// 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.KeyRangesIntersect3(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 si.KeyRange == nil || sourceShardInfo.KeyRange == nil || key.KeyRangesIntersect3(si.KeyRange, sourceShardInfo.KeyRange) {
delete(shardMap, name)
return si
}
}
}
return nil
}
// CreateShard creates a new shard and tries to fill in the right information.
// This should be called while holding the keyspace lock for the shard.
// (call topotools.CreateShard to do that for you).
// In unit tests (that are not parallel), this function can be called directly.
func (ts Server) CreateShard(ctx context.Context, 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.
servedTypes := map[pb.TabletType]bool{
pb.TabletType_MASTER: true,
pb.TabletType_REPLICA: true,
pb.TabletType_RDONLY: true,
}
value := &pb.Shard{
KeyRange: keyRange,
}
if IsShardUsingRangeBasedSharding(name) {
// if we are using range-based sharding, we don't want
// overlapping shards to all serve and confuse the clients.
sis, err := ts.FindAllShardsInKeyspace(ctx, keyspace)
if err != nil && err != ErrNoNode {
return err
}
for _, si := range sis {
if si.KeyRange == nil || key.KeyRangesIntersect3(si.KeyRange, keyRange) {
for _, st := range si.ServedTypes {
delete(servedTypes, st.TabletType)
}
}
}
}
for st := range servedTypes {
value.ServedTypes = append(value.ServedTypes, &pb.Shard_ServedType{
TabletType: st,
})
}
if err := ts.Impl.CreateShard(ctx, keyspace, name, value); err != nil {
return err
}
event.Dispatch(&events.ShardChange{
KeyspaceName: keyspace,
ShardName: shard,
Shard: value,
Status: "created",
})
return nil
}