PHP ZipArchive は、圧縮パッケージ内のファイルの圧縮率をどのようにチェックしますか?

$zip = new ZipArchive;
$zipFile = 'path/to/archive.zip';

if ($zip->open($zipFile) === true) {
    // 在这里实现对压缩包文件压缩率的查看
} else {
    echo '无法打开ZIP文件';
}

$totalSizeBefore = 0;
$totalSizeAfter = 0;

for ($i = 0; $i < $zip->numFiles; $i++) {
    $fileName = $zip->getNameIndex($i);
    $stat = $zip->statIndex($i);
    $sizeBefore = $stat['size'];
    $sizeAfter = $stat['comp_size'];
    
    $totalSizeBefore += $sizeBefore;
    $totalSizeAfter += $sizeAfter;
    
    $compressionRate = ($sizeBefore - $sizeAfter) / $sizeBefore * 100; // 计算压缩率
    
    echo "文件名：{$fileName}<br/>";
    echo "压缩前大小：{$sizeBefore} bytes<br/>";
    echo "压缩后大小：{$sizeAfter} bytes<br/>";
    echo "压缩率：{$compressionRate}%<br/>";
    echo "<br/>";
}

$averageCompressionRate = ($totalSizeBefore - $totalSizeAfter) / $totalSizeBefore * 100 / $zip->numFiles; // 计算平均压缩率

echo "总压缩前大小：{$totalSizeBefore} bytes<br/>";
echo "总压缩后大小：{$totalSizeAfter} bytes<br/>";
echo "平均压缩率：{$averageCompressionRate}%<br/>";

$zip->close();