vendor fastCache to use as ledger cache

FastCache is chosen as the caching library.

FAB-15537 #done

Change-Id: I4733fa64872e5743f38d1dd46adf1fad6d70d59e
Signed-off-by: senthil <cendhu@gmail.com>

Author: cendhu

Gopkg.lock

@@ -188,3 +188,7 @@ noverify = [
 [[constraint]]
   branch = "master"
   name = "github.com/hyperledger/fabric-chaincode-go"
+
+[[constraint]]
+  name = "github.com/VictoriaMetrics/fastcache"
+  version = "1.4.6"

Gopkg.toml

@@ -0,0 +1,37 @@
+/*
+Copyright IBM Corp. All Rights Reserved.
+
+SPDX-License-Identifier: Apache-2.0
+*/
+
+package statedb
+
+import (
+	"github.com/VictoriaMetrics/fastcache"
+)
+
+// Cache holds both the system and user cache
+type Cache struct {
+	sysCache *fastcache.Cache
+	usrCache *fastcache.Cache
+}
+
+// New creates a Cache. The cache consists of both system state cache (for lscc, _lifecycle)
+// and user state cache (for all user deployed chaincodes). The size of the
+// system state cache is 64 MB, by default. The size of the user state cache, in terms of MB, is
+// specified via usrCacheSize parameter. Note that the fastcache allocates memory
+// only in the multiples of 32 MB (due to 512 buckets & an equal number of 64 KB chunks per bucket).
+// If the usrCacheSize is not a multiple of 32 MB, the fastcache would round the size
+// to the next multiple of 32 MB.
+func New(usrCacheSize int) *Cache {
+	cache := &Cache{}
+	// By default, 64 MB is allocated for the system cache
+	cache.sysCache = fastcache.New(64 * 1024 * 1024)
+
+	// User passed size is used to allocate memory for the user cache
+	if usrCacheSize <= 0 {
+		return cache
+	}
+	cache.usrCache = fastcache.New(usrCacheSize * 1024 * 1024)
+	return cache
+}

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

@@ -0,0 +1,30 @@
+/*
+Copyright IBM Corp. All Rights Reserved.
+
+SPDX-License-Identifier: Apache-2.0
+*/
+
+package statedb
+
+import (
+	"testing"
+
+	"github.com/VictoriaMetrics/fastcache"
+	"github.com/stretchr/testify/assert"
+)
+
+func TestNewCache(t *testing.T) {
+	cache := New(10)
+	expectedCache := &Cache{
+		sysCache: fastcache.New(64 * 1024 * 1024),
+		usrCache: fastcache.New(10 * 1024 * 1024),
+	}
+	assert.Equal(t, expectedCache, cache)
+
+	cache = New(0)
+	expectedCache = &Cache{
+		sysCache: fastcache.New(64 * 1024 * 1024),
+		usrCache: nil,
+	}
+	assert.Equal(t, expectedCache, cache)
+}