add sql txn where needed. closes lbryio/reflector-cluster#58

cluster/cluster.go

@@ -1,6 +1,9 @@
 package cluster
 
 import (
+	"io/ioutil"
+	baselog "log"
+
 	"github.com/lbryio/lbry.go/errors"
 
 	"github.com/hashicorp/serf/serf"
@@ -13,6 +16,9 @@ func Connect(nodeName, addr string, port int) (*serf.Serf, <-chan serf.Event, er
 	conf.MemberlistConfig.AdvertisePort = port
 	conf.NodeName = nodeName
 
+	nullLogger := baselog.New(ioutil.Discard, "", 0)
+	conf.Logger = nullLogger
+
 	eventCh := make(chan serf.Event)
 	conf.EventCh = eventCh
 

cmd/cluster.go

@@ -69,8 +69,9 @@ func clusterCmd(cmd *cobra.Command, args []string) {
 					if event.EventType() == serf.EventMemberJoin && len(memberEvent.Members) == 1 && memberEvent.Members[0].Name == nodeName {
 						// ignore event from my own joining of the cluster
 					} else {
-						spew.Dump(c.Members())
+						//spew.Dump(c.Members())
-						log.Printf("my hash range is now %d\n", getHashRangeStart(nodeName, getAliveMembers(c.Members())))
+						alive := getAliveMembers(c.Members())
+						log.Printf("%s: my hash range is now %d of %d\n", nodeName, getHashRangeStart(nodeName, alive), len(alive))
 						// figure out my new hash range based on the start and the number of alive members
 						// get hashes in that range that need announcing
 						// announce them

db/db.go

@@ -3,10 +3,9 @@ package db
 import (
 	"database/sql"
 
-	"github.com/lbryio/reflector.go/types"
-
 	"github.com/lbryio/lbry.go/errors"
 	qtools "github.com/lbryio/query.go"
+	"github.com/lbryio/reflector.go/types"
 
 	_ "github.com/go-sql-driver/mysql"
 	log "github.com/sirupsen/logrus"
@@ -48,6 +47,12 @@ func (s *SQL) AddBlob(hash string, length int, stored bool) error {
 		return errors.Err("not connected")
 	}
 
+	return withTx(s.conn, func(tx *sql.Tx) error {
+		return addBlob(tx, hash, length, stored)
+	})
+}
+
+func addBlob(tx *sql.Tx, hash string, length int, stored bool) error {
 	if length <= 0 {
 		return errors.Err("length must be positive")
 	}
@@ -57,7 +62,7 @@ func (s *SQL) AddBlob(hash string, length int, stored bool) error {
 
 	logQuery(query, args...)
 
-	stmt, err := s.conn.Prepare(query)
+	stmt, err := tx.Prepare(query)
 	if err != nil {
 		return errors.Err(err)
 	}
@@ -93,10 +98,9 @@ func (s *SQL) AddSDBlob(sdHash string, sdBlobLength int, sdBlob types.SdBlob) er
 		return errors.Err("not connected")
 	}
 
-	// TODO: should do all this in transaction
+	return withTx(s.conn, func(tx *sql.Tx) error {
-
 		// insert sd blob
-	err := s.AddBlob(sdHash, sdBlobLength, true)
+		err := addBlob(tx, sdHash, sdBlobLength, true)
 		if err != nil {
 			return err
 		}
@@ -107,7 +111,7 @@ func (s *SQL) AddSDBlob(sdHash string, sdBlobLength int, sdBlob types.SdBlob) er
 
 		logQuery(query, args...)
 
-	stmt, err := s.conn.Prepare(query)
+		stmt, err := tx.Prepare(query)
 		if err != nil {
 			return errors.Err(err)
 		}
@@ -124,7 +128,7 @@ func (s *SQL) AddSDBlob(sdHash string, sdBlobLength int, sdBlob types.SdBlob) er
 				continue
 			}
 
-		err := s.AddBlob(contentBlob.BlobHash, contentBlob.Length, false)
+			err := addBlob(tx, contentBlob.BlobHash, contentBlob.Length, false)
 			if err != nil {
 				return err
 			}
@@ -134,7 +138,7 @@ func (s *SQL) AddSDBlob(sdHash string, sdBlobLength int, sdBlob types.SdBlob) er
 
 			logQuery(query, args...)
 
-		stmt, err := s.conn.Prepare(query)
+			stmt, err := tx.Prepare(query)
 			if err != nil {
 				return errors.Err(err)
 			}
@@ -144,8 +148,41 @@ func (s *SQL) AddSDBlob(sdHash string, sdBlobLength int, sdBlob types.SdBlob) er
 				return errors.Err(err)
 			}
 		}
-
 		return nil
+	})
+}
+
+// txFunc is a function that can be wrapped in a transaction
+type txFunc func(tx *sql.Tx) error
+
+// withTx wraps a function in an sql transaction. the transaction is committed if there's no error, or rolled back if there is one.
+// if dbOrTx is an sql.DB, a new transaction is started
+func withTx(dbOrTx interface{}, f txFunc) (err error) {
+	var tx *sql.Tx
+
+	switch t := dbOrTx.(type) {
+	case *sql.Tx:
+		tx = t
+	case *sql.DB:
+		tx, err = t.Begin()
+		if err != nil {
+			return err
+		}
+		defer func() {
+			if p := recover(); p != nil {
+				tx.Rollback()
+				panic(p)
+			} else if err != nil {
+				tx.Rollback()
+			} else {
+				err = errors.Err(tx.Commit())
+			}
+		}()
+	default:
+		return errors.Err("db or tx required")
+	}
+
+	return f(tx)
 }
 
 func schema() {