Component-wide TransactionWriters (#1290)

* Offset updates take place using TransactionWriter

* Refactor TransactionWriter in current state server

* Refactor TransactionWriter in federation sender

* Refactor TransactionWriter in key server

* Refactor TransactionWriter in media API

* Refactor TransactionWriter in server key API

* Refactor TransactionWriter in sync API

* Refactor TransactionWriter in user API

* Fix deadlocking Sync API tests

* Un-deadlock device database

* Fix appservice API

* Rename TransactionWriters to Writers

* Move writers up a layer in sync API

* Document sqlutil.Writer interface

* Add note to Writer documentation

1 files changed, 13 insertions, 12 deletions

diff --git a/userapi/storage/accounts/postgres/storage.go b/userapi/storage/accounts/postgres/storage.go
index 9653c019..b36264dd 100644
--- a/userapi/storage/accounts/postgres/storage.go
+++ b/userapi/storage/accounts/postgres/storage.go
@@ -34,7 +34,8 @@ import (
 
 // Database represents an account database
 type Database struct {
-	db *sql.DB
+	db     *sql.DB
+	writer sqlutil.Writer
 	sqlutil.PartitionOffsetStatements
 	accounts     accountsStatements
 	profiles     profilesStatements
@@ -49,27 +50,27 @@ func NewDatabase(dbProperties *config.DatabaseOptions, serverName gomatrixserver
 	if err != nil {
 		return nil, err
 	}
-	partitions := sqlutil.PartitionOffsetStatements{}
-	if err = partitions.Prepare(db, "account"); err != nil {
+	d := &Database{
+		serverName: serverName,
+		db:         db,
+		writer:     sqlutil.NewDummyWriter(),
+	}
+	if err = d.PartitionOffsetStatements.Prepare(db, d.writer, "account"); err != nil {
 		return nil, err
 	}
-	a := accountsStatements{}
-	if err = a.prepare(db, serverName); err != nil {
+	if err = d.accounts.prepare(db, serverName); err != nil {
 		return nil, err
 	}
-	p := profilesStatements{}
-	if err = p.prepare(db); err != nil {
+	if err = d.profiles.prepare(db); err != nil {
 		return nil, err
 	}
-	ac := accountDataStatements{}
-	if err = ac.prepare(db); err != nil {
+	if err = d.accountDatas.prepare(db); err != nil {
 		return nil, err
 	}
-	t := threepidStatements{}
-	if err = t.prepare(db); err != nil {
+	if err = d.threepids.prepare(db); err != nil {
 		return nil, err
 	}
-	return &Database{db, partitions, a, p, ac, t, serverName}, nil
+	return d, nil
 }
 
 // GetAccountByPassword returns the account associated with the given localpart and password.