PHP 頁面執行時間統計類：微秒級精度、啟動/停止/顯示分離設計

類代碼（優化版）

<?php
class RunTime {
    private $startTime = 0.0;
    private $stopTime  = 0.0;

    public function start(): void {
        $this->startTime = $this->microtimeFloat();
    }

    public function stop(): float {
        $this->stopTime = $this->microtimeFloat();
        return $this->stopTime - $this->startTime;
    }

    public function getElapsed(): float {
        return $this->stopTime - $this->startTime;
    }

    public function display(int $precision = 6): void {
        printf('
執行時間：%.%df 秒
', $precision, $this->getElapsed());
    }

    private function microtimeFloat(): float {
        // PHP 7.3+ 可直接用 hrtime(true) / 1e9 取奈秒更精準
        [$usec, $sec] = explode(' ', microtime());
        return (float)$usec + (float)$sec;
    }
}
?>

使用方式

<?php
require 'RunTime.php';

$timer = new RunTime();
$timer->start();

// ... 業務邏輯、資料庫查詢、API 呼叫 ...
usleep(123456); // 模擬耗時

$timer->stop();
$timer->display(4); // 輸出：執行時間：0.1235 秒

// 或取得浮點數自行處理
$elapsed = $timer->getElapsed();
error_log("API 回應耗時: {$elapsed}s");

設計優化說明

進階應用：區段計時

class SegmentTimer {
    private $segments = [];
    private $current = null;
    private $start = 0;

    public function begin(string $name): void {
        if ($this->current) $this->end();
        $this->current = $name;
        $this->start = hrtime(true);
    }

    public function end(): ?float {
        if (!$this->current) return null;
        $ns = hrtime(true) - $this->start;
        $this->segments[$this->current] = $ns / 1e9;
        $this->current = null;
        return $this->segments[$this->current];
    }

    public function report(): array {
        if ($this->current) $this->end();
        return $this->segments;
    }
}

// 使用
$st = new SegmentTimer();
$st->begin('db_query');  $db->query(...);  $st->end();
$st->begin('api_call');  $http->get(...);  $st->end();
print_r($st->report());
// ['db_query' => 0.045, 'api_call' => 0.123]

生產環境建議

• 整合至框架中介軟體，自動記錄每請求總耗時與路由耗時。
• 搭配 auto_prepend_file/auto_append_file 或 RUM（Real User Monitoring）工具。
• 長時間執行腳本（CLI）建議用 hrtime() 避免系統時間調整影響。