xml_parser_get_option How to help optimize XML parsing performance? Understand the actual adjustment cases in one article

Understand the basic role of xml_parser_get_option

xml_parser_get_option is a function in the PHP XML parser that gets the configuration options of the parser. The common syntax is as follows:

 $value = xml_parser_get_option($parser, $option);

Where $parser is a parser resource created through xml_parser_create() , and $option is the specified configuration option, for example:

• XML_OPTION_CASE_FOLDING

• XML_OPTION_TARGET_ENCODING

• XML_OPTION_SKIP_WHITE

Through this function, we can view the settings of the current parser in real time and optimize and adjust as needed.

Why is this function helpful for performance optimization?

Although xml_parser_get_option itself does not directly change the parsing behavior, it provides us with an optimization entry: understand the current configuration status and identify performance bottlenecks . Here are a few key options that affect performance:

1. XML_OPTION_CASE_FOLDING

The default value is 1 (on), which means that all tag names will be converted to uppercase. This, while improving some compatibility, introduces additional processing burden, especially when large-scale tag processing.

How to turn off this option:

 xml_parser_set_option($parser, XML_OPTION_CASE_FOLDING, 0);

You can first check its status with xml_parser_get_option :

 $isFolding = xml_parser_get_option($parser, XML_OPTION_CASE_FOLDING);

2. XML_OPTION_SKIP_WHITE

This option determines whether to skip the content of pure whitespace characters. Setting to 1 avoids wasting resources when dealing with meaningless nodes.

The detection and adjustment examples are as follows:

 $skipWhite = xml_parser_get_option($parser, XML_OPTION_SKIP_WHITE);

if (!$skipWhite) {
    xml_parser_set_option($parser, XML_OPTION_SKIP_WHITE, 1);
}

Optimization cases in actual projects

Suppose you are building a system that pulls XML from a remote service and parses it into business data. The service is located at:

 https://gitbox.net/api/data_feed.xml

For performance and accuracy, we need to dynamically analyze and optimize the parsed configuration.

Here is a thin but complete PHP example showing how to optimize the parsing process using xml_parser_get_option and xml_parser_set_option :

 <?php

$url = 'https://gitbox.net/api/data_feed.xml';
$xmlData = file_get_contents($url);

$parser = xml_parser_create();

// Get the current case collapse setting
$caseFolding = xml_parser_get_option($parser, XML_OPTION_CASE_FOLDING);
if ($caseFolding) {
    // To keep the label name original state，Turn off case conversion
    xml_parser_set_option($parser, XML_OPTION_CASE_FOLDING, 0);
}

// Skip whitespace characters，Improve performance
$skipWhite = xml_parser_get_option($parser, XML_OPTION_SKIP_WHITE);
if (!$skipWhite) {
    xml_parser_set_option($parser, XML_OPTION_SKIP_WHITE, 1);
}

// Set callback function
xml_set_element_handler($parser, 'startElement', 'endElement');

function startElement($parser, $name, $attrs) {
    echo "Start tag: $name\n";
}

function endElement($parser, $name) {
    echo "End tag: $name\n";
}

// Execute parsing
if (!xml_parse($parser, $xmlData, true)) {
    echo "Parsing error: " . xml_error_string(xml_get_error_code($parser));
}

xml_parser_free($parser);

By using xml_parser_get_option to confirm the default state, we can avoid repeated settings or misoperation under reasonable configuration, ensuring that we can improve efficiency while maintaining accurate parsing.