/*
* Copyright (C) 2013 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 com.android.externalstorage;
import android.content.ContentResolver;
import android.content.Context;
import android.content.Intent;
import android.content.res.AssetFileDescriptor;
import android.database.Cursor;
import android.database.MatrixCursor;
import android.database.MatrixCursor.RowBuilder;
import android.graphics.Point;
import android.net.Uri;
import android.os.CancellationSignal;
import android.os.FileObserver;
import android.os.FileUtils;
import android.os.Handler;
import android.os.ParcelFileDescriptor;
import android.os.ParcelFileDescriptor.OnCloseListener;
import android.os.UserHandle;
import android.os.storage.StorageManager;
import android.os.storage.VolumeInfo;
import android.provider.DocumentsContract;
import android.provider.DocumentsContract.Document;
import android.provider.DocumentsContract.Root;
import android.provider.DocumentsProvider;
import android.text.TextUtils;
import android.util.ArrayMap;
import android.util.DebugUtils;
import android.util.Log;
import android.webkit.MimeTypeMap;
import com.android.internal.annotations.GuardedBy;
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.LinkedList;
import java.util.List;
public class ExternalStorageProvider extends DocumentsProvider {
private static final String TAG = "ExternalStorage";
private static final boolean LOG_INOTIFY = false;
public static final String AUTHORITY = "com.android.externalstorage.documents";
private static final Uri BASE_URI =
new Uri.Builder().scheme(ContentResolver.SCHEME_CONTENT).authority(AUTHORITY).build();
// docId format: root:path/to/file
private static final String[] DEFAULT_ROOT_PROJECTION = new String[] {
Root.COLUMN_ROOT_ID, Root.COLUMN_FLAGS, Root.COLUMN_ICON, Root.COLUMN_TITLE,
Root.COLUMN_DOCUMENT_ID, Root.COLUMN_AVAILABLE_BYTES,
};
private static final String[] DEFAULT_DOCUMENT_PROJECTION = new String[] {
Document.COLUMN_DOCUMENT_ID, Document.COLUMN_MIME_TYPE, Document.COLUMN_DISPLAY_NAME,
Document.COLUMN_LAST_MODIFIED, Document.COLUMN_FLAGS, Document.COLUMN_SIZE,
};
private static class RootInfo {
public String rootId;
public int flags;
public String title;
public String docId;
public File visiblePath;
public File path;
}
private static final String ROOT_ID_PRIMARY_EMULATED = "primary";
private StorageManager mStorageManager;
private Handler mHandler;
private final Object mRootsLock = new Object();
@GuardedBy("mRootsLock")
private ArrayMap<String, RootInfo> mRoots = new ArrayMap<>();
@GuardedBy("mObservers")
private ArrayMap<File, DirectoryObserver> mObservers = new ArrayMap<>();
@Override
public boolean onCreate() {
mStorageManager = (StorageManager) getContext().getSystemService(Context.STORAGE_SERVICE);
mHandler = new Handler();
updateVolumes();
return true;
}
public void updateVolumes() {
synchronized (mRootsLock) {
updateVolumesLocked();
}
}
private void updateVolumesLocked() {
mRoots.clear();
final int userId = UserHandle.myUserId();
final List<VolumeInfo> volumes = mStorageManager.getVolumes();
for (VolumeInfo volume : volumes) {
if (!volume.isMountedReadable()) continue;
final String rootId;
final String title;
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
rootId = ROOT_ID_PRIMARY_EMULATED;
if (VolumeInfo.ID_EMULATED_INTERNAL.equals(volume.getId())) {
title = getContext().getString(R.string.root_internal_storage);
} else {
final VolumeInfo privateVol = mStorageManager.findPrivateForEmulated(volume);
title = mStorageManager.getBestVolumeDescription(privateVol);
}
} else if (volume.getType() == VolumeInfo.TYPE_PUBLIC) {
rootId = volume.getFsUuid();
title = mStorageManager.getBestVolumeDescription(volume);
} else {
// Unsupported volume; ignore
continue;
}
if (TextUtils.isEmpty(rootId)) {
Log.d(TAG, "Missing UUID for " + volume.getId() + "; skipping");
continue;
}
if (mRoots.containsKey(rootId)) {
Log.w(TAG, "Duplicate UUID " + rootId + " for " + volume.getId() + "; skipping");
continue;
}
try {
final RootInfo root = new RootInfo();
mRoots.put(rootId, root);
root.rootId = rootId;
root.flags = Root.FLAG_SUPPORTS_CREATE | Root.FLAG_LOCAL_ONLY | Root.FLAG_ADVANCED
| Root.FLAG_SUPPORTS_SEARCH | Root.FLAG_SUPPORTS_IS_CHILD;
root.title = title;
if (volume.getType() == VolumeInfo.TYPE_PUBLIC) {
root.flags |= Root.FLAG_HAS_SETTINGS;
}
if (volume.isVisibleForRead(userId)) {
root.visiblePath = volume.getPathForUser(userId);
} else {
root.visiblePath = null;
}
root.path = volume.getInternalPathForUser(userId);
root.docId = getDocIdForFile(root.path);
} catch (FileNotFoundException e) {
throw new IllegalStateException(e);
}
}
Log.d(TAG, "After updating volumes, found " + mRoots.size() + " active roots");
// Note this affects content://com.android.externalstorage.documents/root/39BD-07C5
// as well as content://com.android.externalstorage.documents/document/*/children,
// so just notify on content://com.android.externalstorage.documents/.
getContext().getContentResolver().notifyChange(BASE_URI, null, false);
}
private static String[] resolveRootProjection(String[] projection) {
return projection != null ? projection : DEFAULT_ROOT_PROJECTION;
}
private static String[] resolveDocumentProjection(String[] projection) {
return projection != null ? projection : DEFAULT_DOCUMENT_PROJECTION;
}
private String getDocIdForFile(File file) throws FileNotFoundException {
String path = file.getAbsolutePath();
// Find the most-specific root path
String mostSpecificId = null;
String mostSpecificPath = null;
synchronized (mRootsLock) {
for (int i = 0; i < mRoots.size(); i++) {
final String rootId = mRoots.keyAt(i);
final String rootPath = mRoots.valueAt(i).path.getAbsolutePath();
if (path.startsWith(rootPath) && (mostSpecificPath == null
|| rootPath.length() > mostSpecificPath.length())) {
mostSpecificId = rootId;
mostSpecificPath = rootPath;
}
}
}
if (mostSpecificPath == null) {
throw new FileNotFoundException("Failed to find root that contains " + path);
}
// Start at first char of path under root
final String rootPath = mostSpecificPath;
if (rootPath.equals(path)) {
path = "";
} else if (rootPath.endsWith("/")) {
path = path.substring(rootPath.length());
} else {
path = path.substring(rootPath.length() + 1);
}
return mostSpecificId + ':' + path;
}
private File getFileForDocId(String docId) throws FileNotFoundException {
return getFileForDocId(docId, false);
}
private File getFileForDocId(String docId, boolean visible) throws FileNotFoundException {
final int splitIndex = docId.indexOf(':', 1);
final String tag = docId.substring(0, splitIndex);
final String path = docId.substring(splitIndex + 1);
RootInfo root;
synchronized (mRootsLock) {
root = mRoots.get(tag);
}
if (root == null) {
throw new FileNotFoundException("No root for " + tag);
}
File target = visible ? root.visiblePath : root.path;
if (target == null) {
return null;
}
if (!target.exists()) {
target.mkdirs();
}
target = new File(target, path);
if (!target.exists()) {
throw new FileNotFoundException("Missing file for " + docId + " at " + target);
}
return target;
}
private void includeFile(MatrixCursor result, String docId, File file)
throws FileNotFoundException {
if (docId == null) {
docId = getDocIdForFile(file);
} else {
file = getFileForDocId(docId);
}
int flags = 0;
if (file.canWrite()) {
if (file.isDirectory()) {
flags |= Document.FLAG_DIR_SUPPORTS_CREATE;
flags |= Document.FLAG_SUPPORTS_DELETE;
flags |= Document.FLAG_SUPPORTS_RENAME;
} else {
flags |= Document.FLAG_SUPPORTS_WRITE;
flags |= Document.FLAG_SUPPORTS_DELETE;
flags |= Document.FLAG_SUPPORTS_RENAME;
}
}
final String displayName = file.getName();
final String mimeType = getTypeForFile(file);
if (mimeType.startsWith("image/")) {
flags |= Document.FLAG_SUPPORTS_THUMBNAIL;
}
final RowBuilder row = result.newRow();
row.add(Document.COLUMN_DOCUMENT_ID, docId);
row.add(Document.COLUMN_DISPLAY_NAME, displayName);
row.add(Document.COLUMN_SIZE, file.length());
row.add(Document.COLUMN_MIME_TYPE, mimeType);
row.add(Document.COLUMN_FLAGS, flags);
// Only publish dates reasonably after epoch
long lastModified = file.lastModified();
if (lastModified > 31536000000L) {
row.add(Document.COLUMN_LAST_MODIFIED, lastModified);
}
}
@Override
public Cursor queryRoots(String[] projection) throws FileNotFoundException {
final MatrixCursor result = new MatrixCursor(resolveRootProjection(projection));
synchronized (mRootsLock) {
for (RootInfo root : mRoots.values()) {
final RowBuilder row = result.newRow();
row.add(Root.COLUMN_ROOT_ID, root.rootId);
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.path.getFreeSpace());
}
}
return result;
}
@Override
public boolean isChildDocument(String parentDocId, String docId) {
try {
final File parent = getFileForDocId(parentDocId).getCanonicalFile();
final File doc = getFileForDocId(docId).getCanonicalFile();
return FileUtils.contains(parent, doc);
} catch (IOException e) {
throw new IllegalArgumentException(
"Failed to determine if " + docId + " is child of " + parentDocId + ": " + e);
}
}
@Override
public String createDocument(String docId, String mimeType, String displayName)
throws FileNotFoundException {
displayName = FileUtils.buildValidFatFilename(displayName);
final File parent = getFileForDocId(docId);
if (!parent.isDirectory()) {
throw new IllegalArgumentException("Parent document isn't a directory");
}
final File file = FileUtils.buildUniqueFile(parent, mimeType, displayName);
if (Document.MIME_TYPE_DIR.equals(mimeType)) {
if (!file.mkdir()) {
throw new IllegalStateException("Failed to mkdir " + file);
}
} else {
try {
if (!file.createNewFile()) {
throw new IllegalStateException("Failed to touch " + file);
}
} catch (IOException e) {
throw new IllegalStateException("Failed to touch " + file + ": " + e);
}
}
return getDocIdForFile(file);
}
@Override
public String renameDocument(String docId, String displayName) throws FileNotFoundException {
// Since this provider treats renames as generating a completely new
// docId, we're okay with letting the MIME type change.
displayName = FileUtils.buildValidFatFilename(displayName);
final File before = getFileForDocId(docId);
final File after = new File(before.getParentFile(), displayName);
if (after.exists()) {
throw new IllegalStateException("Already exists " + after);
}
if (!before.renameTo(after)) {
throw new IllegalStateException("Failed to rename to " + after);
}
final String afterDocId = getDocIdForFile(after);
if (!TextUtils.equals(docId, afterDocId)) {
return afterDocId;
} else {
return null;
}
}
@Override
public void deleteDocument(String docId) throws FileNotFoundException {
final File file = getFileForDocId(docId);
if (file.isDirectory()) {
FileUtils.deleteContents(file);
}
if (!file.delete()) {
throw new IllegalStateException("Failed to delete " + file);
}
}
@Override
public Cursor queryDocument(String documentId, String[] projection)
throws FileNotFoundException {
final MatrixCursor result = new MatrixCursor(resolveDocumentProjection(projection));
includeFile(result, documentId, null);
return result;
}
@Override
public Cursor queryChildDocuments(
String parentDocumentId, String[] projection, String sortOrder)
throws FileNotFoundException {
final File parent = getFileForDocId(parentDocumentId);
final MatrixCursor result = new DirectoryCursor(
resolveDocumentProjection(projection), parentDocumentId, parent);
for (File file : parent.listFiles()) {
includeFile(result, null, file);
}
return result;
}
@Override
public Cursor querySearchDocuments(String rootId, String query, String[] projection)
throws FileNotFoundException {
final MatrixCursor result = new MatrixCursor(resolveDocumentProjection(projection));
final File parent;
synchronized (mRootsLock) {
parent = mRoots.get(rootId).path;
}
final LinkedList<File> pending = new LinkedList<File>();
pending.add(parent);
while (!pending.isEmpty() && result.getCount() < 24) {
final File file = pending.removeFirst();
if (file.isDirectory()) {
for (File child : file.listFiles()) {
pending.add(child);
}
}
if (file.getName().toLowerCase().contains(query)) {
includeFile(result, null, file);
}
}
return result;
}
@Override
public String getDocumentType(String documentId) throws FileNotFoundException {
final File file = getFileForDocId(documentId);
return getTypeForFile(file);
}
@Override
public ParcelFileDescriptor openDocument(
String documentId, String mode, CancellationSignal signal)
throws FileNotFoundException {
final File file = getFileForDocId(documentId);
final File visibleFile = getFileForDocId(documentId, true);
final int pfdMode = ParcelFileDescriptor.parseMode(mode);
if (pfdMode == ParcelFileDescriptor.MODE_READ_ONLY || visibleFile == null) {
return ParcelFileDescriptor.open(file, pfdMode);
} else {
try {
// When finished writing, kick off media scanner
return ParcelFileDescriptor.open(file, pfdMode, mHandler, new OnCloseListener() {
@Override
public void onClose(IOException e) {
final Intent intent = new Intent(
Intent.ACTION_MEDIA_SCANNER_SCAN_FILE);
intent.setData(Uri.fromFile(visibleFile));
getContext().sendBroadcast(intent);
}
});
} catch (IOException e) {
throw new FileNotFoundException("Failed to open for writing: " + e);
}
}
}
@Override
public AssetFileDescriptor openDocumentThumbnail(
String documentId, Point sizeHint, CancellationSignal signal)
throws FileNotFoundException {
final File file = getFileForDocId(documentId);
return DocumentsContract.openImageThumbnail(file);
}
@Override
public void dump(FileDescriptor fd, PrintWriter writer, String[] args) {
final IndentingPrintWriter pw = new IndentingPrintWriter(writer, " ", 160);
synchronized (mRootsLock) {
for (int i = 0; i < mRoots.size(); i++) {
final RootInfo root = mRoots.valueAt(i);
pw.println("Root{" + root.rootId + "}:");
pw.increaseIndent();
pw.printPair("flags", DebugUtils.flagsToString(Root.class, "FLAG_", root.flags));
pw.println();
pw.printPair("title", root.title);
pw.printPair("docId", root.docId);
pw.println();
pw.printPair("path", root.path);
pw.printPair("visiblePath", root.visiblePath);
pw.decreaseIndent();
pw.println();
}
}
}
private static String getTypeForFile(File file) {
if (file.isDirectory()) {
return Document.MIME_TYPE_DIR;
} else {
return getTypeForName(file.getName());
}
}
private static String getTypeForName(String name) {
final int lastDot = name.lastIndexOf('.');
if (lastDot >= 0) {
final String extension = name.substring(lastDot + 1).toLowerCase();
final String mime = MimeTypeMap.getSingleton().getMimeTypeFromExtension(extension);
if (mime != null) {
return mime;
}
}
return "application/octet-stream";
}
private void startObserving(File file, Uri notifyUri) {
synchronized (mObservers) {
DirectoryObserver observer = mObservers.get(file);
if (observer == null) {
observer = new DirectoryObserver(
file, getContext().getContentResolver(), notifyUri);
observer.startWatching();
mObservers.put(file, observer);
}
observer.mRefCount++;
if (LOG_INOTIFY) Log.d(TAG, "after start: " + observer);
}
}
private void stopObserving(File file) {
synchronized (mObservers) {
DirectoryObserver observer = mObservers.get(file);
if (observer == null) return;
observer.mRefCount--;
if (observer.mRefCount == 0) {
mObservers.remove(file);
observer.stopWatching();
}
if (LOG_INOTIFY) Log.d(TAG, "after stop: " + observer);
}
}
private static class DirectoryObserver extends FileObserver {
private static final int NOTIFY_EVENTS = ATTRIB | CLOSE_WRITE | MOVED_FROM | MOVED_TO
| CREATE | DELETE | DELETE_SELF | MOVE_SELF;
private final File mFile;
private final ContentResolver mResolver;
private final Uri mNotifyUri;
private int mRefCount = 0;
public DirectoryObserver(File file, ContentResolver resolver, Uri notifyUri) {
super(file.getAbsolutePath(), NOTIFY_EVENTS);
mFile = file;
mResolver = resolver;
mNotifyUri = notifyUri;
}
@Override
public void onEvent(int event, String path) {
if ((event & NOTIFY_EVENTS) != 0) {
if (LOG_INOTIFY) Log.d(TAG, "onEvent() " + event + " at " + path);
mResolver.notifyChange(mNotifyUri, null, false);
}
}
@Override
public String toString() {
return "DirectoryObserver{file=" + mFile.getAbsolutePath() + ", ref=" + mRefCount + "}";
}
}
private class DirectoryCursor extends MatrixCursor {
private final File mFile;
public DirectoryCursor(String[] columnNames, String docId, File file) {
super(columnNames);
final Uri notifyUri = DocumentsContract.buildChildDocumentsUri(
AUTHORITY, docId);
setNotificationUri(getContext().getContentResolver(), notifyUri);
mFile = file;
startObserving(mFile, notifyUri);
}
@Override
public void close() {
super.close();
stopObserving(mFile);
}
}
}