github.com/mysteriumnetwork/node@v0.0.0-20240516044423-365054f76801/core/connection/smartconnect.go (about)

     1  /*
     2   * Copyright (C) 2022 The "MysteriumNetwork/node" Authors.
     3   *
     4   * This program is free software: you can redistribute it and/or modify
     5   * it under the terms of the GNU General Public License as published by
     6   * the Free Software Foundation, either version 3 of the License, or
     7   * (at your option) any later version.
     8   *
     9   * This program is distributed in the hope that it will be useful,
    10   * but WITHOUT ANY WARRANTY; without even the implied warranty of
    11   * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
    12   * GNU General Public License for more details.
    13   *
    14   * You should have received a copy of the GNU General Public License
    15   * along with this program.  If not, see <http://www.gnu.org/licenses/>.
    16   */
    17  
    18  package connection
    19  
    20  import (
    21  	"fmt"
    22  	"time"
    23  
    24  	"github.com/mysteriumnetwork/node/core/discovery/proposal"
    25  )
    26  
    27  type proposalRepository interface {
    28  	Proposals(filter *proposal.Filter) ([]proposal.PricedServiceProposal, error)
    29  }
    30  
    31  // FilteredProposals create an function to keep getting proposals from the discovery based on the provided filters.
    32  func FilteredProposals(f *proposal.Filter, sortBy string, repo proposalRepository) func() (*proposal.PricedServiceProposal, error) {
    33  	usedProposals := make(map[string]time.Time)
    34  
    35  	return func() (*proposal.PricedServiceProposal, error) {
    36  		proposals, err := repo.Proposals(f)
    37  		if err != nil {
    38  			return nil, err
    39  		}
    40  
    41  		proposals, err = proposal.Sort(proposals, sortBy)
    42  		if err != nil {
    43  			return nil, fmt.Errorf("failed to sort proposals: %w", err)
    44  		}
    45  
    46  		for _, p := range proposals { // Trying to find providers that we didn't try to connect during 5 minutes.
    47  			if t, ok := usedProposals[p.ProviderID]; !ok || time.Since(t) > 5*time.Minute {
    48  				usedProposals[p.ProviderID] = time.Now()
    49  				return &p, nil
    50  			}
    51  		}
    52  
    53  		for _, p := range proposals { // If we failed to find new provider, trying the old ones.
    54  			usedProposals[p.ProviderID] = time.Now()
    55  			return &p, nil
    56  		}
    57  
    58  		return nil, fmt.Errorf("no providers available for the filter")
    59  	}
    60  }