database.go (1684B)
1 // Copyright (c) 2017-2021 Ivan Jelincic <parazyd@dyne.org> 2 // 3 // This file is part of tordam 4 // 5 // This program is free software: you can redistribute it and/or modify 6 // it under the terms of the GNU Affero General Public License as published by 7 // the Free Software Foundation, either version 3 of the License, or 8 // (at your option) any later version. 9 // 10 // This program is distributed in the hope that it will be useful, 11 // but WITHOUT ANY WARRANTY; without even the implied warranty of 12 // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 13 // GNU Affero General Public License for more details. 14 // 15 // You should have received a copy of the GNU Affero General Public License 16 // along with this program. If not, see <https://www.gnu.org/licenses/>. 17 18 package tordam 19 20 import ( 21 "encoding/json" 22 "io/ioutil" 23 "log" 24 ) 25 26 // WritePeersDB marshals the Peers global to JSON and writes to given file. 27 // Please note that this should be probably used in conjunction with some sort 28 // of semaphore. 29 func WritePeersDB(file string) error { 30 j, err := json.Marshal(Peers) 31 if err != nil { 32 return err 33 } 34 return ioutil.WriteFile(file, j, 0600) 35 } 36 37 // writePeersDBWithSem is an internal function to call WritePeersDB safely 38 // using an internal semaphore. Programs using this library should probably 39 // implement something similar if they want to write Peers to a file. 40 func writePeersDBWithSem(file string) { 41 if err := dbSem.Acquire(dbSemCtx, 1); err != nil { 42 log.Println("warning: failed to acquire sem for writing:", err) 43 return 44 } 45 go func() { 46 if err := WritePeersDB(file); err != nil { 47 log.Println("warning: failed to write peers db:", err) 48 } 49 dbSem.Release(1) 50 }() 51 }