Switch over to the google3 unix_file File*.
I also moved macros.h to base/macros.h to ease google3 porting, at
the expense of a larger than necessary change. (I learned my lesson,
though, and didn't make the equivalent base/logging.h change.)
I'm not sure whether we want to keep the unix_file MappedFile given
our existing MemMap, but it's easier to bring it over and then remove
it (and possibly revert the removal) than to bring it over later.
Change-Id: Id50a66faa5ab17b9bc936cc9043dbc26f791f0ca
diff --git a/src/base/unix_file/null_file.h b/src/base/unix_file/null_file.h
new file mode 100644
index 0000000..e716603
--- /dev/null
+++ b/src/base/unix_file/null_file.h
@@ -0,0 +1,50 @@
+/*
+ * Copyright (C) 2009 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 BASE_UNIX_FILE_NULL_FILE_H_
+#define BASE_UNIX_FILE_NULL_FILE_H_
+
+#include "base/unix_file/random_access_file.h"
+#include "base/macros.h"
+
+namespace unix_file {
+
+// A RandomAccessFile implementation equivalent to /dev/null. Writes are
+// discarded, and there's no data to be read. Callers could use FdFile in
+// conjunction with /dev/null, but that's not portable and costs a file
+// descriptor. NullFile is "free".
+//
+// Thread safe.
+class NullFile : public RandomAccessFile {
+ public:
+ NullFile();
+ virtual ~NullFile();
+
+ // RandomAccessFile API.
+ virtual int Close();
+ virtual int Flush();
+ virtual int64_t Read(char* buf, int64_t byte_count, int64_t offset) const;
+ virtual int SetLength(int64_t new_length);
+ virtual int64_t GetLength() const;
+ virtual int64_t Write(const char* buf, int64_t byte_count, int64_t offset);
+
+ private:
+ DISALLOW_COPY_AND_ASSIGN(NullFile);
+};
+
+} // namespace unix_file
+
+#endif // BASE_UNIX_FILE_NULL_FILE_H_