remove existing lscc state cache

This CR removes the lscc state cache. This cache will be replaced
with a new system cache.

FAB-15561 #done

Change-Id: If166f6c493b7f0d3ddde45e471f9fa32df8371b7
Signed-off-by: senthil <cendhu@gmail.com>

core/ledger/kvledger/txmgmt/statedb/statecouchdb/statecouchdb.go

@@ -26,8 +26,6 @@ import (
 var logger = flogging.MustGetLogger("statecouchdb")
 
 const (
-	// lsccCacheSize denotes the number of entries allowed in the lsccStateCache
-	lsccCacheSize = 50
 	// savepointDocID is used as a key for maintaining savepoint (maintained in metadatadb for a channel)
 	savepointDocID = "statedb_savepoint"
 	// fabricInternalDBName is used to create a db in couch that would be used for internal data such as the version of the data format
@@ -171,59 +169,9 @@ type VersionedDB struct {
 	committedDataCache *versionsCache                    // Used as a local cache during bulk processing of a block.
 	verCacheLock       sync.RWMutex
 	mux                sync.RWMutex
-	lsccStateCache     *lsccStateCache
 	redoLogger         *redoLogger
 }
 
-type lsccStateCache struct {
-	cache   map[string]*statedb.VersionedValue
-	rwMutex sync.RWMutex
-}
-
-func (l *lsccStateCache) getState(key string) *statedb.VersionedValue {
-	l.rwMutex.RLock()
-	defer l.rwMutex.RUnlock()
-
-	if versionedValue, ok := l.cache[key]; ok {
-		logger.Debugf("key:[%s] found in the lsccStateCache", key)
-		return versionedValue
-	}
-	return nil
-}
-
-func (l *lsccStateCache) updateState(key string, value *statedb.VersionedValue) {
-	l.rwMutex.Lock()
-	defer l.rwMutex.Unlock()
-
-	if _, ok := l.cache[key]; ok {
-		logger.Debugf("key:[%s] is updated in lsccStateCache", key)
-		l.cache[key] = value
-	}
-}
-
-func (l *lsccStateCache) setState(key string, value *statedb.VersionedValue) {
-	l.rwMutex.Lock()
-	defer l.rwMutex.Unlock()
-
-	if l.isCacheFull() {
-		l.evictARandomEntry()
-	}
-
-	logger.Debugf("key:[%s] is stored in lsccStateCache", key)
-	l.cache[key] = value
-}
-
-func (l *lsccStateCache) isCacheFull() bool {
-	return len(l.cache) == lsccCacheSize
-}
-
-func (l *lsccStateCache) evictARandomEntry() {
-	for key := range l.cache {
-		delete(l.cache, key)
-		return
-	}
-}
-
 // newVersionedDB constructs an instance of VersionedDB
 func newVersionedDB(couchInstance *couchdb.CouchInstance, redoLogger *redoLogger, dbName string) (*VersionedDB, error) {
 	// CreateCouchDatabase creates a CouchDB database object, as well as the underlying database if it does not exist
@@ -241,10 +189,7 @@ func newVersionedDB(couchInstance *couchdb.CouchInstance, redoLogger *redoLogger
 		chainName:          chainName,
 		namespaceDBs:       namespaceDBMap,
 		committedDataCache: newVersionCache(),
-		lsccStateCache: &lsccStateCache{
-			cache: make(map[string]*statedb.VersionedValue),
-		},
-		redoLogger: redoLogger,
+		redoLogger:         redoLogger,
 	}
 	logger.Debugf("chain [%s]: checking for redolog record", chainName)
 	redologRecord, err := redoLogger.load()
@@ -398,11 +343,6 @@ func (vdb *VersionedDB) BytesKeySupported() bool {
 // GetState implements method in VersionedDB interface
 func (vdb *VersionedDB) GetState(namespace string, key string) (*statedb.VersionedValue, error) {
 	logger.Debugf("GetState(). ns=%s, key=%s", namespace, key)
-	if namespace == "lscc" {
-		if value := vdb.lsccStateCache.getState(key); value != nil {
-			return value, nil
-		}
-	}
 
 	db, err := vdb.getNamespaceDBHandle(namespace)
 	if err != nil {
@@ -420,10 +360,6 @@ func (vdb *VersionedDB) GetState(namespace string, key string) (*statedb.Version
 		return nil, err
 	}
 
-	if namespace == "lscc" {
-		vdb.lsccStateCache.setState(key, kv.VersionedValue)
-	}
-
 	return kv.VersionedValue, nil
 }
 
@@ -668,10 +604,6 @@ func (vdb *VersionedDB) applyUpdates(updates *statedb.UpdateBatch, height *versi
 		return err
 	}
 
-	lsccUpdates := updates.GetUpdates("lscc")
-	for key, value := range lsccUpdates {
-		vdb.lsccStateCache.updateState(key, value)
-	}
 	return nil
 }
 

core/ledger/kvledger/txmgmt/statedb/statecouchdb/statecouchdb_test.go

@@ -10,7 +10,6 @@ import (
 	"fmt"
 	"io/ioutil"
 	"os"
-	"strconv"
 	"strings"
 	"testing"
 	"time"
@@ -660,75 +659,6 @@ func TestPaginatedQueryValidation(t *testing.T) {
 	assert.Error(t, err, "An should have been thrown for an invalid options")
 }
 
-func TestLSCCStateCache(t *testing.T) {
-	env := NewTestVDBEnv(t)
-	defer env.Cleanup()
-
-	db, err := env.DBProvider.GetDBHandle("testinit")
-	assert.NoError(t, err)
-	db.Open()
-	defer db.Close()
-
-	// Scenario 1: Storing two keys in the lscc name space.
-	// Checking whether the cache is populated correctly during
-	// GetState()
-	batch := statedb.NewUpdateBatch()
-	batch.Put("lscc", "key1", []byte("value1"), version.NewHeight(1, 1))
-	batch.Put("lscc", "key2", []byte("value2"), version.NewHeight(1, 1))
-
-	savePoint := version.NewHeight(1, 1)
-	db.ApplyUpdates(batch, savePoint)
-
-	// cache should not contain key1 and key2
-	assert.Nil(t, db.(*VersionedDB).lsccStateCache.getState("key1"))
-	assert.Nil(t, db.(*VersionedDB).lsccStateCache.getState("key2"))
-
-	// GetState() populates the cache
-	valueFromDB, err := db.GetState("lscc", "key1")
-	assert.NoError(t, err)
-	valueFromCache := db.(*VersionedDB).lsccStateCache.getState("key1")
-	assert.Equal(t, valueFromCache, valueFromDB)
-
-	// Scenario 2: updates an existing key in lscc namespace. Note that the
-	// key in lsccStateCache should be updated
-	batch = statedb.NewUpdateBatch()
-	batch.Put("lscc", "key1", []byte("new-value1"), version.NewHeight(1, 2))
-	savePoint = version.NewHeight(1, 2)
-	db.ApplyUpdates(batch, savePoint)
-
-	valueFromCache = db.(*VersionedDB).lsccStateCache.getState("key1")
-	expectedValue := &statedb.VersionedValue{Value: []byte("new-value1"), Version: version.NewHeight(1, 2)}
-	assert.Equal(t, expectedValue, valueFromCache)
-
-	// Scenario 3: adds LsccCacheSize number of keys in lscc namespace.
-	// Read all keys in lscc namespace to make the cache full. This is to
-	// test the eviction.
-	batch = statedb.NewUpdateBatch()
-	for i := 0; i < lsccCacheSize; i++ {
-		batch.Put("lscc", "key"+strconv.Itoa(i), []byte("value"+strconv.Itoa(i)), version.NewHeight(1, 3))
-	}
-	savePoint = version.NewHeight(1, 3)
-	db.ApplyUpdates(batch, savePoint)
-
-	for i := 0; i < lsccCacheSize; i++ {
-		_, err := db.GetState("lscc", "key"+strconv.Itoa(i))
-		assert.NoError(t, err)
-	}
-	assert.Equal(t, true, db.(*VersionedDB).lsccStateCache.isCacheFull())
-
-	batch = statedb.NewUpdateBatch()
-	batch.Put("lscc", "key50", []byte("value1"), version.NewHeight(1, 4))
-	savePoint = version.NewHeight(1, 4)
-	db.ApplyUpdates(batch, savePoint)
-
-	// GetState() populates the cache after a eviction
-	valueFromDB, err = db.GetState("lscc", "key50")
-	assert.NoError(t, err)
-	valueFromCache = db.(*VersionedDB).lsccStateCache.getState("key50")
-	assert.Equal(t, valueFromCache, valueFromDB)
-	assert.Equal(t, true, db.(*VersionedDB).lsccStateCache.isCacheFull())
-}
-
 func TestApplyUpdatesWithNilHeight(t *testing.T) {
 	env := NewTestVDBEnv(t)
 	defer env.Cleanup()