func (r *rangeBuilder) buildFormBinOp(expr *expression.ScalarFunction) []rangePoint {
// This has been checked that the binary operation is comparison operation, and one of
// the operand is column name expression.
var value types.Datum
var op string
if v, ok := expr.Args[0].(*expression.Constant); ok {
value = v.Value
switch expr.FuncName.L {
case ast.GE:
op = ast.LE
case ast.GT:
op = ast.LT
case ast.LT:
op = ast.GT
case ast.LE:
op = ast.GE
default:
op = expr.FuncName.L
}
} else {
value = expr.Args[1].(*expression.Constant).Value
op = expr.FuncName.L
}
if value.IsNull() {
return nil
}
switch op {
case ast.EQ:
startPoint := rangePoint{value: value, start: true}
endPoint := rangePoint{value: value}
return []rangePoint{startPoint, endPoint}
case ast.NE:
startPoint1 := rangePoint{value: types.MinNotNullDatum(), start: true}
endPoint1 := rangePoint{value: value, excl: true}
startPoint2 := rangePoint{value: value, start: true, excl: true}
endPoint2 := rangePoint{value: types.MaxValueDatum()}
return []rangePoint{startPoint1, endPoint1, startPoint2, endPoint2}
case ast.LT:
startPoint := rangePoint{value: types.MinNotNullDatum(), start: true}
endPoint := rangePoint{value: value, excl: true}
return []rangePoint{startPoint, endPoint}
case ast.LE:
startPoint := rangePoint{value: types.MinNotNullDatum(), start: true}
endPoint := rangePoint{value: value}
return []rangePoint{startPoint, endPoint}
case ast.GT:
startPoint := rangePoint{value: value, start: true, excl: true}
endPoint := rangePoint{value: types.MaxValueDatum()}
return []rangePoint{startPoint, endPoint}
case ast.GE:
startPoint := rangePoint{value: value, start: true}
endPoint := rangePoint{value: types.MaxValueDatum()}
return []rangePoint{startPoint, endPoint}
}
return nil
}
func (r *rangeBuilder) buildFromPatternLike(x *ast.PatternLikeExpr) []rangePoint {
if x.Not {
// Pattern not like is not supported.
r.err = ErrUnsupportedType.Gen("NOT LIKE is not supported.")
return fullRange
}
pattern, err := types.ToString(x.Pattern.GetValue())
if err != nil {
r.err = errors.Trace(err)
return fullRange
}
lowValue := make([]byte, 0, len(pattern))
// unscape the pattern
var exclude bool
for i := 0; i < len(pattern); i++ {
if pattern[i] == x.Escape {
i++
if i < len(pattern) {
lowValue = append(lowValue, pattern[i])
} else {
lowValue = append(lowValue, x.Escape)
}
continue
}
if pattern[i] == '%' {
break
} else if pattern[i] == '_' {
exclude = true
break
}
lowValue = append(lowValue, pattern[i])
}
if len(lowValue) == 0 {
return []rangePoint{{value: types.MinNotNullDatum(), start: true}, {value: types.MaxValueDatum()}}
}
startPoint := rangePoint{start: true, excl: exclude}
startPoint.value.SetBytesAsString(lowValue)
highValue := make([]byte, len(lowValue))
copy(highValue, lowValue)
endPoint := rangePoint{excl: true}
for i := len(highValue) - 1; i >= 0; i-- {
highValue[i]++
if highValue[i] != 0 {
endPoint.value.SetBytesAsString(highValue)
break
}
if i == 0 {
endPoint.value = types.MaxValueDatum()
break
}
}
ranges := make([]rangePoint, 2)
ranges[0] = startPoint
ranges[1] = endPoint
return ranges
}
func (r *rangeBuilder) buildFromColumn(expr *expression.Column) []rangePoint {
// column name expression is equivalent to column name is true.
startPoint1 := rangePoint{value: types.MinNotNullDatum(), start: true}
endPoint1 := rangePoint{excl: true}
endPoint1.value.SetInt64(0)
startPoint2 := rangePoint{excl: true, start: true}
startPoint2.value.SetInt64(0)
endPoint2 := rangePoint{value: types.MaxValueDatum()}
return []rangePoint{startPoint1, endPoint1, startPoint2, endPoint2}
}
func (r *rangeBuilder) buildFromIsNull(x *ast.IsNullExpr) []rangePoint {
if x.Not {
startPoint := rangePoint{value: types.MinNotNullDatum(), start: true}
endPoint := rangePoint{value: types.MaxValueDatum()}
return []rangePoint{startPoint, endPoint}
}
startPoint := rangePoint{start: true}
endPoint := rangePoint{}
return []rangePoint{startPoint, endPoint}
}
func (r *rangeBuilder) buildFromIsTrue(expr *expression.ScalarFunction, isNot int) []rangePoint {
if isNot == 1 {
// NOT TRUE range is {[null null] [0, 0]}
startPoint1 := rangePoint{start: true}
endPoint1 := rangePoint{}
startPoint2 := rangePoint{start: true}
startPoint2.value.SetInt64(0)
endPoint2 := rangePoint{}
endPoint2.value.SetInt64(0)
return []rangePoint{startPoint1, endPoint1, startPoint2, endPoint2}
}
// TRUE range is {[-inf 0) (0 +inf]}
startPoint1 := rangePoint{value: types.MinNotNullDatum(), start: true}
endPoint1 := rangePoint{excl: true}
endPoint1.value.SetInt64(0)
startPoint2 := rangePoint{excl: true, start: true}
startPoint2.value.SetInt64(0)
endPoint2 := rangePoint{value: types.MaxValueDatum()}
return []rangePoint{startPoint1, endPoint1, startPoint2, endPoint2}
}
func (r *rangeBuilder) buildFromNot(expr *expression.ScalarFunction) []rangePoint {
switch n := expr.FuncName.L; n {
case ast.IsTruth:
return r.buildFromIsTrue(expr, 1)
case ast.IsFalsity:
return r.buildFromIsFalse(expr, 1)
case ast.In:
// Pattern not in is not supported.
r.err = ErrUnsupportedType.Gen("NOT IN is not supported")
return fullRange
case ast.Like:
// Pattern not like is not supported.
r.err = ErrUnsupportedType.Gen("NOT LIKE is not supported.")
return fullRange
case ast.IsNull:
startPoint := rangePoint{value: types.MinNotNullDatum(), start: true}
endPoint := rangePoint{value: types.MaxValueDatum()}
return []rangePoint{startPoint, endPoint}
}
return nil
}
func (r *rangeBuilder) buildFromIsTruth(x *ast.IsTruthExpr) []rangePoint {
if x.True != 0 {
if x.Not {
// NOT TRUE range is {[null null] [0, 0]}
startPoint1 := rangePoint{start: true}
endPoint1 := rangePoint{}
startPoint2 := rangePoint{start: true}
startPoint2.value.SetInt64(0)
endPoint2 := rangePoint{}
endPoint2.value.SetInt64(0)
return []rangePoint{startPoint1, endPoint1, startPoint2, endPoint2}
}
// TRUE range is {[-inf 0) (0 +inf]}
startPoint1 := rangePoint{value: types.MinNotNullDatum(), start: true}
endPoint1 := rangePoint{excl: true}
endPoint1.value.SetInt64(0)
startPoint2 := rangePoint{excl: true, start: true}
startPoint2.value.SetInt64(0)
endPoint2 := rangePoint{value: types.MaxValueDatum()}
return []rangePoint{startPoint1, endPoint1, startPoint2, endPoint2}
}
if x.Not {
startPoint1 := rangePoint{start: true}
endPoint1 := rangePoint{excl: true}
endPoint1.value.SetInt64(0)
startPoint2 := rangePoint{start: true, excl: true}
startPoint2.value.SetInt64(0)
endPoint2 := rangePoint{value: types.MaxValueDatum()}
return []rangePoint{startPoint1, endPoint1, startPoint2, endPoint2}
}
startPoint := rangePoint{start: true}
startPoint.value.SetInt64(0)
endPoint := rangePoint{}
endPoint.value.SetInt64(0)
return []rangePoint{startPoint, endPoint}
}
func (r *rangeBuilder) newBuildFromPatternLike(expr *expression.ScalarFunction) []rangePoint {
pattern, err := expr.Args[1].(*expression.Constant).Value.ToString()
if err != nil {
r.err = errors.Trace(err)
return fullRange
}
if pattern == "" {
startPoint := rangePoint{value: types.NewStringDatum(""), start: true}
endPoint := rangePoint{value: types.NewStringDatum("")}
return []rangePoint{startPoint, endPoint}
}
lowValue := make([]byte, 0, len(pattern))
escape := byte(expr.Args[2].(*expression.Constant).Value.GetInt64())
var exclude bool
isExactMatch := true
for i := 0; i < len(pattern); i++ {
if pattern[i] == escape {
i++
if i < len(pattern) {
lowValue = append(lowValue, pattern[i])
} else {
lowValue = append(lowValue, escape)
}
continue
}
if pattern[i] == '%' {
// Get the prefix.
isExactMatch = false
break
} else if pattern[i] == '_' {
// Get the prefix, but exclude the prefix.
// e.g., "abc_x", the start point exclude "abc",
// because the string length is more than 3.
exclude = true
isExactMatch = false
break
}
lowValue = append(lowValue, pattern[i])
}
if len(lowValue) == 0 {
return []rangePoint{{value: types.MinNotNullDatum(), start: true}, {value: types.MaxValueDatum()}}
}
if isExactMatch {
val := types.NewStringDatum(string(lowValue))
return []rangePoint{{value: val, start: true}, {value: val}}
}
startPoint := rangePoint{start: true, excl: exclude}
startPoint.value.SetBytesAsString(lowValue)
highValue := make([]byte, len(lowValue))
copy(highValue, lowValue)
endPoint := rangePoint{excl: true}
for i := len(highValue) - 1; i >= 0; i-- {
// Make the end point value more than the start point value,
// and the length of the end point value is the same as the length of the start point value.
// e.g., the start point value is "abc", so the end point value is "abd".
highValue[i]++
if highValue[i] != 0 {
endPoint.value.SetBytesAsString(highValue)
break
}
// If highValue[i] is 255 and highValue[i]++ is 0, then the end point value is max value.
if i == 0 {
endPoint.value = types.MaxValueDatum()
}
}
return []rangePoint{startPoint, endPoint}
}
func (r *rangeBuilder) buildFromBinop(x *ast.BinaryOperationExpr) []rangePoint {
if x.Op == opcode.OrOr {
return r.union(r.build(x.L), r.build(x.R))
} else if x.Op == opcode.AndAnd {
return r.intersection(r.build(x.L), r.build(x.R))
}
// This has been checked that the binary operation is comparison operation, and one of
// the operand is column name expression.
var value types.Datum
var op opcode.Op
if _, ok := x.L.(*ast.ValueExpr); ok {
value = types.NewDatum(x.L.GetValue())
switch x.Op {
case opcode.GE:
op = opcode.LE
case opcode.GT:
op = opcode.LT
case opcode.LT:
op = opcode.GT
case opcode.LE:
op = opcode.GE
default:
op = x.Op
}
} else {
value = types.NewDatum(x.R.GetValue())
op = x.Op
}
if value.IsNull() {
return nil
}
switch op {
case opcode.EQ:
startPoint := rangePoint{value: value, start: true}
endPoint := rangePoint{value: value}
return []rangePoint{startPoint, endPoint}
case opcode.NE:
startPoint1 := rangePoint{value: types.MinNotNullDatum(), start: true}
endPoint1 := rangePoint{value: value, excl: true}
startPoint2 := rangePoint{value: value, start: true, excl: true}
endPoint2 := rangePoint{value: types.MaxValueDatum()}
return []rangePoint{startPoint1, endPoint1, startPoint2, endPoint2}
case opcode.LT:
startPoint := rangePoint{value: types.MinNotNullDatum(), start: true}
endPoint := rangePoint{value: value, excl: true}
return []rangePoint{startPoint, endPoint}
case opcode.LE:
startPoint := rangePoint{value: types.MinNotNullDatum(), start: true}
endPoint := rangePoint{value: value}
return []rangePoint{startPoint, endPoint}
case opcode.GT:
startPoint := rangePoint{value: value, start: true, excl: true}
endPoint := rangePoint{value: types.MaxValueDatum()}
return []rangePoint{startPoint, endPoint}
case opcode.GE:
startPoint := rangePoint{value: value, start: true}
endPoint := rangePoint{value: types.MaxValueDatum()}
return []rangePoint{startPoint, endPoint}
}
return nil
}
func (r *rangeBuilder) buildFromScalarFunc(expr *expression.ScalarFunction) []rangePoint {
// TODO: It only implements the binary operation range building. And it needs to implement other scalar functions.
if len(expr.Args) != 2 {
return nil
}
if expr.FuncName.L == ast.OrOr {
return r.union(r.newBuild(expr.Args[0]), r.newBuild(expr.Args[1]))
}
if expr.FuncName.L == ast.AndAnd {
return r.intersection(r.newBuild(expr.Args[0]), r.newBuild(expr.Args[1]))
}
// This has been checked that the binary operation is comparison operation, and one of
// the operand is column name expression.
var value types.Datum
var op string
if v, ok := expr.Args[0].(*expression.Constant); ok {
value = v.Value
switch expr.FuncName.L {
case ast.GE:
op = ast.LE
case ast.GT:
op = ast.LT
case ast.LT:
op = ast.GT
case ast.LE:
op = ast.GE
default:
op = expr.FuncName.L
}
} else {
value = expr.Args[1].(*expression.Constant).Value
op = expr.FuncName.L
}
if value.IsNull() {
return nil
}
switch op {
case ast.EQ:
startPoint := rangePoint{value: value, start: true}
endPoint := rangePoint{value: value}
return []rangePoint{startPoint, endPoint}
case ast.NE:
startPoint1 := rangePoint{value: types.MinNotNullDatum(), start: true}
endPoint1 := rangePoint{value: value, excl: true}
startPoint2 := rangePoint{value: value, start: true, excl: true}
endPoint2 := rangePoint{value: types.MaxValueDatum()}
return []rangePoint{startPoint1, endPoint1, startPoint2, endPoint2}
case ast.LT:
startPoint := rangePoint{value: types.MinNotNullDatum(), start: true}
endPoint := rangePoint{value: value, excl: true}
return []rangePoint{startPoint, endPoint}
case ast.LE:
startPoint := rangePoint{value: types.MinNotNullDatum(), start: true}
endPoint := rangePoint{value: value}
return []rangePoint{startPoint, endPoint}
case ast.GT:
startPoint := rangePoint{value: value, start: true, excl: true}
endPoint := rangePoint{value: types.MaxValueDatum()}
return []rangePoint{startPoint, endPoint}
case ast.GE:
startPoint := rangePoint{value: value, start: true}
endPoint := rangePoint{value: types.MaxValueDatum()}
return []rangePoint{startPoint, endPoint}
}
return nil
}