zero_copy_stream_impl.h | Explore in Territory

// Protocol Buffers - Google's data interchange format
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// https://developers.google.com/protocol-buffers/
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// Author: [email protected] (Kenton Varda)
//  Based on original Protocol Buffers design by
//  Sanjay Ghemawat, Jeff Dean, and others.
//
// This file contains common implementations of the interfaces defined in
// zero_copy_stream.h which are only included in the full (non-lite)
// protobuf library.  These implementations include Unix file descriptors
// and C++ iostreams.  See also:  zero_copy_stream_impl_lite.h

#ifndef GOOGLE_PROTOBUF_IO_ZERO_COPY_STREAM_IMPL_H__
#define GOOGLE_PROTOBUF_IO_ZERO_COPY_STREAM_IMPL_H__


#include <iosfwd>
#include <string>

#include <google/protobuf/stubs/common.h>
#include <google/protobuf/io/zero_copy_stream.h>
#include <google/protobuf/io/zero_copy_stream_impl_lite.h>

// Must be included last.
#include <google/protobuf/port_def.inc>

namespace google {
namespace protobuf {
namespace io {

// ===================================================================

// A ZeroCopyInputStream which reads from a file descriptor.
//
// FileInputStream is preferred over using an ifstream with IstreamInputStream.
// The latter will introduce an extra layer of buffering, harming performance.
// Also, it's conceivable that FileInputStream could someday be enhanced
// to use zero-copy file descriptors on OSs which support them.
class PROTOBUF_EXPORT FileInputStream PROTOBUF_FUTURE_FINAL
    : public ZeroCopyInputStream { … };

// ===================================================================

// A ZeroCopyOutputStream which writes to a file descriptor.
//
// FileOutputStream is preferred over using an ofstream with
// OstreamOutputStream.  The latter will introduce an extra layer of buffering,
// harming performance.  Also, it's conceivable that FileOutputStream could
// someday be enhanced to use zero-copy file descriptors on OSs which
// support them.
class PROTOBUF_EXPORT FileOutputStream PROTOBUF_FUTURE_FINAL
    : public CopyingOutputStreamAdaptor { … };

// ===================================================================

// A ZeroCopyInputStream which reads from a C++ istream.
//
// Note that for reading files (or anything represented by a file descriptor),
// FileInputStream is more efficient.
class PROTOBUF_EXPORT IstreamInputStream PROTOBUF_FUTURE_FINAL
    : public ZeroCopyInputStream { … };

// ===================================================================

// A ZeroCopyOutputStream which writes to a C++ ostream.
//
// Note that for writing files (or anything represented by a file descriptor),
// FileOutputStream is more efficient.
class PROTOBUF_EXPORT OstreamOutputStream PROTOBUF_FUTURE_FINAL
    : public ZeroCopyOutputStream { … };

// ===================================================================

// A ZeroCopyInputStream which reads from several other streams in sequence.
// ConcatenatingInputStream is unable to distinguish between end-of-stream
// and read errors in the underlying streams, so it assumes any errors mean
// end-of-stream.  So, if the underlying streams fail for any other reason,
// ConcatenatingInputStream may do odd things.  It is suggested that you do
// not use ConcatenatingInputStream on streams that might produce read errors
// other than end-of-stream.
class PROTOBUF_EXPORT ConcatenatingInputStream PROTOBUF_FUTURE_FINAL
    : public ZeroCopyInputStream { … };

// ===================================================================

}  // namespace io
}  // namespace protobuf
}  // namespace google

#include <google/protobuf/port_undef.inc>

#endif  // GOOGLE_PROTOBUF_IO_ZERO_COPY_STREAM_IMPL_H__
chromium/third_party/protobuf/src/google/protobuf/io/zero_copy_stream_impl.h
