📜  Node.js process.hrtime() 方法

📅  最后修改于: 2022-05-13 01:56:44.999000             🧑  作者: Mango

Node.js process.hrtime() 方法

用于测量代码执行时间的process.hrtime( ) 方法 返回包含当前高分辨率实时的数组,以 [秒,纳秒] 为单位。我们通过提供第一个 process.hrtime() 调用返回的时间作为第二个 process.hrtime() 调用中的参数来测量代码执行时间。

process.hrtime() 的优点是它测量时间非常准确,执行时间持续不到一毫秒。

句法:

process.hrtime([time])

参数:此方法接受一个如上所述的单个参数,如下所述。

  • time :时间是一个可选参数r,它必须是先前 process.hrtime() 调用与当前时间不同的结果。

返回类型:它返回一个 2 个整数的数组。 1. int包含秒,2. int包含纳秒。这些时间与过去的任意时间相关,与一天中的时间无关。

示例 1:

Javascript
// Implement the function..
 
var hrTime = process.hrtime()
 
// Time in millisecond...
console.log("Time in millisecond is: ", hrTime[0] * 1000 + hrTime[1] / 1000000)


Javascript
// Create a variable and call the process.hrtime() function.
var start_time = process.hrtime();
 
 
 
// Print the Start time:
console.log("Start Time:",start_time);
 
// Make the add function
setTimeout(function(){
 
// Create two variable
var a = '40',
b = '50';
 
// Print the Addition result:
console.log("Add of two number is :",(a - 0) + (b - 0));
  
 
    // Create a variable and call the second process.hrtime()
    // function and pass the start time as parameter.
    var end_time = process.hrtime(start_time);
    // Print the Execution time.
    console.log("End Time:",end_time);
     
}, 1000);


Javascript
// Create a variable and call the process.hrtime() function.
var start_time = process.hrtime();
 
 
 
// Print the Start time:
console.log("Start Time:",start_time);
 
// Make the add function
setTimeout(function(){
 
    console.log("Execution time will be calculated"+
                " for printing this message....");
 
    // Create a variable and call the second process.hrtime()
    // function and pass the start time as.
    var end_time = process.hrtime(start_time);
    // Print the Execution time.
    console.log("End Time:",end_time);
     
}, 1000);



输出:

Time in millisecond is:  218394926745.5

示例 2:

Javascript

// Create a variable and call the process.hrtime() function.
var start_time = process.hrtime();
 
 
 
// Print the Start time:
console.log("Start Time:",start_time);
 
// Make the add function
setTimeout(function(){
 
// Create two variable
var a = '40',
b = '50';
 
// Print the Addition result:
console.log("Add of two number is :",(a - 0) + (b - 0));
  
 
    // Create a variable and call the second process.hrtime()
    // function and pass the start time as parameter.
    var end_time = process.hrtime(start_time);
    // Print the Execution time.
    console.log("End Time:",end_time);
     
}, 1000);

输出:这意味着从开始到结束的时间为 1 秒和 8779100 纳秒。

Start Time: [ 682340, 452477300 ]
Add of two number is : 90
End Time: [ 1, 8779100 ]

示例 3:

Javascript

// Create a variable and call the process.hrtime() function.
var start_time = process.hrtime();
 
 
 
// Print the Start time:
console.log("Start Time:",start_time);
 
// Make the add function
setTimeout(function(){
 
    console.log("Execution time will be calculated"+
                " for printing this message....");
 
    // Create a variable and call the second process.hrtime()
    // function and pass the start time as.
    var end_time = process.hrtime(start_time);
    // Print the Execution time.
    console.log("End Time:",end_time);
     
}, 1000);


输出:这意味着从开始到结束的时间为 1 秒和 10987200 纳秒。

Start Time: [ 682865, 516565300 ]
Execution time will be calculated for printing this message....
End Time: [ 1, 10987200 ]

参考: https://nodejs.org/api/process.html#process_process_hrtime_time