Upstream DocumentTabModelImpl and related classes

chrome/android/java/src/org/chromium/chrome/browser/tabmodel/document/StorageDelegate.java

Index: chrome/android/java/src/org/chromium/chrome/browser/tabmodel/document/StorageDelegate.java
diff --git a/chrome/android/java/src/org/chromium/chrome/browser/tabmodel/document/StorageDelegate.java b/chrome/android/java/src/org/chromium/chrome/browser/tabmodel/document/StorageDelegate.java
new file mode 100644
index 0000000000000000000000000000000000000000..2d2f7fe15bbf64766dec01337bfab2d07a428bb5
--- /dev/null
+++ b/chrome/android/java/src/org/chromium/chrome/browser/tabmodel/document/StorageDelegate.java
@@ -0,0 +1,154 @@
+// Copyright 2014 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+package org.chromium.chrome.browser.tabmodel.document;
+
+import android.content.Context;
+import android.util.Log;
+
+import org.chromium.base.ApplicationStatus;
+import org.chromium.chrome.browser.TabState;
+import org.chromium.chrome.browser.util.StreamUtil;
+
+import java.io.ByteArrayOutputStream;
+import java.io.File;
+import java.io.FileInputStream;
+import java.io.FileNotFoundException;
+import java.io.FileOutputStream;
+import java.io.IOException;
+
+/**
+ * Contains functions for interacting with the file system.
+ */
+public class StorageDelegate {
+    private static final String TAG = "StorageDelegate";
+
+    /** Filename to use for the DocumentTabModel that stores regular tabs. */
+    private static final String REGULAR_FILE_NAME = "chrome_document_activity.store";
+
+    /** Directory to store TabState files in. */
+    private static final String STATE_DIRECTORY = "ChromeDocumentActivity";
+
+    /** The buffer size to use when reading the DocumentTabModel file, set to 4k bytes. */
+    private static final int BUF_SIZE = 0x1000;
+
+    /** Whether this is dealing with incognito state. */
+    protected final boolean mIsIncognito;
+
+    public StorageDelegate(boolean isIncognito) {
+        mIsIncognito = isIncognito;
+    }
+
+    /**
+     * Reads the file containing the minimum info required to restore the state of the
+     * {@link DocumentTabModel}.
+     * @return Byte buffer containing the task file's data, or null if it wasn't read.
+     */
+    public byte[] readTaskFileBytes() {
+        // Incognito mode doesn't save its state out.
+        if (mIsIncognito) return null;
+
+        // Read in the file.
+        byte[] bytes = null;
+        FileInputStream streamIn = null;
+        try {
+            String filename = getFilename();
+            streamIn = ApplicationStatus.getApplicationContext().openFileInput(filename);
+
+            // Read the file from the file into the out stream.
+            ByteArrayOutputStream streamOut = new ByteArrayOutputStream();
+            byte[] buf = new byte[BUF_SIZE];
+            int r;
+            while ((r = streamIn.read(buf)) != -1) {
+                streamOut.write(buf, 0, r);
+            }
+            bytes = streamOut.toByteArray();
+        } catch (FileNotFoundException e) {
+            Log.e(TAG, "DocumentTabModel file not found.");
+        } catch (IOException e) {
+            Log.e(TAG, "I/O exception", e);
+        } finally {
+            StreamUtil.closeQuietly(streamIn);
+        }
+
+        return bytes;
+    }
+
+    /**
+     * Writes the file containing the minimum info required to restore the state of the
+     * {@link DocumentTabModel}.
+     * @param isIncognito Whether the TabModel is incognito.
+     * @param bytes Byte buffer containing the tab's data.
+     */
+    public void writeTaskFileBytes(byte[] bytes) {
+        // Incognito mode doesn't save its state out.
+        if (mIsIncognito) return;
+
+        FileOutputStream outputStream = null;
+        try {
+            outputStream = ApplicationStatus.getApplicationContext().openFileOutput(
+                    getFilename(), Context.MODE_PRIVATE);
+            outputStream.write(bytes);
+        } catch (FileNotFoundException e) {
+            Log.e(TAG, "DocumentTabModel file not found", e);
+        } catch (IOException e) {
+            Log.e(TAG, "I/O exception", e);
+        } finally {
+            StreamUtil.closeQuietly(outputStream);
+        }
+    }
+
+    /** @return The directory that stores the TabState files. */
+    public File getStateDirectory() {
+        return ApplicationStatus.getApplicationContext().getDir(
+                STATE_DIRECTORY, Context.MODE_PRIVATE);
+    }
+
+    /**
+     * Restores the TabState with the given ID.
+     * @param tabId ID of the Tab.
+     * @return TabState for the Tab.
+     */
+    public TabState restoreTabState(int tabId) {
+        return TabState.restoreTabState(getTabFile(tabId), mIsIncognito);
+    }
+
+    /**
+     * Saves the TabState with the given ID.
+     * @param tabId ID of the Tab.
+     * @param state TabState for the Tab.
+     */
+    public void saveTabState(int tabId, TabState state) {
+        FileOutputStream stream = null;
+        try {
+            stream = new FileOutputStream(getTabFile(tabId));
+            TabState.saveState(stream, state, mIsIncognito);
+        } catch (FileNotFoundException exception) {
+            Log.e(TAG, "Failed to save out tab state for tab " + tabId, exception);
+        } catch (IOException exception) {
+            Log.e(TAG, "Failed to save out tab state.", exception);
+        } finally {
+            StreamUtil.closeQuietly(stream);
+        }
+    }
+
+    /**
+     * Deletes the TabState file for the given ID.
+     * @param tabId ID of the TabState file to delete.
+     */
+    public void deleteTabStateFile(int tabId) {
+        boolean success = getTabFile(tabId).delete();
+        if (!success) Log.w(TAG, "Failed to delete file for tab " + tabId);
+    }
+
+    private File getTabFile(int tabId) {
+        String tabStateFilename = TabState.getTabStateFilename(tabId, mIsIncognito);
+        return new File(getStateDirectory(), tabStateFilename);
+    }
+
+    /** @return the filename of the persisted TabModel state. */
+    private String getFilename() {
+        return mIsIncognito ? null : REGULAR_FILE_NAME;
+    }
+}