From a5ff9b41b8d828056c55f0f5410e673c652594a6 Mon Sep 17 00:00:00 2001
From: polyrabbit <mcx_221@foxmail.com>
Date: Thu, 26 Sep 2019 16:59:07 +0800
Subject: [PATCH] Make builtinCastTimeAsRealSig support vectorized evaluation

---
 expression/builtin_cast_vec.go      | 34 +++++++++++++++++++++++++++--
 expression/builtin_cast_vec_test.go |  1 +
 2 files changed, 33 insertions(+), 2 deletions(-)

diff --git a/expression/builtin_cast_vec.go b/expression/builtin_cast_vec.go
index 2fa60f5ea5df0..762b021642f41 100644
--- a/expression/builtin_cast_vec.go
+++ b/expression/builtin_cast_vec.go
@@ -258,11 +258,41 @@ func (b *builtinCastRealAsIntSig) vecEvalInt(input *chunk.Chunk, result *chunk.C
 }
 
 func (b *builtinCastTimeAsRealSig) vectorized() bool {
-	return false
+	return true
 }
 
 func (b *builtinCastTimeAsRealSig) vecEvalReal(input *chunk.Chunk, result *chunk.Column) error {
-	return errors.Errorf("not implemented")
+	n := input.NumRows()
+	buf, err := b.bufAllocator.get(types.ETDatetime, n)
+	if err != nil {
+		return err
+	}
+	defer b.bufAllocator.put(buf)
+	if err := b.args[0].VecEvalTime(b.ctx, input, buf); err != nil {
+		return err
+	}
+	result.ResizeFloat64(n, false)
+	result.MergeNulls(buf)
+	times := buf.Times()
+	f64s := result.Float64s()
+	for i := 0; i < n; i++ {
+		if result.IsNull(i) {
+			continue
+		}
+		f64, err := times[i].ToNumber().ToFloat64()
+		if err != nil {
+			if types.ErrOverflow.Equal(err) {
+				err = b.ctx.GetSessionVars().StmtCtx.HandleOverflow(err, err)
+			}
+			if err != nil {
+				return err
+			}
+			result.SetNull(i, true)
+			continue
+		}
+		f64s[i] = f64
+	}
+	return nil
 }
 
 func (b *builtinCastStringAsJSONSig) vectorized() bool {
diff --git a/expression/builtin_cast_vec_test.go b/expression/builtin_cast_vec_test.go
index bc7f517808432..82005ce27a158 100644
--- a/expression/builtin_cast_vec_test.go
+++ b/expression/builtin_cast_vec_test.go
@@ -28,6 +28,7 @@ var vecBuiltinCastCases = map[string][]vecExprBenchCase{
 		{retEvalType: types.ETDuration, childrenTypes: []types.EvalType{types.ETInt}, geners: []dataGenerator{new(randDurInt)}},
 		{retEvalType: types.ETReal, childrenTypes: []types.EvalType{types.ETReal}},
 		{retEvalType: types.ETReal, childrenTypes: []types.EvalType{types.ETDecimal}},
+		{retEvalType: types.ETReal, childrenTypes: []types.EvalType{types.ETDatetime}},
 	},
 }