data_snk.h

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/*
* DataSink
* (C) 1999-2007 Jack Lloyd
*     2017 Philippe Lieser
*
* Botan is released under the Simplified BSD License (see license.txt)
*/
 
#ifndef BOTAN_DATA_SINK_H_
#define BOTAN_DATA_SINK_H_
 
#include <botan/filter.h>
#include <iosfwd>
#include <memory>
 
namespace Botan {
 
/**
* This class represents abstract data sink objects.
*/
class BOTAN_PUBLIC_API(2, 0) DataSink : public Filter {
   public:
      /**
      * Check whether this filter is an attachable filter
      * @return always false, since nothing may be attached after a sink
      */
      bool attachable() override { return false; }
};
 
/**
* This class represents a data sink which writes its output to a stream.
*/
class BOTAN_PUBLIC_API(2, 0) DataSink_Stream final : public DataSink {
   public:
      /**
      * Construct a DataSink_Stream from a stream.
      * @param stream the stream to write to
      * @param name identifier
      */
      BOTAN_FUTURE_EXPLICIT DataSink_Stream(std::ostream& stream, std::string_view name = "<std::ostream>");
 
#if defined(BOTAN_TARGET_OS_HAS_FILESYSTEM)
 
      /**
      * Construct a DataSink_Stream from a filesystem path name.
      * @param pathname the name of the file to open a stream to
      * @param use_binary indicates whether to treat the file
      * as a binary file or not
      */
      BOTAN_FUTURE_EXPLICIT DataSink_Stream(std::string_view pathname, bool use_binary = false);
#endif
 
      DataSink_Stream(const DataSink_Stream& other) = delete;
      DataSink_Stream(DataSink_Stream&& other) = delete;
      DataSink_Stream& operator=(const DataSink_Stream& other) = delete;
      DataSink_Stream& operator=(DataSink_Stream&& other) = delete;
 
      /**
      * Return a descriptive name for this filter
      * @return the identifier given at construction
      */
      std::string name() const override { return m_identifier; }
 
      /**
      * Write a portion of a message to the stream
      * @param buf the input as a byte array
      * @param len the length of the byte array buf
      */
      void write(const uint8_t buf[], size_t len) override;
 
      /**
      * Notify that the current message is finished and flush the stream
      */
      void end_msg() override;
 
      ~DataSink_Stream() override;
 
   private:
      const std::string m_identifier;
 
      // May be null, if m_sink was an external reference
      std::unique_ptr<std::ostream> m_sink_memory;
      std::ostream& m_sink;
};
 
}  // namespace Botan
 
#endif