distributor.cpp

/*
  Copyright 2018-2021, Barcelona Supercomputing Center (BSC), Spain
  Copyright 2015-2021, Johannes Gutenberg Universitaet Mainz, Germany

  This software was partially supported by the
  EC H2020 funded project NEXTGenIO (Project ID: 671951, www.nextgenio.eu).

  This software was partially supported by the
  ADA-FS project under the SPPEXA project funded by the DFG.

  This file is part of GekkoFS.

  GekkoFS 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.

  GekkoFS 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 GekkoFS.  If not, see <https://www.gnu.org/licenses/>.

  SPDX-License-Identifier: GPL-3.0-or-later
*/

#include <common/rpc/distributor.hpp>

using namespace std;

namespace gkfs::rpc {

SimpleHashDistributor::SimpleHashDistributor(host_t localhost,
                                             unsigned int hosts_size)
    : localhost_(localhost), hosts_size_(hosts_size), all_hosts_(hosts_size) {
    ::iota(all_hosts_.begin(), all_hosts_.end(), 0);
}

host_t
SimpleHashDistributor::localhost() const {
    return localhost_;
}

host_t
SimpleHashDistributor::locate_data(const string& path,
                                   const chunkid_t& chnk_id) const {
    return str_hash(path + ::to_string(chnk_id)) % hosts_size_;
}

host_t
SimpleHashDistributor::locate_file_metadata(const string& path) const {
    return str_hash(path) % hosts_size_;
}

::vector<host_t>
SimpleHashDistributor::locate_directory_metadata(const string& path) const {
    return all_hosts_;
}

LocalOnlyDistributor::LocalOnlyDistributor(host_t localhost)
    : localhost_(localhost) {}

host_t
LocalOnlyDistributor::localhost() const {
    return localhost_;
}

host_t
LocalOnlyDistributor::locate_data(const string& path,
                                  const chunkid_t& chnk_id) const {
    return localhost_;
}

host_t
LocalOnlyDistributor::locate_file_metadata(const string& path) const {
    return localhost_;
}

::vector<host_t>
LocalOnlyDistributor::locate_directory_metadata(const string& path) const {
    return {localhost_};
}

ForwarderDistributor::ForwarderDistributor(host_t fwhost,
                                           unsigned int hosts_size)
    : fwd_host_(fwhost), hosts_size_(hosts_size), all_hosts_(hosts_size) {
    ::iota(all_hosts_.begin(), all_hosts_.end(), 0);
}

host_t
ForwarderDistributor::localhost() const {
    return fwd_host_;
}

host_t
ForwarderDistributor::locate_data(const std::string& path,
                                  const chunkid_t& chnk_id) const {
    return fwd_host_;
}

host_t
ForwarderDistributor::locate_file_metadata(const std::string& path) const {
    return str_hash(path) % hosts_size_;
}

std::vector<host_t>
ForwarderDistributor::locate_directory_metadata(const std::string& path) const {
    return all_hosts_;
}
} // namespace gkfs::rpc