tge/engine/core/stream.h

//-----------------------------------------------------------------------------
// Torque Game Engine
// Copyright (C) GarageGames.com, Inc.
//-----------------------------------------------------------------------------

#ifndef _STREAM_H_
#define _STREAM_H_

//Includes
#ifndef _PLATFORM_H_
#include "platform/platform.h"
#endif


// This should ideally be done with templates...
//
/// @defgroup stream_overload Primitive Type Stream Operation Overloads
/// These macros define the read and write functions for all primitive types.
/// @{

#define DECLARE_OVERLOADED_READ(type)      \
   bool read(type* out_read) {             \
      return read(sizeof(type), out_read); \
   }
#define DECLARE_OVERLOADED_WRITE(type)       \
   bool write(type in_write) {               \
      return write(sizeof(type), &in_write); \
   }

#define DECLARE_ENDIAN_OVERLOADED_READ(type)       \
   bool read(type* out_read) {                     \
      type temp;                                   \
      bool success = read(sizeof(type), &temp);    \
      *out_read = convertLEndianToHost(temp);      \
      return success;                              \
   }
#define DECLARE_ENDIAN_OVERLOADED_WRITE(type)      \
   bool write(type in_write) {                     \
      type temp = convertHostToLEndian(in_write);  \
      return write(sizeof(type), &temp);           \
   }
/// @}

class ColorI;
class ColorF;

//------------------------------------------------------------------------------
//-------------------------------------- Base Stream class
//
/// Base stream class for streaming data across a specific media
class Stream {
   // Public structs and enumerations...
  public:
     /// Status constantants for the stream
   enum Status {
      Ok = 0,           ///< Ok!
      IOError,          ///< Read or Write error
      EOS,              ///< End of Stream reached (mostly for reads)
      IllegalCall,      ///< An unsupported operation used.  Always w/ accompanied by AssertWarn
      Closed,           ///< Tried to operate on a closed stream (or detached filter)
      UnknownError      ///< Catchall
   };

   enum Capability {
      StreamWrite    = BIT(0), ///< Can this stream write?
      StreamRead     = BIT(1), ///< Can this stream read?
      StreamPosition = BIT(2)  ///< Can this stream position?
   };

   // Accessible only through inline accessors
  private:
   Status m_streamStatus;

   // Derived accessible data modifiers...
  protected:
   void setStatus(const Status in_newStatus) { m_streamStatus = in_newStatus; }

  public:
   Stream();
   virtual ~Stream();

   /// Gets the status of the stream
   Stream::Status getStatus() const { return m_streamStatus; }
   /// Gets a printable string form of the status
   static const char* getStatusString(const Status in_status);

   // Derived classes must override these...
  protected:
   virtual bool _read(const U32 in_numBytes,  void* out_pBuffer)      = 0;
   virtual bool _write(const U32 in_numBytes, const void* in_pBuffer) = 0;
  public:
     /// Checks to see if this stream has the capability of a given function
   virtual bool hasCapability(const Capability) const = 0;

   /// Gets the position in the stream
   virtual U32  getPosition() const                      = 0;
   /// Sets the position of the stream.  Returns if the new position is valid or not
   virtual bool setPosition(const U32 in_newPosition) = 0;
   /// Gets the size of the stream
   virtual U32  getStreamSize() = 0;

   /// Reads a line from the stream.
   /// @param buffer buffer to be read into
   /// @param bufferSize max size of the buffer.  Will not read more than the "bufferSize"
   void readLine(U8 *buffer, U32 bufferSize);
   /// writes a line to the stream
   void writeLine(U8 *buffer);

   /// Reads a string and inserts it into the StringTable
   /// @see StringTable
   const char *readSTString(bool casesens = false);
   /// Reads a string of maximum 255 characters long
   virtual void readString(char stringBuf[256]);
   /// Reads a string that could potentially be more than 255 characters long.
   /// @param maxStringLen Maximum length to read.  If the string is longer than maxStringLen, only maxStringLen bytes will be read.
   /// @param stringBuf buffer where data is read into
   void readLongString(U32 maxStringLen, char *stringBuf);
   /// Writes a string to the stream.  This function is slightly unstable.
   /// Only use this if you have a valid string that is not empty.
   /// writeString is safer.
   void writeLongString(U32 maxStringLen, const char *string);

   /// Writes a string to the stream.
   virtual void writeString(const char *stringBuf, S32 maxLen=255);

   /// Write an integral color to the stream.
   bool write(const ColorI&);
   /// Write a floating point color to the stream.
   bool write(const ColorF&);
   /// Read an integral color from the stream.
   bool read(ColorI*);
   /// Read a floating point color from the stream.
   bool read(ColorF*);


   // Overloaded write and read ops..
  public:
   bool read(const U32 in_numBytes,  void* out_pBuffer) {
      return _read(in_numBytes, out_pBuffer);
   }
   bool write(const U32 in_numBytes, const void* in_pBuffer) {
      return _write(in_numBytes, in_pBuffer);
   }
   DECLARE_OVERLOADED_WRITE(S8)
   DECLARE_OVERLOADED_WRITE(U8)

   DECLARE_ENDIAN_OVERLOADED_WRITE(S16)
   DECLARE_ENDIAN_OVERLOADED_WRITE(S32)
   DECLARE_ENDIAN_OVERLOADED_WRITE(U16)
   DECLARE_ENDIAN_OVERLOADED_WRITE(U32)
   DECLARE_ENDIAN_OVERLOADED_WRITE(F32)
   DECLARE_ENDIAN_OVERLOADED_WRITE(F64)

   DECLARE_OVERLOADED_READ(S8)
   DECLARE_OVERLOADED_READ(U8)

   DECLARE_ENDIAN_OVERLOADED_READ(S16)
   DECLARE_ENDIAN_OVERLOADED_READ(S32)
   DECLARE_ENDIAN_OVERLOADED_READ(U16)
   DECLARE_ENDIAN_OVERLOADED_READ(U32)
   DECLARE_ENDIAN_OVERLOADED_READ(F32)
   DECLARE_ENDIAN_OVERLOADED_READ(F64)

   // We have to do the bool's by hand, since they are different sizes
   //  on different compilers...
   //
   bool read(bool* out_pRead) {
      U8 translate;
      bool success = read(&translate);
      if (success == false)
         return false;

      *out_pRead = translate != 0;
      return true;
   }
   bool write(const bool& in_rWrite) {
      U8 translate = in_rWrite ? U8(1) : U8(0);
      return write(translate);
   }
};

#endif //_STREAM_H_