Nativehelper: Export header-only version of helpers
Export a version of the nativehelper helpers that doesn't have
a dependency on the libnativehelper library. Instead, provide an
inline function for null throw.
Test: m
Change-Id: Idfab8809873d54db824c8bc089f003265fe5a9b9
diff --git a/header_only_include/nativehelper/scoped_utf_chars.h b/header_only_include/nativehelper/scoped_utf_chars.h
new file mode 100644
index 0000000..75cbe50
--- /dev/null
+++ b/header_only_include/nativehelper/scoped_utf_chars.h
@@ -0,0 +1,94 @@
+/*
+ * Copyright (C) 2010 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.
+ */
+
+#ifndef SCOPED_UTF_CHARS_H_
+#define SCOPED_UTF_CHARS_H_
+
+#include <string.h>
+
+#include "jni.h"
+#include "nativehelper_utils.h"
+
+// A smart pointer that provides read-only access to a Java string's UTF chars.
+// Unlike GetStringUTFChars, we throw NullPointerException rather than abort if
+// passed a null jstring, and c_str will return nullptr.
+// This makes the correct idiom very simple:
+//
+// ScopedUtfChars name(env, java_name);
+// if (name.c_str() == nullptr) {
+// return nullptr;
+// }
+class ScopedUtfChars {
+ public:
+ ScopedUtfChars(JNIEnv* env, jstring s) : env_(env), string_(s) {
+ if (s == nullptr) {
+ utf_chars_ = nullptr;
+ jniThrowNullPointerException(env, nullptr);
+ } else {
+ utf_chars_ = env->GetStringUTFChars(s, nullptr);
+ }
+ }
+
+ ScopedUtfChars(ScopedUtfChars&& rhs) :
+ env_(rhs.env_), string_(rhs.string_), utf_chars_(rhs.utf_chars_) {
+ rhs.env_ = nullptr;
+ rhs.string_ = nullptr;
+ rhs.utf_chars_ = nullptr;
+ }
+
+ ~ScopedUtfChars() {
+ if (utf_chars_) {
+ env_->ReleaseStringUTFChars(string_, utf_chars_);
+ }
+ }
+
+ ScopedUtfChars& operator=(ScopedUtfChars&& rhs) {
+ if (this != &rhs) {
+ // Delete the currently owned UTF chars.
+ this->~ScopedUtfChars();
+
+ // Move the rhs ScopedUtfChars and zero it out.
+ env_ = rhs.env_;
+ string_ = rhs.string_;
+ utf_chars_ = rhs.utf_chars_;
+ rhs.env_ = nullptr;
+ rhs.string_ = nullptr;
+ rhs.utf_chars_ = nullptr;
+ }
+ return *this;
+ }
+
+ const char* c_str() const {
+ return utf_chars_;
+ }
+
+ size_t size() const {
+ return strlen(utf_chars_);
+ }
+
+ const char& operator[](size_t n) const {
+ return utf_chars_[n];
+ }
+
+ private:
+ JNIEnv* env_;
+ jstring string_;
+ const char* utf_chars_;
+
+ DISALLOW_COPY_AND_ASSIGN(ScopedUtfChars);
+};
+
+#endif // SCOPED_UTF_CHARS_H_