StdVector.h

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/***************************************************************************
 *
 * Copyright (C) 2009-2010 Cassio Neri Moreira
 *
 * This file is part of the KeyValue library.
 *
 * The KeyValue library is free software; you can redistribute it and/or
 * modify it under the terms of the GNU General Public License as published
 * by the Free Software Foundation, either version 3 of the License, or (at
 * your option) any later version.
 *
 * The KeyValue 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 General
 * Public License for more details.
 *
 * You should have received a copy of the GNU General Public License along
 * with KeyValue. If not, see <http://www.gnu.org/licenses/>.
 *
 **************************************************************************/

#ifndef KEYVALUE_KEY_CONVERTER_STDVECTOR_H_
#define KEYVALUE_KEY_CONVERTER_STDVECTOR_H_

#include "keyvalue/extern/SharedPtr.h"
#include "keyvalue/extern/Vector.h"
#include "keyvalue/sys/exception/KV_ASSERT.h"
#include "keyvalue/value/Variant.h"
#include "keyvalue/value/Vector.h"

namespace keyvalue {
namespace key {

template <typename ElementType>
class StdVector {

public:

  typedef value::Vector InputType_;

  typedef shared_ptr<std::vector<ElementType> > OutputType_;

  StdVector(const InputType_& input, OutputType_* cache);

  bool
  isEmpty() const;

  value::Variant
  pop();

  void
  insert(const ElementType& element);

  OutputType_
  getOutput() const;

  bool
  mustUpdate() const;

private:

  const InputType_&   input_;
  OutputType_          output_;
  OutputType_* const  cache_;
  const size_t        size_;
  size_t               i_;
  bool                mustUpdate_;

};

/*--------------------------------------------------------------------------
 * StdVector()
 *------------------------------------------------------------------------*/

template <typename ElementType>
StdVector<ElementType>::StdVector(const InputType_& input,
  OutputType_* const cache) : input_(input),
  output_(new std::vector<ElementType>), cache_(cache),
  size_(input.getSize()), i_(0), mustUpdate_(!cache) {

  output_->reserve(size_);
  mustUpdate_ = mustUpdate_ || size_ != (*cache_)->size();
}

/*--------------------------------------------------------------------------
 * end()
 *------------------------------------------------------------------------*/

template <typename ElementType>
bool
StdVector<ElementType>::isEmpty() const {
  return i_ == size_;
}

/*--------------------------------------------------------------------------
 * pop()
 *------------------------------------------------------------------------*/

template <typename ElementType>
value::Variant
StdVector<ElementType>::pop() {
  KV_ASSERT(!isEmpty(), "All elements have been processed!");
  return input_(i_++);
}

/*--------------------------------------------------------------------------
 * insert()
 *------------------------------------------------------------------------*/

template <typename ElementType>
void
StdVector<ElementType>::insert(const ElementType& element) {
  output_->push_back(element);
  KV_ASSERT(i_ <= size_, "Calls to StdVector.pop() and StdVector.insert() "
    "must be intercalated!");
  mustUpdate_ = mustUpdate_ || (*(*cache_))[i_-1] != element;
}

/*--------------------------------------------------------------------------
 * getOutput()
 *------------------------------------------------------------------------*/

template <typename ElementType>
typename StdVector<ElementType>::OutputType_
StdVector<ElementType>::getOutput() const {
  return output_;
}

/*--------------------------------------------------------------------------
 * mustUpdate()
 *------------------------------------------------------------------------*/

template <typename ElementType>
bool
StdVector<ElementType>::mustUpdate() const {
  return mustUpdate_;
}

} // namespace key
} // namespace keyvalue

#endif // KEYVALUE_KEY_CONVERTER_STDVECTOR_H_