store: correct comments mistake. (#9190)

store/mockstore/mocktikv/cluster.go

@@ -336,7 +336,7 @@ func (c *Cluster) splitRange(mvccStore MVCCStore, start, end MvccKey, count int)
 	c.createNewRegions(regionPairs, start, end)
 }
 
-// getPairsGroupByRegions groups the key value pairs into splitted regions.
+// getEntriesGroupByRegions groups the key value pairs into splitted regions.
 func (c *Cluster) getEntriesGroupByRegions(mvccStore MVCCStore, start, end MvccKey, count int) [][]Pair {
 	startTS := uint64(math.MaxUint64)
 	limit := int(math.MaxInt32)

store/mockstore/mocktikv/mvcc_leveldb.go

@@ -52,7 +52,10 @@ type MVCCLevelDB struct {
 	// NextKey_0       -- (11)
 	// ...
 	// EOF
+
+	// db represents leveldb
 	db *leveldb.DB
+	// mu used for lock
 	// leveldb can not guarantee multiple operations to be atomic, for example, read
 	// then write, another write may happen during it, so this lock is necessory.
 	mu sync.RWMutex
@@ -177,7 +180,7 @@ type lockDecoder struct {
 	expectKey []byte
 }
 
-// lockDecoder decodes the lock value if current iterator is at expectKey::lock.
+// Decode decodes the lock value if current iterator is at expectKey::lock.
 func (dec *lockDecoder) Decode(iter *Iterator) (bool, error) {
 	if iter.Error() != nil || !iter.Valid() {
 		return false, iter.Error()
@@ -210,7 +213,7 @@ type valueDecoder struct {
 	expectKey []byte
 }
 
-// valueDecoder decodes a mvcc value if iter key is expectKey.
+// Decode decodes a mvcc value if iter key is expectKey.
 func (dec *valueDecoder) Decode(iter *Iterator) (bool, error) {
 	if iter.Error() != nil || !iter.Valid() {
 		return false, iter.Error()
@@ -241,7 +244,7 @@ type skipDecoder struct {
 	currKey []byte
 }
 
-// skipDecoder skips the iterator as long as its key is currKey, the new key would be stored.
+// Decode skips the iterator as long as its key is currKey, the new key would be stored.
 func (dec *skipDecoder) Decode(iter *Iterator) (bool, error) {
 	if iter.Error() != nil {
 		return false, iter.Error()
@@ -262,11 +265,11 @@ func (dec *skipDecoder) Decode(iter *Iterator) (bool, error) {
 
 type mvccEntryDecoder struct {
 	expectKey []byte
-	// Just values and lock is valid.
+	// mvccEntry represents values and lock is valid.
 	mvccEntry
 }
 
-// mvccEntryDecoder decodes a mvcc entry.
+// Decode decodes a mvcc entry.
 func (dec *mvccEntryDecoder) Decode(iter *Iterator) (bool, error) {
 	ldec := lockDecoder{expectKey: dec.expectKey}
 	ok, err := ldec.Decode(iter)

store/mockstore/mocktikv/rpc.go

@@ -101,15 +101,15 @@ type rpcHandler struct {
 	cluster   *Cluster
 	mvccStore MVCCStore
 
-	// store id for current request
+	// storeID stores id for current request
 	storeID uint64
-	// Used for handling normal request.
+	// startKey is used for handling normal request.
 	startKey []byte
 	endKey   []byte
-	// Used for handling coprocessor request.
+	// rawStartKey is used for handling coprocessor request.
 	rawStartKey []byte
 	rawEndKey   []byte
-	// Used for current request.
+	// isolationLevel is used for current request.
 	isolationLevel kvrpcpb.IsolationLevel
 }
 

store/tikv/2pc.go

@@ -78,7 +78,7 @@ type twoPhaseCommitter struct {
 	syncLog  bool
 	connID   uint64 // connID is used for log.
 	cleanWg  sync.WaitGroup
-	// The max time a Txn may use (in ms) from its startTS to commitTS.
+	// maxTxnTimeUse represents max time a Txn may use (in ms) from its startTS to commitTS.
 	// We use it to guarantee GC worker will not influence any active txn. The value
 	// should be less than GC life time.
 	maxTxnTimeUse uint64

store/tikv/2pc_slow_test.go

@@ -17,6 +17,7 @@ package tikv
 
 import . "github.com/pingcap/check"
 
+// TestCommitMultipleRegions tests commit multiple regions.
 // The test takes too long under the race detector.
 func (s *testCommitterSuite) TestCommitMultipleRegions(c *C) {
 	m := make(map[string]string)

store/tikv/client.go

@@ -74,10 +74,10 @@ type Client interface {
 type connArray struct {
 	index uint32
 	v     []*grpc.ClientConn
-	// Bind with a background goroutine to process coprocessor streaming timeout.
+	// streamTimeout binds with a background goroutine to process coprocessor streaming timeout.
 	streamTimeout chan *tikvrpc.Lease
 
-	// For batch commands.
+	// batchCommandsCh used for batch commands.
 	batchCommandsCh        chan *batchCommandsEntry
 	batchCommandsClients   []*batchCommandsClient
 	tikvTransportLayerLoad uint64
@@ -90,9 +90,9 @@ type batchCommandsClient struct {
 	idAlloc                uint64
 	tikvTransportLayerLoad *uint64
 
-	// Indicates the batch client is closed explicitly or not.
+	// closed indicates the batch client is closed explicitly or not.
 	closed int32
-	// Protect client when re-create the streaming.
+	// clientLock protects client when re-create the streaming.
 	clientLock sync.Mutex
 }
 
@@ -302,7 +302,7 @@ type batchCommandsEntry struct {
 	req *tikvpb.BatchCommandsRequest_Request
 	res chan *tikvpb.BatchCommandsResponse_Response
 
-	// Indicated the request is canceled or not.
+	// canceled indicated the request is canceled or not.
 	canceled int32
 	err      error
 }

store/tikv/coprocessor.go

@@ -214,7 +214,7 @@ func (r *copRanges) toPBRanges() []*coprocessor.KeyRange {
 	return ranges
 }
 
-// Split ranges into (left, right) by key.
+// split ranges into (left, right) by key.
 func (r *copRanges) split(key []byte) (*copRanges, *copRanges) {
 	n := sort.Search(r.len(), func(i int) bool {
 		cur := r.at(i)
@@ -354,6 +354,7 @@ type copIterator struct {
 	req         *kv.Request
 	concurrency int
 	finishCh    chan struct{}
+	// closed represents when the Close is called.
 	// There are two cases we need to close the `finishCh` channel, one is when context is done, the other one is
 	// when the Close is called. we use atomic.CompareAndSwap `closed` to to make sure the channel is not closed twice.
 	closed uint32

store/tikv/delete_range_test.go

@@ -99,7 +99,7 @@ func deleteRangeFromMap(m map[string]string, startKey []byte, endKey []byte) {
 	}
 }
 
-// testDeleteRangeOnce does delete range on both the map and the storage, and assert they are equal after deleting
+// mustDeleteRange does delete range on both the map and the storage, and assert they are equal after deleting
 func (s *testDeleteRangeSuite) mustDeleteRange(c *C, startKey []byte, endKey []byte, expected map[string]string) {
 	s.deleteRange(c, startKey, endKey)
 	deleteRangeFromMap(expected, startKey, endKey)

store/tikv/gcworker/gc_worker.go

@@ -230,7 +230,7 @@ func (w *GCWorker) storeIsBootstrapped() bool {
 	return ver > notBootstrappedVer
 }
 
-// Leader of GC worker checks if it should start a GC job every tick.
+// leaderTick of GC worker checks if it should start a GC job every tick.
 func (w *GCWorker) leaderTick(ctx context.Context) error {
 	if w.gcIsRunning {
 		log.Infof("[gc worker] leaderTick on %s: there's already a gc job running. skipped.", w.uuid)
@@ -437,7 +437,7 @@ func (w *GCWorker) runGCJob(ctx context.Context, safePoint uint64) {
 	w.done <- nil
 }
 
-// `deleteRanges` processes all delete range records whose ts < safePoint in table `gc_delete_range`
+// deleteRanges processes all delete range records whose ts < safePoint in table `gc_delete_range`
 func (w *GCWorker) deleteRanges(ctx context.Context, safePoint uint64) error {
 	metrics.GCWorkerCounter.WithLabelValues("delete_range").Inc()
 
@@ -470,7 +470,7 @@ func (w *GCWorker) deleteRanges(ctx context.Context, safePoint uint64) error {
 	return nil
 }
 
-// `redoDeleteRanges` checks all deleted ranges whose ts is at least `lifetime + 24h` ago. See TiKV RFC #2.
+// redoDeleteRanges checks all deleted ranges whose ts is at least `lifetime + 24h` ago. See TiKV RFC #2.
 func (w *GCWorker) redoDeleteRanges(ctx context.Context, safePoint uint64) error {
 	metrics.GCWorkerCounter.WithLabelValues("redo_delete_range").Inc()
 
@@ -729,7 +729,7 @@ type gcTaskWorker struct {
 	store      tikv.Storage
 	taskCh     chan *gcTask
 	wg         *sync.WaitGroup
-	// use atomic to read and set
+	// successRegions and failedRegions use atomic to read and set.
 	successRegions *int32
 	failedRegions  *int32
 }
@@ -801,6 +801,7 @@ func (w *gcTaskWorker) doGCForRange(startKey []byte, endKey []byte, safePoint ui
 	return nil
 }
 
+// doGCForRegion used for gc for region.
 // these two errors should not return together, for more, see the func 'doGC'
 func (w *gcTaskWorker) doGCForRegion(bo *tikv.Backoffer, safePoint uint64, region tikv.RegionVerID) (*errorpb.Error, error) {
 	req := &tikvrpc.Request{

store/tikv/isolation_test.go

@@ -27,6 +27,7 @@ import (
 	"github.com/pingcap/tidb/kv"
 )
 
+// testIsolationSuite represents test isolation suite.
 // The test suite takes too long under the race detector.
 type testIsolationSuite struct {
 	OneByOneSuite

store/tikv/latch/latch.go

@@ -45,14 +45,15 @@ type latch struct {
 // Lock is the locks' information required for a transaction.
 type Lock struct {
 	keys [][]byte
+	// requiredSlots represents required slots.
 	// The slot IDs of the latches(keys) that a startTS must acquire before being able to processed.
 	requiredSlots []int
-	// The number of latches that the transaction has acquired. For status is stale, it include the
-	// latch whose front is current lock already.
+	// acquiredCount represents the number of latches that the transaction has acquired.
+	// For status is stale, it include the latch whose front is current lock already.
 	acquiredCount int
-	// Current transaction's startTS.
+	// startTS represents current transaction's.
 	startTS uint64
-	// Current transaction's commitTS.
+	// commitTS represents current transaction's.
 	commitTS uint64
 
 	wg      sync.WaitGroup

store/tikv/pd_codec.go

@@ -40,7 +40,7 @@ func (c *codecPDClient) GetPrevRegion(ctx context.Context, key []byte) (*metapb.
 	return processRegionResult(region, peer, err)
 }
 
-// GetRegion encodes the key before send requests to pd-server and decodes the
+// GetRegionByID encodes the key before send requests to pd-server and decodes the
 // returned StartKey && EndKey from pd-server.
 func (c *codecPDClient) GetRegionByID(ctx context.Context, regionID uint64) (*metapb.Region, *metapb.Peer, error) {
 	region, peer, err := c.Client.GetRegionByID(ctx, regionID)

store/tikv/region_request_test.go

@@ -159,7 +159,7 @@ func (c *cancelContextClient) SendRequest(ctx context.Context, addr string, req
 // mockTikvGrpcServer mock a tikv gprc server for testing.
 type mockTikvGrpcServer struct{}
 
-// KV commands with mvcc/txn supported.
+// KvGet commands with mvcc/txn supported.
 func (s *mockTikvGrpcServer) KvGet(context.Context, *kvrpcpb.GetRequest) (*kvrpcpb.GetResponse, error) {
 	return nil, errors.New("unreachable")
 }