/* 
 * Copyright © 2012 Intel Corporation
 *
 * This library is free software; you can redistribute it and/or
 * modify it under the terms of the GNU Lesser General Public
 * License as published by the Free Software Foundation; either
 * version 2.1 of the License, or (at your option) any later version.
 *
 * This library is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
 * Lesser General Public License for more details.
 *
 * You should have received a copy of the GNU Lesser General Public
 * License along with this library. If not, see <http://www.gnu.org/licenses/>.
 *
 * Author: Benjamin Segovia <benjamin.segovia@intel.com>
 */

/**
 * \file constant.cpp
 *
 * \author Benjamin Segovia <benjamin.segovia@intel.com>
 */
#ifndef __GBE_IR_CONSTANT_HPP__
#define __GBE_IR_CONSTANT_HPP__

#include "sys/vector.hpp"

namespace gbe {
namespace ir {

  /*! Describe one constant (may be a scalar or an array) */
  class Constant
  {
  public:
    /*! Build a constant description */
    INLINE Constant(const std::string &name, uint32_t size, uint32_t alignment, uint32_t offset) :
      name(name), size(size), alignment(alignment), offset(offset) {}
    /*! Copy constructor */
    INLINE Constant(const Constant &other) :
      name(other.name), size(other.size), alignment(other.alignment), offset(other.offset) {}
    /*! Copy operator */
    INLINE Constant& operator= (const Constant &other) {
      this->name = other.name;
      this->size = other.size;
      this->alignment = other.alignment;
      this->offset = other.offset;
      return *this;
    }
    /*! Nothing happens here */
    INLINE ~Constant(void) {}
    const std::string& getName(void) const { return name; }
    uint32_t getSize (void) const { return size; }
    uint32_t getAlignment (void) const { return alignment; }
    uint32_t getOffset(void) const { return offset; }
  private:
    std::string name; //!< Optional name of the constant
    uint32_t size;      //!< Size of the constant
    uint32_t alignment; //!< Alignment required for each constant
    uint32_t offset;    //!< Offset of the constant in the data segment
    GBE_CLASS(Constant);
  };

  /*! A constant set is a set of immutable data associated to a compilation
   *  unit
   */
  class ConstantSet : public Serializable
  {
  public:
    /*! Append a new constant in the constant set */
    void append(const char*, const std::string&, uint32_t size, uint32_t alignment);
    /*! Number of constants */
    size_t getConstantNum(void) const { return constants.size(); }
    /*! Get a special constant */
    Constant& getConstant(size_t i) { return constants[i]; }
    /*! Get a special constant */
    Constant& getConstant(const std::string & name) {
      for (size_t i = 0; i < constants.size(); ++i) {
        Constant& c = constants[i];
        if (c.getName() == name)
          return c;
      }
      GBE_ASSERT(false);
      return *(Constant *)NULL;
    }
    /*! Number of bytes of serialized constant data */
    size_t getDataSize(void) const { return data.size(); }
    /*! Store serialized constant data into an array */
    void getData(char *mem) const {
      for (size_t i = 0; i < data.size(); i ++)
        mem[i] = data[i];
    }
    ConstantSet() {}
    ConstantSet(const ConstantSet& other) : Serializable(other),
                data(other.data), constants(other.constants) {}
    ConstantSet & operator = (const ConstantSet& other) {
      if (&other != this) {
        data = other.data;
        constants = other.constants;
      }
      return *this;
    }

    static const uint32_t magic_begin = TO_MAGIC('C', 'N', 'S', 'T');
    static const uint32_t magic_end = TO_MAGIC('T', 'S', 'N', 'C');

    /* format:
       magic_begin     |
       const_data_size |
       const_data      |
       constant_1_size |
       constant_1      |
       ........        |
       constant_n_size |
       constant_n      |
       magic_end       |
       total_size
    */

    /*! Implements the serialization. */
    virtual size_t serializeToBin(std::ostream& outs);
    virtual size_t deserializeFromBin(std::istream& ins);

  private:
    vector<char> data;         //!< The constant data serialized in one array
    vector<Constant> constants;//!< Each constant description
    GBE_CLASS(ConstantSet);
  };

} /* namespace ir */
} /* namespace gbe */

#endif /* __GBE_IR_CONSTANT_HPP__ */

