kv, table: use minimal kv interfaces

kv/index_iter.go

@@ -173,12 +173,12 @@ func (c *kvIndex) Create(rm RetrieverMutator, indexedValues []interface{}, h int
 }
 
 // Delete removes the entry for handle h and indexdValues from KV index.
-func (c *kvIndex) Delete(rm RetrieverMutator, indexedValues []interface{}, h int64) error {
+func (c *kvIndex) Delete(m Mutator, indexedValues []interface{}, h int64) error {
 	key, _, err := c.GenIndexKey(indexedValues, h)
 	if err != nil {
 		return errors.Trace(err)
 	}
-	err = rm.Delete(key)
+	err = m.Delete(key)
 	return errors.Trace(err)
 }
 
@@ -209,12 +209,12 @@ func (c *kvIndex) Drop(rm RetrieverMutator) error {
 }
 
 // Seek searches KV index for the entry with indexedValues.
-func (c *kvIndex) Seek(rm RetrieverMutator, indexedValues []interface{}) (iter IndexIterator, hit bool, err error) {
+func (c *kvIndex) Seek(r Retriever, indexedValues []interface{}) (iter IndexIterator, hit bool, err error) {
 	key, _, err := c.GenIndexKey(indexedValues, 0)
 	if err != nil {
 		return nil, false, errors.Trace(err)
 	}
-	it, err := rm.Seek(key)
+	it, err := r.Seek(key)
 	if err != nil {
 		return nil, false, errors.Trace(err)
 	}
@@ -227,9 +227,9 @@ func (c *kvIndex) Seek(rm RetrieverMutator, indexedValues []interface{}) (iter I
 }
 
 // SeekFirst returns an iterator which points to the first entry of the KV index.
-func (c *kvIndex) SeekFirst(rm RetrieverMutator) (iter IndexIterator, err error) {
+func (c *kvIndex) SeekFirst(r Retriever) (iter IndexIterator, err error) {
 	prefix := []byte(c.prefix)
-	it, err := rm.Seek(prefix)
+	it, err := r.Seek(prefix)
 	if err != nil {
 		return nil, errors.Trace(err)
 	}

kv/kv.go

@@ -252,17 +252,17 @@ type IndexIterator interface {
 // Index is the interface for index data on KV store.
 type Index interface {
 	// Create supports insert into statement.
-	Create(rw RetrieverMutator, indexedValues []interface{}, h int64) error
+	Create(rm RetrieverMutator, indexedValues []interface{}, h int64) error
 	// Delete supports delete from statement.
-	Delete(rw RetrieverMutator, indexedValues []interface{}, h int64) error
+	Delete(m Mutator, indexedValues []interface{}, h int64) error
 	// Drop supports drop table, drop index statements.
-	Drop(rw RetrieverMutator) error
+	Drop(rm RetrieverMutator) error
 	// Exist supports check index exists or not.
-	Exist(rw RetrieverMutator, indexedValues []interface{}, h int64) (bool, int64, error)
+	Exist(rm RetrieverMutator, indexedValues []interface{}, h int64) (bool, int64, error)
 	// GenIndexKey generates an index key.
 	GenIndexKey(indexedValues []interface{}, h int64) (key []byte, distinct bool, err error)
 	// Seek supports where clause.
-	Seek(rw RetrieverMutator, indexedValues []interface{}) (iter IndexIterator, hit bool, err error)
+	Seek(r Retriever, indexedValues []interface{}) (iter IndexIterator, hit bool, err error)
 	// SeekFirst supports aggregate min and ascend order by.
-	SeekFirst(rw RetrieverMutator) (iter IndexIterator, err error)
+	SeekFirst(r Retriever) (iter IndexIterator, err error)
 }

stmt/stmts/truncate.go

@@ -18,6 +18,7 @@
 package stmts
 
 import (
+	"github.com/juju/errors"
 	"github.com/pingcap/tidb/context"
 	"github.com/pingcap/tidb/rset"
 	"github.com/pingcap/tidb/stmt"
@@ -61,5 +62,9 @@ func (s *TruncateTableStmt) Exec(ctx context.Context) (rset.Recordset, error) {
 	if err != nil {
 		return nil, err
 	}
-	return nil, t.Truncate(ctx)
+	txn, err := ctx.GetTxn(false)
+	if err != nil {
+		return nil, errors.Trace(err)
+	}
+	return nil, t.Truncate(txn)
 }

table/table.go

@@ -76,7 +76,7 @@ type Table interface {
 	RecordKey(h int64, col *column.Col) []byte
 
 	// Truncate truncates the table.
-	Truncate(ctx context.Context) (err error)
+	Truncate(rm kv.RetrieverMutator) (err error)
 
 	// AddRecord inserts a row into the table. Is h is 0, it will alloc an unique id inside.
 	AddRecord(ctx context.Context, r []interface{}, h int64) (recordID int64, err error)

table/tables/tables.go

@@ -282,12 +282,12 @@ func (t *Table) FindIndexByColName(name string) *column.IndexedCol {
 }
 
 // Truncate implements table.Table Truncate interface.
-func (t *Table) Truncate(ctx context.Context) error {
-	err := util.DelKeyWithPrefix(ctx, t.KeyPrefix())
+func (t *Table) Truncate(rm kv.RetrieverMutator) error {
+	err := util.DelKeyWithPrefix(rm, t.KeyPrefix())
 	if err != nil {
 		return errors.Trace(err)
 	}
-	return util.DelKeyWithPrefix(ctx, t.IndexPrefix())
+	return util.DelKeyWithPrefix(rm, t.IndexPrefix())
 }
 
 // UpdateRecord implements table.Table UpdateRecord interface.

table/tables/tables_test.go

@@ -106,7 +106,7 @@ func (ts *testSuite) TestBasic(c *C) {
 	c.Assert(err, IsNil)
 	c.Assert(indexCnt(), Greater, 0)
 	// Make sure index data is also removed after tb.Truncate().
-	c.Assert(tb.Truncate(ctx), IsNil)
+	c.Assert(tb.Truncate(txn), IsNil)
 	c.Assert(indexCnt(), Equals, 0)
 
 	_, err = ts.se.Execute("drop table test.t")

util/prefix_helper.go

@@ -22,13 +22,12 @@ import (
 	"strings"
 
 	"github.com/juju/errors"
-	"github.com/pingcap/tidb/context"
 	"github.com/pingcap/tidb/kv"
 )
 
 // ScanMetaWithPrefix scans metadata with the prefix.
-func ScanMetaWithPrefix(txn kv.Transaction, prefix string, filter func([]byte, []byte) bool) error {
-	iter, err := txn.Seek([]byte(prefix))
+func ScanMetaWithPrefix(retriever kv.Retriever, prefix string, filter func([]byte, []byte) bool) error {
+	iter, err := retriever.Seek([]byte(prefix))
 	if err != nil {
 		return errors.Trace(err)
 	}
@@ -56,14 +55,9 @@ func ScanMetaWithPrefix(txn kv.Transaction, prefix string, filter func([]byte, [
 }
 
 // DelKeyWithPrefix deletes keys with prefix.
-func DelKeyWithPrefix(ctx context.Context, prefix string) error {
-	txn, err := ctx.GetTxn(false)
-	if err != nil {
-		return errors.Trace(err)
-	}
-
+func DelKeyWithPrefix(rm kv.RetrieverMutator, prefix string) error {
 	var keys []string
-	iter, err := txn.Seek([]byte(prefix))
+	iter, err := rm.Seek([]byte(prefix))
 	if err != nil {
 		return errors.Trace(err)
 	}
@@ -86,7 +80,7 @@ func DelKeyWithPrefix(ctx context.Context, prefix string) error {
 	}
 
 	for _, key := range keys {
-		err := txn.Delete([]byte(key))
+		err := rm.Delete([]byte(key))
 		if err != nil {
 			return errors.Trace(err)
 		}

util/prefix_helper_test.go

@@ -120,12 +120,14 @@ func (c *MockContext) FinishTxn(rollback bool) error {
 func (s *testPrefixSuite) TestPrefix(c *C) {
 	ctx := &MockContext{10000000, make(map[fmt.Stringer]interface{}), s.s, nil}
 	ctx.fillTxn()
-	err := DelKeyWithPrefix(ctx, string(encodeInt(ctx.prefix)))
+	txn, err := ctx.GetTxn(false)
+	c.Assert(err, IsNil)
+	err = DelKeyWithPrefix(txn, string(encodeInt(ctx.prefix)))
 	c.Assert(err, IsNil)
 	err = ctx.FinishTxn(false)
 	c.Assert(err, IsNil)
 
-	txn, err := s.s.Begin()
+	txn, err = s.s.Begin()
 	c.Assert(err, IsNil)
 	str := "key100jfowi878230"
 	err = txn.Set([]byte(str), []byte("val32dfaskli384757^*&%^"))