IO operation optimization skills in C++

C is a feature-rich programming language, in which IO operations (input and output operations) are problems that developers inevitably face. From reading data files to printing to the screen, IO is used in a wide range of applications. However, IO operations are not always fast and efficient, especially when working with large data sets or debugging programs. Therefore, in this article, we will explore IO operation optimization techniques in C to improve the performance and efficiency of your program.

1. Selection of file type

In C, there are two types of files: text files and binary files. Text files are usually in ASCII format, where all characters are stored as text or strings. Binary files are usually binary formats where data is stored in bytes. While text files are easy to process and edit, binary files are more efficient when processing large amounts of data. For a system or application, the appropriate file type should be selected based on the needs.

2. Use cache

Cache is a location where data is saved for quick access. In C, the stream library supports caching, which is retaining a certain amount of data so that it can be read or written faster when needed. The amount of cache can be controlled by adjusting the buffer size. However, for large files or files that need to be read continuously, consider disabling caching. This is because cache data needs to be stored in memory during cache processing. If the cache area is set too large, it will cause memory shortage. For such applications, it is recommended to disable caching or refresh the cache on demand to improve efficiency.

3. Use C standard library functions

C's STDIO library functions and C standard library functions (such as fread and fwrite, etc.) support caching and are easy to use, so it is easy to optimize IO operations. These functions also provide a variety of options for reading and writing binary and text files. However, you need to be careful when using C standard library functions, as they may produce undefined behavior that may cause serious problems in large applications.

4. Use custom operations

In some cases, you can use the operation functions provided by the operating system (such as read and write) or the underlying I/O framework of C to write custom IO function. While this approach may require more code, it provides greater flexibility and speed. For example, when dealing with files with complex formats, these files can be handled well using custom IO functions. However, this still requires some technical skill in manipulation.

5. Turn off unnecessary output

When processing large amounts of data, outputting to the console or file will affect the performance of the application. Output can be disabled if it is not necessary, this can be achieved in C by using redirection of cout, and by closing the output stream in the program. This reduces the amount of output and makes the application run faster.

6. Adjust the buffer size

Due to file IO optimization, file performance can be improved by adjusting the buffer size. If you read small files, you can shrink the buffer to reduce memory usage. If you read large files, you can increase the cache to reduce read and write operations on the disk. The buffer size can be adjusted by passing the buffer size to the setbuf function or the buffered_streambuf class constructor.

Summary

Optimizing IO operations in C can improve the performance and efficiency of the program. Properly selecting file types, using caching, using C standard library functions, using custom operations, turning off unnecessary output, and adjusting buffer sizes are all effective ways to optimize IO operations. But remember, optimizing IO operations requires developers to have corresponding skills and experience to truly improve performance. Therefore, the appropriate technique should be based on actual usage.

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