itImplement writing of JSON peer database file. - tordam - A library for peer discovery inside the Tor network	Err	parazyd.org	70
hgit clone https://git.parazyd.org/tordam	URL:https://git.parazyd.org/tordam	parazyd.org	70
1Log	/git/tordam/log.gph	parazyd.org	70
1Files	/git/tordam/files.gph	parazyd.org	70
1Refs	/git/tordam/refs.gph	parazyd.org	70
1README	/git/tordam/file/README.md.gph	parazyd.org	70
1LICENSE	/git/tordam/file/LICENSE.gph	parazyd.org	70
i---	Err	parazyd.org	70
1commit 0ca20205f1d320ec19d1b0091c5a998fbe2b6cde	/git/tordam/commit/0ca20205f1d320ec19d1b0091c5a998fbe2b6cde.gph	parazyd.org	70
1parent 3e58d2fb3e30da2e28c8fbc94731f64ecd645ef9	/git/tordam/commit/3e58d2fb3e30da2e28c8fbc94731f64ecd645ef9.gph	parazyd.org	70
hAuthor: parazyd <parazyd@dyne.org>	URL:mailto:parazyd@dyne.org	parazyd.org	70
iDate:   Mon,  8 Mar 2021 00:55:09 +0100	Err	parazyd.org	70
i	Err	parazyd.org	70
iImplement writing of JSON peer database file.	Err	parazyd.org	70
i	Err	parazyd.org	70
iWe use semaphores to limit concurrency.	Err	parazyd.org	70
i	Err	parazyd.org	70
iDiffstat:	Err	parazyd.org	70
i  M config.go                           |      12 ++++++++++++	Err	parazyd.org	70
i  A database.go                         |      50 +++++++++++++++++++++++++++++++	Err	parazyd.org	70
i  M go.mod                              |       1 +	Err	parazyd.org	70
i  M go.sum                              |       2 ++	Err	parazyd.org	70
i  M peer_announce.go                    |       2 ++	Err	parazyd.org	70
i  M rpc_announce.go                     |       3 +++	Err	parazyd.org	70
i	Err	parazyd.org	70
i6 files changed, 70 insertions(+), 0 deletions(-)	Err	parazyd.org	70
i---	Err	parazyd.org	70
1diff --git a/config.go b/config.go	/git/tordam/file/config.go.gph	parazyd.org	70
it@@ -18,8 +18,11 @@	Err	parazyd.org	70
i package tordam	Err	parazyd.org	70
i 	Err	parazyd.org	70
i import (	Err	parazyd.org	70
i+        "context"	Err	parazyd.org	70
i         "crypto/ed25519"	Err	parazyd.org	70
i         "net"	Err	parazyd.org	70
i+	Err	parazyd.org	70
i+        "golang.org/x/sync/semaphore"	Err	parazyd.org	70
i )	Err	parazyd.org	70
i 	Err	parazyd.org	70
i // Config is the configuration structure, to be filled by library user.	Err	parazyd.org	70
it@@ -42,3 +45,12 @@ var Cfg = Config{}	Err	parazyd.org	70
i 	Err	parazyd.org	70
i // Peers is the global map of peers	Err	parazyd.org	70
i var Peers = map[string]Peer{}	Err	parazyd.org	70
i+	Err	parazyd.org	70
i+// dbSem is the internal semaphore for writing the peer db	Err	parazyd.org	70
i+var dbSem = semaphore.NewWeighted(1)	Err	parazyd.org	70
i+	Err	parazyd.org	70
i+// dbSemCtx is the context for dbSem	Err	parazyd.org	70
i+var dbSemCtx = context.Background()	Err	parazyd.org	70
i+	Err	parazyd.org	70
i+// dbFile is the filename for the Peers JSON database	Err	parazyd.org	70
i+var dbFile = "peers.json"	Err	parazyd.org	70
1diff --git a/database.go b/database.go	/git/tordam/file/database.go.gph	parazyd.org	70
it@@ -0,0 +1,50 @@	Err	parazyd.org	70
i+// Copyright (c) 2017-2021 Ivan Jelincic <parazyd@dyne.org>	Err	parazyd.org	70
i+//	Err	parazyd.org	70
i+// This file is part of tordam	Err	parazyd.org	70
i+//	Err	parazyd.org	70
i+// This program is free software: you can redistribute it and/or modify	Err	parazyd.org	70
i+// it under the terms of the GNU Affero General Public License as published by	Err	parazyd.org	70
i+// the Free Software Foundation, either version 3 of the License, or	Err	parazyd.org	70
i+// (at your option) any later version.	Err	parazyd.org	70
i+//	Err	parazyd.org	70
i+// This program is distributed in the hope that it will be useful,	Err	parazyd.org	70
i+// but WITHOUT ANY WARRANTY; without even the implied warranty of	Err	parazyd.org	70
i+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the	Err	parazyd.org	70
i+// GNU Affero General Public License for more details.	Err	parazyd.org	70
i+//	Err	parazyd.org	70
i+// You should have received a copy of the GNU Affero General Public License	Err	parazyd.org	70
i+// along with this program. If not, see <https://www.gnu.org/licenses/>.	Err	parazyd.org	70
i+	Err	parazyd.org	70
i+package tordam	Err	parazyd.org	70
i+	Err	parazyd.org	70
i+import (	Err	parazyd.org	70
i+        "encoding/json"	Err	parazyd.org	70
i+        "io/ioutil"	Err	parazyd.org	70
i+        "log"	Err	parazyd.org	70
i+)	Err	parazyd.org	70
i+	Err	parazyd.org	70
i+// WritePeersDB marshals the Peers global to JSON and writes to given file.	Err	parazyd.org	70
i+// Please note that this should be probably used in conjuction with a semaphore.	Err	parazyd.org	70
i+func WritePeersDB(file string) error {	Err	parazyd.org	70
i+        j, err := json.Marshal(Peers)	Err	parazyd.org	70
i+        if err != nil {	Err	parazyd.org	70
i+                return err	Err	parazyd.org	70
i+        }	Err	parazyd.org	70
i+        return ioutil.WriteFile(file, j, 0600)	Err	parazyd.org	70
i+}	Err	parazyd.org	70
i+	Err	parazyd.org	70
i+// writePeersDBWithSem is an internal function to call WritePeersDB safely	Err	parazyd.org	70
i+// using an internal semafore. Programs using this library should probably	Err	parazyd.org	70
i+// implement something similar.	Err	parazyd.org	70
i+func writePeersDBWithSem(file string) {	Err	parazyd.org	70
i+        if err := dbSem.Acquire(dbSemCtx, 1); err != nil {	Err	parazyd.org	70
i+                log.Println("warning: failed to acquire sem for writing:", err)	Err	parazyd.org	70
i+                return	Err	parazyd.org	70
i+        }	Err	parazyd.org	70
i+        go func() {	Err	parazyd.org	70
i+                if err := WritePeersDB(file); err != nil {	Err	parazyd.org	70
i+                        log.Println("warning: failed to write peers db:", err)	Err	parazyd.org	70
i+                }	Err	parazyd.org	70
i+                dbSem.Release(1)	Err	parazyd.org	70
i+        }()	Err	parazyd.org	70
i+}	Err	parazyd.org	70
1diff --git a/go.mod b/go.mod	/git/tordam/file/go.mod.gph	parazyd.org	70
it@@ -5,4 +5,5 @@ go 1.16	Err	parazyd.org	70
i require (	Err	parazyd.org	70
i         github.com/creachadair/jrpc2 v0.12.0	Err	parazyd.org	70
i         golang.org/x/net v0.0.0-20210226172049-e18ecbb05110	Err	parazyd.org	70
i+        golang.org/x/sync v0.0.0-20210220032951-036812b2e83c // indirect	Err	parazyd.org	70
i )	Err	parazyd.org	70
1diff --git a/go.sum b/go.sum	/git/tordam/file/go.sum.gph	parazyd.org	70
it@@ -11,6 +11,8 @@ golang.org/x/net v0.0.0-20210226172049-e18ecbb05110 h1:qWPm9rbaAMKs8Bq/9LRpbMqxW	Err	parazyd.org	70
i golang.org/x/net v0.0.0-20210226172049-e18ecbb05110/go.mod h1:m0MpNAwzfU5UDzcl9v0D8zg8gWTRqZa9RBIspLL5mdg=	Err	parazyd.org	70
i golang.org/x/sync v0.0.0-20201207232520-09787c993a3a h1:DcqTD9SDLc+1P/r1EmRBwnVsrOwW+kk2vWf9n+1sGhs=	Err	parazyd.org	70
i golang.org/x/sync v0.0.0-20201207232520-09787c993a3a/go.mod h1:RxMgew5VJxzue5/jJTE5uejpjVlOe/izrB70Jof72aM=	Err	parazyd.org	70
i+golang.org/x/sync v0.0.0-20210220032951-036812b2e83c h1:5KslGYwFpkhGh+Q16bwMP3cOontH8FOep7tGV86Y7SQ=	Err	parazyd.org	70
i+golang.org/x/sync v0.0.0-20210220032951-036812b2e83c/go.mod h1:RxMgew5VJxzue5/jJTE5uejpjVlOe/izrB70Jof72aM=	Err	parazyd.org	70
i golang.org/x/sys v0.0.0-20201119102817-f84b799fce68/go.mod h1:h1NjWce9XRLGQEsW7wpKNCjG9DtNlClVuFLEZdDNbEs=	Err	parazyd.org	70
i golang.org/x/term v0.0.0-20201126162022-7de9c90e9dd1/go.mod h1:bj7SfCRtBDWHUb9snDiAeCFNEtKQo2Wmx5Cou7ajbmo=	Err	parazyd.org	70
i golang.org/x/text v0.3.3/go.mod h1:5Zoc/QRtKVWzQhOtBMvqHzDpF6irO9z98xDceosuGiQ=	Err	parazyd.org	70
1diff --git a/peer_announce.go b/peer_announce.go	/git/tordam/file/peer_announce.go.gph	parazyd.org	70
it@@ -105,5 +105,7 @@ func AppendPeers(p []string) error {	Err	parazyd.org	70
i                 }	Err	parazyd.org	70
i                 Peers[i] = Peer{}	Err	parazyd.org	70
i         }	Err	parazyd.org	70
i+	Err	parazyd.org	70
i+        writePeersDBWithSem(strings.Join([]string{Cfg.Datadir, dbFile}, "/"))	Err	parazyd.org	70
i         return nil	Err	parazyd.org	70
i }	Err	parazyd.org	70
1diff --git a/rpc_announce.go b/rpc_announce.go	/git/tordam/file/rpc_announce.go.gph	parazyd.org	70
it@@ -122,6 +122,7 @@ func (Ann) Init(ctx context.Context, vals []string) ([]string, error) {	Err	parazyd.org	70
i         peer.Trusted = 0	Err	parazyd.org	70
i         Peers[onion] = peer	Err	parazyd.org	70
i 	Err	parazyd.org	70
i+        writePeersDBWithSem(strings.Join([]string{Cfg.Datadir, dbFile}, "/"))	Err	parazyd.org	70
i         return []string{nonce, newrevoke}, nil	Err	parazyd.org	70
i }	Err	parazyd.org	70
i 	Err	parazyd.org	70
it@@ -194,6 +195,8 @@ func (Ann) Validate(ctx context.Context, vals []string) ([]string, error) {	Err	parazyd.org	70
i         peer.LastSeen = time.Now().Unix()	Err	parazyd.org	70
i         Peers[onion] = peer	Err	parazyd.org	70
i 	Err	parazyd.org	70
i+        writePeersDBWithSem(strings.Join([]string{Cfg.Datadir, dbFile}, "/"))	Err	parazyd.org	70
i+	Err	parazyd.org	70
i         rpcInfo("ann.Validate", "sending back list of peers to", onion)	Err	parazyd.org	70
i         return ret, nil	Err	parazyd.org	70
i }	Err	parazyd.org	70
.