nearest_neighbor_recommender.cpp

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// Jubatus: Online machine learning framework for distributed environment
// Copyright (C) 2013 Preferred Networks and Nippon Telegraph and Telephone Corporation.
//
// This library is free software; you can redistribute it and/or
// modify it under the terms of the GNU Lesser General Public
// License version 2.1 as published by the Free Software Foundation.
//
// 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, write to the Free Software
// Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301  USA

#include "nearest_neighbor_recommender.hpp"

#include <string>
#include <utility>
#include <vector>
#include "jubatus/util/data/serialization.h"
#include "jubatus/util/lang/shared_ptr.h"
#include "../common/exception.hpp"
#include "../nearest_neighbor/nearest_neighbor_base.hpp"
#include "../unlearner/unlearner.hpp"

using jubatus::util::lang::shared_ptr;

namespace jubatus {
namespace core {
namespace recommender {

class nearest_neighbor_recommender::unlearning_callback {
 public:
  explicit unlearning_callback(nearest_neighbor_recommender* recommender)
      : recommender_(recommender) {
  }

  void operator()(const std::string& id) {
    recommender_->unlearn_row(id);
  }

 private:
  nearest_neighbor_recommender* recommender_;
};

nearest_neighbor_recommender::nearest_neighbor_recommender(
    jubatus::util::lang::shared_ptr<nearest_neighbor::nearest_neighbor_base>
        nearest_neighbor_engine)
    : nearest_neighbor_engine_(nearest_neighbor_engine) {
}

nearest_neighbor_recommender::nearest_neighbor_recommender(
    jubatus::util::lang::shared_ptr<nearest_neighbor::nearest_neighbor_base>
        nearest_neighbor_engine,
    jubatus::util::lang::shared_ptr<unlearner::unlearner_base> unlearner)
    : nearest_neighbor_engine_(nearest_neighbor_engine),
      unlearner_(unlearner) {
  unlearner_->set_callback(unlearning_callback(this));
}

void nearest_neighbor_recommender::similar_row(
    const common::sfv_t& query,
    std::vector<std::pair<std::string, float> >& ids,
    size_t ret_num) const {
  nearest_neighbor_engine_->similar_row(query, ids, ret_num);
}

void nearest_neighbor_recommender::neighbor_row(
    const common::sfv_t& query,
    std::vector<std::pair<std::string, float> >& ids,
    size_t ret_num) const {
  nearest_neighbor_engine_->neighbor_row(query, ids, ret_num);
}

void nearest_neighbor_recommender::clear() {
  orig_.clear();
  nearest_neighbor_engine_->clear();
  if (unlearner_) {
    unlearner_->clear();
  }
}

void nearest_neighbor_recommender::clear_row(const std::string& id) {
  orig_.remove_row(id);
  get_table()->delete_row(id);
  if (unlearner_) {
    unlearner_->remove(id);
  }
}

void nearest_neighbor_recommender::unlearn_row(const std::string& id) {
  orig_.remove_row(id);
  get_table()->delete_row(id);
}

void nearest_neighbor_recommender::update_row(
    const std::string& id,
    const common::sfv_t& diff) {
  if (unlearner_) {
    if (!unlearner_->touch(id)) {
      throw JUBATUS_EXCEPTION(common::exception::runtime_error(
          "no more space available to add new ID: " + id));
    }
  }
  orig_.set_row(id, diff);
  common::sfv_t row;
  orig_.get_row(id, row);
  nearest_neighbor_engine_->set_row(id, row);
}

void nearest_neighbor_recommender::get_all_row_ids(
    std::vector<std::string>& ids) const {
  nearest_neighbor_engine_->get_all_row_ids(ids);
}

std::string nearest_neighbor_recommender::type() const {
  return "nearest_neighbor_recommender:" + nearest_neighbor_engine_->type();
}

framework::mixable* nearest_neighbor_recommender::get_mixable() const {
  return nearest_neighbor_engine_->get_mixable();
}

void nearest_neighbor_recommender::pack(framework::packer& packer) const {
  packer.pack_array(2);
  orig_.pack(packer);
  nearest_neighbor_engine_->pack(packer);
}

void nearest_neighbor_recommender::unpack(msgpack::object o) {
  if (o.type != msgpack::type::ARRAY || o.via.array.size != 2) {
    throw msgpack::type_error();
  }
  orig_.unpack(o.via.array.ptr[0]);
  nearest_neighbor_engine_->unpack(o.via.array.ptr[1]);
}

jubatus::util::lang::shared_ptr<storage::column_table>
nearest_neighbor_recommender::get_table() {
  return nearest_neighbor_engine_->get_table();
}

jubatus::util::lang::shared_ptr<const storage::column_table>
nearest_neighbor_recommender::get_const_table() const {
  return nearest_neighbor_engine_->get_const_table();
}

jubatus::util::lang::shared_ptr<unlearner::unlearner_base>
nearest_neighbor_recommender::get_unlearner() {
  return unlearner_;
}

}  // namespace recommender
}  // namespace core
}  // namespace jubatus