new transaction mechanism that eliminates a lot of excess cruft

database/base.go

@@ -10,11 +10,13 @@
 package database
 
 import (
+	"context"
 	"slices"
 
 	"git.erbosoft.com/amy/amsterdam/config"
 	_ "github.com/go-sql-driver/mysql"
 	"github.com/jmoiron/sqlx"
+	log "github.com/sirupsen/logrus"
 )
 
 // amdb is the reference to the Amsterdam database.
@@ -42,3 +44,36 @@ func SetupDb() (func(), error) {
 		amdb.Close()
 	}, err
 }
+
+/* transaction starts a transaction and returns functions for commit and rollback. The rollback
+ * function can be immediately deferred; if commit is called successfully, rollback becomes a no-op.
+ * Parameters:
+ *     ctx - Standard Go error status.
+ * Returns:
+ *     The sqlx transaction object
+ *     The commit function (no parameters, returns error)
+ *     The rollback function (no parameters or return)
+ */
+func transaction(ctx context.Context) (*sqlx.Tx, func() error, func()) {
+	tx := amdb.MustBeginTx(ctx, nil)
+	live := true
+	fCom := func() error {
+		var err error = nil
+		if live {
+			err = tx.Commit()
+			if err == nil {
+				live = false
+			}
+		}
+		return err
+	}
+	fRoll := func() {
+		if live {
+			if err := tx.Rollback(); err != nil {
+				log.Errorf("***ROLLBACK ERROR*** %v", err)
+			}
+			live = false
+		}
+	}
+	return tx, fCom, fRoll
+}

database/community.go

@@ -336,13 +336,9 @@ func (c *Community) ListMembers(ctx context.Context, field int, oper int, term s
  *     Standard Go error status.
  */
 func (c *Community) SetMembership(ctx context.Context, u *User, level uint16, locked bool, personUID int32, ipaddr string) error {
-	success := false
+	tx, commit, rollback := transaction(ctx)
-	tx := amdb.MustBegin()
+	defer rollback()
-	defer func() {
+
-		if !success {
-			tx.Rollback()
-		}
-	}()
 	if level == 0 {
 		res, err := tx.ExecContext(ctx, "DELETE FROM commmember WHERE commid = ? AND uid = ?", c.Id, u.Uid)
 		if err != nil {
@@ -382,11 +378,14 @@ func (c *Community) SetMembership(ctx context.Context, u *User, level uint16, lo
 			return err
 		}
 	}
-	if err := c.TouchUpdateTx(ctx, tx); err == nil {
+	var err error
+	if err = c.TouchUpdateTx(ctx, tx); err == nil {
+		if err = commit(); err == nil {
 			AmStoreAudit(AmNewCommAudit(AuditCommunitySetMembership, personUID, c.Id, ipaddr, fmt.Sprintf("cid=%d", c.Id),
 				fmt.Sprintf("uid=%d", u.Uid), fmt.Sprintf("level=%d", level)))
 		}
-	return nil
+	}
+	return err
 }
 
 /* TestPermission is shorthand that tests if a user has a permission with respect to the community.
@@ -541,13 +540,13 @@ func (c *Community) TouchUpdateTx(ctx context.Context, tx *sqlx.Tx) error {
 
 // TouchUpdateTx updates the last access and last update times of the community.
 func (c *Community) TouchUpdate(ctx context.Context) error {
-	tx := amdb.MustBegin()
+	tx, commit, rollback := transaction(ctx)
 	err := c.TouchUpdateTx(ctx, tx)
 	if err != nil {
-		err = tx.Commit()
+		err = commit()
 	}
 	if err != nil {
-		tx.Rollback()
+		rollback()
 	}
 	return err
 }
@@ -854,13 +853,8 @@ func AmSetCommunityProperty(ctx context.Context, cid int32, ndx int32, val *stri
  */
 func AmCreateCommunity(ctx context.Context, name string, alias string, hostUid int32, language *string, synopsis *string,
 	rules *string, joinkey *string, hideDirectory bool, hideSearch bool, remoteIP string) (*Community, error) {
-	success := false
+	tx, commit, rollback := transaction(ctx)
-	tx := amdb.MustBegin()
+	defer rollback()
-	defer func() {
-		if !success {
-			tx.Rollback()
-		}
-	}()
 
 	// validate alias does not already exist
 	row := tx.QueryRowContext(ctx, "SELECT commid FROM communities WHERE alias = ?", alias)
@@ -907,10 +901,9 @@ func AmCreateCommunity(ctx context.Context, name string, alias string, hostUid i
 		return nil, err
 	}
 
-	if err = tx.Commit(); err != nil {
+	if err = commit(); err != nil {
 		return nil, err
 	}
-	success = true
 
 	// operation was a success - add an audit record
 	AmStoreAudit(AmNewCommAudit(AuditCommunityCreate, hostUid, comm.Id, remoteIP, fmt.Sprintf("id=%d", comm.Id),

database/conference.go

@@ -588,13 +588,8 @@ func (c *Conference) Fixseen(ctx context.Context, u *User) error {
 	if u.IsAnon {
 		return nil
 	}
-	success := false
+	tx, commit, rollback := transaction(ctx)
-	tx := amdb.MustBegin()
+	defer rollback()
-	defer func() {
-		if !success {
-			tx.Rollback()
-		}
-	}()
 
 	// Get a count of topics beforehand.
 	row := tx.QueryRowContext(ctx, "SELECT COUNT(*) FROM topics WHERE confid = ?", c.ConfId)
@@ -634,10 +629,9 @@ func (c *Conference) Fixseen(ctx context.Context, u *User) error {
 		return err
 	}
 
-	if err = tx.Commit(); err != nil {
+	if err = commit(); err != nil {
 		return err
 	}
-	success = true
 	return nil
 }
 
@@ -657,13 +651,8 @@ func (c *Conference) GetCustomBlocks(ctx context.Context) (string, string, error
 
 // SetCustomBlocks sets the custom HTML blocks for this conference.
 func (c *Conference) SetCustomBlocks(ctx context.Context, topBlock, bottomBlock string) error {
-	success := false
+	tx, commit, rollback := transaction(ctx)
-	tx := amdb.MustBegin()
+	defer rollback()
-	defer func() {
-		if !success {
-			tx.Rollback()
-		}
-	}()
 	row := tx.QueryRowContext(ctx, "SELECT COUNT(*) FROM confcustom WHERE confid = ?", c.ConfId)
 	ct := 0
 	err := row.Scan(&ct)
@@ -678,10 +667,9 @@ func (c *Conference) SetCustomBlocks(ctx context.Context, topBlock, bottomBlock
 	if err != nil {
 		return err
 	}
-	if err = tx.Commit(); err != nil {
+	if err = commit(); err != nil {
 		return err
 	}
-	success = true
 	return nil
 }
 
@@ -815,7 +803,7 @@ func (c *Conference) Stats(ctx context.Context) (int, int, error) {
 // backgroundPurgeConference purges out all the conference information in the background.
 func backgroundPurgeConference(ctx context.Context, confid int32) error {
 	// Purge out auxiliary conference tables first.
-	tx := amdb.MustBegin()
+	tx, commit, rollback := transaction(ctx)
 	_, err := tx.ExecContext(ctx, "DELETE FROM confmember WHERE confid = ?", confid)
 	if err != nil {
 		log.Warnf("backgroundPurgeConference(%d): failed purging confmember: %v", confid, err)
@@ -836,9 +824,9 @@ func backgroundPurgeConference(ctx context.Context, confid int32) error {
 	if err != nil {
 		log.Warnf("backgroundPurgeConference(%d): failed purging confcustom: %v", confid, err)
 	}
-	err = tx.Commit()
+	err = commit()
 	if err != nil {
-		tx.Rollback()
+		rollback()
 		return err
 	}
 
@@ -851,13 +839,13 @@ func backgroundPurgeConference(ctx context.Context, confid int32) error {
 
 	// Erase each topic in turn by calling two of the "delete topic" internal functions.
 	for _, topicId := range topicIds {
-		tx := amdb.MustBegin()
+		tx, commit, rollback := transaction(ctx)
 		err = eraseTopicRecords(ctx, tx, topicId)
 		if err == nil {
-			err = tx.Commit()
+			err = commit()
 		}
 		if err != nil {
-			tx.Rollback()
+			rollback()
 			return err
 		}
 		err = backgroundPurgeTopic(ctx, topicId)
@@ -870,13 +858,8 @@ func backgroundPurgeConference(ctx context.Context, confid int32) error {
 
 // Delete unlinks this conference from the community, deleting it entirely if the last link is gone.
 func (c *Conference) Delete(ctx context.Context, comm *Community, u *User, ipaddr string, background *util.WorkerPool) error {
-	success := false
+	tx, commit, rollback := transaction(ctx)
-	tx := amdb.MustBegin()
+	defer rollback()
-	defer func() {
-		if !success {
-			tx.Rollback()
-		}
-	}()
 	getConferenceMutex.Lock()
 	defer getConferenceMutex.Unlock()
 
@@ -904,10 +887,9 @@ func (c *Conference) Delete(ctx context.Context, comm *Community, u *User, ipadd
 		return err
 	}
 
-	if err = tx.Commit(); err != nil {
+	if err = commit(); err != nil {
 		return err
 	}
-	success = true
 
 	if refCount == 0 {
 		// kick the conference out of the cache
@@ -1154,13 +1136,8 @@ func AmSetConferenceProperty(ctx context.Context, confid int32, ndx int32, val *
 
 // AmReorderConferences reorders two conferences by sequence number.
 func AmReorderConferences(ctx context.Context, cid int32, seq1, seq2 int16) error {
-	success := false
+	tx, commit, rollback := transaction(ctx)
-	tx := amdb.MustBegin()
+	defer rollback()
-	defer func() {
-		if !success {
-			tx.Rollback()
-		}
-	}()
 	_, err := tx.ExecContext(ctx, "UPDATE commtoconf SET sequence = -1 WHERE commid = ? AND sequence = ?", cid, seq1)
 	if err == nil {
 		_, err = tx.ExecContext(ctx, "UPDATE commtoconf SET sequence = ? WHERE commid = ? AND sequence = ?", seq1, cid, seq2)
@@ -1171,10 +1148,9 @@ func AmReorderConferences(ctx context.Context, cid int32, seq1, seq2 int16) erro
 	if err != nil {
 		return err
 	}
-	if err = tx.Commit(); err != nil {
+	if err = commit(); err != nil {
 		return err
 	}
-	success = true
 	return nil
 }
 
@@ -1214,13 +1190,8 @@ func AmCreateConference(ctx context.Context, comm *Community, name, alias, descr
 		newConf.CreateLevel = AmDefaultRole("Conference.Create.Public").Level()
 	}
 
-	success := false
+	tx, commit, rollback := transaction(ctx)
-	tx := amdb.MustBegin()
+	defer rollback()
-	defer func() {
-		if !success {
-			tx.Rollback()
-		}
-	}()
 	getConferenceMutex.Lock()
 	defer getConferenceMutex.Unlock()
 
@@ -1279,10 +1250,9 @@ func AmCreateConference(ctx context.Context, comm *Community, name, alias, descr
 		return nil, err
 	}
 
-	if err = tx.Commit(); err != nil {
+	if err = commit(); err != nil {
 		return nil, err
 	}
-	success = true
 
 	// Add the new conference to the cache, and create our audit record.
 	conferenceCache.Add(rc[0].ConfId, &(rc[0]))

database/hotlist.go

@@ -49,35 +49,24 @@ func AmCopyConferenceHotlist(ctx context.Context, from, to *User) error {
 		return err
 	}
 
-	success := false
+	tx, commit, rollback := transaction(ctx)
-	tx := amdb.MustBegin()
+	defer rollback()
-	defer func() {
-		if !success {
-			tx.Rollback()
-		}
-	}()
 	for _, hl := range hotlist {
 		if _, err = tx.ExecContext(ctx, "INSERT INTO confhotlist (uid, sequence, commid, confid) VALUES (?, ?, ?, ?)",
 			to.Uid, hl.Sequence, hl.CommId, hl.ConfId); err != nil {
 			return err
 		}
 	}
-	if err = tx.Commit(); err != nil {
+	if err = commit(); err != nil {
 		return err
 	}
-	success = true
 	return nil
 }
 
 // AmReorderHotlist exchanges the position of two items on the user's hotlist.
 func AmReorderHotlist(ctx context.Context, u *User, seq1, seq2 int16) error {
-	success := false
+	tx, commit, rollback := transaction(ctx)
-	tx := amdb.MustBegin()
+	defer rollback()
-	defer func() {
-		if !success {
-			tx.Rollback()
-		}
-	}()
 
 	_, err := tx.ExecContext(ctx, "UPDATE confhotlist SET sequence = -1 WHERE uid = ? AND sequence = ?", u.Uid, seq1)
 	if err == nil {
@@ -89,22 +78,16 @@ func AmReorderHotlist(ctx context.Context, u *User, seq1, seq2 int16) error {
 	if err != nil {
 		return err
 	}
-	if err = tx.Commit(); err != nil {
+	if err = commit(); err != nil {
 		return err
 	}
-	success = true
 	return nil
 }
 
 // AmRemoveEntryFromHotlist removes an entry from the user's hotlist.
 func AmRemoveEntryFromHotlist(ctx context.Context, u *User, seq int16) error {
-	success := false
+	tx, commit, rollback := transaction(ctx)
-	tx := amdb.MustBegin()
+	defer rollback()
-	defer func() {
-		if !success {
-			tx.Rollback()
-		}
-	}()
 
 	_, err := tx.ExecContext(ctx, "DELETE FROM confhotlist WHERE uid = ? AND sequence = ?", u.Uid, seq)
 	if err == nil {
@@ -113,22 +96,16 @@ func AmRemoveEntryFromHotlist(ctx context.Context, u *User, seq int16) error {
 	if err != nil {
 		return err
 	}
-	if err = tx.Commit(); err != nil {
+	if err = commit(); err != nil {
 		return err
 	}
-	success = true
 	return nil
 }
 
 // AmAppendToHotlist adds a community/conference ID to the end of the user's hotlist.
 func AmAppendToHotlist(ctx context.Context, u *User, commid, confid int32) error {
-	success := false
+	tx, commit, rollback := transaction(ctx)
-	tx := amdb.MustBegin()
+	defer rollback()
-	defer func() {
-		if !success {
-			tx.Rollback()
-		}
-	}()
 
 	var newseq int16
 	row := tx.QueryRowContext(ctx, "SELECT sequence FROM confhotlist WHERE uid = ? AND commid = ? AND confid = ?", u.Uid, commid, confid)
@@ -150,10 +127,9 @@ func AmAppendToHotlist(ctx context.Context, u *User, commid, confid int32) error
 	if err != nil {
 		return err
 	}
-	if err = tx.Commit(); err != nil {
+	if err = commit(); err != nil {
 		return err
 	}
-	success = true
 	return nil
 }
 

database/post.go

@@ -294,13 +294,8 @@ func (p *PostHeader) Scribble(ctx context.Context, u *User, comm *Community, ipa
 		return errors.New("cannot scribble an already-scribbled post")
 	}
 
-	success := false
+	tx, commit, rollback := transaction(ctx)
-	tx := amdb.MustBegin()
+	defer rollback()
-	defer func() {
-		if !success {
-			tx.Rollback()
-		}
-	}()
 	// Scribble on the post header.
 	scribblePseud := "<EM><B>(Scribbled)</B></EM>" // FUTURE: configurable option
 	_, err := tx.ExecContext(ctx, "UPDATE posts SET linecount = 0, hidden = 0, scribble_uid = ?, scribble_date = NOW(), pseud = ? WHERE postid = ?", u.Uid, scribblePseud, p.PostId)
@@ -327,10 +322,9 @@ func (p *PostHeader) Scribble(ctx context.Context, u *User, comm *Community, ipa
 		return err
 	}
 
-	if err = tx.Commit(); err != nil {
+	if err = commit(); err != nil {
 		return err
 	}
-	success = true
 
 	// Patch fields in the post header
 	var newLines int32 = 0
@@ -348,13 +342,8 @@ func (p *PostHeader) Scribble(ctx context.Context, u *User, comm *Community, ipa
 
 // Nuke causes a post to be nuked (deleted entirely from the topic).
 func (p *PostHeader) Nuke(ctx context.Context, u *User, comm *Community, ipaddr string) error {
-	success := false
+	tx, commit, rollback := transaction(ctx)
-	tx := amdb.MustBegin()
+	defer rollback()
-	defer func() {
-		if !success {
-			tx.Rollback()
-		}
-	}()
 
 	// Delete all the references to this post.
 	_, err := tx.ExecContext(ctx, "DELETE FROM posts WHERE postid = ?", p.PostId)
@@ -394,10 +383,9 @@ func (p *PostHeader) Nuke(ctx context.Context, u *User, comm *Community, ipaddr
 		return err
 	}
 
-	if err = tx.Commit(); err != nil {
+	if err = commit(); err != nil {
 		return err
 	}
-	success = true
 	AmStoreAudit(AmNewCommAudit(AuditConferenceNukeMessage, u.Uid, comm.Id, ipaddr, fmt.Sprintf("post=%d", p.PostId)))
 	return nil
 }
@@ -408,13 +396,8 @@ func (p *PostHeader) Publish(ctx context.Context, comm *Community, publisher *Us
 		return errors.New("cannot publish scribbled post")
 	}
 
-	success := false
+	tx, commit, rollback := transaction(ctx)
-	tx := amdb.MustBegin()
+	defer rollback()
-	defer func() {
-		if !success {
-			tx.Rollback()
-		}
-	}()
 
 	// Check if we were already published.
 	row := tx.QueryRowContext(ctx, "SELECT by_uid FROM postpublish WHERE postid = ?", p.PostId)
@@ -431,10 +414,9 @@ func (p *PostHeader) Publish(ctx context.Context, comm *Community, publisher *Us
 		comm.Id, p.PostId, publisher.Uid); err != nil {
 		return err
 	}
-	if err = tx.Commit(); err != nil {
+	if err = commit(); err != nil {
 		return err
 	}
-	success = true
 	AmStoreAudit(AmNewAudit(AuditPublishToFrontPage, publisher.Uid, ipaddr, fmt.Sprintf("comm=%d,post=%d", comm.Id, p.PostId)))
 	return nil
 }
@@ -463,13 +445,8 @@ func (p *PostHeader) MoveTo(ctx context.Context, target *Topic, u *User, comm *C
 		return err
 	}
 
-	success := false
+	tx, commit, rollback := transaction(ctx)
-	tx := amdb.MustBegin()
+	defer rollback()
-	defer func() {
-		if !success {
-			tx.Rollback()
-		}
-	}()
 
 	// Adjust post record in the database to make it part of the new topic.
 	_, err = tx.ExecContext(ctx, "UPDATE posts SET parent = 0, topicid = ?, num = ? WHERE postid = ?", target.TopicId, target.TopMessage+1, p.PostId)
@@ -511,10 +488,9 @@ func (p *PostHeader) MoveTo(ctx context.Context, target *Topic, u *User, comm *C
 		return err
 	}
 
-	if err = tx.Commit(); err != nil {
+	if err = commit(); err != nil {
 		return err
 	}
-	success = true
 
 	// Now patch the data structures we have.
 	p.Parent = 0
@@ -589,13 +565,8 @@ func AmGetPostRange(ctx context.Context, topic *Topic, first, last int32) ([]*Po
  */
 func AmNewPost(ctx context.Context, conf *Conference, topic *Topic, user *User, pseud string, post string, postLines int32,
 	comm *Community, ipaddr string) (*PostHeader, error) {
-	success := false
+	tx, commit, rollback := transaction(ctx)
-	tx := amdb.MustBegin()
+	defer rollback()
-	defer func() {
-		if !success {
-			tx.Rollback()
-		}
-	}()
 
 	// Add the post header information.
 	rs, err := tx.ExecContext(ctx, "INSERT INTO posts (topicid, num, linecount, creator_uid, posted, pseud) VALUES (?, ?, ?, ?, NOW(), ?)",
@@ -644,10 +615,9 @@ func AmNewPost(ctx context.Context, conf *Conference, topic *Topic, user *User,
 		return nil, err
 	}
 
-	if err = tx.Commit(); err != nil {
+	if err = commit(); err != nil {
 		return nil, err
 	}
-	success = true
 
 	// create audit record
 	AmStoreAudit(AmNewCommAudit(AuditConferencePostMessage, user.Uid, comm.Id, ipaddr, fmt.Sprintf("confid=%d", conf.ConfId),

database/sidebox.go

@@ -66,13 +66,8 @@ func AmGetSideboxes(ctx context.Context, uid int32) ([]*Sidebox, error) {
 
 // AmReorderSideboxes changes the position of two sideboxes on the user's list.
 func AmReorderSideboxes(ctx context.Context, uid int32, seq1, seq2 int32) error {
-	success := false
+	tx, commit, rollback := transaction(ctx)
-	tx := amdb.MustBegin()
+	defer rollback()
-	defer func() {
-		if !success {
-			tx.Rollback()
-		}
-	}()
 
 	_, err := tx.ExecContext(ctx, "UPDATE sideboxes SET sequence = -1 WHERE uid = ? AND sequence = ?", uid, seq1)
 	if err == nil {
@@ -84,22 +79,16 @@ func AmReorderSideboxes(ctx context.Context, uid int32, seq1, seq2 int32) error
 	if err != nil {
 		return err
 	}
-	if err = tx.Commit(); err != nil {
+	if err = commit(); err != nil {
 		return err
 	}
-	success = true
 	return nil
 }
 
 // AmRemoveSidebox removes a sidebox from the user configuration.
 func AmRemoveSidebox(ctx context.Context, uid int32, boxid int32) error {
-	success := false
+	tx, commit, rollback := transaction(ctx)
-	tx := amdb.MustBegin()
+	defer rollback()
-	defer func() {
-		if !success {
-			tx.Rollback()
-		}
-	}()
 
 	// Get the old sequence number.
 	row := tx.QueryRowContext(ctx, "SELECT sequence FROM sideboxes WHERE uid = ? AND boxid = ?", uid, boxid)
@@ -118,22 +107,16 @@ func AmRemoveSidebox(ctx context.Context, uid int32, boxid int32) error {
 	if err != nil {
 		return err
 	}
-	if err = tx.Commit(); err != nil {
+	if err = commit(); err != nil {
 		return err
 	}
-	success = true
 	return nil
 }
 
 // AmAppendSidebox appends a new sidebox to the existing user's configuration.
 func AmAppendSidebox(ctx context.Context, uid int32, boxid int32, param *string) error {
-	success := false
+	tx, commit, rollback := transaction(ctx)
-	tx := amdb.MustBegin()
+	defer rollback()
-	defer func() {
-		if !success {
-			tx.Rollback()
-		}
-	}()
 
 	row := tx.QueryRowContext(ctx, "SELECT MAX(sequence) FROM sideboxes WHERE uid = ?", uid)
 	var topseq int32
@@ -147,9 +130,8 @@ func AmAppendSidebox(ctx context.Context, uid int32, boxid int32, param *string)
 	if err != nil {
 		return err
 	}
-	if err = tx.Commit(); err != nil {
+	if err = commit(); err != nil {
 		return err
 	}
-	success = true
 	return nil
 }

database/topic.go

@@ -372,13 +372,8 @@ func (t *Topic) GetActiveUserEMailAddrs(ctx context.Context, userSelect, dayLimi
 
 // backgroundPurgeTopic removes all posts from a topic that's been deleted.
 func backgroundPurgeTopic(ctx context.Context, topicid int32) error {
-	success := false
+	tx, commit, rollback := transaction(ctx)
-	tx := amdb.MustBegin()
+	defer rollback()
-	defer func() {
-		if !success {
-			tx.Rollback()
-		}
-	}()
 
 	// Get some stats on the posts we have to remove.
 	row := tx.QueryRowContext(ctx, "SELECT MAX(postid) FROM posts WHERE topicid = ?", topicid)
@@ -408,10 +403,9 @@ func backgroundPurgeTopic(ctx context.Context, topicid int32) error {
 	if err != nil {
 		return err
 	}
-	if err = tx.Commit(); err != nil {
+	if err = commit(); err != nil {
 		return err
 	}
-	success = true
 	return nil
 }
 
@@ -429,13 +423,8 @@ func eraseTopicRecords(ctx context.Context, tx *sqlx.Tx, topicid int32) error {
 
 // Delete deletes this topic.
 func (t *Topic) Delete(ctx context.Context, u *User, comm *Community, ipaddr string, background *util.WorkerPool) error {
-	success := false
+	tx, commit, rollback := transaction(ctx)
-	tx := amdb.MustBegin()
+	defer rollback()
-	defer func() {
-		if !success {
-			tx.Rollback()
-		}
-	}()
 
 	conf, err := AmGetConference(ctx, t.ConfId)
 	if err != nil {
@@ -450,10 +439,9 @@ func (t *Topic) Delete(ctx context.Context, u *User, comm *Community, ipaddr str
 	if err = conf.TouchUpdate(ctx, tx, time.Now()); err != nil {
 		return err
 	}
-	if err = tx.Commit(); err != nil {
+	if err = commit(); err != nil {
 		return err
 	}
-	success = true
 
 	// create audit record
 	AmStoreAudit(AmNewCommAudit(AuditConferenceDeleteTopic, u.Uid, comm.Id, ipaddr, fmt.Sprintf("confid=%d", conf.ConfId),
@@ -732,13 +720,8 @@ func AmListTopics(ctx context.Context, confid int32, uid int32, viewOption int,
  */
 func AmNewTopic(ctx context.Context, conf *Conference, user *User, title string, zeroPostPseud string, zeroPost string,
 	zeroPostLines int32, comm *Community, ipaddr string) (*Topic, error) {
-	success := false
+	tx, commit, rollback := transaction(ctx)
-	tx := amdb.MustBegin()
+	defer rollback()
-	defer func() {
-		if !success {
-			tx.Rollback()
-		}
-	}()
 
 	// Insert the new topic into the database.
 	conf.Mutex.Lock()
@@ -800,10 +783,9 @@ func AmNewTopic(ctx context.Context, conf *Conference, user *User, title string,
 		return nil, err
 	}
 
-	if err = tx.Commit(); err != nil {
+	if err = commit(); err != nil {
 		return nil, err
 	}
-	success = true
 
 	// create audit record
 	AmStoreAudit(AmNewCommAudit(AuditConferenceCreateTopic, user.Uid, comm.Id, ipaddr, fmt.Sprintf("confid=%d", conf.ConfId),

database/user.go

@@ -593,13 +593,8 @@ func touchUser(ctx context.Context, tx *sqlx.Tx, user *User) {
  */
 func AmAuthenticateUser(ctx context.Context, name string, password string, remoteIP string) (*User, error) {
 	log.Debugf("AmAuthenticateUser() authenticating user %s...", name)
-	success := false
+	tx, commit, rollback := transaction(ctx)
-	tx := amdb.MustBegin()
+	defer rollback()
-	defer func() {
-		if !success {
-			tx.Rollback()
-		}
-	}()
 
 	user, err := AmGetUserByName(ctx, name, tx)
 	if err != nil {
@@ -631,10 +626,9 @@ func AmAuthenticateUser(ctx context.Context, name string, password string, remot
 	}
 	log.Debug("...authenticated")
 	touchUser(ctx, tx, user)
-	if err = tx.Commit(); err != nil {
+	if err = commit(); err != nil {
 		return nil, err
 	}
-	success = true
 	AmStoreAudit(AmNewAudit(AuditLoginOK, user.Uid, remoteIP))
 	return user, nil
 }
@@ -673,13 +667,8 @@ func crackAuthString(authString string) (int32, string, error) {
  *     Standard Go error status.
  */
 func AmAuthenticateUserByToken(ctx context.Context, authString string, remoteIP string) (*User, error) {
-	success := false
+	tx, commit, rollback := transaction(ctx)
-	tx := amdb.MustBegin()
+	defer rollback()
-	defer func() {
-		if !success {
-			tx.Rollback()
-		}
-	}()
 
 	uid, token, err := crackAuthString(authString)
 	if err != nil {
@@ -710,10 +699,9 @@ func AmAuthenticateUserByToken(ctx context.Context, authString string, remoteIP
 	}
 	log.Debug("...authenticated")
 	touchUser(ctx, tx, user)
-	if err = tx.Commit(); err != nil {
+	if err = commit(); err != nil {
 		return nil, err
 	}
-	success = true
 	AmStoreAudit(AmNewAudit(AuditLoginOK, user.Uid, remoteIP))
 	return user, nil
 }
@@ -732,13 +720,8 @@ func AmAuthenticateUserByToken(ctx context.Context, authString string, remoteIP
  */
 func AmCreateNewUser(ctx context.Context, username string, password string, reminder string, dob *time.Time, remoteIP string) (*User, error) {
 	anon, _ := AmGetAnonUser(ctx)
-	success := false
+	tx, commit, rollback := transaction(ctx)
-	tx := amdb.MustBegin()
+	defer rollback()
-	defer func() {
-		if !success {
-			tx.Rollback()
-		}
-	}()
 
 	// Test if the user name is already taken.
 	row := tx.QueryRowContext(ctx, "SELECT uid FROM users WHERE username = ?", username)
@@ -787,10 +770,9 @@ func AmCreateNewUser(ctx context.Context, username string, password string, remi
 		return nil, err
 	}
 
-	if err = tx.Commit(); err != nil {
+	if err = commit(); err != nil {
 		return nil, err
 	}
-	success = true
 
 	// auto-join communities
 	if err = AmAutoJoinCommunities(ctx, user); err != nil {