Create JNI for ImportantFileWriter

Create an interface so that files that must not be corrupted can be
written atomically from Java, using the C++ base::ImportantFileWriter
class.

BUG=148011
TEST=ImportantFileWriterAndroidTest#testAtomicWrite


Review URL: https://chromiumcodereview.appspot.com/12382025

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@185569 0039d316-1c4b-4281-b951-d872f2087c98

6 files changed, 91 insertions, 0 deletions

diff --git a/base/android/base_jni_registrar.cc b/base/android/base_jni_registrar.cc
index 2f761ac..6aabd0d 100644
--- a/base/android/base_jni_registrar.cc
+++ b/base/android/base_jni_registrar.cc
@@ -7,6 +7,7 @@
 #include "base/basictypes.h"
 #include "base/android/build_info.h"
 #include "base/android/cpu_features.h"
+#include "base/android/important_file_writer_android.h"
 #include "base/android/jni_android.h"
 #include "base/android/jni_registrar.h"
 #include "base/android/locale_utils.h"
@@ -22,6 +23,8 @@ namespace android {
 static RegistrationMethod kBaseRegisteredMethods[] = {
   { "BuildInfo", base::android::BuildInfo::RegisterBindings },
   { "CpuFeatures", base::android::RegisterCpuFeatures },
+  { "ImportantFileWriterAndroid",
+    base::android::RegisterImportantFileWriterAndroid },
   { "LocaleUtils", base::android::RegisterLocaleUtils },
   { "PathService", base::android::RegisterPathService },
   { "PathUtils", base::android::RegisterPathUtils },
diff --git a/base/android/important_file_writer_android.cc b/base/android/important_file_writer_android.cc
new file mode 100644
index 0000000..f2275c1
--- /dev/null
+++ b/base/android/important_file_writer_android.cc
@@ -0,0 +1,38 @@
+// Copyright 2013 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.
+
+#include "base/android/important_file_writer_android.h"
+
+#include <string>
+
+#include "base/android/jni_string.h"
+#include "base/files/important_file_writer.h"
+#include "jni/ImportantFileWriterAndroid_jni.h"
+
+namespace base {
+namespace android {
+
+static jboolean WriteFileAtomically(JNIEnv* env,
+                                    jclass /* clazz */,
+                                    jstring file_name,
+                                    jbyteArray data) {
+  std::string native_file_name;
+  base::android::ConvertJavaStringToUTF8(env, file_name, &native_file_name);
+  base::FilePath path(native_file_name);
+  int data_length = env->GetArrayLength(data);
+  jbyte* native_data = env->GetByteArrayElements(data, NULL);
+  std::string native_data_string(reinterpret_cast<char *>(native_data),
+                                 data_length);
+  bool result = base::ImportantFileWriter::WriteFileAtomically(
+      path, native_data_string);
+  env->ReleaseByteArrayElements(data, native_data, JNI_ABORT);
+  return result;
+}
+
+bool RegisterImportantFileWriterAndroid(JNIEnv* env) {
+  return RegisterNativesImpl(env);
+}
+
+}  // namespace android
+}  // namespace base
diff --git a/base/android/important_file_writer_android.h b/base/android/important_file_writer_android.h
new file mode 100644
index 0000000..20956ba
--- /dev/null
+++ b/base/android/important_file_writer_android.h
@@ -0,0 +1,18 @@
+// Copyright 2013 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.
+
+#ifndef NATIVE_FRAMEWORK_CHROME_IMPORTANT_FILE_WRITE_ANDROID_H_
+#define NATIVE_FRAMEWORK_CHROME_IMPORTANT_FILE_WRITE_ANDROID_H_
+
+#include <jni.h>
+
+namespace base {
+namespace android {
+
+bool RegisterImportantFileWriterAndroid(JNIEnv* env);
+
+}  // namespace android
+}  // namespace base
+
+#endif  // NATIVE_FRAMEWORK_CHROME_IMPORTANT_FILE_WRITE_ANDROID_H_
diff --git a/base/android/java/src/org/chromium/base/ImportantFileWriterAndroid.java b/base/android/java/src/org/chromium/base/ImportantFileWriterAndroid.java
new file mode 100644
index 0000000..1c7c018
--- /dev/null
+++ b/base/android/java/src/org/chromium/base/ImportantFileWriterAndroid.java
@@ -0,0 +1,29 @@
+// Copyright (c) 2013 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.base;
+
+/**
+ * This class provides an interface to the native class for writing
+ * important data files without risking data loss.
+ */
+@JNINamespace("base::android")
+public class ImportantFileWriterAndroid {
+
+    /**
+     * Write a binary file atomically.
+     *
+     * This either writes all the data or leaves the file unchanged.
+     *
+     * @param fileName The complete path of the file to be written
+     * @param data The data to be written to the file
+     * @return true if the data was written to the file, false if not.
+     */
+    public static boolean writeFileAtomically(String fileName, byte[] data) {
+        return nativeWriteFileAtomically(fileName, data);
+    }
+
+    private static native boolean nativeWriteFileAtomically(
+            String fileName, byte[] data);
+}
diff --git a/base/base.gyp b/base/base.gyp
index 33c334d..2dd072a 100644
--- a/base/base.gyp
+++ b/base/base.gyp
@@ -1103,6 +1103,7 @@
           'sources': [
             'android/java/src/org/chromium/base/BuildInfo.java',
             'android/java/src/org/chromium/base/CpuFeatures.java',
+            'android/java/src/org/chromium/base/ImportantFileWriterAndroid.java',
             'android/java/src/org/chromium/base/LocaleUtils.java',
             'android/java/src/org/chromium/base/PathService.java',
             'android/java/src/org/chromium/base/PathUtils.java',
diff --git a/base/base.gypi b/base/base.gypi
index 6e7013f..8f16a34 100644
--- a/base/base.gypi
+++ b/base/base.gypi
@@ -38,6 +38,8 @@
           'android/build_info.cc',
           'android/build_info.h',
           'android/cpu_features.cc',
+          'android/important_file_writer_android.cc',
+          'android/important_file_writer_android.h',
           'android/scoped_java_ref.cc',
           'android/scoped_java_ref.h',
           'android/jni_android.cc',