github.com/tenywen/fabric@v1.0.0-beta.0.20170620030522-a5b1ed380643/core/ledger/kvledger/txmgmt/version/version.go (about) 1 /* 2 Copyright IBM Corp. 2016 All Rights Reserved. 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 version 18 19 import "github.com/hyperledger/fabric/common/ledger/util" 20 21 // Height represents the height of a transaction in blockchain 22 type Height struct { 23 BlockNum uint64 24 TxNum uint64 25 } 26 27 // NewHeight constructs a new instance of Height 28 func NewHeight(blockNum, txNum uint64) *Height { 29 return &Height{blockNum, txNum} 30 } 31 32 // NewHeightFromBytes constructs a new instance of Height from serialized bytes 33 func NewHeightFromBytes(b []byte) (*Height, int) { 34 blockNum, n1 := util.DecodeOrderPreservingVarUint64(b) 35 txNum, n2 := util.DecodeOrderPreservingVarUint64(b[n1:]) 36 return NewHeight(blockNum, txNum), n1 + n2 37 } 38 39 // ToBytes serializes the Height 40 func (h *Height) ToBytes() []byte { 41 blockNumBytes := util.EncodeOrderPreservingVarUint64(h.BlockNum) 42 txNumBytes := util.EncodeOrderPreservingVarUint64(h.TxNum) 43 return append(blockNumBytes, txNumBytes...) 44 } 45 46 // Compare return a -1, zero, or +1 based on whether this height is 47 // less than, equals to, or greater than the specified height respectively. 48 func (h *Height) Compare(h1 *Height) int { 49 res := 0 50 switch { 51 case h.BlockNum != h1.BlockNum: 52 res = int(h.BlockNum - h1.BlockNum) 53 break 54 case h.TxNum != h1.TxNum: 55 res = int(h.TxNum - h1.TxNum) 56 break 57 default: 58 return 0 59 } 60 if res > 0 { 61 return 1 62 } 63 return -1 64 } 65 66 // AreSame returns true if both the heights are either nil or equal 67 func AreSame(h1 *Height, h2 *Height) bool { 68 if h1 == nil { 69 return h2 == nil 70 } 71 if h2 == nil { 72 return false 73 } 74 return h1.Compare(h2) == 0 75 }