Introduce MinidumpStringWriter and its test

minidump/minidump_string_writer.h

Index: minidump/minidump_string_writer.h
diff --git a/minidump/minidump_string_writer.h b/minidump/minidump_string_writer.h
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+// Copyright 2014 The Crashpad Authors. All rights reserved.
+//
+// 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 CRASHPAD_MINIDUMP_MINIDUMP_STRING_WRITER_H_
+#define CRASHPAD_MINIDUMP_MINIDUMP_STRING_WRITER_H_
+
+#include <dbghelp.h>
+#include <stdint.h>
+#include <sys/types.h>
+
+#include <string>
+
+#include "base/basictypes.h"
+#include "base/strings/string16.h"
+#include "minidump/minidump_extensions.h"
+#include "minidump/minidump_writable.h"
+#include "util/file/file_writer.h"
+
+namespace crashpad {
+namespace internal {
+
+//! \cond
+
+struct MinidumpStringWriterUTF16Traits {
+  typedef string16 StringType;
+  typedef MINIDUMP_STRING MinidumpStringType;
+};
+
+struct MinidumpStringWriterUTF8Traits {
+  typedef std::string StringType;
+  typedef MinidumpUTF8String MinidumpStringType;
+};
+
+//! \endcond
+
+//! \brief Writes a variable-length string to a minidump file in accordance with
+//!     the string type’s characteristics.
+//!
+//! MinidumpStringWriter objects should not be instantiated directly. To write
+//! strings to minidump file, use the MinidumpUTF16StringWriter and
+//! MinidumpUTF8StringWriter subclasses instead.
+template <typename Traits>
+class MinidumpStringWriter : public MinidumpWritable {
+ public:
+  MinidumpStringWriter();
+  ~MinidumpStringWriter();
+
+ protected:
+  typedef typename Traits::MinidumpStringType MinidumpStringType;
+  typedef typename Traits::StringType StringType;
+
+  virtual bool Freeze() override;
+  virtual size_t SizeOfObject() override;
+  virtual bool WriteObject(FileWriterInterface* file_writer) override;
+
+  //! \brief Sets the string to be written.
+  //!
+  //! \note Valid in #kStateMutable.
+  void set_string(const StringType& string) { string_.assign(string); }
+
+ private:
+  MinidumpStringType string_base_;
+  StringType string_;
+
+  DISALLOW_COPY_AND_ASSIGN(MinidumpStringWriter);
+};
+
+//! \brief Writes a variable-length UTF-16-encoded MINIDUMP_STRING to a minidump
+//!     file.
+//!
+//! MinidumpUTF16StringWriter objects should not be instantiated directly
+//! outside of the MinidumpWritable family of classes.
+class MinidumpUTF16StringWriter final
+    : public MinidumpStringWriter<MinidumpStringWriterUTF16Traits> {
+ public:
+  MinidumpUTF16StringWriter() : MinidumpStringWriter() {}
+  ~MinidumpUTF16StringWriter() {}
+
+  //! \brief Converts a UTF-8 string to UTF-16 and sets it as the string to be
+  //!     written.
+  //!
+  //! \note Valid in #kStateMutable.
+  void SetUTF8(const std::string& string_utf8);
+
+ private:
+  DISALLOW_COPY_AND_ASSIGN(MinidumpUTF16StringWriter);
+};
+
+//! \brief Writes a variable-length UTF-8-encoded MinidumpUTF8String to a
+//!     minidump file.
+//!
+//! MinidumpUTF8StringWriter objects should not be instantiated directly outside
+//! of the MinidumpWritable family of classes.
+class MinidumpUTF8StringWriter final
+    : public MinidumpStringWriter<MinidumpStringWriterUTF8Traits> {
+ public:
+  MinidumpUTF8StringWriter() : MinidumpStringWriter() {}
+  ~MinidumpUTF8StringWriter() {}
+
+  //! \brief Sets the string to be written.
+  //!
+  //! \note Valid in #kStateMutable.
+  void SetUTF8(const std::string& string_utf8) { set_string(string_utf8); }
+
+ private:
+  DISALLOW_COPY_AND_ASSIGN(MinidumpUTF8StringWriter);
+};
+
+}  // namespace internal
+}  // namespace crashpad
+
+#endif  // CRASHPAD_MINIDUMP_MINIDUMP_STRING_WRITER_H_