How does PHP ZipArchive implement compression quality settings for files in compressed packages?

How does PHP ZipArchive implement compression quality settings for files in compressed packages?

Compressing files is a very common operation when processing files and data. In PHP, files can be compressed and decompressed easily using the ZipArchive class. But when compressing files, we may face a problem, which is how to set the compression quality of the files in the compressed file. Let's take a look at how to use PHP's ZipArchive class to set the compression quality of the files in the compressed package.

First, we need to create a ZipArchive object to operate compressed files. The code is as follows:

$zip = new ZipArchive();

Then, we need to open the file we want to compress. Use the open method to pass in two parameters, which are the file name and operation mode of the compressed file to be created. The operation mode can be ZipArchive::CREATE to create and open a compressed file, or ZipArchive::OVERWRITE to overwrite an existing compressed file. The code is as follows:

if ($zip->open('archive.zip', ZipArchive::CREATE) === true) {
    // 文件打开成功
} else {
    // 文件打开失败
}

Next, we can add files to the compressed file. Use the addFile method to pass in two parameters, which are the file path to be added and the file name in the compressed file. The code is as follows:

$zip->addFile('path/to/file.txt', 'file.txt');

Before adding the file, we can set the compression quality of the file by setting the properties of the ZipArchive class setCompressionName. There are several options to choose from for compression quality, including ZipArchive::CM_STORE for no compression, and ZipArchive::CM_DEFLATE for compression using the DEFLATE algorithm. By default, the compression quality is ZipArchive::CM_STORE, which means no compression.

Code example:

$zip->setCompressionName('file.txt', ZipArchive::CM_DEFLATE);

In addition to setting the compression quality of the entire compressed file, we can also set the compression quality for individual files. The code example is as follows:

$zip->setCompressionIndex(0, ZipArchive::CM_DEFLATE);

Finally, we The ZipArchive object needs to be closed to complete the entire compression process:

$zip->close();

The above is how to use PHP's ZipArchive class to set the compression quality of the files in the compressed package. We can easily set different compression qualities for files in a compressed file by setting the setCompressionName and setCompressionIndex methods. This gives us more flexibility and control over how we process compressed files.

Hope this article is helpful to you!

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