<?php
declare(strict_types=1);
namespace PhpMyAdmin\Query;
use PhpMyAdmin\Util;
use function array_shift;
use function count;
use function is_array;
/**
* Handles caching results
*/
class Cache
{
/** @var array Table data cache */
private $tableCache = [];
/**
* Caches table data so Table does not require to issue
* SHOW TABLE STATUS again
*
* @param array $tables information for tables of some databases
* @param string|bool $table table name
*/
public function cacheTableData(array $tables, $table): void
{
// Note: I don't see why we would need array_merge_recursive() here,
// as it creates double entries for the same table (for example a double
// entry for Comment when changing the storage engine in Operations)
// Note 2: Instead of array_merge(), simply use the + operator because
// array_merge() renumbers numeric keys starting with 0, therefore
// we would lose a db name that consists only of numbers
foreach ($tables as $one_database => $_) {
if (isset($this->tableCache[$one_database])) {
// the + operator does not do the intended effect
// when the cache for one table already exists
if ($table && isset($this->tableCache[$one_database][$table])) {
unset($this->tableCache[$one_database][$table]);
}
$this->tableCache[$one_database] += $tables[$one_database];
} else {
$this->tableCache[$one_database] = $tables[$one_database];
}
}
}
/**
* Set an item in table cache using dot notation.
*
* @param array|null $contentPath Array with the target path
* @param mixed $value Target value
*/
public function cacheTableContent(?array $contentPath, $value): void
{
$loc = &$this->tableCache;
if (! isset($contentPath)) {
$loc = $value;
return;
}
while (count($contentPath) > 1) {
$key = array_shift($contentPath);
// If the key doesn't exist at this depth, we will just create an empty
// array to hold the next value, allowing us to create the arrays to hold
// final values at the correct depth. Then we'll keep digging into the
// array.
if (! isset($loc[$key]) || ! is_array($loc[$key])) {
$loc[$key] = [];
}
$loc = &$loc[$key];
}
$loc[array_shift($contentPath)] = $value;
}
/**
* Get a cached value from table cache.
*
* @param array $contentPath Array of the name of the target value
* @param mixed $default Return value on cache miss
*
* @return mixed cached value or default
*/
public function getCachedTableContent(array $contentPath, $default = null)
{
return Util::getValueByKey($this->tableCache, $contentPath, $default);
}
public function getCache(): array
{
return $this->tableCache;
}
public function clearTableCache(): void
{
$this->tableCache = [];
}
}