forked from huawei/mindspore2022
58 lines
1.9 KiB
C++
58 lines
1.9 KiB
C++
/**
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* Copyright 2021 Huawei Technologies Co., Ltd
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*
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* Licensed under the Apache License, Version 2.0 (the "License");
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* you may not use this file except in compliance with the License.
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* You may obtain a copy of the License at
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*
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* http://www.apache.org/licenses/LICENSE-2.0
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*
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* Unless required by applicable law or agreed to in writing, software
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* distributed under the License is distributed on an "AS IS" BASIS,
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* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
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* See the License for the specific language governing permissions and
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* limitations under the License.
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*/
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#include "ps/server/consistent_hash_ring.h"
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namespace mindspore {
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namespace ps {
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namespace server {
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bool ConsistentHashRing::Insert(uint32_t rank) {
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for (uint32_t i = 0; i < virtual_node_num_; i++) {
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std::string physical_node_hash_key = std::to_string(rank) + "#" + std::to_string(i);
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size_t hash_value = std::hash<std::string>()(physical_node_hash_key);
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MS_LOG(DEBUG) << "Insert virtual node " << physical_node_hash_key << " for node " << rank << ", hash value is "
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<< hash_value;
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if (ring_.count(hash_value) != 0) {
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MS_LOG(INFO) << "Virtual node " << physical_node_hash_key << " is already mapped to the ring.";
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continue;
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}
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ring_[hash_value] = rank;
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}
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return true;
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}
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bool ConsistentHashRing::Erase(uint32_t rank) {
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for (auto iterator = ring_.begin(); iterator != ring_.end();) {
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if (iterator->second == rank) {
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ring_.erase(iterator++);
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}
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}
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return true;
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}
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uint32_t ConsistentHashRing::Find(const std::string &key) {
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size_t hash_value = std::hash<std::string>()(key);
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auto iterator = ring_.lower_bound(hash_value);
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if (iterator == ring_.end()) {
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// If the virtual node is not found clockwise, the key will be mapped to the first virtual node on the ring.
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iterator = ring_.begin();
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}
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return iterator->second;
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}
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} // namespace server
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} // namespace ps
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} // namespace mindspore
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