Ethereum Smart Contract Development in Solidity

337 Pages·2021·7.645 MB·English

by  Gavin Zheng, Longxiang Gao, Liqun Huang, Jian Guan

Gavin Zheng
Longxiang Gao
Liqun Huang
Jian Guan
Ethereum
Smart Contract
Development
in Solidity
Ethereum Smart Contract Development in Solidity
(cid:129) (cid:129) (cid:129)
Gavin Zheng Longxiang Gao Liqun Huang
Jian Guan
Ethereum Smart Contract
Development in Solidity
GavinZheng LongxiangGao
NenglianTechnologyCo.Ltd. SchoolofInformationTechnology
Beijing,China DeakinUniversity
Burwood,VIC,Australia
LiqunHuang JianGuan
HuazhongUniversityofScience MuhuaTechnologyCo.Ltd.
andTechnology Beijing,China
Wuhan,Hubei,China
ISBN978-981-15-6217-4 ISBN978-981-15-6218-1 (eBook)
https://doi.org/10.1007/978-981-15-6218-1
©SpringerNatureSingaporePteLtd.2021
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Preface
Smart contract isoneofthecornerstonesofblockchain technology. Amongallthe
smart contract programming languages in market (such as Viper, Bamboo, etc.),
Solidity running on Ethereum Virtual Machine (EVM) is the most popular one in
termsofnumberofusers,developercommunity,scopeofuse,numberofcontracts
in use, and the public recognition. This book introduces the Solidity programming
languagefromscratchandexplainsthecorefeaturesofSolidityindetail.
About the Book Structure
Thebookisorganizedinanorderlywayasbelow:
PartI:Preliminary
Chapter1:ConceptsandtermsofEthereum
Chapter2:ConfigurationandinstallationofSoliditydevelopmentenvironment
PartII:SolidityBasics
Chapter3:BasicsofSolidity:keywords,statements,modifiers,etc.
Chapter4:PopularEthereumRequestforComments(ERC)protocols
PartIII:SolidityAdvancedTopics
Chapter5:ABIspecificationandcoding
Chapter 6: Advanced topics of Solidity programming: design pattern, GAS,
assembly
Chapter7:Upgradeablesmartcontractdesignandimplementation
Chapter8:SecurityofSolidityprogrammingandbestpractice
PartIV:Application
Chapter9:DecentralizedApplication(DApp)programmingtechnique
Chapter10:Testinganddebugging
PartV:Prospect
Chapter 11: Primer of Web Assembly programming which is believed to be the
future
v
vi Preface
InPartI,Chap.1introducesallthebasicconceptsandtermsofEthereumusedin
the book for understanding of subsequent content; you can skip it if you already
know them well. And Chap. 2 tells you how to set up Solidity development and
testing environment. After all the preparation work being done, Part II guides you
throughSoliditylanguagedetailsandcodingsimplecontracts.Todevelopcomplex
contracts, Part III collects all the information you need: interface, design pattern,
GAS, assembly, upgrade, security, and best practices. In Part IV, the authors shed
some light on developing DApp which showcases how to interact with Solidity
contract.Atlast,thebookalsoexploresWASMalittlebit,whichisthoughttobea
futurestarinsmartcontractprogramming.
Beijing,China GavinZheng
Burwood,VIC,Australia LongxiangGao
Wuhan,Hubei,China LiqunHuang
Beijing,China JianGuan
April,2020
Intended Audience
Thebookisintendedforreaderswithpriorexperienceofusingatleastoneobject-
oriented programming language (e.g., C++, Java, etc.). If you have a solid under-
standing of object-oriented concepts, such as inheritance, polymorphism, etc., and
you desire to jump into the blockchain industry and ramp up on smart contract
developmentonEthereumplatform,thisbookisthebestfitforyou.Steppingfrom
thisbook,thereadersshoulddivedeepintoEthereumVirtualMachine(EVM)and
WebAssembly(WASM)forcontinuingstudy.
vii
Acknowledgement
I would like to thank the co-authors: Dr. Jian Guan—CTO of xuetangx.com,
Dr. Longxiang Gao at Deakin University, Geelong, VIC, Australia, and Associate
Professor Liqun Huang at Huazhong University of Science and Technology
(HUST), Wuhan, PRC, for their valuable efforts and contributions in writing this
book. Besides, I would like to thank the responsible editor of this book—Dr. Wei
Zhuwhoorganizestoturntheinitiativeintoreality.
ix
Contents
PartI Preliminary
1 BasicConcepts. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3
1.1 Ethereum. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3
1.1.1 AsynchronizedCryptography. . . . . . . . . . . . . . . . . . . 4
1.1.2 CryptographicHashFunction. . . . . . . . . . . . . . . . . . . 7
1.1.3 Peer-to-PeerNetwork. . . . . . . . . . . . . . . . . . . . . . . . . 8
1.1.4 Blockchain. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8
1.1.5 EthereumVirtualMachine(EVM). . . . . . . . . . . . . . . . 9
1.1.6 Node. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9
1.1.7 Miner. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9
1.1.8 ProofofWork(PoW). . . . . . . . . . . . . . . . . . . . . . . . . 10
1.1.9 DecentralizedApp(DApp). . . . . . . . . . . . . . . . . . . . . 10
1.1.10 Solidity. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10
1.2 SmartContract. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11
1.3 GAS. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11
1.3.1 WhyGAS?. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12
1.3.2 ComponentsofGAS. . . . . . . . . . . . . . . . . . . . . . . . . 13
1.4 Ether(ETH). . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14
1.5 Account. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14
1.6 Transaction. .. . . . . . . .. . . . . . . . .. . . . . . . . .. . . . . . . .. . . 15
2 Preparation. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17
2.1 ASimpleExample. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17
2.2 ToolPreparation. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18
2.2.1 DevelopmentEnvironment. . . . . . . . . . . . . . . . . . . . . 18
2.2.2 DevelopmentTools. . . . . . . . . . . . . . . . . . . . . . . . . . 23
2.2.3 BlockchainExplorer. . . . . . . . . . . . . . . . . . . . . . . . . . 38
xi
xii Contents
2.3 TestingEnvironment. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 40
2.3.1 MetamaskSwitchingBetweenTestingEnvironments. . 41
2.3.2 ObtainTestingCoins. . . . . . . . . . . . . . . . . . . . . . . . . 41
2.3.3 ConnecttoTestingEnvironment. . . . . . . . . . . . . . . . . 41
2.4 EthereumSourceCodeCompilation. . . . . . . . . . . . . . . . . . . . . 44
PartII SolidityBasics
3 SolidityBasics. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 49
3.1 SolFileStructure. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 49
3.1.1 Pragma. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 49
3.1.2 Import. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 49
3.1.3 Comment. . . . . . .. . . . . . . . .. . . . . . . .. . . . . . . .. . 50
3.1.4 Contract. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 51
3.1.5 Library. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 51
3.1.6 Interface. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 52
3.2 StructureofContract. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 52
3.3 Variable. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 53
3.3.1 ValueType. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 53
3.3.2 ReferenceType. . . . . . . . . . . . . . . . . . . . . . . . . . . . . 55
3.3.3 Mapping. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 58
3.3.4 SpecialCase. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 58
3.4 Operators. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 59
3.5 Statement. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 60
3.5.1 ConditionalStatement. . . . . . . . . . . . . . . . . . . . . . . . 60
3.5.2 Loop. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 61
3.5.3 Miscellaneous. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 61
3.6 DataLocation. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 61
3.7 Modifier. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 63
3.7.1 StandardModifier. . . . . . . . . . . . . . . . . . . . . . . . . . . 64
3.7.2 Self-definedModifier. . . . . . . . . . . . . . . . . . . . . . . . . 68
3.8 Event. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 70
3.8.1 ReturnValuetoUI. . . . . . . . . . . . . . . . . . . . . . . . . . . 71
3.8.2 AsyncTriggerwithData. . . . . . .. . . . . . . . . . . . . .. . 72
3.8.3 CheapStorage. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 72
3.8.4 IndexedParameterinEvent. . . . . . . . . . . . . . . . . . . . 74
3.9 Inheritance. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 74
3.9.1 SingleInheritance. . . . . . . . . . . . . . . . . . . . . . . . . . . 74
3.9.2 Multi-Inheritance. . . . . . . . . . . . . . . . . . . . . . . . . . . . 75
3.10 Miscellaneous. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 76
3.10.1 Built-inVariable. . . . . . . . . . . . . . . . . . . . . . . . . . . . 76
3.10.2 SpecialUnit. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 79
3.10.3 TypeCastandInference. . . . . . . . . . . . . . . . . . . . . . . 80
3.10.4 Exception. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 82
3.10.5 Assembly. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 82