Merge "Surface tree statistics through metadata."

3 files changed, 71 insertions, 7 deletions

diff --git a/api/current.txt b/api/current.txt
index ed9ac402847a..b8a37d492303 100644
--- a/api/current.txt
+++ b/api/current.txt
@@ -37454,6 +37454,8 @@ package android.provider {
     field public static final java.lang.String EXTRA_ORIENTATION = "android.provider.extra.ORIENTATION";
     field public static final java.lang.String EXTRA_PROMPT = "android.provider.extra.PROMPT";
     field public static final java.lang.String METADATA_EXIF = "android:documentExif";
+    field public static final java.lang.String METADATA_TREE_COUNT = "android:metadataTreeCount";
+    field public static final java.lang.String METADATA_TREE_SIZE = "android:metadataTreeSize";
     field public static final java.lang.String METADATA_TYPES = "android:documentMetadataTypes";
     field public static final java.lang.String PROVIDER_INTERFACE = "android.content.action.DOCUMENTS_PROVIDER";
     field public static final java.lang.String QUERY_ARG_DISPLAY_NAME = "android:query-arg-display-name";
diff --git a/core/java/android/provider/DocumentsContract.java b/core/java/android/provider/DocumentsContract.java
index ff772287de25..d9c16a700cb9 100644
--- a/core/java/android/provider/DocumentsContract.java
+++ b/core/java/android/provider/DocumentsContract.java
@@ -244,18 +244,34 @@ public final class DocumentsContract {
      * Get string array identifies the type or types of metadata returned
      * using DocumentsContract#getDocumentMetadata.
      *
-     * @see #getDocumentMetadata(ContentResolver, Uri)
+     * @see #getDocumentMetadata(ContentInterface, Uri)
      */
     public static final String METADATA_TYPES = "android:documentMetadataTypes";
 
     /**
      * Get Exif information using DocumentsContract#getDocumentMetadata.
      *
-     * @see #getDocumentMetadata(ContentResolver, Uri)
+     * @see #getDocumentMetadata(ContentInterface, Uri)
      */
     public static final String METADATA_EXIF = "android:documentExif";
 
     /**
+     * Get total count of all documents currently stored under the given
+     * directory tree. Only valid for {@link Document#MIME_TYPE_DIR} documents.
+     *
+     * @see #getDocumentMetadata(ContentInterface, Uri)
+     */
+    public static final String METADATA_TREE_COUNT = "android:metadataTreeCount";
+
+    /**
+     * Get total size of all documents currently stored under the given
+     * directory tree. Only valid for {@link Document#MIME_TYPE_DIR} documents.
+     *
+     * @see #getDocumentMetadata(ContentInterface, Uri)
+     */
+    public static final String METADATA_TREE_SIZE = "android:metadataTreeSize";
+
+    /**
      * Constants related to a document, including {@link Cursor} column names
      * and flags.
      * <p>
@@ -519,7 +535,7 @@ public final class DocumentsContract {
          * using DocumentsContract#getDocumentMetadata
          *
          * @see #COLUMN_FLAGS
-         * @see DocumentsContract#getDocumentMetadata(ContentResolver, Uri)
+         * @see DocumentsContract#getDocumentMetadata(ContentInterface, Uri)
          */
         public static final int FLAG_SUPPORTS_METADATA = 1 << 14;
     }
diff --git a/core/java/com/android/internal/content/FileSystemProvider.java b/core/java/com/android/internal/content/FileSystemProvider.java
index 8bc90a891352..a27dbeae2f3a 100644
--- a/core/java/com/android/internal/content/FileSystemProvider.java
+++ b/core/java/com/android/internal/content/FileSystemProvider.java
@@ -39,6 +39,7 @@ import android.provider.DocumentsContract.Document;
 import android.provider.DocumentsProvider;
 import android.provider.MediaStore;
 import android.provider.MetadataReader;
+import android.system.Int64Ref;
 import android.text.TextUtils;
 import android.util.ArrayMap;
 import android.util.Log;
@@ -53,6 +54,12 @@ import java.io.FileInputStream;
 import java.io.FileNotFoundException;
 import java.io.IOException;
 import java.io.InputStream;
+import java.nio.file.FileSystems;
+import java.nio.file.FileVisitResult;
+import java.nio.file.FileVisitor;
+import java.nio.file.Files;
+import java.nio.file.Path;
+import java.nio.file.attribute.BasicFileAttributes;
 import java.util.LinkedList;
 import java.util.List;
 import java.util.Set;
@@ -122,18 +129,56 @@ public abstract class FileSystemProvider extends DocumentsProvider {
             throw new FileNotFoundException("Can't find the file for documentId: " + documentId);
         }
 
+        final String mimeType = getDocumentType(documentId);
+        if (Document.MIME_TYPE_DIR.equals(mimeType)) {
+            final Int64Ref treeCount = new Int64Ref(0);
+            final Int64Ref treeSize = new Int64Ref(0);
+            try {
+                final Path path = FileSystems.getDefault().getPath(file.getAbsolutePath());
+                Files.walkFileTree(path, new FileVisitor<Path>() {
+                    @Override
+                    public FileVisitResult preVisitDirectory(Path dir, BasicFileAttributes attrs) {
+                        return FileVisitResult.CONTINUE;
+                    }
+
+                    @Override
+                    public FileVisitResult visitFile(Path file, BasicFileAttributes attrs) {
+                        treeCount.value += 1;
+                        treeSize.value += attrs.size();
+                        return FileVisitResult.CONTINUE;
+                    }
+
+                    @Override
+                    public FileVisitResult visitFileFailed(Path file, IOException exc) {
+                        return FileVisitResult.CONTINUE;
+                    }
+
+                    @Override
+                    public FileVisitResult postVisitDirectory(Path dir, IOException exc) {
+                        return FileVisitResult.CONTINUE;
+                    }
+                });
+            } catch (IOException e) {
+                Log.e(TAG, "An error occurred retrieving the metadata", e);
+                return null;
+            }
+
+            final Bundle res = new Bundle();
+            res.putLong(DocumentsContract.METADATA_TREE_COUNT, treeCount.value);
+            res.putLong(DocumentsContract.METADATA_TREE_SIZE, treeSize.value);
+            return res;
+        }
+
         if (!file.isFile()) {
             Log.w(TAG, "Can't stream non-regular file. Returning empty metadata.");
             return null;
         }
-
         if (!file.canRead()) {
             Log.w(TAG, "Can't stream non-readable file. Returning empty metadata.");
             return null;
         }
-
-        String mimeType = getDocumentType(documentId);
         if (!MetadataReader.isSupportedMimeType(mimeType)) {
+            Log.w(TAG, "Unsupported type " + mimeType + ". Returning empty metadata.");
             return null;
         }
 
@@ -562,7 +607,8 @@ public abstract class FileSystemProvider extends DocumentsProvider {
     }
 
     protected boolean typeSupportsMetadata(String mimeType) {
-        return MetadataReader.isSupportedMimeType(mimeType);
+        return MetadataReader.isSupportedMimeType(mimeType)
+                || Document.MIME_TYPE_DIR.equals(mimeType);
     }
 
     protected final File getFileForDocId(String docId) throws FileNotFoundException {