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

     1  /*
     2   * Copyright (C) 2019 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  /*
    19  Package discovery is responsible for:
    20   - handling discovery related communications
    21   - keeping track of currently active proposals in local storage
    22   - finding and filtering proposals in local storage
    23  
    24  
    25  Proposal storage filtering can be done with ProposalReducer callbacks.
    26  ProposalReducer is simple callback which is run against list of proposals.
    27  Proposal storage filtering is performed with discovery.Finder:
    28  ```
    29  finder := discovery.NewFinder(discovery.NewStorage())
    30  proposal, err := finder.GetProposal(market.ProposalID{ServiceType: "streaming", ProviderID: "0x1"})
    31  proposals, err = finder.MatchProposals(reducer.Equal(reducer.ProviderID, "0x2"))
    32  ```
    33  
    34  - Most simple noop reducer:
    35  ```
    36  finder.MatchProposals(
    37    reducer.All(),
    38  )
    39  ```
    40  - By proposal field:
    41  ```
    42  finder.MatchProposals(
    43    reducer.EqualString(reducer.ProviderID, "0x1"),
    44  )
    45  ```
    46  - By custom callback:
    47  ```
    48  finder.MatchProposals(func(proposal market.ServiceProposal) bool {
    49    return proposal.ProviderID == "0x3" || proposal.ServiceType == "wireguard"
    50  })
    51  ```
    52  - By several conditions:
    53  ```
    54  finder.MatchProposals(reducer.And(
    55    reducer.EqualString(reducer.ProviderID, "0x1"),
    56    reducer.InString(reducer.ServiceType, "openvpn", "wireguard")),
    57    reducer.AccessPolicy("mysterium", ""),
    58  ))
    59  ```
    60  - By nesting several conditions:
    61  ```
    62  finder.MatchProposals(reducer.Or(
    63    reducer.And(
    64      reducer.EqualString(reducer.ServiceType, "wireguard"),
    65      reducer.InString(reducer.Country, "US", "CA"),
    66      reducer.EqualString(reducer.IPType, "residential"),
    67    ),
    68    reducer.And(
    69      reducer.EqualString(reducer.ServiceType, "openvpn"),
    70      reducer.Or(
    71        reducer.EqualString(reducer.Country, "US")),
    72        reducer.EqualString(reducer.Country, "CA")),
    73      ),
    74      reducer.Not(reducer.EqualString(reducer.IPType, "datacenter")),
    75    )
    76  ))
    77  ```
    78  */
    79  
    80  package discovery