Author Ethereum Intelligent Contract Developer Translation Shanouba Bitcoin Trading Network Introduction This paper deeply discusses Ethereum Virtual Machine and the realization of intelligent contract optimization and security. Ethereum Virtual Machine is the core component of Ethereum Network. It is a software that allows the deployment and execution of contracts written in high-level languages, such as smart contracts, and then compiles them into bytecodes and deploys them to every node running in Ethereum Network. It is a low-level programming language that allows developers to be closer to their own level. Writing code, which provides finer control over the execution of smart contracts, allows optimization and customization that cannot be achieved only through higher-level code. The language used for inline assembly is called the programming language, which acts as the intermediary for compiling into bytecode. It is designed as a low-level language to enable developers to control the execution of smart contracts more finely. It can be used in independent mode or inline assembly in. It is designed as a language based on low-level stack to enable developers to write more. Optimizing more efficient code before explaining the assembly, we need to know how the components work. It is a quasi-Turing complete state machine. In this case, the term quasi means that the execution of the process is limited to a limited number of calculation steps, which depends on the available amount of any given intelligent contract execution. This is the way for Ethereum to deal with the stop problem and the execution of the situation that may be malicious or unexpected forever running, thus avoiding the complete paralysis of the Ethereum platform, and it is a measure to complete the handover in Ethereum. The concept of easy-to-need calculation, the transaction cost is paid in etheric currency and related to the price. Our goal in this process is to learn how to minimize the total amount of consumption without affecting security. Code optimization is a method of accessing at a lower level. It bypasses several important security functions and checks that the correct use of inline assembly can significantly reduce the execution cost, but you should only use it for tasks that need it and only when you know what you are doing. When to use inline assembly to optimize code may bring new security problems to your code. To master inline assembly, we need to understand the working principle of its components. Every time we access any storage variable for the first time, we have to pay for it. This is called cold access, and it takes a second time or a continuous time to be called hot access. The following code is how to use the example function of optimized code to set a new value for the global variable value in the traditional way. We need to allocate this new value for the first time. The second cost is much less, that is, the function realizes inline assembly, and the inline assembly block is marked, in which the code in braces is the language code. At this time, you don't need to know the source code, just remember that the software is accessing the storage space at a lower level, so the execution cost will be lower. In our example, it will take several consecutive times to modify the value for the first time. The difference may not seem significant, but we should consider why this code may be executed thousands of times. Please remember. We are in a decentralized world. Data is not only stored in one place, but also stored in tens of thousands of nodes. If future transactions need to access or change it, it must also be easily used by every node in the network. The total cost of the data is equal to the sum of the storage space it consumes and the amount of calculation to generate the data on the whole network. Stack storage and memory is a stack-based machine. It runs on a data structure called stack, saves values and performs operations. One's own set of instructions is called operation code, which is used for reading, writing, storing, calling other contracts, and performing mathematical operations. The task stack runs in LIFO mode. Please refer to the figure. This means that the recently inserted item is stored at the top of the stack and is the first item to be deleted. When the smart contract is executed, an execution context containing various data structures and state variables is created. After the execution is completed, the execution context will be discarded to prepare for the next contract, and a temporary one will be maintained during the execution. There will not be a stack machine with execution depth between transactions in this memory. Each item is a bit word. This size is selected to facilitate the use of bit hash and elliptic curve encryption. The stack with the following components is a data structure that operates in a last-in first-out mode. It is used to store temporary values during the execution of smart contracts. Permanent storage is part of the Ethereum state. It is only initialized to zero memory volatility at the first time. A byte array with dynamic size is used for storage. Intermediate data during contract execution, the memory will be initialized to zero every time a new execution context is created. This is also a volatile data storage area similar to memory, but it stores immutable data. It is designed to store data sent as part of smart contract transactions. The program counter points to the next instruction to be executed. Usually, after an instruction is executed, a byte is added. Virtual smart contracts are stored in this area as bytecodes, and the virtual read-only stack is in this architecture. The instructions and data of the program are stored in memory, and the execution of the program is controlled by the stack pointer pointing to the top of the stack. The stack pointer tracks the position where the next value or instruction will be saved or retrieved on the stack. When the program runs, it adds the value to the stack and performs operations on the existing value. When the code wants to add two numbers, it pushes the number onto the stack and then performs the addition operation on the top two values, and then the result is returned to the stack. One of the most important features of the stack-based architecture is that it allows. Highly simple and efficient operation execution. Because the stack is a data structure, data and instructions can be processed easily and quickly. It has its own set of instructions called opcodes, which are used to perform reading and writing, storing, calling other contracts, and performing mathematical operations. The instruction set provides most of the operations you may expect, including stack operation arithmetic comparison, memory operation according to bit environment, storage of operating procedures, counter related opcodes, stopping opcode storage, and storing bits in nonvolatile space. The total number of storage slots in the key-value pair contract is this is a very large number of slots. Each smart contract in the blockchain has its own storage space, which is used to store data that needs to be remembered between function calls. It is used to store variables and data structures that need to be available even after the smart contract is executed. The storage operation code of the account is permanent data storage, and only the smart contract uses the externally owned account, which will always have no code and the storage space is empty. Memory is volatile memory in the architecture, and its data is not persistent memory in the blockchain, which is a random access. 比特币今日价格行情网_okx交易所app_永续合约_比特币怎么买卖交易_虚拟币交易所平台

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