github.com/matrixorigin/matrixone@v1.2.0/pkg/sql/colexec/value_scan/value_scan.go (about)

     1  // Copyright 2021-2023 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 value_scan
    16  
    17  import (
    18  	"bytes"
    19  
    20  	"github.com/matrixorigin/matrixone/pkg/vm"
    21  	"github.com/matrixorigin/matrixone/pkg/vm/process"
    22  )
    23  
    24  const argName = "value_scan"
    25  
    26  func (arg *Argument) String(buf *bytes.Buffer) {
    27  	buf.WriteString(argName)
    28  	buf.WriteString(": value_scan ")
    29  }
    30  
    31  func (arg *Argument) Prepare(proc *process.Process) (err error) {
    32  	return nil
    33  }
    34  
    35  func (arg *Argument) Call(proc *process.Process) (vm.CallResult, error) {
    36  	if err, isCancel := vm.CancelCheck(proc); isCancel {
    37  		return vm.CancelResult, err
    38  	}
    39  
    40  	result := vm.NewCallResult()
    41  
    42  	//select {
    43  	//case <-proc.Ctx.Done():
    44  	//	result.Status = vm.ExecStop
    45  	//	return result, proc.Ctx.Err()
    46  	//default:
    47  	//}
    48  
    49  	if arg.idx < len(arg.Batchs) {
    50  		result.Batch = arg.Batchs[arg.idx]
    51  		if arg.idx > 0 {
    52  			proc.PutBatch(arg.Batchs[arg.idx-1])
    53  			arg.Batchs[arg.idx-1] = nil
    54  		}
    55  		arg.idx += 1
    56  	}
    57  
    58  	return result, nil
    59  }