func (self *ClusterConfiguration) getShardsToMatchQuery(querySpec *parser.QuerySpec) ([]*ShardData, error) {
self.shardLock.RLock()
defer self.shardLock.RUnlock()
seriesNames, fromRegex := querySpec.TableNamesAndRegex()
db := querySpec.Database()
if fromRegex != nil {
seriesNames = self.MetaStore.GetSeriesForDatabaseAndRegex(db, fromRegex)
}
uniqueShards := make(map[uint32]*ShardData)
for _, name := range seriesNames {
if fs := self.MetaStore.GetFieldsForSeries(db, name); len(fs) == 0 {
return nil, fmt.Errorf("Couldn't find series: %s", name)
}
space := self.getShardSpaceToMatchSeriesName(db, name)
if space == nil {
continue
}
for _, shard := range space.shards {
uniqueShards[shard.id] = shard
}
}
shards := make([]*ShardData, 0, len(uniqueShards))
for _, shard := range uniqueShards {
shards = append(shards, shard)
}
SortShardsByTimeDescending(shards)
return shards, nil
}