JByteArrayIO.hh

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#ifndef __JIO__JBYTEARRAYIO__
#define __JIO__JBYTEARRAYIO__

#include <cstring>
#include <algorithm>
#include <vector>

#include "JIO/JSerialisable.hh"


/**
 * \author mdejong
 */

namespace JIO {}
namespace JPP { using namespace JIO; }

namespace JIO {


  /**
   * Byte array binary input.
   * This class implements the JReader interface.
   */
  class JByteArrayReader : 
    public JReader 
  {
  public:
    /**
     * Default constructor.
     */
    JByteArrayReader() :
      __data(NULL),
      __size(0),
      __pos (0)
    {}


    /**
     * Constructor.
     *
     * \param  buffer  pointer to input data
     * \param  length  number of bytes
     */
    JByteArrayReader(const char* buffer, const int length = 0) :
      __data(buffer),
      __size(length),
      __pos (0)
    {}


    /**
     * Get size.
     *
     * \return         number of bytes
     */
    int size() const
    {
      return __size;
    }


    /**
     * Get data.
     *
     * \return         pointer to data
     */
    const char* data() const
    {
      return __data;
    }


    /**
     * Get remaining size.
     *
     * \return         number of bytes
     */
    int getRemainingSize() const
    {
      return __size - __pos;
    }


    /**
     * Get remaining data.
     *
     * \return         pointer to remaining data
     */
    const char* getRemainingData() const
    {
      return __data + __pos;
    }


    /**
     * Get read position.
     *
     * \return         read position
     */
    int tellg() const
    {
      return __pos;
    }


    /**
     * Set read position.
     *
     * \param pos      read position
     */
    void seekg(const int pos)
    {
      __pos = pos;
    }


    /**
     * Status of reader.
     *
     * \return         status of this reader
     */
    virtual bool getStatus() const override 
    { 
      return __size - __pos >= 0; 
    }


    /**
     * Read byte array.
     *
     * \param  buffer  pointer to byte array
     * \param  length  number of bytes
     * \return         number of bytes
     */
    virtual int read(char* buffer, const int length) override 
    { 
      memcpy(buffer, __data + __pos, length);
        
      __pos += length;

      return length;
    }


  protected:
    const char* __data;
    int         __size;
    int         __pos;
  };


  /**
   * Byte array binary output.
   * This class implements the JWriter interface.
   */
  class JByteArrayWriter : 
    public JWriter,
    public std::vector<char>
  {
  public:
    /**
     * Constructor.
     *
     * \param  size    reserved number of bytes
     */
    JByteArrayWriter(const int size = 65536) :
      std::vector<char>(),
      __pos(0)
    {
      reserve(size);
    }


    /**
     * Status of writer.
     *
     * \return         status of this writer
     */
    virtual bool getStatus() const override 
    { 
      return true; 
    }


    /**
     * Clear buffer.
     */
    void clear()
    {
      std::vector<char>::clear();

      __pos = 0;
    }


    /**
     * Get write position.
     *
     * \return         write position
     */
    int tellp() const
    {
      return __pos;
    }


    /**
     * Set write position.
     *
     * \param pos      write position
     */
    void seekp(const int pos)
    {
      __pos = pos;
    }


    /**
     * Write byte array.
     *
     * \param  buffer  pointer to byte array
     * \param  length  number of bytes
     * \return         number of bytes
     */
    virtual int write(const char* buffer, const int length) override 
    { 
      if (__pos + length > (int) this->size()) {
        this->resize(__pos + length);
      }

      memcpy(this->data() + __pos, buffer, length);

      __pos += length;

      return length;
    }


  protected:
    int   __pos;
  };
}

#endif