go_study/fabric-main/core/ledger/pvtdatapolicy/btlpolicy.go

98 lines
2.9 KiB
Go

/*
Copyright IBM Corp. All Rights Reserved.
SPDX-License-Identifier: Apache-2.0
*/
package pvtdatapolicy
import (
"math"
"sync"
"github.com/hyperledger/fabric-protos-go/peer"
"github.com/hyperledger/fabric/core/common/privdata"
)
var defaultBTL uint64 = math.MaxUint64
// BTLPolicy BlockToLive policy for the pvt data
type BTLPolicy interface {
// GetBTL returns BlockToLive for a given namespace and collection
GetBTL(ns string, coll string) (uint64, error)
// GetExpiringBlock returns the block number by which the pvtdata for given namespace,collection, and committingBlock should expire
GetExpiringBlock(namespace string, collection string, committingBlock uint64) (uint64, error)
}
// LSCCBasedBTLPolicy implements interface BTLPolicy.
// This implementation loads the BTL policy from lscc namespace which is populated
// with the collection configuration during chaincode initialization
type LSCCBasedBTLPolicy struct {
collInfoProvider collectionInfoProvider
cache map[btlkey]uint64
lock sync.Mutex
}
type btlkey struct {
ns string
coll string
}
// ConstructBTLPolicy constructs an instance of LSCCBasedBTLPolicy
func ConstructBTLPolicy(collInfoProvider collectionInfoProvider) BTLPolicy {
return &LSCCBasedBTLPolicy{
collInfoProvider: collInfoProvider,
cache: make(map[btlkey]uint64),
}
}
// GetBTL implements corresponding function in interface `BTLPolicyMgr`
func (p *LSCCBasedBTLPolicy) GetBTL(namespace string, collection string) (uint64, error) {
var btl uint64
var ok bool
key := btlkey{namespace, collection}
p.lock.Lock()
defer p.lock.Unlock()
btl, ok = p.cache[key]
if !ok {
collConfig, err := p.collInfoProvider.CollectionInfo(namespace, collection)
if err != nil {
return 0, err
}
if collConfig == nil {
return 0, privdata.NoSuchCollectionError{Namespace: namespace, Collection: collection}
}
btlConfigured := collConfig.BlockToLive
if btlConfigured > 0 {
btl = uint64(btlConfigured)
} else {
btl = defaultBTL
}
p.cache[key] = btl
}
return btl, nil
}
// GetExpiringBlock implements function from the interface `BTLPolicy`
func (p *LSCCBasedBTLPolicy) GetExpiringBlock(namespace string, collection string, committingBlock uint64) (uint64, error) {
btl, err := p.GetBTL(namespace, collection)
if err != nil {
return 0, err
}
return ComputeExpiringBlock(namespace, collection, committingBlock, btl), nil
}
func ComputeExpiringBlock(namespace, collection string, committingBlock, btl uint64) uint64 {
expiryBlk := committingBlock + btl + uint64(1)
if expiryBlk <= committingBlock { // committingBlk + btl overflows uint64-max
expiryBlk = math.MaxUint64
}
return expiryBlk
}
type collectionInfoProvider interface {
CollectionInfo(chaincodeName, collectionName string) (*peer.StaticCollectionConfig, error)
}
//go:generate counterfeiter -o mock/coll_info_provider.go -fake-name CollectionInfoProvider . collectionInfoProvider