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

     1  // Copyright 2021 - 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 multi
    16  
    17  import (
    18  	"github.com/matrixorigin/matrixone/pkg/container/nulls"
    19  	"github.com/matrixorigin/matrixone/pkg/container/types"
    20  	"github.com/matrixorigin/matrixone/pkg/container/vector"
    21  	"github.com/matrixorigin/matrixone/pkg/vm/process"
    22  )
    23  
    24  func Concat(vectors []*vector.Vector, proc *process.Process) (*vector.Vector, error) {
    25  	resultType := types.Type{Oid: types.T_varchar, Size: 24, Width: types.MaxVarcharLen}
    26  	isAllConst := true
    27  
    28  	for i := range vectors {
    29  		if vectors[i].IsScalarNull() {
    30  			return proc.AllocScalarNullVector(resultType), nil
    31  		}
    32  		if !vectors[i].IsScalar() {
    33  			isAllConst = false
    34  		}
    35  	}
    36  	if isAllConst {
    37  		return concatWithAllConst(vectors, proc)
    38  	}
    39  	return concatWithSomeCols(vectors, proc)
    40  }
    41  
    42  func concatWithAllConst(vectors []*vector.Vector, proc *process.Process) (*vector.Vector, error) {
    43  	length := vector.Length(vectors[0])
    44  	vct := types.T_varchar.ToType()
    45  	res := ""
    46  	for i := range vectors {
    47  		res += vectors[i].GetString(0)
    48  	}
    49  	return vector.NewConstString(vct, length, res, proc.Mp()), nil
    50  }
    51  
    52  func concatWithSomeCols(vectors []*vector.Vector, proc *process.Process) (*vector.Vector, error) {
    53  	length := vector.Length(vectors[0])
    54  	vct := types.T_varchar.ToType()
    55  	nsp := new(nulls.Nulls)
    56  	val := make([]string, length)
    57  	for i := 0; i < length; i++ {
    58  		for j := range vectors {
    59  			if nulls.Contains(vectors[j].Nsp, uint64(i)) {
    60  				nulls.Add(nsp, uint64(i))
    61  				break
    62  			}
    63  			if vectors[j].IsScalar() {
    64  				val[i] += vectors[j].GetString(int64(0))
    65  			} else {
    66  				val[i] += vectors[j].GetString(int64(i))
    67  			}
    68  		}
    69  	}
    70  	return vector.NewWithStrings(vct, val, nsp, proc.Mp()), nil
    71  }