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Merged
mehul0810 merged 1 commit into from
May 21, 2026
Merged

Harden cache runtime writes #89

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120 changes: 105 additions & 15 deletions src/Modules/Cache/PageCache.php
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Original file line number Diff line number Diff line change
Expand Up @@ -249,17 +249,10 @@ public function store_cache( $html ) {
return $html;
}

if ( http_response_code() >= 400 ) {
if ( ! $this->is_cacheable_response( $html ) ) {
return $html;
}

// Don't cache responses setting cookies.
foreach ( headers_list() as $header_line ) {
if ( 0 === stripos( $header_line, 'Set-Cookie:' ) ) {
return $html;
}
}

$ttl_seconds = (int) Helpers::get_option( 'page_cache_ttl', 'perform_settings', 3600 );
$swr_seconds = (int) Helpers::get_option( 'page_cache_swr_ttl', 'perform_settings', 21600 );
$created = time();
Expand All @@ -270,8 +263,13 @@ public function store_cache( $html ) {
'swr_expires' => $created + max( 120, $ttl_seconds + $swr_seconds ),
];

$this->write_cache_meta( $this->current_cache_key, $meta_payload );
$this->write_cache_body( $this->current_cache_key, $html );
if ( ! $this->write_cache_body( $this->current_cache_key, $html ) ) {
return $html;
}

if ( ! $this->write_cache_meta( $this->current_cache_key, $meta_payload ) ) {
wp_delete_file( $this->get_body_file_path( $this->current_cache_key ) );
}
} finally {
$this->release_lock();
}
Expand Down Expand Up @@ -891,6 +889,62 @@ private function is_cacheable_request() {
return true;
}

/**
* Whether the rendered response is safe to persist as a page-cache entry.
*
* @param string $html Rendered response body.
*
* @return bool
*/
private function is_cacheable_response( $html ) {
$current_status = http_response_code();
$status_code = false === $current_status ? 200 : (int) $current_status;
if ( 200 !== $status_code ) {
return false;
}

$has_content_type = false;

foreach ( headers_list() as $header_line ) {
if ( 0 === stripos( $header_line, 'Set-Cookie:' ) ) {
return false;
}

if ( 0 === stripos( $header_line, 'Location:' ) ) {
return false;
}

if ( 0 === stripos( $header_line, 'Content-Type:' ) ) {
$has_content_type = true;

if ( false === stripos( $header_line, 'text/html' ) ) {
return false;
}
}
}

if ( ! $has_content_type && ! $this->looks_like_html_response( $html ) ) {
return false;
}

return true;
}

/**
* Lightweight fallback for hosts that have not sent Content-Type yet.
*
* @param string $html Rendered response body.
*
* @return bool
*/
private function looks_like_html_response( $html ) {
$body_start = ltrim( substr( $html, 0, 1024 ) );

return 0 === stripos( $body_start, '<!doctype html' )
|| 0 === stripos( $body_start, '<html' )
|| false !== stripos( $body_start, '<html' );
}

/**
* Normalize current request URL.
*
Expand Down Expand Up @@ -1040,11 +1094,17 @@ private function read_cache_body( $key ) {
* @param string $key Cache key.
* @param array<string, int|string> $meta Metadata.
*
* @return void
* @return bool
*/
private function write_cache_meta( $key, $meta ) {
$path = $this->get_meta_file_path( $key );
file_put_contents( $path, wp_json_encode( $meta ) ); // phpcs:ignore WordPress.WP.AlternativeFunctions.file_system_operations_file_put_contents
$path = $this->get_meta_file_path( $key );
$contents = wp_json_encode( $meta );

if ( ! is_string( $contents ) ) {
return false;
}

return $this->write_file_atomically( $path, $contents );
}

/**
Expand All @@ -1053,11 +1113,41 @@ private function write_cache_meta( $key, $meta ) {
* @param string $key Cache key.
* @param string $body Body.
*
* @return void
* @return bool
*/
private function write_cache_body( $key, $body ) {
$path = $this->get_body_file_path( $key );
file_put_contents( $path, $body ); // phpcs:ignore WordPress.WP.AlternativeFunctions.file_system_operations_file_put_contents
return $this->write_file_atomically( $path, $body );
}

/**
* Write cache file through a same-directory temp file and atomic rename.
*
* @param string $path Target file path.
* @param string $contents File contents.
*
* @return bool
*/
private function write_file_atomically( $path, $contents ) {
$directory = dirname( $path );
if ( ! is_dir( $directory ) || ! is_writable( $directory ) ) {
return false;
}

$tmp_path = $path . '.' . uniqid( 'tmp-', true );
$written = file_put_contents( $tmp_path, $contents, LOCK_EX ); // phpcs:ignore WordPress.WP.AlternativeFunctions.file_system_operations_file_put_contents

if ( false === $written ) {
wp_delete_file( $tmp_path );
return false;
}

if ( ! rename( $tmp_path, $path ) ) { // phpcs:ignore WordPress.WP.AlternativeFunctions.rename_rename
wp_delete_file( $tmp_path );
return false;
}

return true;
}

/**
Expand Down
41 changes: 40 additions & 1 deletion src/Modules/Cache/StatsStore.php
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Original file line number Diff line number Diff line change
Expand Up @@ -35,6 +35,18 @@ final class StatsStore {
*/
private $dirty = false;

/**
* High-traffic counters that should be sampled instead of persisted per request.
*
* @var array<string, bool>
*/
private $sampled_counter_keys = [
'hits' => true,
'stale_hits' => true,
'bypasses' => true,
'lock_waits' => true,
];

/**
* Constructor.
*/
Expand All @@ -51,10 +63,37 @@ public function __construct() {
* @return void
*/
public function increment( $key ) {
$this->stats[ $key ] = isset( $this->stats[ $key ] ) ? ( (int) $this->stats[ $key ] + 1 ) : 1;
$increment = $this->get_increment_sample_size( $key );
if ( 0 === $increment ) {
return;
}

$this->stats[ $key ] = isset( $this->stats[ $key ] ) ? ( (int) $this->stats[ $key ] + $increment ) : $increment;
$this->dirty = true;
}

/**
* Get sampled increment size for hot cache counters.
*
* @param string $key Stat key.
*
* @return int
*/
private function get_increment_sample_size( $key ) {
if ( empty( $this->sampled_counter_keys[ $key ] ) ) {
return 1;
}

$sample_rate = (int) apply_filters( 'perform_cache_stats_sample_rate', 20, $key );
$sample_rate = max( 1, $sample_rate );

if ( 1 === $sample_rate ) {
return 1;
}

return 1 === wp_rand( 1, $sample_rate ) ? $sample_rate : 0;
}

/**
* Set value for stat key.
*
Expand Down
14 changes: 7 additions & 7 deletions uninstall.php
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Original file line number Diff line number Diff line change
Expand Up @@ -18,7 +18,7 @@
*/
function perform_handle_plugin_uninstall() {

$setting_types = array(
$option_keys = array(
'perform_settings',
'perform_common',
'perform_ssl',
Expand All @@ -27,6 +27,9 @@ function perform_handle_plugin_uninstall() {
'perform_advanced',
'perform_import_export',
'perform_support',
'perform_assets_manager_options',
'perform_cache_preload_queue',
'perform_cache_stats',
);

$remove_data_on_uninstall = false;
Expand All @@ -45,18 +48,15 @@ function perform_handle_plugin_uninstall() {

if ( ! empty( $sites ) ) {
foreach ( $sites as $site ) {
foreach ( $setting_types as $option ) {
foreach ( $option_keys as $option ) {
delete_blog_option( (int) $site->blog_id, $option );
}
}
}
}
} else {
foreach ( $setting_types as $option ) {
foreach ( $option_keys as $option ) {
delete_option( $option );
}
delete_option( 'perform_assets_manager_options' );
delete_option( 'perform_cache_preload_queue' );
delete_option( 'perform_cache_stats' );
}
}
}
Expand Down
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