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ReplicationConn refactor

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This commit is contained in:
Kris Wehner
2017-01-09 11:32:02 -08:00
parent 5584040249
commit c88c110169
6 changed files with 89 additions and 43 deletions
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replication.go
+64 -31
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@@ -151,11 +151,28 @@ func NewStandbyStatus(walPositions ...uint64) (status *StandbyStatus, err error)
return
}
func ReplicationConnect(config ConnConfig) (r *ReplicationConn, err error) {
if config.RuntimeParams == nil {
config.RuntimeParams = make(map[string]string)
}
config.RuntimeParams["replication"] = "database"
c,err := Connect(config)
if err != nil {
return
}
return &ReplicationConn{c: c}, nil
}
type ReplicationConn struct {
c *Conn
}
// Send standby status to the server, which both acts as a keepalive
// message to the server, as well as carries the WAL position of the
// client, which then updates the server's replication slot position.
func (c *Conn) SendStandbyStatus(k *StandbyStatus) (err error) {
writeBuf := newWriteBuf(c, copyData)
func (rc *ReplicationConn) SendStandbyStatus(k *StandbyStatus) (err error) {
writeBuf := newWriteBuf(rc.c, copyData)
writeBuf.WriteByte(standbyStatusUpdate)
writeBuf.WriteInt64(int64(k.WalWritePosition))
writeBuf.WriteInt64(int64(k.WalFlushPosition))
@@ -165,9 +182,9 @@ func (c *Conn) SendStandbyStatus(k *StandbyStatus) (err error) {
writeBuf.closeMsg()
_, err = c.conn.Write(writeBuf.buf)
_, err = rc.c.conn.Write(writeBuf.buf)
if err != nil {
c.die(err)
rc.c.die(err)
}
return
@@ -175,37 +192,41 @@ func (c *Conn) SendStandbyStatus(k *StandbyStatus) (err error) {
// Send the message to formally stop the replication stream. This
// is done before calling Close() during a clean shutdown.
func (c *Conn) StopReplication() (err error) {
writeBuf := newWriteBuf(c, copyDone)
func (rc *ReplicationConn) StopReplication() (err error) {
writeBuf := newWriteBuf(rc.c, copyDone)
writeBuf.closeMsg()
_, err = c.conn.Write(writeBuf.buf)
_, err = rc.c.conn.Write(writeBuf.buf)
if err != nil {
c.die(err)
rc.c.die(err)
}
return
}
func (rc *ReplicationConn) Close() error {
return rc.c.Close()
}
func (c *Conn) readReplicationMessage() (r *ReplicationMessage, err error) {
func (rc *ReplicationConn) readReplicationMessage() (r *ReplicationMessage, err error) {
var t byte
var reader *msgReader
t, reader, err = c.rxMsg()
t, reader, err = rc.c.rxMsg()
if err != nil {
return
}
switch t {
case noticeResponse:
pgError := c.rxErrorResponse(reader)
if c.shouldLog(LogLevelInfo) {
c.log(LogLevelInfo, pgError.Error())
pgError := rc.c.rxErrorResponse(reader)
if rc.c.shouldLog(LogLevelInfo) {
rc.c.log(LogLevelInfo, pgError.Error())
}
case errorResponse:
err = c.rxErrorResponse(reader)
if c.shouldLog(LogLevelError) {
c.log(LogLevelError, err.Error())
err = rc.c.rxErrorResponse(reader)
if rc.c.shouldLog(LogLevelError) {
rc.c.log(LogLevelError, err.Error())
}
return
case copyBothResponse:
@@ -235,13 +256,13 @@ func (c *Conn) readReplicationMessage() (r *ReplicationMessage, err error) {
h := &ServerHeartbeat{ServerWalEnd: uint64(serverWalEnd), ServerTime: uint64(serverTime), ReplyRequested: replyNow}
return &ReplicationMessage{ServerHeartbeat: h}, nil
default:
if c.shouldLog(LogLevelError) {
c.log(LogLevelError,"Unexpected data playload message type %v", t)
if rc.c.shouldLog(LogLevelError) {
rc.c.log(LogLevelError,"Unexpected data playload message type %v", t)
}
}
default:
if c.shouldLog(LogLevelError) {
c.log(LogLevelError,"Unexpected replication message type %v", t)
if rc.c.shouldLog(LogLevelError) {
rc.c.log(LogLevelError,"Unexpected replication message type %v", t)
}
}
return
@@ -256,7 +277,7 @@ func (c *Conn) readReplicationMessage() (r *ReplicationMessage, err error) {
//
// This returns pgx.ErrNotificationTimeout when there is no replication message by the specified
// duration.
func (c *Conn) WaitForReplicationMessage(timeout time.Duration) (r *ReplicationMessage, err error) {
func (rc *ReplicationConn) WaitForReplicationMessage(timeout time.Duration) (r *ReplicationMessage, err error) {
var zeroTime time.Time
deadline := time.Now().Add(timeout)
@@ -269,27 +290,27 @@ func (c *Conn) WaitForReplicationMessage(timeout time.Duration) (r *ReplicationM
// deadline and peek into the reader. If a timeout error occurs there
// we don't break the pgx connection. If the Peek returns that data
// is available then we turn off the read deadline before the rxMsg.
err = c.conn.SetReadDeadline(deadline)
err = rc.c.conn.SetReadDeadline(deadline)
if err != nil {
return nil, err
}
// Wait until there is a byte available before continuing onto the normal msg reading path
_, err = c.reader.Peek(1)
_, err = rc.c.reader.Peek(1)
if err != nil {
c.conn.SetReadDeadline(zeroTime) // we can only return one error and we already have one -- so ignore possiple error from SetReadDeadline
rc.c.conn.SetReadDeadline(zeroTime) // we can only return one error and we already have one -- so ignore possiple error from SetReadDeadline
if err, ok := err.(*net.OpError); ok && err.Timeout() {
return nil, ErrNotificationTimeout
}
return nil, err
}
err = c.conn.SetReadDeadline(zeroTime)
err = rc.c.conn.SetReadDeadline(zeroTime)
if err != nil {
return nil, err
}
return c.readReplicationMessage()
return rc.readReplicationMessage()
}
// Start a replication connection, sending WAL data to the given replication
@@ -303,7 +324,7 @@ func (c *Conn) WaitForReplicationMessage(timeout time.Duration) (r *ReplicationM
//
// This function assumes that slotName has already been created. In order to omit the timeline argument
// pass a -1 for the timeline to get the server default behavior.
func (c *Conn) StartReplication(slotName string, startLsn uint64, timeline int64, pluginArguments ...string) (err error) {
func (rc *ReplicationConn) StartReplication(slotName string, startLsn uint64, timeline int64, pluginArguments ...string) (err error) {
var queryString string
if timeline >= 0 {
queryString = fmt.Sprintf("START_REPLICATION SLOT %s LOGICAL %s TIMELINE %d", slotName, FormatLSN(startLsn), timeline)
@@ -315,7 +336,7 @@ func (c *Conn) StartReplication(slotName string, startLsn uint64, timeline int64
queryString += fmt.Sprintf(" %s", arg)
}
if err = c.sendQuery(queryString); err != nil {
if err = rc.c.sendQuery(queryString); err != nil {
return
}
@@ -324,12 +345,24 @@ func (c *Conn) StartReplication(slotName string, startLsn uint64, timeline int64
// started. This call will either return nil, nil or if it returns an error
// that indicates the start replication command failed
var r *ReplicationMessage
r, err = c.WaitForReplicationMessage(initialReplicationResponseTimeout)
r, err = rc.WaitForReplicationMessage(initialReplicationResponseTimeout)
if err != nil && r != nil {
if c.shouldLog(LogLevelError) {
c.log(LogLevelError, "Unxpected replication message %v", r)
if rc.c.shouldLog(LogLevelError) {
rc.c.log(LogLevelError, "Unxpected replication message %v", r)
}
}
return
}
// Create the replication slot, using the given name and output plugin.
func (rc *ReplicationConn) CreateReplicationSlot(slotName, outputPlugin string) (err error) {
_, err = rc.c.Exec(fmt.Sprintf("CREATE_REPLICATION_SLOT %s LOGICAL %s", slotName, outputPlugin))
return
}
// Drop the replication slot for the given name
func (rc *ReplicationConn) DropReplicationSlot(slotName, outputPlugin string) (err error) {
_, err = rc.c.Exec(fmt.Sprintf("DROP_REPLICATION_SLOT %s", slotName))
return
}