageProvider.java
index b958c2873019..f844cc163bbe 100644
--- a/packages/ExternalStorageProvider/src/com/android/externalstorage/ExternalStorageProvider.java
+++ b/packages/ExternalStorageProvider/src/com/android/externalstorage/ExternalStorageProvider.java
@@ -17,6 +17,7 @@
 package com.android.externalstorage;
 
 import android.annotation.Nullable;
+import android.app.usage.StorageStatsManager;
 import android.content.ContentResolver;
 import android.content.Context;
 import android.content.UriPermission;
@@ -49,10 +50,12 @@ import com.android.internal.util.IndentingPrintWriter;
 import java.io.File;
 import java.io.FileDescriptor;
 import java.io.FileNotFoundException;
+import java.io.IOException;
 import java.io.PrintWriter;
 import java.util.Collections;
 import java.util.List;
 import java.util.Objects;
+import java.util.UUID;
 
 public class ExternalStorageProvider extends FileSystemProvider {
     private static final String TAG = "ExternalStorage";
@@ -79,6 +82,7 @@ public class ExternalStorageProvider extends FileSystemProvider {
     private static class RootInfo {
         public String rootId;
         public String volumeId;
+        public UUID storageUuid;
         public int flags;
         public String title;
         public String docId;
@@ -124,6 +128,7 @@ public class ExternalStorageProvider extends FileSystemProvider {
 
             final String rootId;
             final String title;
+            final UUID storageUuid;
             if (volume.getType() == VolumeInfo.TYPE_EMULATED) {
                 // We currently only support a single emulated volume mounted at
                 // a time, and it's always considered the primary
@@ -142,17 +147,20 @@ public class ExternalStorageProvider extends FileSystemProvider {
                     title = !TextUtils.isEmpty(deviceName)
                             ? deviceName
                             : getContext().getString(R.string.root_internal_storage);
+                    storageUuid = StorageManager.UUID_DEFAULT;
                 } else {
                     // This should cover all other storage devices, like an SD card
                     // or USB OTG drive plugged in. Using getBestVolumeDescription()
                     // will give us a nice string like "Samsung SD card" or "SanDisk USB drive"
                     final VolumeInfo privateVol = mStorageManager.findPrivateForEmulated(volume);
                     title = mStorageManager.getBestVolumeDescription(privateVol);
+                    storageUuid = StorageManager.convert(privateVol.fsUuid);
                 }
             } else if (volume.getType() == VolumeInfo.TYPE_PUBLIC
                     && volume.getMountUserId() == userId) {
                 rootId = volume.getFsUuid();
                 title = mStorageManager.getBestVolumeDescription(volume);
+                storageUuid = null;
             } else {
                 // Unsupported volume; ignore
                 continue;
@@ -172,6 +180,7 @@ public class ExternalStorageProvider extends FileSystemProvider {
 
             root.rootId = rootId;
             root.volumeId = volume.id;
+            root.storageUuid = storageUuid;
             root.flags = Root.FLAG_LOCAL_ONLY
                     | Root.FLAG_SUPPORTS_SEARCH
                     | Root.FLAG_SUPPORTS_IS_CHILD;
@@ -385,8 +394,22 @@ public class ExternalStorageProvider extends FileSystemProvider {
                 row.add(Root.COLUMN_FLAGS, root.flags);
                 row.add(Root.COLUMN_TITLE, root.title);
                 row.add(Root.COLUMN_DOCUMENT_ID, root.docId);
-                row.add(Root.COLUMN_AVAILABLE_BYTES,
-                        root.reportAvailableBytes ? root.path.getUsableSpace() : -1);
+
+                long availableBytes = -1;
+                if (root.reportAvailableBytes) {
+                    if (root.storageUuid != null) {
+                        try {
+                            availableBytes = getContext()
+                                    .getSystemService(StorageStatsManager.class)
+                                    .getFreeBytes(root.storageUuid);
+                        } catch (IOException e) {
+                            Log.w(TAG, e);
+                        }
+                    } else {
+                        availableBytes = root.path.getUsableSpace();
+                    }
+                }
+                row.add(Root.COLUMN_AVAILABLE_BYTES, availableBytes);
             }
         }
         return result;