// UpdateShardReplicationFields implements topo.Server.
func (s *Server) UpdateShardReplicationFields(ctx context.Context, cell, keyspace, shard string, updateFunc func(*topodatapb.ShardReplication) error) error {
var sri *topo.ShardReplicationInfo
var version int64
var err error
for {
if sri, version, err = s.getShardReplication(cell, keyspace, shard); err != nil {
if err == topo.ErrNoNode {
// Pass an empty struct to the update func, as specified in topo.Server.
sri = topo.NewShardReplicationInfo(&topodatapb.ShardReplication{}, cell, keyspace, shard)
version = -1
} else {
return err
}
}
if err = updateFunc(sri.ShardReplication); err != nil {
return err
}
if version == -1 {
if _, err = s.createShardReplication(sri); err != topo.ErrNodeExists {
return err
}
} else {
if _, err = s.updateShardReplication(sri, version); err != topo.ErrBadVersion {
return err
}
}
}
}
// GetShardReplication is part of the topo.Server interface
func (zkts *Server) GetShardReplication(ctx context.Context, cell, keyspace, shard string) (*topo.ShardReplicationInfo, error) {
zkPath := shardReplicationPath(cell, keyspace, shard)
data, _, err := zkts.zconn.Get(zkPath)
if err != nil {
return nil, convertError(err)
}
sr := &topodatapb.ShardReplication{}
if err = json.Unmarshal([]byte(data), sr); err != nil {
return nil, fmt.Errorf("bad ShardReplication data %v", err)
}
return topo.NewShardReplicationInfo(sr, cell, keyspace, shard), nil
}
func (zkts *Server) GetShardReplication(cell, keyspace, shard string) (*topo.ShardReplicationInfo, error) {
zkPath := shardReplicationPath(cell, keyspace, shard)
data, _, err := zkts.zconn.Get(zkPath)
if err != nil {
if zookeeper.IsError(err, zookeeper.ZNONODE) {
err = topo.ErrNoNode
}
return nil, err
}
sr := &topo.ShardReplication{}
if err = json.Unmarshal([]byte(data), sr); err != nil {
return nil, fmt.Errorf("bad ShardReplication data %v", err)
}
return topo.NewShardReplicationInfo(sr, cell, keyspace, shard), nil
}
// GetShardReplication should return all the nodes in a shard,
// but instead we cheat for this test and just return all the
// tablets in the cell.
func (ft *fakeTopo) GetShardReplication(ctx context.Context, cell, keyspace, shard string) (*topo.ShardReplicationInfo, error) {
if ft.expectGetTabletsByCell {
return nil, fmt.Errorf("unexpected GetShardReplication")
}
ft.mu.RLock()
defer ft.mu.RUnlock()
nodes := make([]*topodatapb.ShardReplication_Node, 0, 1)
for alias, tablet := range ft.tablets {
if tablet.Alias.Cell == cell {
nodes = append(nodes, &topodatapb.ShardReplication_Node{
TabletAlias: &alias,
})
}
}
return topo.NewShardReplicationInfo(&topodatapb.ShardReplication{
Nodes: nodes,
}, cell, keyspace, shard), nil
}
func (s *Server) getShardReplication(cellName, keyspace, shard string) (*topo.ShardReplicationInfo, int64, error) {
cell, err := s.getCell(cellName)
if err != nil {
return nil, -1, err
}
resp, err := cell.Get(shardReplicationFilePath(keyspace, shard), false /* sort */, false /* recursive */)
if err != nil {
return nil, -1, convertError(err)
}
if resp.Node == nil {
return nil, -1, ErrBadResponse
}
value := &topodatapb.ShardReplication{}
if err := json.Unmarshal([]byte(resp.Node.Value), value); err != nil {
return nil, -1, fmt.Errorf("bad shard replication data (%v): %q", err, resp.Node.Value)
}
return topo.NewShardReplicationInfo(value, cellName, keyspace, shard), int64(resp.Node.ModifiedIndex), nil
}