column_type.hpp

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// Jubatus: Online machine learning framework for distributed environment
// Copyright (C) 2012,2013 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

#ifndef JUBATUS_CORE_STORAGE_COLUMN_TYPE_HPP_
#define JUBATUS_CORE_STORAGE_COLUMN_TYPE_HPP_

#include <algorithm>
#include <string>
#include <vector>
#include <iosfwd>

#include "storage_exception.hpp"
#include "bit_vector.hpp"

namespace jubatus {
namespace core {
namespace storage {

class column_type {
 public:
  enum type_name {
    int8_type,
    int16_type,
    int32_type,
    int64_type,
    uint8_type,
    uint16_type,
    uint32_type,
    uint64_type,
    float_type,
    double_type,
    bit_vector_type,
    string_type,
    array_type,  // not implemented yet
    invalid_type
  };
  column_type():type_(invalid_type), bit_vector_length_(0) {}
  explicit column_type(type_name name) : type_(name), bit_vector_length_(0) {
    if (name == bit_vector_type) {
      throw argument_unmatch_exception(
          "bit_vector_type expects bit_vector's length as second argument");
    }
  }
  column_type(type_name name, int length)
      : type_(name),
        bit_vector_length_(length) {
    if (name != bit_vector_type) {
      throw argument_unmatch_exception(
          "unneeded second parameter, it is used only for bit_vector_type");
    }
  }

  bool is(const type_name& type) const {
    return type_ == type;
  }

  std::string type_as_string() const {
    if (type_ == int8_type) {
      return "int8";
    } else if (type_ == int16_type) {
      return "int16";
    } else if (type_ == int32_type) {
      return "int32";
    } else if (type_ == int64_type) {
      return "int64";
    } else if (type_ == uint8_type) {
      return "uint8";
    } else if (type_ == uint16_type) {
      return "uint16";
    } else if (type_ == uint32_type) {
      return "uint32";
    } else if (type_ == uint64_type) {
      return "uint64";
    } else if (type_ == float_type) {
      return "float";
    } else if (type_ == double_type) {
      return "double";
    } else if (type_ == bit_vector_type) {
      return "bit_vector";
    } else if (type_ == string_type) {
      return "string";
    }
    throw type_unmatch_exception("in type_as_string(): unknown type");
  }

  size_t size() const {
    switch (type_) {
      case int8_type:
      case uint8_type:
        return 1;
      case int16_type:
      case uint16_type:
        return 2;
      case int32_type:
      case uint32_type:
      case float_type:
        return 4;
      case int64_type:
      case uint64_type:
      case double_type:
      case string_type:
        return 8;
      case bit_vector_type:
        return bit_vector::memory_size(bit_vector_length_);
      case array_type:
      case invalid_type:
      default:
        return 0;
    }
  }


  size_t bit_vector_length() const {
    if (type_ != bit_vector_type) {
      throw type_unmatch_exception(
          "bit_vector length expected but type was" + type_as_string());
    }
    return bit_vector_length_;
  }

  column_type& operator=(const column_type& orig) {
    type_ = orig.type_;
    bit_vector_length_ = orig.bit_vector_length_;
    return *this;
  }

  void swap(column_type& rhs) {
    using std::swap;
    swap(type_, rhs.type_);
    swap(bit_vector_length_, rhs.bit_vector_length_);
  }

  friend std::ostream& operator<<(std::ostream& os, const column_type& type) {
    os << "{ " << type.type_as_string();
    if (type.type_ == bit_vector_type) {
      os << ": " << type.bit_vector_length_;
    }
    os << " }";
    return os;
  }

  friend bool operator==(const column_type& x, const column_type& y) {
    return x.type_ == y.type_ && x.bit_vector_length_ == y.bit_vector_length_;
  }
  friend bool operator!=(const column_type& x, const column_type& y) {
    return !(x == y);
  }

  template<class Buffer>
  void msgpack_pack(msgpack::packer<Buffer>& packer) const {
    packer.pack_array(2);
    packer.pack(static_cast<uint8_t>(type_));
    packer.pack(static_cast<uint64_t>(bit_vector_length_));
  }
  void msgpack_unpack(msgpack::object o) {
    if (o.type != msgpack::type::ARRAY || o.via.array.size != 2) {
      throw msgpack::type_error();
    }
    uint8_t type;
    o.via.array.ptr[0].convert(&type);
    uint64_t bit_vector_length;
    o.via.array.ptr[1].convert(&bit_vector_length);
    type_ = static_cast<type_name>(type);
    bit_vector_length_ = bit_vector_length;
  }

 private:
  type_name type_;
  int bit_vector_length_;
};

}  // namespace storage
}  // namespace core
}  // namespace jubatus

#endif  // JUBATUS_CORE_STORAGE_COLUMN_TYPE_HPP_