Line data    Source code

       1             : /*
       2             :  * Copyright 2017 Dgraph Labs, Inc. and Contributors
       3             :  * Modifications copyright (C) 2017 Andy Kimball and Contributors
       4             :  *
       5             :  * Licensed under the Apache License, Version 2.0 (the "License");
       6             :  * you may not use this file except in compliance with the License.
       7             :  * You may obtain a copy of the License at
       8             :  *
       9             :  *     http://www.apache.org/licenses/LICENSE-2.0
      10             :  *
      11             :  * Unless required by applicable law or agreed to in writing, software
      12             :  * distributed under the License is distributed on an "AS IS" BASIS,
      13             :  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
      14             :  * See the License for the specific language governing permissions and
      15             :  * limitations under the License.
      16             :  */
      17             : 
      18             : package arenaskl
      19             : 
      20             : import "github.com/cockroachdb/pebble/internal/base"
      21             : 
      22             : // flushIterator is an iterator over the skiplist object. Use Skiplist.NewFlushIter
      23             : // to construct an iterator. The current state of the iterator can be cloned by
      24             : // simply value copying the struct.
      25             : type flushIterator struct {
      26             :         Iterator
      27             : }
      28             : 
      29             : // flushIterator implements the base.InternalIterator interface.
      30             : var _ base.InternalIterator = (*flushIterator)(nil)
      31             : 
      32           0 : func (it *flushIterator) String() string {
      33           0 :         return "memtable"
      34           0 : }
      35             : 
      36           0 : func (it *flushIterator) SeekGE(key []byte, flags base.SeekGEFlags) *base.InternalKV {
      37           0 :         panic("pebble: SeekGE unimplemented")
      38             : }
      39             : 
      40           0 : func (it *flushIterator) SeekPrefixGE(prefix, key []byte, flags base.SeekGEFlags) *base.InternalKV {
      41           0 :         panic("pebble: SeekPrefixGE unimplemented")
      42             : }
      43             : 
      44           0 : func (it *flushIterator) SeekLT(key []byte, flags base.SeekLTFlags) *base.InternalKV {
      45           0 :         panic("pebble: SeekLT unimplemented")
      46             : }
      47             : 
      48             : // First seeks position at the first entry in list. Returns the key and value
      49             : // if the iterator is pointing at a valid entry, and (nil, nil) otherwise. Note
      50             : // that First only checks the upper bound. It is up to the caller to ensure
      51             : // that key is greater than or equal to the lower bound.
      52           1 : func (it *flushIterator) First() *base.InternalKV {
      53           1 :         return it.Iterator.First()
      54           1 : }
      55             : 
      56             : // Next advances to the next position. Returns the key and value if the
      57             : // iterator is pointing at a valid entry, and (nil, nil) otherwise.
      58             : // Note: flushIterator.Next mirrors the implementation of Iterator.Next
      59             : // due to performance. Keep the two in sync.
      60           1 : func (it *flushIterator) Next() *base.InternalKV {
      61           1 :         it.nd = it.list.getNext(it.nd, 0)
      62           1 :         if it.nd == it.list.tail {
      63           1 :                 return nil
      64           1 :         }
      65           1 :         it.decodeKey()
      66           1 :         it.kv.V = base.MakeInPlaceValue(it.value())
      67           1 :         return &it.kv
      68             : }
      69             : 
      70           0 : func (it *flushIterator) NextPrefix(succKey []byte) *base.InternalKV {
      71           0 :         panic("pebble: NextPrefix unimplemented")
      72             : }
      73             : 
      74           0 : func (it *flushIterator) Prev() *base.InternalKV {
      75           0 :         panic("pebble: Prev unimplemented")
      76             : }