Block chain Note: The contract is called intelligent contracts, RPC / IPC calls, RPC call common framework on web3 the object, based on the example Nodejs

Contract Called

• The contract calls in three ways
  • IPC方式
    • Usually by way of the console
    • Ethernet nodes After running, you can open a console
    • In the console inside it by means of input commands can be retrieved some of the smart contract method
    • IPC may also be the way the pipe communication
    • A call between the main way process
  • HTTP的方式
    • This is more common in some way
    • Usually do JSON format data serialization and deserialization
    • That is the way of HTTP JSON RPC
  • websocket的方式
    • Square supports the use of internal Ethernet protocol websocket directly interfaces to the internal nodes of some contracts call
• In these three ways, if we are to adjust the latter two by the client, HTTP JSON RPC of the way and manner websocket
• And more IPC first way is to do some debugging in the machine access node, a pipeline of communication between processes

RPC / IPC calls

• Go language versions of the above is a full-node Ethernet Square
• A version of the highest priority of a node is also the official maintenance of Ethernet Square called geth, that is, eth node Go language
• After it runs, you can command $ geth console, so bring a sub-command, after so run full node, will enter into a console, the console will be able to enter into
• In the console which it will print some information associated with the connection, here we can see that it has IPC endpoint, that is a connection address of IPC
• This is used to run the MAC system, which is in the /Users/mac/Library/Ethereum/geth.ipcgeneration of such a file a default locationgeth.ipc
• The IPC communication connection is to connect through a shared document that
• You can also open another console just to point to the file can ipc
• The other is the HTTP link address, we are locally, so it is 127.0.0.1, port number 8545
• After entering the console node can be a lot of commands to access the ether
• Console type exit to exit

Common RPC Invocation Framework

• For an Ethernet node is concerned, it is an internal support RPC server node
• For the client is concerned, at present has supported many languages ​​versions, such as support for language versions of Javascript called web3.js, this version is the most commonly used version
• In addition, there are Java-oriented language web3j
• For C # Nethereum
• Ruby language support ethereum-ruby
• With the development and may also support other language versions go
• Of course, you can own to encapsulate, this may be because the RPC supports Ethernet interfaces are open source, we can come to do their own packages as needed

Library	Language	Project Page
web3.js	JavaScript	https://github.com/ethereum/web3.js
web3j	Java	https://github.com/web3j/web3j
Nethereum	C# .NET	https://github.com/Nethereum/Nethereum
ethereum-ruby	Ruby	https://github.com/DigixGlobal/ethereum-ruby

About web3 objects

• web3.js objects
  • Ethernet Square JavaScript API
    • This can be seen in web3 github repository, https://github.com/ethereum/web3.js/tree/1.x/packages this directory
    • That contains a set of library calls have been packaged client, it is Js Ethernet version of the SDK Square
    • Once imported, there is a class called Web3, call the library at the top of each sub web3 this library to implement a package so you can view network example Officer
  • Ordinary JSON RPC
    • Parameters and return values ​​are serialized by json and deserialization
  • Need to meet the Ethernet nodes Square
    • Main network node can be formal, but also to test the deployment of private or simulated node
• Call test code web3 object

  var Web3 = require('web3');
  if(typeof web3 !== 'undefined') {
      web3 = new Web3(web3.currentProvider);
  } else {
      // set the provider you want from Web3.providers
      web3 = new Web3(new Web3.providers.HttpProvider("http://localhost:8545"));
  }
  var Version = web3.version;
  console.log("client version: " + version);
  

Based Nodejs example

var Web3 = require('web3');
if(typeof web3 !== 'undefined') {
    web3 = new Web3(web3.currentProvider);
} else {
    // set the provider you want from Web3.providers
    web3 = new Web3(new Web3.providers.HttpProvider("http://localhost:8545"));
}

web3.eth.getAccounts(console.log);

10 outputs the generated address

null [
  '0x437615686191efF890C7cCa136cfbf21Cb6451E6',
  '0xe4a56746DAfDf247BF125d5809B2D6168722Eb37',
  '0x23604b6563d63D5f3b4C9a09ADe681F5f2811DB6',
  '0x4900AEeA7CC7F76E473805c50E8F0e49c1F99D8E',
  '0x1A32509bC3DAA2AC5493AE212064e59ebeaED34c',
  '0x7c0c971814dBA35D5c53E5650b71E91ecb8C31fa',
  '0x2DB7594e84DC79EE782f3962C1ea9cC2912c3EF1',
  '0x9D86096d38B4460Be319dA56265499D863ccB5c4',
  '0xD03cbC188201EB3AB61aC465Dc1e3A2fa517245C',
  '0x77238F0407aF96Fd26Fe22A9996B2349F1ebb91f'
]