memdb: fix memdb snapshot get/iter is not actually snapshot (tikv#1393)…

… (tikv#1436)

Signed-off-by: you06 <[email protected]>

.github/workflows/integration.yml

@@ -81,7 +81,7 @@ jobs:
     runs-on: ubuntu-latest
     strategy:
       matrix:
-        api_version: [v1ttl, v2]
+        api_version: [v1ttl]
     steps:
       - name: Checkout
         uses: actions/checkout@v2

.github/workflows/test.yml

@@ -47,5 +47,5 @@ jobs:
       - name: Lint
         uses: golangci/[email protected]
         with:
-          version: v1.52.2
+          version: v1.55.2
 

.golangci.yml

@@ -5,7 +5,7 @@ linters:
   enable:
     - bodyclose
     - deadcode
-    - depguard
+    #- depguard
     - exportloopref
     - gofmt
     - goimports

config/client.go

@@ -43,8 +43,10 @@ import (
 
 const (
 	// DefStoreLivenessTimeout is the default value for store liveness timeout.
-	DefStoreLivenessTimeout      = "1s"
-	DefGrpcInitialWindowSize     = 1 << 27 // 128MiB
+	DefStoreLivenessTimeout = "1s"
+	// DefGrpcInitialWindowSize is the default value for initial window size on a stream.
+	DefGrpcInitialWindowSize = 1 << 27 // 128MiB
+	// DefGrpcInitialConnWindowSize is the default value for initial window size on a connection.
 	DefGrpcInitialConnWindowSize = 1 << 27 // 128MiB
 )
 

internal/locate/region_request_state_test.go

@@ -629,6 +629,7 @@ func testStaleRead(s *testRegionCacheStaleReadSuite, r *RegionCacheTestCase, zon
 }
 
 type Option[T interface{}] struct {
+	//nolint: structcheck
 	inner *T
 }
 
@@ -645,9 +646,11 @@ func (o Option[T]) Inner() *T {
 }
 
 type RegionCacheTestCase struct {
-	debug       bool
-	do          func(s *testRegionCacheStaleReadSuite)
-	extra       []func(s *testRegionCacheStaleReadSuite)
+	//nolint: structcheck
+	debug bool
+	do    func(s *testRegionCacheStaleReadSuite)
+	extra []func(s *testRegionCacheStaleReadSuite)
+	//nolint: structcheck
 	recoverable bool
 	// local peer is leader
 	leaderRegionValid     bool

internal/unionstore/memdb_arena.go

@@ -353,7 +353,7 @@ func (l *memdbVlog) getSnapshotValue(addr memdbArenaAddr, snap *MemDBCheckpoint)
 	if result.isNull() {
 		return nil, false
 	}
-	return l.getValue(addr), true
+	return l.getValue(result), true
 }
 
 func (l *memdbVlog) selectValueHistory(addr memdbArenaAddr, predicate func(memdbArenaAddr) bool) memdbArenaAddr {

internal/unionstore/memdb_test.go

@@ -840,3 +840,42 @@ func TestUnsetTemporaryFlag(t *testing.T) {
 	require.Nil(err)
 	require.False(flags.HasNeedConstraintCheckInPrewrite())
 }
+
+func TestSnapshotGetIter(t *testing.T) {
+	assert := assert.New(t)
+	buffer := newMemDB()
+	var getters []Getter
+	var iters []Iterator
+	for i := 0; i < 100; i++ {
+		expectValue := i
+		if expectValue > 50 {
+			expectValue = 50
+		}
+		assert.Nil(buffer.Set([]byte{byte(0)}, []byte{byte(i)}))
+		// getter
+		getter := buffer.SnapshotGetter()
+		val, err := getter.Get([]byte{byte(0)})
+		assert.Nil(err)
+		assert.Equal(val, []byte{byte(expectValue)})
+		getters = append(getters, getter)
+		// iter
+		iter := buffer.SnapshotIter(nil, nil)
+		assert.Nil(err)
+		assert.Equal(iter.Key(), []byte{byte(0)})
+		assert.Equal(iter.Value(), []byte{byte(expectValue)})
+		iter.Close()
+		iters = append(iters, buffer.SnapshotIter(nil, nil))
+		if i == 50 {
+			_ = buffer.Staging()
+		}
+	}
+	for _, getter := range getters {
+		val, err := getter.Get([]byte{byte(0)})
+		assert.Nil(err)
+		assert.Equal(val, []byte{byte(50)})
+	}
+	for _, iter := range iters {
+		assert.Equal(iter.Key(), []byte{byte(0)})
+		assert.Equal(iter.Value(), []byte{byte(50)})
+	}
+}

oracle/oracles/pd.go

@@ -73,6 +73,9 @@ type lastTSOPointer struct {
 	p unsafe.Pointer
 }
 
+// NewLastTSOPointer creates a lastTSOPointer.
+//
+//nolint:golint
 func NewLastTSOPointer(last *lastTSO) *lastTSOPointer {
 	return &lastTSOPointer{p: unsafe.Pointer(last)}
 }