milvus/internal/queryservice/meta_replica.go

package queryservice

import (
	"github.com/zilliztech/milvus-distributed/internal/errors"
	"github.com/zilliztech/milvus-distributed/internal/proto/querypb"
)

type metaReplica interface {
	getCollections(dbID UniqueID) ([]*collection, error)
	getPartitions(dbID UniqueID, collectionID UniqueID) ([]*partition, error)
	getSegments(dbID UniqueID, collectionID UniqueID, partitionID UniqueID) ([]*segment, error)
	loadCollection(dbID UniqueID, collectionID UniqueID) (*collection, error)
	loadPartition(dbID UniqueID, collectionID UniqueID, partitionID UniqueID) (*partition, error)
	updatePartitionState(dbID UniqueID, collectionID UniqueID, partitionID UniqueID, state querypb.PartitionState) error
	getPartitionStates(dbID UniqueID, collectionID UniqueID, partitionIDs []UniqueID) ([]*querypb.PartitionStates, error)
}

type segment struct {
	id UniqueID
}

type partition struct {
	id       UniqueID
	segments map[UniqueID]*segment
	state    querypb.PartitionState
}

type collection struct {
	id           UniqueID
	partitions   map[UniqueID]*partition
	node2channel map[int][]string
}

type metaReplicaImpl struct {
	dbID           []UniqueID
	db2collections map[UniqueID][]*collection
}

func newMetaReplica() metaReplica {
	db2collections := make(map[UniqueID][]*collection)
	db2collections[0] = make([]*collection, 0)
	dbIDs := make([]UniqueID, 0)
	dbIDs = append(dbIDs, UniqueID(0))
	return &metaReplicaImpl{
		dbID:           dbIDs,
		db2collections: db2collections,
	}
}

func (mp *metaReplicaImpl) addCollection(dbID UniqueID, collectionID UniqueID) (*collection, error) {
	if _, ok := mp.db2collections[dbID]; ok {
		partitions := make(map[UniqueID]*partition)
		node2channel := make(map[int][]string)
		newCollection := &collection{
			id:           collectionID,
			partitions:   partitions,
			node2channel: node2channel,
		}
		mp.db2collections[dbID] = append(mp.db2collections[dbID], newCollection)
		return newCollection, nil
	}
	return nil, errors.New("can't find dbID when add collection")
}

func (mp *metaReplicaImpl) addPartition(dbID UniqueID, collectionID UniqueID, partitionID UniqueID) (*partition, error) {
	if collections, ok := mp.db2collections[dbID]; ok {
		for _, collection := range collections {
			if collection.id == collectionID {
				partitions := collection.partitions
				segments := make(map[UniqueID]*segment)
				partition := &partition{
					id:       partitionID,
					state:    querypb.PartitionState_NotPresent,
					segments: segments,
				}
				partitions[partitionID] = partition
				return partition, nil
			}
		}
	}
	return nil, errors.New("can't find collection when add partition")
}

func (mp *metaReplicaImpl) getCollections(dbID UniqueID) ([]*collection, error) {
	if collections, ok := mp.db2collections[dbID]; ok {
		return collections, nil
	}

	return nil, errors.New("can't find collectionID")
}

func (mp *metaReplicaImpl) getPartitions(dbID UniqueID, collectionID UniqueID) ([]*partition, error) {
	if collections, ok := mp.db2collections[dbID]; ok {
		for _, collection := range collections {
			if collectionID == collection.id {
				partitions := make([]*partition, 0)
				for _, partition := range collection.partitions {
					partitions = append(partitions, partition)
				}
				return partitions, nil
			}
		}
	}

	return nil, errors.New("can't find partitionIDs")
}

func (mp *metaReplicaImpl) getSegments(dbID UniqueID, collectionID UniqueID, partitionID UniqueID) ([]*segment, error) {
	if collections, ok := mp.db2collections[dbID]; ok {
		for _, collection := range collections {
			if collectionID == collection.id {
				if partition, ok := collection.partitions[partitionID]; ok {
					segments := make([]*segment, 0)
					for _, segment := range partition.segments {
						segments = append(segments, segment)
					}
					return segments, nil
				}
			}
		}
	}
	return nil, errors.New("can't find segmentID")
}

func (mp *metaReplicaImpl) loadCollection(dbID UniqueID, collectionID UniqueID) (*collection, error) {
	var res *collection = nil
	if collections, err := mp.getCollections(dbID); err == nil {
		for _, collection := range collections {
			if collectionID == collection.id {
				return res, nil
			}
		}
	} else {
		res, err = mp.addCollection(dbID, collectionID)
		if err != nil {
			return nil, err
		}
	}
	return res, nil
}

func (mp *metaReplicaImpl) loadPartition(dbID UniqueID, collectionID UniqueID, partitionID UniqueID) (*partition, error) {
	var collection *collection = nil
	var partition *partition = nil
	var err error
	for _, col := range mp.db2collections[dbID] {
		if col.id == collectionID {
			collection = col
		}
	}
	if collection == nil {
		collection, err = mp.addCollection(dbID, collectionID)
		if err != nil {
			return partition, err
		}
	}
	if _, ok := collection.partitions[partitionID]; !ok {
		partition, err = mp.addPartition(dbID, collectionID, partitionID)
		if err != nil {
			return partition, err
		}
		return partition, nil
	}

	return nil, nil
}

func (mp *metaReplicaImpl) updatePartitionState(dbID UniqueID,
	collectionID UniqueID,
	partitionID UniqueID,
	state querypb.PartitionState) error {
	for _, collection := range mp.db2collections[dbID] {
		if collection.id == collectionID {
			if partition, ok := collection.partitions[partitionID]; ok {
				partition.state = state
				return nil
			}
		}
	}
	return errors.New("update partition state fail")
}

func (mp *metaReplicaImpl) getPartitionStates(dbID UniqueID,
	collectionID UniqueID,
	partitionIDs []UniqueID) ([]*querypb.PartitionStates, error) {
	partitionStates := make([]*querypb.PartitionStates, 0)
	for _, collection := range mp.db2collections[dbID] {
		if collection.id == collectionID {
			for _, partitionID := range partitionIDs {
				if partition, ok := collection.partitions[partitionID]; ok {
					partitionStates = append(partitionStates, &querypb.PartitionStates{
						PartitionID: partitionID,
						State:       partition.state,
					})
				} else {
					partitionStates = append(partitionStates, &querypb.PartitionStates{
						PartitionID: partitionID,
						State:       querypb.PartitionState_NotPresent,
					})
				}
			}
		}
	}
	return partitionStates, nil
}