github.com/matrixorigin/matrixone@v0.7.0/pkg/vm/engine/tae/logstore/store/index.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 store 16 17 import ( 18 "encoding/binary" 19 "fmt" 20 "io" 21 ) 22 23 type Index struct { 24 LSN uint64 25 CSN uint32 26 Size uint32 27 } 28 29 func NewIndex(lsn uint64, csn, size uint32) *Index { 30 return &Index{ 31 LSN: lsn, 32 CSN: csn, 33 Size: size, 34 } 35 } 36 37 func (index *Index) Compare(o *Index) int { 38 if index.LSN > o.LSN { 39 return 1 40 } else if index.LSN < o.LSN { 41 return -1 42 } 43 if index.CSN > o.CSN { 44 return 1 45 } else if index.CSN < o.CSN { 46 return -1 47 } 48 return 0 49 } 50 51 func (index *Index) WriteTo(w io.Writer) (n int64, err error) { 52 if err = binary.Write(w, binary.BigEndian, index.LSN); err != nil { 53 return 54 } 55 if err = binary.Write(w, binary.BigEndian, index.CSN); err != nil { 56 return 57 } 58 if err = binary.Write(w, binary.BigEndian, index.Size); err != nil { 59 return 60 } 61 n = 16 62 return 63 } 64 65 func (index *Index) ReadFrom(r io.Reader) (n int64, err error) { 66 if err = binary.Read(r, binary.BigEndian, &index.LSN); err != nil { 67 return 68 } 69 if err = binary.Read(r, binary.BigEndian, &index.CSN); err != nil { 70 return 71 } 72 if err = binary.Read(r, binary.BigEndian, &index.Size); err != nil { 73 return 74 } 75 n = 16 76 return 77 } 78 79 func (index *Index) Clone() *Index { 80 if index == nil { 81 return nil 82 } 83 return &Index{ 84 LSN: index.LSN, 85 CSN: index.CSN, 86 Size: index.Size, 87 } 88 } 89 func (index *Index) String() string { 90 if index == nil { 91 return "<nil index>" 92 } 93 return fmt.Sprintf("<Index[%d:%d/%d]>", index.LSN, index.CSN, index.Size) 94 }