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/*
* 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_
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