github.com/matrixorigin/matrixone@v1.2.0/pkg/txn/storage/memorystorage/memorytable/tree.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 memorytable
    16  
    17  type Tree[
    18  	K Ordered[K],
    19  	V any,
    20  ] interface {
    21  	Copy() Tree[K, V]
    22  	Get(TreeNode[K, V]) (TreeNode[K, V], bool)
    23  	Set(TreeNode[K, V]) (TreeNode[K, V], bool)
    24  	Delete(TreeNode[K, V])
    25  	Iter() TreeIter[K, V]
    26  }
    27  
    28  type TreeNode[
    29  	K Ordered[K],
    30  	V any,
    31  ] struct {
    32  	IndexEntry *IndexEntry[K, V]
    33  	KVPair     *KVPair[K, V]
    34  }
    35  
    36  type TreeIter[
    37  	K Ordered[K],
    38  	V any,
    39  ] interface {
    40  	SeekIter[TreeNode[K, V]]
    41  }
    42  
    43  func compareTreeNode[
    44  	K Ordered[K],
    45  	V any,
    46  ](a, b TreeNode[K, V]) bool {
    47  	if a.KVPair != nil && b.KVPair != nil {
    48  		return compareKVPair(*a.KVPair, *b.KVPair)
    49  	}
    50  	if a.IndexEntry != nil && b.IndexEntry != nil {
    51  		return compareIndexEntry(a.IndexEntry, b.IndexEntry)
    52  	}
    53  	if a.KVPair != nil && b.IndexEntry != nil {
    54  		return true
    55  	}
    56  	if a.IndexEntry != nil && b.KVPair != nil {
    57  		return false
    58  	}
    59  	panic("impossible")
    60  }