frostfs-node/pkg/services/object_manager/placement/cache.go
Evgenii Stratonikov 286df198c9 [] placement: Decouple ContainerNodes() cache from the placement builder.
Also, write tests.

Signed-off-by: Evgenii Stratonikov <e.stratonikov@yadro.com>
2024-07-16 12:21:30 +00:00

69 lines
2 KiB
Go

package placement
import (
"crypto/sha256"
"fmt"
"sync"
cid "git.frostfs.info/TrueCloudLab/frostfs-sdk-go/container/id"
netmapSDK "git.frostfs.info/TrueCloudLab/frostfs-sdk-go/netmap"
"github.com/hashicorp/golang-lru/v2/simplelru"
)
// ContainerNodesCache caches results of ContainerNodes() invocation between epochs.
type ContainerNodesCache struct {
// mtx protects lastEpoch and containerCache fields.
mtx sync.Mutex
// lastEpoch contains network map epoch for all values in the container cache.
lastEpoch uint64
// containerCache caches container nodes by ID. It is used to skip `GetContainerNodes` invocation if
// neither netmap nor container has changed.
containerCache simplelru.LRUCache[cid.ID, [][]netmapSDK.NodeInfo]
}
// defaultContainerCacheSize is the default size for the container cache.
const defaultContainerCacheSize = 10
// NewContainerNodesCache creates new cache which saves the result of the ContainerNodes() invocations.
// If size is <= 0, defaultContainerCacheSize (10) is used.
func NewContainerNodesCache(size int) *ContainerNodesCache {
if size <= 0 {
size = defaultContainerCacheSize
}
cache, _ := simplelru.NewLRU[cid.ID, [][]netmapSDK.NodeInfo](size, nil) // no error
return &ContainerNodesCache{
containerCache: cache,
}
}
// ContainerNodes returns the result of nm.ContainerNodes(), possibly from the cache.
func (c *ContainerNodesCache) ContainerNodes(nm *netmapSDK.NetMap, cnr cid.ID, p netmapSDK.PlacementPolicy) ([][]netmapSDK.NodeInfo, error) {
c.mtx.Lock()
if nm.Epoch() == c.lastEpoch {
raw, ok := c.containerCache.Get(cnr)
c.mtx.Unlock()
if ok {
return raw, nil
}
} else {
c.lastEpoch = nm.Epoch()
c.containerCache.Purge()
c.mtx.Unlock()
}
binCnr := make([]byte, sha256.Size)
cnr.Encode(binCnr)
cn, err := nm.ContainerNodes(p, binCnr)
if err != nil {
return nil, fmt.Errorf("could not get container nodes: %w", err)
}
c.mtx.Lock()
if c.lastEpoch == nm.Epoch() {
c.containerCache.Add(cnr, cn)
}
c.mtx.Unlock()
return cn, nil
}