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#ifndef UTIL_STREAM_IO_H
#define UTIL_STREAM_IO_H
#include "util/exception.hh"
#include "util/file.hh"
namespace util {
namespace stream {
class ChainPosition;
class ReadSizeException : public util::Exception {
public:
ReadSizeException() throw();
~ReadSizeException() throw();
};
class Read {
public:
explicit Read(int fd) : file_(fd) {}
void Run(const ChainPosition &position);
private:
int file_;
};
// Like read but uses pread so that the file can be accessed from multiple threads.
class PRead {
public:
explicit PRead(int fd, bool take_own = false) : file_(fd), own_(take_own) {}
void Run(const ChainPosition &position);
private:
int file_;
bool own_;
};
class Write {
public:
explicit Write(int fd) : file_(fd) {}
void Run(const ChainPosition &position);
private:
int file_;
};
// It's a common case that stuff is written and then recycled. So rather than
// spawn another thread to Recycle, this combines the two roles.
class WriteAndRecycle {
public:
explicit WriteAndRecycle(int fd) : file_(fd) {}
void Run(const ChainPosition &position);
private:
int file_;
};
class PWriteAndRecycle {
public:
explicit PWriteAndRecycle(int fd) : file_(fd) {}
void Run(const ChainPosition &position);
private:
int file_;
};
// Reuse the same file over and over again to buffer output.
class FileBuffer {
public:
explicit FileBuffer(int fd) : file_(fd) {}
PWriteAndRecycle Sink() const {
util::SeekOrThrow(file_.get(), 0);
return PWriteAndRecycle(file_.get());
}
PRead Source() const {
return PRead(file_.get());
}
uint64_t Size() const {
return SizeOrThrow(file_.get());
}
private:
scoped_fd file_;
};
} // namespace stream
} // namespace util
#endif // UTIL_STREAM_IO_H
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