Clean up the CharsetDecoder/CharsetEncoder implementation a bit more.

This removes the duplicated error-checking in the ICU classes that started
this investigation, but also cleans up a bunch of other stuff. There shouldn't
be any other behavioral differences, just clearer code.

Bug: 3418769
Change-Id: I4da4d2a5b2fce1b152e527909b7c76a6db76c5c0

1 files changed, 51 insertions, 0 deletions

diff --git a/include/ScopedStringChars.h b/include/ScopedStringChars.h
new file mode 100644
index 0000000..9f543b7
--- /dev/null
+++ b/include/ScopedStringChars.h
@@ -0,0 +1,51 @@
+/*
+ * Copyright (C) 2011 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_STRING_CHARS_H_included
+#define SCOPED_STRING_CHARS_H_included
+
+#include "JNIHelp.h"
+
+// A smart pointer that provides access to a jchar* given a JNI jstring.
+class ScopedStringChars {
+public:
+    ScopedStringChars(JNIEnv* env, jstring s) : mEnv(env), mString(s), mSize(0) {
+        mChars = env->GetStringChars(mString, NULL);
+        if (mChars != NULL) {
+            mSize = env->GetStringLength(mString);
+        }
+    }
+
+    ~ScopedStringChars() {
+        mEnv->ReleaseStringChars(mString, mChars);
+    }
+
+    const jchar* get() const { return mChars; }
+    const jchar& operator[](size_t n) const { return mChars[n]; }
+    size_t size() const { return mSize; }
+
+private:
+    JNIEnv* mEnv;
+    jstring mString;
+    const UChar* mChars;
+    size_t mSize;
+
+    // Disallow copy and assignment.
+    ScopedStringChars(const ScopedStringChars&);
+    void operator=(const ScopedStringChars&);
+};
+
+#endif  // SCOPED_STRING_CHARS_H_included