// GetZoneConfig returns the zone config for the object with 'id'.
func GetZoneConfig(cfg *config.SystemConfig, id uint32) (*config.ZoneConfig, error) {
// Look in the zones table.
if val, ok := cfg.Get(MakeZoneKey(ID(id))); ok {
zone := &config.ZoneConfig{}
if err := gogoproto.Unmarshal(val, zone); err != nil {
return nil, err
}
// We're done.
return zone, nil
}
// No zone config for this ID. We need to figure out if it's a database
// or table. Lookup its descriptor.
rawDesc, ok := cfg.Get(MakeDescMetadataKey(ID(id)))
if !ok {
// No descriptor. This table/db could have been deleted,
// just return the default config.
return config.DefaultZoneConfig, nil
}
// Determine whether this is a database or table.
// TODO(marc): we need a better way of doing this. Options include:
// - add a type field on the descriptor table
// - separate descriptor tables for databases and tables
// - prebuild list of databases and tables in the system config
var dbDesc DatabaseDescriptor
if err := gogoproto.Unmarshal(rawDesc, &dbDesc); err == nil {
// parses as a database: return default config.
return config.DefaultZoneConfig, nil
}
var tableDesc TableDescriptor
if err := gogoproto.Unmarshal(rawDesc, &tableDesc); err != nil {
// does not parse as a table either: this means an entry in the
// descriptor table we're not familiar with.
return nil, util.Errorf("descriptor for object ID %d is not a table or database", id)
}
// This is a table descriptor. Lookup its parent database zone config.
return GetZoneConfig(cfg, uint32(tableDesc.ParentID))
}