github.com/matrixorigin/matrixone@v1.2.0/pkg/vm/engine/tae/iface/handle/iterator.go (about)

     1  // Copyright 2021 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 handle
    16  
    17  import (
    18  	"io"
    19  	"sync"
    20  
    21  	"github.com/matrixorigin/matrixone/pkg/common/moerr"
    22  )
    23  
    24  var (
    25  	ErrIteratorEnd = moerr.NewInternalErrorNoCtx("end of interator")
    26  )
    27  
    28  // Iterator TODO: this is not thread-safe
    29  type Iterator interface {
    30  	sync.Locker
    31  	RLock()
    32  	RUnlock()
    33  	io.Closer
    34  	Valid() bool
    35  	Next()
    36  	GetError() error
    37  }