distsql: Unify endian for Chunk encode format

distsql/distsql.go

@@ -16,6 +16,7 @@ package distsql
 import (
 	"context"
 	"fmt"
+	"unsafe"
 
 	"github.com/opentracing/opentracing-go"
 	"github.com/pingcap/errors"
@@ -146,6 +147,7 @@ func Checksum(ctx context.Context, client kv.Client, kvReq *kv.Request, vars *kv
 func SetEncodeType(ctx sessionctx.Context, dagReq *tipb.DAGRequest) {
 	if canUseChunkRPC(ctx) {
 		dagReq.EncodeType = tipb.EncodeType_TypeChunk
+		setChunkMemoryLayout(dagReq)
 	} else {
 		dagReq.EncodeType = tipb.EncodeType_TypeDefault
 	}
@@ -158,5 +160,41 @@ func canUseChunkRPC(ctx sessionctx.Context) bool {
 	if ctx.GetSessionVars().EnableStreaming {
 		return false
 	}
+	if !checkAlignment() {
+		return false
+	}
 	return true
 }
+
+var supportedAlignment = !(unsafe.Sizeof(types.MysqlTime{}) != 16 ||
+	unsafe.Sizeof(types.Time{}) != 20 ||
+	unsafe.Sizeof(types.MyDecimal{}) != 40)
+
+// checkAlignment checks the alignment in current system environment.
+// The alignment is influenced by system, machine and Golang version.
+// Using this function can guarantee the alignment is we want.
+func checkAlignment() bool {
+	return supportedAlignment
+}
+
+var systemEndian tipb.Endian
+
+// setChunkMemoryLayout sets the chunk memory layout for the DAGRequest.
+func setChunkMemoryLayout(dagReq *tipb.DAGRequest) {
+	dagReq.ChunkMemoryLayout = &tipb.ChunkMemoryLayout{Endian: GetSystemEndian()}
+}
+
+// GetSystemEndian gets the system endian.
+func GetSystemEndian() tipb.Endian {
+	return systemEndian
+}
+
+func init() {
+	var i int = 0x0100
+	ptr := unsafe.Pointer(&i)
+	if 0x01 == *(*byte)(ptr) {
+		systemEndian = tipb.Endian_BigEndian
+	} else {
+		systemEndian = tipb.Endian_LittleEndian
+	}
+}

go.mod

@@ -40,7 +40,7 @@ require (
 	github.com/pingcap/pd v1.1.0-beta.0.20190923032047-5c648dc365e0
 	github.com/pingcap/sysutil v0.0.0-20191126040022-986c5b3ed9a3
 	github.com/pingcap/tidb-tools v3.0.6-0.20191106033616-90632dda3863+incompatible
-	github.com/pingcap/tipb v0.0.0-20191120020146-6161b015e21e
+	github.com/pingcap/tipb v0.0.0-20191127084114-0820b784842f
 	github.com/prometheus/client_golang v1.0.0
 	github.com/prometheus/client_model v0.0.0-20190812154241-14fe0d1b01d4
 	github.com/remyoudompheng/bigfft v0.0.0-20190512091148-babf20351dd7 // indirect

go.sum

@@ -194,8 +194,8 @@ github.com/pingcap/sysutil v0.0.0-20191126040022-986c5b3ed9a3 h1:HCNif3lukL83gNC
 github.com/pingcap/sysutil v0.0.0-20191126040022-986c5b3ed9a3/go.mod h1:Futrrmuw98pEsbEmoPsjw8aKLCmixwHEmT2rF+AsXGw=
 github.com/pingcap/tidb-tools v3.0.6-0.20191106033616-90632dda3863+incompatible h1:H1jg0aDWz2SLRh3hNBo2HFtnuHtudIUvBumU7syRkic=
 github.com/pingcap/tidb-tools v3.0.6-0.20191106033616-90632dda3863+incompatible/go.mod h1:XGdcy9+yqlDSEMTpOXnwf3hiTeqrV6MN/u1se9N8yIM=
-github.com/pingcap/tipb v0.0.0-20191120020146-6161b015e21e h1:OWgXsJ2Zwa+q+sqi87fGuNda+ChJrclVd7wiGP5Epps=
-github.com/pingcap/tipb v0.0.0-20191120020146-6161b015e21e/go.mod h1:RtkHW8WbcNxj8lsbzjaILci01CtYnYbIkQhjyZWrWVI=
+github.com/pingcap/tipb v0.0.0-20191127084114-0820b784842f h1:ywyH6JKJIf+gEYg2kRlU8SaPMryHgu5SoXKtPdkeZPU=
+github.com/pingcap/tipb v0.0.0-20191127084114-0820b784842f/go.mod h1:RtkHW8WbcNxj8lsbzjaILci01CtYnYbIkQhjyZWrWVI=
 github.com/pkg/errors v0.8.0/go.mod h1:bwawxfHBFNV+L2hUp1rHADufV3IMtnDRdf1r5NINEl0=
 github.com/pkg/errors v0.8.1 h1:iURUrRGxPUNPdy5/HRSm+Yj6okJ6UtLINN0Q9M4+h3I=
 github.com/pkg/errors v0.8.1/go.mod h1:bwawxfHBFNV+L2hUp1rHADufV3IMtnDRdf1r5NINEl0=

store/mockstore/mocktikv/cop_handler_dag.go

@@ -28,6 +28,7 @@ import (
 	"github.com/pingcap/parser/model"
 	"github.com/pingcap/parser/mysql"
 	"github.com/pingcap/parser/terror"
+	"github.com/pingcap/tidb/distsql"
 	"github.com/pingcap/tidb/expression"
 	"github.com/pingcap/tidb/expression/aggregation"
 	"github.com/pingcap/tidb/kv"
@@ -574,6 +575,9 @@ func (h *rpcHandler) fillUpData4SelectResponse(selResp *tipb.SelectResponse, dag
 	case tipb.EncodeType_TypeDefault:
 		h.encodeDefault(selResp, rows, dagReq.OutputOffsets)
 	case tipb.EncodeType_TypeChunk:
+		if dagReq.GetChunkMemoryLayout().GetEndian() != distsql.GetSystemEndian() {
+			return errors.Errorf("Mocktikv endian must be the same as TiDB system endian.")
+		}
 		colTypes := h.constructRespSchema(dagCtx)
 		loc := dagCtx.evalCtx.sc.TimeZone
 		err := h.encodeChunk(selResp, rows, colTypes, dagReq.OutputOffsets, loc)