(wip) create new driver for KeyDB

* move GC and prometheus aware storage functions to separate interfaces

storage/keydb/storage.go

@@ -0,0 +1,126 @@
+// Package keydb implements the storage interface.
+// This storage mostly is the same as redis, but it collects peers
+// not in hashes, but in sets and uses KeyDB-specific command
+// `EXPIREMEMBER` and, so it does not need garbage collection.
+// Note: this storage also does not support statistics collection
+package keydb
+
+import (
+	"context"
+	"errors"
+
+	"github.com/go-redis/redis/v8"
+
+	"github.com/sot-tech/mochi/bittorrent"
+	"github.com/sot-tech/mochi/pkg/conf"
+	"github.com/sot-tech/mochi/pkg/log"
+	"github.com/sot-tech/mochi/pkg/stop"
+	"github.com/sot-tech/mochi/storage"
+	r "github.com/sot-tech/mochi/storage/redis"
+)
+
+// Name is name of this storage
+const (
+	Name            = "keydb"
+	expireMemberCmd = "EXPIREMEMBER"
+)
+
+// ErrNotKeyDB returned from initializer if connected does not support KeyDB
+// specific command (EXPIREMEMBER)
+var ErrNotKeyDB = errors.New("provided instance seems not KeyDB")
+
+func init() {
+	// Register the storage driver.
+	storage.RegisterBuilder(Name, Builder)
+}
+
+func Builder(icfg conf.MapConfig) (storage.PeerStorage, error) {
+	var cfg r.Config
+	var err error
+
+	if err = icfg.Unmarshal(&cfg); err != nil {
+		return nil, err
+	}
+
+	return New(cfg)
+}
+
+func New(cfg r.Config) (*store, error) {
+	var err error
+	if cfg, err = cfg.Validate(); err != nil {
+		return nil, err
+	}
+
+	var rs r.Connection
+
+	if rs, err = cfg.Connect(); err != nil {
+		return nil, err
+	}
+
+	cmd := redis.NewCommandsInfoCmd(context.Background(), "COMMAND", "INFO", expireMemberCmd)
+	_ = rs.Process(context.Background(), cmd)
+	err = r.AsNil(cmd.Err())
+	if err == nil && len(cmd.Val()) == 0 {
+		err = ErrNotKeyDB
+	}
+
+	var st *store
+	if err == nil {
+		st = &store{rs, cfg.LogFields()}
+	}
+
+	return st, err
+}
+
+type store struct {
+	r.Connection
+	logFields log.Fields
+}
+
+func (s store) PutSeeder(infoHash bittorrent.InfoHash, peer bittorrent.Peer) error {
+	// TODO implement me
+	panic("implement me")
+}
+
+func (s store) DeleteSeeder(infoHash bittorrent.InfoHash, peer bittorrent.Peer) error {
+	// TODO implement me
+	panic("implement me")
+}
+
+func (s store) PutLeecher(infoHash bittorrent.InfoHash, peer bittorrent.Peer) error {
+	// TODO implement me
+	panic("implement me")
+}
+
+func (s store) DeleteLeecher(infoHash bittorrent.InfoHash, peer bittorrent.Peer) error {
+	// TODO implement me
+	panic("implement me")
+}
+
+func (s store) GraduateLeecher(infoHash bittorrent.InfoHash, peer bittorrent.Peer) error {
+	// TODO implement me
+	panic("implement me")
+}
+
+func (s store) AnnouncePeers(infoHash bittorrent.InfoHash, seeder bool, numWant int, peer bittorrent.Peer) (peers []bittorrent.Peer, err error) {
+	// TODO implement me
+	panic("implement me")
+}
+
+func (s store) ScrapeSwarm(infoHash bittorrent.InfoHash, peer bittorrent.Peer) bittorrent.Scrape {
+	// TODO implement me
+	panic("implement me")
+}
+
+func (s *store) Stop() stop.Result {
+	c := make(stop.Channel)
+	if s.UniversalClient != nil {
+		c.Done(s.UniversalClient.Close())
+		s.UniversalClient = nil
+	}
+	return c.Result()
+}
+
+func (s store) LogFields() log.Fields {
+	return s.logFields
+}