// CreateShard creates a new shard and tries to fill in the right information.
func CreateShard(ts Server, keyspace, shard string) error {
name, keyRange, err := ValidateShardName(shard)
if err != nil {
return err
}
// start the shard with all serving types. If it overlaps with
// other shards for some serving types, remove them.
s := &Shard{
KeyRange: keyRange,
ServedTypesMap: map[TabletType]*ShardServedType{
TYPE_MASTER: &ShardServedType{},
TYPE_REPLICA: &ShardServedType{},
TYPE_RDONLY: &ShardServedType{},
},
}
sis, err := FindAllShardsInKeyspace(ts, keyspace)
if err != nil && err != ErrNoNode {
return err
}
for _, si := range sis {
if key.KeyRangesIntersect(si.KeyRange, keyRange) {
for t, _ := range si.ServedTypesMap {
delete(s.ServedTypesMap, t)
}
}
}
if len(s.ServedTypesMap) == 0 {
s.ServedTypesMap = nil
}
return ts.CreateShard(keyspace, name, s)
}
// intersect returns true if the provided shard intersect with any shard
// in the destination array
func intersect(si *topo.ShardInfo, allShards []*topo.ShardInfo) bool {
for _, shard := range allShards {
if key.KeyRangesIntersect(si.KeyRange, shard.KeyRange) {
return true
}
}
return false
}
// findIntersectingShard will go through the map and take the first
// entry in there that intersect with the source array, remove it from
// the map, and return it
func findIntersectingShard(shardMap map[string]*topo.ShardInfo, sourceArray []*topo.ShardInfo) *topo.ShardInfo {
for name, si := range shardMap {
for _, sourceShardInfo := range sourceArray {
if key.KeyRangesIntersect(si.KeyRange, sourceShardInfo.KeyRange) {
delete(shardMap, name)
return si
}
}
}
return nil
}
// This maps a list of keyranges to shard names.
func resolveKeyRangeToShards(allShards []topo.SrvShard, kr key.KeyRange) ([]string, error) {
shards := make([]string, 0, 1)
if !kr.IsPartial() {
for j := 0; j < len(allShards); j++ {
shards = append(shards, allShards[j].ShardName())
}
return shards, nil
}
for j := 0; j < len(allShards); j++ {
shard := allShards[j]
if key.KeyRangesIntersect(kr, shard.KeyRange) {
shards = append(shards, shard.ShardName())
}
}
return shards, nil
}