Code implementation blockchain
In a narrow sense, blockchain is a kind of chain data structure that combines data blocks in a sequential way according to the time sequence, and it is a distributed account book that can not be tampered with and forged by means of cryptography
broadly speaking, blockchain technology is a new distributed infrastructure and computing method, which uses blockchain data structure to verify and store data, uses distributed node consensus algorithm to generate and update data, uses cryptography to ensure the security of data transmission and access, and uses intelligent contracts composed of automated script code to program and operate data
working principle
blockchain system is composed of data layer, network layer, consensus layer, incentive layer, contract layer and application layer. Among them, the data layer encapsulates the underlying data blocks and related basic data and algorithms such as data encryption and timestamp; The network layer includes distributed networking mechanism, data transmission mechanism and data verification mechanism; The consensus layer mainly encapsulates all kinds of consensus algorithms of network nodes; The incentive layer integrates economic factors into the blockchain technology system, mainly including the issuance mechanism and distribution mechanism of economic incentives; The contract layer mainly encapsulates all kinds of scripts, algorithms and smart contracts, which is the basis of the programmable characteristics of blockchain; The application layer encapsulates various application scenarios and cases of blockchain. In this model, chain block structure based on timestamp, consensus mechanism of distributed nodes, economic incentive based on consensus computing power and flexible and programmable smart contract are the most representative innovations of blockchain technology
you should be talking about the technology of virtual currency. This source code is usually developed by C + +.
blockchain is an important concept of bitcoin, which is essentially a decentralized database and serves as the underlying technology of bitcoin. Blockchain is a series of data blocks generated by cryptography. Each data block contains the information of a bitcoin network transaction, which is used to verify the validity of the information (anti-counterfeiting) and generate the next block
in a narrow sense, blockchain is a kind of chained data structure that combines data blocks in chronological order in a sequential way, and it can not be tampered with and forged by cryptography
broadly speaking, blockchain technology uses blockchain data structure to verify and store data, uses distributed node consensus algorithm to generate and update data, and uses cryptography to ensure the security of data transmission and access A new distributed infrastructure and computing method for programming and operating data by using intelligent contract composed of automated script code
go language + blockchain training course:
1 What are the advantages of go
advantages of go
1: performance
2: language performance is very important
3: developer efficiency & don't be too innovative
4: concurrency & Channel
5: fast compile time
6: team building ability
7: powerful ecosystem
8: gofmt, Mandatory code format
9: grpc and protocol buffers
can be directly compiled into machine code, independent of other libraries. Glibc version has certain requirements, and deployment is completed by throwing a file
static type language has the feeling of dynamic language. Static type language can check out most hidden problems when compiling, while dynamic language has the feeling that there are many packages that can be used and the efficiency of writing is very high.
from the characteristics of the language itself, go is a very efficient language, which highly supports concurrency. Go language itself pays more attention to distributed systems, and concurrency processing is relatively good, such as advertising and search, which are high concurrency servers
go language advantages:
excellent performance, can be directly compiled into machine code, does not rely on other libraries, go is extremely fast. Its performance is similar to Java or C + +
concurrency is supported at the language level, which is the biggest feature of go. It is born to support concurrency, and go is the concurrency supported in gene, which can make full use of multi-core and make it easy to use concurrency
the built-in runtime supports garbage collection, which is one of the features of dynamic language. Although GC is not perfect at present, it is enough to cope with most of the situations we can encounter, especially GC after go1.1
it's easy to learn. The authors of go language all have the gene of C, so go naturally has the gene of C. There are 25 go keywords, but the expressive ability is very strong. It almost supports most of the features you've seen in other languages: inheritance, overloading, object, etc
rich standard libraries, go has built a large number of libraries, especially the network library, which is also my favorite part< As like as two peas, br / > built-in powerful tools, Go language is built with many tools chain, the best should be gofmt tools, automatic formatting code, make team review become so simple, code format is exactly the same, it is very difficult to think differently.
cross platform compilation and fast compilation. Compared with the sluggish compilation speed of Java and C + +, the fast compilation time of go is a major efficiency advantage
disadvantages of go language:
package management: package management of go language is absolutely not perfect. By default, it has no way to make a specific version of the dependency library, nor can it create replicable builds. In contrast, python, node and Ruby all have better package management systems. However, with the right tools, the package management of go language can also perform well
lack of development framework: go language does not have a major framework, such as Ruby's rails framework, Python's Django framework or PHP's laravel. This is a heated discussion in the go language community, because many people think that we should not start with using frameworks. This is true in many cases, but if you just want to build a simple crud API, it's much easier to use Django / djrf, rails laravel, or Phoenix
exception handling: go language can help developers deal with compilation errors by simply returning errors (or call stack) through functions and expected calling codes. Although this method is effective, it is easy to lose the scope of the error, so it is difficult to provide meaningful error information to users. Error package can solve this problem by allowing us to add context and stack trace to return error
another problem is that we may forget to handle errors. Static analysis tools such as errcheck and megacheck can avoid these errors. Although these solutions are very effective, they may not be the right way.
the underlying development of blockchain can't be realized with Java
as the upper development, you just need to dock according to the given open source interface, and then develop what you need with the language you are good at
now there are many blockchain system templates, you can see which development cases
let me analyze it:
1: bitcoin has been broken in China, and its price has dropped sharply, which is unexpected by the global mining pool
2: compared with the current mining cost of bitcoin, it makes money entirely by cheap electricity bills
3: there are only 21 million bitcoins, and most of them have been g up in the early stage, which makes it difficult to dig those bitcoins that have not been g up in the future, and there is too much competition. Many small mines are in a state of loss
and why do many well-known mines turn to TCD
first of all, bitcoin is the optimized and upgraded version of bitcoin, with a constant number of 100 million. The early mining is very good. Unlike bitcoin, which has too high cost and low cost performance ratio, it is appropriate to use bitcoin as a supplement to compare bitcoin. Bitcoin is used for large amount payment and bitcoin is used for small amount payment.
Yes
use PHP code to define blocks:
class block {
public $prevhash
public $hash;
public $timeStamp;
public $data;
}
prevhash: the hash value of the previous block; Hash: hash value of the current block; Timestamp: the time stamp generated by the block; Data: data stored in the block; The fields prevhash, hash and timestamp are called block headers in the blockchain, and the hash value of the block is calculated by SHA-256 algorithm
extended data
the practical use and significance of blockchain:
blockchain is a decentralized distributed ledger. What is decentralization? There is no center, or everyone can be a center. This is different from the traditional way of centralization. Distributed ledger means that the storage of data is not only on each node, but each node will and share the data of the whole ledger
In addition, blockchain has the characteristics of disintermediation and information transparency. For example, for example, when we shop on Taobao, after we place the order, the cost we pay is first hit in Alipay. After we receive the courier and confirm the receipt, the money will be transferred to the seller's account. In the blockchain, buyers and sellers can trade directly without any platform as a third-party certification authoritythe system will broadcast the transaction information of both parties. All hosts will record and back up the transaction data after receiving the information. If the order of one machine is wrong, the backup data of other machines will not be affected