[FAB-6553] Ledger bookkeeping provider

This CR introduces a bookkeeping provider.
This is intented to be used in maintaining different
aspects of ledger data management.

The initial use would be to maintain the expiry schedule
of pvt data items in the pvt statedb

Change-Id: I21f5eef5034cc413c39fdf4bee798fefafbcdf27
Signed-off-by: manish <manish.sethi@gmail.com>

core/ledger/kvledger/bookkeeping/provider.go

@@ -0,0 +1,54 @@
+/*
+Copyright IBM Corp. All Rights Reserved.
+
+SPDX-License-Identifier: Apache-2.0
+*/
+
+package bookkeeping
+
+import (
+	"fmt"
+
+	"github.com/hyperledger/fabric/common/ledger/util/leveldbhelper"
+	"github.com/hyperledger/fabric/core/ledger/ledgerconfig"
+)
+
+// Category is an enum type for representing the bookkeeping of different type
+type Category int
+
+const (
+	// PvtdataExpiry repersents the bookkeeping related to expiry of pvtdata because of BTL policy
+	PvtdataExpiry Category = iota
+)
+
+// Provider provides handle to different bookkeepers for the given ledger
+type Provider interface {
+	// GetDBHandle returns a db handle that can be used for maintaining the bookkeeping of a given category
+	GetDBHandle(ledgerID string, cat Category) *leveldbhelper.DBHandle
+	// Close closes the BookkeeperProvider
+	Close()
+}
+
+type provider struct {
+	dbProvider *leveldbhelper.Provider
+}
+
+// NewProvider instantiates a new provider
+func NewProvider() Provider {
+	dbProvider := leveldbhelper.NewProvider(&leveldbhelper.Conf{DBPath: getInternalBookkeeperPath()})
+	return &provider{dbProvider: dbProvider}
+}
+
+// GetDBHandle implements the function in the interface 'BookkeeperProvider'
+func (provider *provider) GetDBHandle(ledgerID string, cat Category) *leveldbhelper.DBHandle {
+	return provider.dbProvider.GetDBHandle(fmt.Sprintf(ledgerID+"/%d", cat))
+}
+
+// Close implements the function in the interface 'BookKeeperProvider'
+func (provider *provider) Close() {
+	provider.dbProvider.Close()
+}
+
+func getInternalBookkeeperPath() string {
+	return ledgerconfig.GetInternalBookkeeperPath()
+}

core/ledger/kvledger/bookkeeping/provider_test.go

@@ -0,0 +1,31 @@
+/*
+Copyright IBM Corp. All Rights Reserved.
+
+SPDX-License-Identifier: Apache-2.0
+*/
+
+package bookkeeping
+
+import (
+	"os"
+	"testing"
+
+	"github.com/spf13/viper"
+	"github.com/stretchr/testify/assert"
+)
+
+func TestMain(m *testing.M) {
+	viper.Set("peer.fileSystemPath", "/tmp/fabric/ledgertests/kvledger/bookkeeping")
+	os.Exit(m.Run())
+}
+
+func TestProvider(t *testing.T) {
+	testEnv := NewTestEnv(t)
+	defer testEnv.Cleanup()
+	p := testEnv.TestProvider
+	db := p.GetDBHandle("TestLedger", PvtdataExpiry)
+	assert.NoError(t, db.Put([]byte("key"), []byte("value"), true))
+	val, err := db.Get([]byte("key"))
+	assert.NoError(t, err)
+	assert.Equal(t, []byte("value"), val)
+}

core/ledger/kvledger/bookkeeping/test_exports.go

@@ -0,0 +1,49 @@
+/*
+Copyright IBM Corp. 2017 All Rights Reserved.
+
+Licensed under the Apache License, Version 2.0 (the "License");
+you may not use this file except in compliance with the License.
+You may obtain a copy of the License at
+
+		 http://www.apache.org/licenses/LICENSE-2.0
+
+Unless required by applicable law or agreed to in writing, software
+distributed under the License is distributed on an "AS IS" BASIS,
+WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+See the License for the specific language governing permissions and
+limitations under the License.
+*/
+
+package bookkeeping
+
+import (
+	"os"
+	"testing"
+)
+
+// TestEnv provides the bookkeeper provider env for testing
+type TestEnv struct {
+	t            testing.TB
+	TestProvider Provider
+}
+
+// NewTestEnv construct a TestEnv for testing
+func NewTestEnv(t *testing.T) *TestEnv {
+	removePath(t)
+	provider := NewProvider()
+	return &TestEnv{t, provider}
+}
+
+// Cleanup cleansup the  store env after testing
+func (env *TestEnv) Cleanup() {
+	env.TestProvider.Close()
+	removePath(env.t)
+}
+
+func removePath(t testing.TB) {
+	dbPath := getInternalBookkeeperPath()
+	if err := os.RemoveAll(dbPath); err != nil {
+		t.Fatalf("Err: %s", err)
+		t.FailNow()
+	}
+}

core/ledger/ledgerconfig/ledger_config.go

@@ -68,11 +68,6 @@ func GetHistoryLevelDBPath() string {
 	return filepath.Join(GetRootPath(), confHistoryLeveldb)
 }
 
-// GetPvtWritesetStorePath returns the filesystem path that is used for permanent storage of privare write-sets
-func GetPvtWritesetStorePath() string {
-	return filepath.Join(GetRootPath(), confPvtWritesetStore)
-}
-
 // GetBlockStorePath returns the filesystem path that is used for the chain block stores
 func GetBlockStorePath() string {
 	return filepath.Join(GetRootPath(), confChains)
@@ -83,6 +78,11 @@ func GetPvtdataStorePath() string {
 	return filepath.Join(GetRootPath(), confPvtdataStore)
 }
 
+// GetInternalBookkeeperPath returns the filesystem path that is used for bookkeeping the internal stuff by by KVledger (such as expiration time for pvt)
+func GetInternalBookkeeperPath() string {
+	return filepath.Join(GetRootPath(), "bookkeeper")
+}
+
 // GetMaxBlockfileSize returns maximum size of the block file
 func GetMaxBlockfileSize() int {
 	return 64 * 1024 * 1024