vitess.io/vitess@v0.16.2/go/vt/vttablet/tabletmanager/vreplication/shard_sorter.go (about) 1 /* 2 Copyright 2020 The Vitess Authors. 3 4 Licensed under the Apache License, Version 2.0 (the "License"); 5 you may not use this file except in compliance with the License. 6 You may obtain a copy of the License at 7 8 http://www.apache.org/licenses/LICENSE-2.0 9 10 Unless required by applicable law or agreed to in writing, software 11 distributed under the License is distributed on an "AS IS" BASIS, 12 WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 13 See the License for the specific language governing permissions and 14 limitations under the License. 15 */ 16 17 package vreplication 18 19 import "strings" 20 21 // ShardSorter implements a sort.Sort() function for sorting shard ranges 22 type ShardSorter []string 23 24 // Len implements the required interface for a sorting function 25 func (s ShardSorter) Len() int { 26 return len(s) 27 } 28 29 // Swap implements the required interface for a sorting function 30 func (s ShardSorter) Swap(i, j int) { 31 s[i], s[j] = s[j], s[i] 32 } 33 34 // Key returns the prefix of a shard range 35 func (s ShardSorter) Key(ind int) string { 36 return strings.Split(s[ind], "-")[0] 37 } 38 39 // Less implements the required interface for a sorting function 40 func (s ShardSorter) Less(i, j int) bool { 41 return s.Key(i) < s.Key(j) 42 }