WordPress加载缓慢求助：load_plugin_textdomain等函数耗时超60%

Hey there, sorry to hear you're stuck with this 3-second load time tied directly to translation functions—let's break down the most likely fixes for your issue:

1. Optimize Your MO File Integrity & Size #

Corrupted or bloated .mo files are a common culprit here. Even if your .po looks fine, auto-generated .mo files can sometimes carry redundant data or formatting that slows parsing. Try these steps:

• Recompile your .po to .mo using the official msgfmt tool (part of gettext utilities) instead of relying on third-party generators:

  msgfmt -o cs_CZ.mo cs_CZ.po
  

• Audit your .po file for unused entries (like deprecated plugin strings or debug text) and delete them before recompiling—fewer entries mean faster parsing.

2. Add Translation Caching #

WordPress doesn't cache translation data by default, so every page load re-parses the entire .mo file. You can add custom caching via your theme's functions.php to store parsed translations in WordPress object cache:

add_filter('override_load_textdomain', function($override, $domain, $mofile) {
    // Replace 'your-domain' with your theme/plugin's text domain
    if ($domain === 'your-domain') {
        $cache_key = 'translations_' . md5($mofile);
        $cached_translations = wp_cache_get($cache_key);

        if ($cached_translations) {
            // Use cached translations instead of reloading the MO file
            global $l10n;
            $l10n[$domain] = $cached_translations;
            return true;
        }

        // Load and cache the translations if not already cached
        $translations = load_textdomain($domain, $mofile);
        if ($translations) {
            wp_cache_set($cache_key, $translations, '', 86400); // Cache for 24 hours
        }
    }
    return $override;
}, 10, 3);

If you're using a persistent object cache (like Redis or Memcached), this will give even bigger performance gains.

3. Track Down Duplicate Load Calls #

Sometimes plugins or themes accidentally call load_plugin_textdomain multiple times for the same text domain, forcing WordPress to re-parse the MO file repeatedly. Use xDebug's call stack to:

• Identify which scripts are triggering these functions
• Check if you can remove redundant calls (e.g., a plugin loading its translation both on init and plugins_loaded)

4. Verify File System Performance #

Even though both local and production are slow, double-check that your .mo file isn't stored on a slow filesystem (like a network share for production, or a fragmented local drive). Try:

• Moving the MO file to a directory with faster read speeds
• Ensuring file permissions are set correctly (no extra overhead from permission checks)

5. Test with Minimal Environment #

Disable all non-essential plugins and switch to a default theme (like Twenty Twenty-Four) to see if the load time drops. If it does, re-enable plugins one by one to find if a specific plugin is conflicting with the translation loading process.

Once you've tried these steps, use tools like Query Monitor to re-measure the time spent on translation functions—you should see a significant drop if the issue was tied to one of these causes.

内容的提问来源于stack exchange，提问作者Kryštof Matěj