libbase: hex.h adds HexString
This requires a few lines of code to implement in C++, but the
'standard' implementation also triggers ubsan implicit-conversion, so it
can be more involved in some places. It's really common to convert
binary data into hex strings.
Future considerations:
- adding the reverse direction (parse binary data into uint8_t*)
- adding templated versions, which can be useful while debugging certain
issues (though, perhaps a bit overkill)
template <typename T>
std::string HexObject(const T& t) {
return HexString(reinterpret_cast<void*>(&t), sizeof(T));
}
Bug: N/A
Test: libbase_test
Change-Id: I93d3708a9740a0682c8cbd91f067e2dfeab35380
diff --git a/include/android-base/hex.h b/include/android-base/hex.h
new file mode 100644
index 0000000..cbb26a8
--- /dev/null
+++ b/include/android-base/hex.h
@@ -0,0 +1,31 @@
+/*
+ * Copyright (C) 2021 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.
+ */
+
+#pragma once
+
+#include <string>
+
+namespace android {
+namespace base {
+
+// Converts binary data into a hexString.
+//
+// Hex values are printed in order, e.g. 0xDEAD will result in 'adde' because
+// Android is little-endian.
+std::string HexString(const void* bytes, size_t len);
+
+} // namespace base
+} // namespace android