Add BugreportStorageProvider

BugreportStorageProvider provides storage backend for bugreports.

BUG:18070208
Change-Id: I8506dd90d69907090295d99df7427fc747b83698
diff --git a/packages/Shell/AndroidManifest.xml b/packages/Shell/AndroidManifest.xml
index 3c44245..9d16501 100644
--- a/packages/Shell/AndroidManifest.xml
+++ b/packages/Shell/AndroidManifest.xml
@@ -105,6 +105,18 @@
                 android:resource="@xml/file_provider_paths" />
         </provider>
 
+        <provider
+            android:name=".BugreportStorageProvider"
+            android:authorities="com.android.shell.documents"
+            android:grantUriPermissions="true"
+            android:exported="true"
+            android:permission="android.permission.MANAGE_DOCUMENTS"
+            android:enabled="false">
+            <intent-filter>
+                <action android:name="android.content.action.DOCUMENTS_PROVIDER" />
+            </intent-filter>
+        </provider>
+
         <activity
             android:name=".BugreportWarningActivity"
             android:theme="@*android:style/Theme.DeviceDefault.Light.Dialog.Alert"
diff --git a/packages/Shell/res/values/strings.xml b/packages/Shell/res/values/strings.xml
index 51e2c95..3db0848 100644
--- a/packages/Shell/res/values/strings.xml
+++ b/packages/Shell/res/values/strings.xml
@@ -30,4 +30,7 @@
     <string name="bugreport_confirm">Bug reports contain data from the system\'s various log files, including personal and private information.  Only share bug reports with apps and people you trust.</string>
     <!-- Checkbox that indicates this dialog should be shown again when the next bugreport is taken. [CHAR LIMIT=50] -->
     <string name="bugreport_confirm_repeat">Show this message next time</string>
+
+    <!-- Title for documents backend that offers bugreports. -->
+    <string name="bugreport_storage_title">Bug reports</string>
 </resources>
diff --git a/packages/Shell/src/com/android/shell/BugreportStorageProvider.java b/packages/Shell/src/com/android/shell/BugreportStorageProvider.java
new file mode 100644
index 0000000..814aa8c
--- /dev/null
+++ b/packages/Shell/src/com/android/shell/BugreportStorageProvider.java
@@ -0,0 +1,164 @@
+/*
+ * Copyright (C) 2015 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.shell;
+
+import android.database.Cursor;
+import android.database.MatrixCursor;
+import android.database.MatrixCursor.RowBuilder;
+import android.os.CancellationSignal;
+import android.os.FileUtils;
+import android.os.ParcelFileDescriptor;
+import android.provider.DocumentsContract.Document;
+import android.provider.DocumentsContract.Root;
+import android.provider.DocumentsProvider;
+import android.webkit.MimeTypeMap;
+
+import java.io.File;
+import java.io.FileNotFoundException;
+
+public class BugreportStorageProvider extends DocumentsProvider {
+    private static final String DOC_ID_ROOT = "bugreport";
+
+    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,
+    };
+
+    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 File mRoot;
+
+    @Override
+    public boolean onCreate() {
+        mRoot = new File(getContext().getFilesDir(), "bugreports");
+        return true;
+    }
+
+    @Override
+    public Cursor queryRoots(String[] projection) throws FileNotFoundException {
+        final MatrixCursor result = new MatrixCursor(resolveRootProjection(projection));
+        final RowBuilder row = result.newRow();
+        row.add(Root.COLUMN_ROOT_ID, DOC_ID_ROOT);
+        row.add(Root.COLUMN_FLAGS, Root.FLAG_LOCAL_ONLY | Root.FLAG_ADVANCED);
+        row.add(Root.COLUMN_ICON, android.R.mipmap.sym_def_app_icon);
+        row.add(Root.COLUMN_TITLE, getContext().getString(R.string.bugreport_storage_title));
+        row.add(Root.COLUMN_DOCUMENT_ID, DOC_ID_ROOT);
+        return result;
+    }
+
+    @Override
+    public Cursor queryDocument(String documentId, String[] projection)
+            throws FileNotFoundException {
+        final MatrixCursor result = new MatrixCursor(resolveDocumentProjection(projection));
+        if (DOC_ID_ROOT.equals(documentId)) {
+            final RowBuilder row = result.newRow();
+            row.add(Document.COLUMN_DOCUMENT_ID, documentId);
+            row.add(Document.COLUMN_MIME_TYPE, Document.MIME_TYPE_DIR);
+            row.add(Document.COLUMN_DISPLAY_NAME, mRoot.getName());
+            row.add(Document.COLUMN_LAST_MODIFIED, mRoot.lastModified());
+            row.add(Document.COLUMN_FLAGS, Document.FLAG_DIR_PREFERS_LAST_MODIFIED);
+        } else {
+            addFileRow(result, getFileForDocId(documentId));
+        }
+        return result;
+    }
+
+    @Override
+    public Cursor queryChildDocuments(
+            String parentDocumentId, String[] projection, String sortOrder)
+            throws FileNotFoundException {
+        final MatrixCursor result = new MatrixCursor(resolveDocumentProjection(projection));
+        if (DOC_ID_ROOT.equals(parentDocumentId)) {
+            final File[] files = mRoot.listFiles();
+            if (files != null) {
+                for (File file : files) {
+                    addFileRow(result, file);
+                }
+            }
+        }
+        return result;
+    }
+
+    @Override
+    public ParcelFileDescriptor openDocument(
+            String documentId, String mode, CancellationSignal signal)
+            throws FileNotFoundException {
+        if (ParcelFileDescriptor.parseMode(mode) != ParcelFileDescriptor.MODE_READ_ONLY) {
+            throw new FileNotFoundException("Failed to open: " + documentId + ", mode = " + mode);
+        }
+        return ParcelFileDescriptor.open(getFileForDocId(documentId),
+                ParcelFileDescriptor.MODE_READ_ONLY);
+    }
+
+    @Override
+    public void deleteDocument(String documentId) throws FileNotFoundException {
+        if (!getFileForDocId(documentId).delete()) {
+            throw new FileNotFoundException("Failed to delete: " + documentId);
+        }
+    }
+
+    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 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 String getDocIdForFile(File file) {
+        return DOC_ID_ROOT + ":" + file.getName();
+    }
+
+    private File getFileForDocId(String documentId) throws FileNotFoundException {
+        final int splitIndex = documentId.indexOf(':', 1);
+        final String name = documentId.substring(splitIndex + 1);
+        if (splitIndex == -1 || !DOC_ID_ROOT.equals(documentId.substring(0, splitIndex)) ||
+                !FileUtils.isValidExtFilename(name)) {
+            throw new FileNotFoundException("Invalid document ID: " + documentId);
+        }
+        final File file = new File(mRoot, name);
+        if (!file.exists()) {
+            throw new FileNotFoundException("File not found: " + documentId);
+        }
+        return file;
+    }
+
+    private void addFileRow(MatrixCursor result, File file) {
+        final RowBuilder row = result.newRow();
+        row.add(Document.COLUMN_DOCUMENT_ID, getDocIdForFile(file));
+        row.add(Document.COLUMN_MIME_TYPE, getTypeForName(file.getName()));
+        row.add(Document.COLUMN_DISPLAY_NAME, file.getName());
+        row.add(Document.COLUMN_LAST_MODIFIED, file.lastModified());
+        row.add(Document.COLUMN_FLAGS, Document.FLAG_SUPPORTS_DELETE);
+        row.add(Document.COLUMN_SIZE, file.length());
+    }
+}