github.com/matrixorigin/matrixone@v0.7.0/pkg/sql/plan/function/builtin/binary/left.go (about)

     1  // Copyright 2022 Matrix Origin
     2  //
     3  // Licensed under the Apache License, Version 2.0 (the "License");
     4  // you may not use this file except in compliance with the License.
     5  // You may obtain a copy of the License at
     6  //
     7  //      http://www.apache.org/licenses/LICENSE-2.0
     8  //
     9  // Unless required by applicable law or agreed to in writing, software
    10  // distributed under the License is distributed on an "AS IS" BASIS,
    11  // WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
    12  // See the License for the specific language governing permissions and
    13  // limitations under the License.
    14  
    15  package binary
    16  
    17  import (
    18  	"github.com/matrixorigin/matrixone/pkg/container/nulls"
    19  	"github.com/matrixorigin/matrixone/pkg/container/vector"
    20  	"github.com/matrixorigin/matrixone/pkg/vectorize/left"
    21  	"github.com/matrixorigin/matrixone/pkg/vm/process"
    22  )
    23  
    24  func Left(vs []*vector.Vector, proc *process.Process) (*vector.Vector, error) {
    25  	leftVec := vs[0]
    26  	rightVec := vs[1]
    27  
    28  	if leftVec.IsScalarNull() || rightVec.IsScalarNull() {
    29  		return proc.AllocScalarNullVector(leftVec.Typ), nil
    30  	}
    31  	strValues := vector.MustStrCols(leftVec)
    32  	lengthValues := vector.MustTCols[int64](rightVec)
    33  
    34  	if leftVec.IsScalar() && rightVec.IsScalar() {
    35  		resultValues := make([]string, 1)
    36  		left.LeftAllConst(strValues, lengthValues, resultValues)
    37  		resultVector := vector.NewConstString(leftVec.Typ, 1, resultValues[0], proc.Mp())
    38  		return resultVector, nil
    39  	} else if leftVec.IsScalar() && !rightVec.IsScalar() {
    40  		resultValues := make([]string, len(lengthValues))
    41  		left.LeftLeftConst(strValues, lengthValues, resultValues)
    42  		resultVector := vector.NewWithStrings(leftVec.Typ, resultValues, rightVec.Nsp, proc.Mp())
    43  		return resultVector, nil
    44  	} else if !leftVec.IsScalar() && rightVec.IsScalar() {
    45  		resultValues := make([]string, len(strValues))
    46  		left.LeftRightConst(strValues, lengthValues, resultValues)
    47  		resultVector := vector.NewWithStrings(leftVec.Typ, resultValues, leftVec.Nsp, proc.Mp())
    48  		return resultVector, nil
    49  	} else {
    50  		resultValues := make([]string, len(strValues))
    51  		left.Left(strValues, lengthValues, resultValues)
    52  		resultNsp := nulls.NewWithSize(len(strValues))
    53  		nulls.Or(leftVec.Nsp, rightVec.Nsp, resultNsp)
    54  		resultVector := vector.NewWithStrings(leftVec.Typ, resultValues, resultNsp, proc.Mp())
    55  		return resultVector, nil
    56  	}
    57  }