StorageManager

ACTION_CLEAR_APP_CACHE

public static final String ACTION_CLEAR_APP_CACHE

Activity Action: Allows the user to free up space by clearing app external cache directories. The intent doesn't automatically clear cache, but shows a dialog and lets the user decide.

This intent should be launched using Activity#startActivityForResult(Intent, int) so that the user knows which app is requesting to clear cache. The returned result will be: Activity#RESULT_OK if the activity was launched and all cache was cleared, OsConstants#EIO if an error occurred while clearing the cache or Activity#RESULT_CANCELED otherwise.
Requires Manifest.permission.MANAGE_EXTERNAL_STORAGE

Constant Value: "android.os.storage.action.CLEAR_APP_CACHE"

ACTION_MANAGE_STORAGE

public static final String ACTION_MANAGE_STORAGE

Activity Action: Allows the user to manage their storage. This activity provides the ability to free up space on the device by deleting data such as apps.

If the sending application has a specific storage device or allocation size in mind, they can optionally define EXTRA_UUID or EXTRA_REQUESTED_BYTES, respectively.

This intent should be launched using Activity#startActivityForResult(Intent, int) so that the user knows which app is requesting the storage space. The returned result will be Activity#RESULT_OK if the requested space was made available, or Activity#RESULT_CANCELED otherwise.

Constant Value: "android.os.storage.action.MANAGE_STORAGE"

EXTRA_REQUESTED_BYTES

public static final String EXTRA_REQUESTED_BYTES

Extra used to indicate the total size (in bytes) that an application is interested in allocating.

When defined, the management UI will help guide the user to free up enough disk space to reach this requested value.

Constant Value: "android.os.storage.extra.REQUESTED_BYTES"

EXTRA_UUID

public static final String EXTRA_UUID

Extra UUID used to indicate the storage volume where an application is interested in allocating or managing disk space.

Constant Value: "android.os.storage.extra.UUID"

UUID_DEFAULT

public static final UUID UUID_DEFAULT

UUID representing the default internal storage of this device which provides Environment#getDataDirectory().

This value is constant across all devices and it will never change, and thus it cannot be used to uniquely identify a particular physical device.

allocateBytes

public void allocateBytes (FileDescriptor fd, 
                long bytes)

Allocate the requested number of bytes for your application to use in the given open file. This will cause the system to delete any cached files necessary to satisfy your request.

Attempts to allocate disk space beyond the value returned by getAllocatableBytes(java.util.UUID) will fail.

This method guarantees that bytes have been allocated to the opened file, otherwise it will throw if fast allocation is not possible. Fast allocation is typically only supported in private app data directories, and on shared/external storage devices which are emulated.

If you're progressively allocating an unbounded amount of storage space (such as when recording a video) you should avoid calling this method more than once every 60 seconds.
This method may take several seconds to complete, so it should only be called from a worker thread.

allocateBytes

public void allocateBytes (UUID storageUuid, 
                long bytes)

Allocate the requested number of bytes for your application to use on the given storage volume. This will cause the system to delete any cached files necessary to satisfy your request.

Attempts to allocate disk space beyond the value returned by getAllocatableBytes(java.util.UUID) will fail.

Since multiple apps can be running simultaneously, this method may be subject to race conditions. If possible, consider using allocateBytes(java.io.FileDescriptor, long) which will guarantee that bytes are allocated to an opened file.

If you're progressively allocating an unbounded amount of storage space (such as when recording a video) you should avoid calling this method more than once every 60 seconds.
This method may take several seconds to complete, so it should only be called from a worker thread.

getAllocatableBytes

public long getAllocatableBytes (UUID storageUuid)

Return the maximum number of new bytes that your app can allocate for itself on the given storage volume. This value is typically larger than File#getUsableSpace(), since the system may be willing to delete cached files to satisfy an allocation request. You can then allocate space for yourself using allocateBytes(java.util.UUID, long) or allocateBytes(java.io.FileDescriptor, long).

This method is best used as a pre-flight check, such as deciding if there is enough space to store an entire music album before you allocate space for each audio file in the album. Attempts to allocate disk space beyond the returned value will fail.

If the returned value is not large enough for the data you'd like to persist, you can launch ACTION_MANAGE_STORAGE with the EXTRA_UUID and EXTRA_REQUESTED_BYTES options to help involve the user in freeing up disk space.

If you're progressively allocating an unbounded amount of storage space (such as when recording a video) you should avoid calling this method more than once every 30 seconds.

Note: if your app uses the android:sharedUserId manifest feature, then allocatable space for all packages in your shared UID is tracked together as a single unit.

getCacheQuotaBytes

public long getCacheQuotaBytes (UUID storageUuid)

Return quota size in bytes for all cached data belonging to the calling app on the given storage volume.

If your app goes above this quota, your cached files will be some of the first to be deleted when additional disk space is needed. Conversely, if your app stays under this quota, your cached files will be some of the last to be deleted when additional disk space is needed.

This quota will change over time depending on how frequently the user interacts with your app, and depending on how much system-wide disk space is used.

Note: if your app uses the android:sharedUserId manifest feature, then cached data for all packages in your shared UID is tracked together as a single unit.

getCacheSizeBytes

public long getCacheSizeBytes (UUID storageUuid)

Return total size in bytes of all cached data belonging to the calling app on the given storage volume.

Cached data tracked by this method always includes Context#getCacheDir() and Context#getCodeCacheDir(), and it also includes Context#getExternalCacheDir() if the primary shared/external storage is hosted on the same storage device as your private data.

Note: if your app uses the android:sharedUserId manifest feature, then cached data for all packages in your shared UID is tracked together as a single unit.

getManageSpaceActivityIntent

public PendingIntent getManageSpaceActivityIntent (String packageName, 
                int requestCode)

Returns a PendingIntent that can be used by Apps with Manifest.permission.MANAGE_EXTERNAL_STORAGE permission to launch the manageSpaceActivity for any App that implements it, irrespective of its exported status.

Caller has the responsibility of supplying a valid packageName which has manageSpaceActivity implemented.
Requires Manifest.permission.MANAGE_EXTERNAL_STORAGE

getMountedObbPath

public String getMountedObbPath (String rawPath)

Check the mounted path of an Opaque Binary Blob (OBB) file. This will give you the path to where you can obtain access to the internals of the OBB.

getPrimaryStorageVolume

public StorageVolume getPrimaryStorageVolume ()

Return the primary shared/external storage volume available to the current user. This volume is the same storage device returned by Environment#getExternalStorageDirectory() and Context#getExternalFilesDir(String).

getRecentStorageVolumes

public List<StorageVolume> getRecentStorageVolumes ()

Return the list of shared/external storage volumes both currently and recently available to the calling user.

Recently available storage volumes are likely to reappear in the future, so apps are encouraged to preserve any indexed metadata related to these volumes to optimize user experiences.

getStorageVolume

public StorageVolume getStorageVolume (File file)

Return the StorageVolume that contains the given file, or null if none.

getStorageVolume

public StorageVolume getStorageVolume (Uri uri)

Return the StorageVolume that contains the given MediaStore item.

getStorageVolumes

public List<StorageVolume> getStorageVolumes ()

Return the list of shared/external storage volumes currently available to the calling user.

These storage volumes are actively attached to the device, but may be in any mount state, as returned by StorageVolume#getState(). Returns both the primary shared storage device and any attached external volumes, including SD cards and USB drives.

getStorageVolumesIncludingSharedProfiles

public List<StorageVolume> getStorageVolumesIncludingSharedProfiles ()

Return the list of shared/external storage volumes currently available to the calling user and the user it shares media with. Please refer to multi-user support for more details.

This is similar to StorageManager#getStorageVolumes() except that the result also includes the volumes belonging to any user it shares media with
Requires Manifest.permission.MANAGE_EXTERNAL_STORAGE

getUuidForPath

public UUID getUuidForPath (File path)

Return a UUID identifying the storage volume that hosts the given filesystem path.

If this path is hosted by the default internal storage of the device at Environment#getDataDirectory(), the returned value will be UUID_DEFAULT.

isAllocationSupported

public boolean isAllocationSupported (FileDescriptor fd)

Test if the given file descriptor supports allocation of disk space using allocateBytes(java.io.FileDescriptor, long).

isCacheBehaviorGroup

public boolean isCacheBehaviorGroup (File path)

Read the current value set by setCacheBehaviorGroup(java.io.File, boolean).

isCacheBehaviorTombstone

public boolean isCacheBehaviorTombstone (File path)

Read the current value set by setCacheBehaviorTombstone(java.io.File, boolean).

isCheckpointSupported

public boolean isCheckpointSupported ()

Check whether the device supports filesystem checkpoint.

isEncrypted

public boolean isEncrypted (File file)

Return if data stored at or under the given path will be encrypted while at rest. This can help apps avoid the overhead of double-encrypting data.

isObbMounted

public boolean isObbMounted (String rawPath)

Check whether an Opaque Binary Blob (OBB) is mounted or not.

mountObb

public boolean mountObb (String rawPath, 
                String key, 
                OnObbStateChangeListener listener)

Mount an Opaque Binary Blob (OBB) file.

The OBB will remain mounted for as long as the StorageManager reference is held by the application. As soon as this reference is lost, the OBBs in use will be unmounted. The OnObbStateChangeListener registered with this call will receive the success or failure of this operation.

Note: you can only mount OBB files for which the OBB tag on the file matches a package ID that is owned by the calling program's UID. That is, shared UID applications can attempt to mount any other application's OBB that shares its UID.

openProxyFileDescriptor

public ParcelFileDescriptor openProxyFileDescriptor (int mode, 
                ProxyFileDescriptorCallback callback, 
                Handler handler)

Opens a seekable ParcelFileDescriptor that proxies all low-level I/O requests back to the given ProxyFileDescriptorCallback.

This can be useful when you want to provide quick access to a large file that isn't backed by a real file on disk, such as a file on a network share, cloud storage service, etc. As an example, you could respond to a ContentResolver#openFileDescriptor(android.net.Uri, String) request by returning a ParcelFileDescriptor created with this method, and then stream the content on-demand as requested.

Another useful example might be where you have an encrypted file that you're willing to decrypt on-demand, but where you want to avoid persisting the cleartext version.

registerStorageVolumeCallback

public void registerStorageVolumeCallback (Executor executor, 
                StorageManager.StorageVolumeCallback callback)

Registers the given callback to listen for StorageVolume changes.

For example, this can be used to detect when a volume changes to the Environment#MEDIA_MOUNTED or Environment#MEDIA_UNMOUNTED states.

setCacheBehaviorGroup

public void setCacheBehaviorGroup (File path, 
                boolean group)

Enable or disable special cache behavior that treats this directory and its contents as an entire group.

When enabled and this directory is considered for automatic deletion by the OS, all contained files will either be deleted together, or not at all. This is useful when you have a directory that contains several related metadata files that depend on each other, such as movie file and a subtitle file.

When enabled, the newest File#lastModified() value of any contained files is considered the modified time of the entire directory.

This behavior can only be set on a directory, and it applies recursively to all contained files and directories.

setCacheBehaviorTombstone

public void setCacheBehaviorTombstone (File path, 
                boolean tombstone)

Enable or disable special cache behavior that leaves deleted cache files intact as tombstones.

When enabled and a file contained in this directory is automatically deleted by the OS, the file will be truncated to have a length of 0 bytes instead of being fully deleted. This is useful if you need to distinguish between a file that was deleted versus one that never existed.

This behavior can only be set on a directory, and it applies recursively to all contained files and directories.

Note: this behavior is ignored completely if the user explicitly requests that all cached data be cleared.

unmountObb

public boolean unmountObb (String rawPath, 
                boolean force, 
                OnObbStateChangeListener listener)

Unmount an Opaque Binary Blob (OBB) file asynchronously. If the force flag is true, it will kill any application needed to unmount the given OBB (even the calling application).

The OnObbStateChangeListener registered with this call will receive the success or failure of this operation.

Note: you can only mount OBB files for which the OBB tag on the file matches a package ID that is owned by the calling program's UID. That is, shared UID applications can obtain access to any other application's OBB that shares its UID.

unregisterStorageVolumeCallback

public void unregisterStorageVolumeCallback (StorageManager.StorageVolumeCallback callback)

Unregisters the given callback from listening for StorageVolume changes.