iOS获取一个方法的执行时间
iOS获取一个方法的执行时间
最后在做一个应用的时候,从电话本时读出数据,如果电话很多,就需要比较长的时间,于是如果能得到每个方法的执行时间,就可以知道代码优化的地方。
在网上看到了一个比较好的方法来获取执行时间。看代码
- #import <mach/mach_time.h> // for mach_absolute_time() and friends
- CGFloat BNRTimeBlock (void (^block)(void)) {
- mach_timebase_info_data_t info;
- if (mach_timebase_info(&info) != KERN_SUCCESS) return -1.0;
- uint64_t start = mach_absolute_time ();
- block ();
- uint64_t end = mach_absolute_time ();
- uint64_t elapsed = end - start;
- uint64_t nanos = elapsed * info.numer / info.denom;
- return (CGFloat)nanos / NSEC_PER_SEC;
- } // BNRTimeBlock
调用方法如下
- #define LOOPAGE 10000000
- #import "BNRTimeBlock.h"
- int main (void) {
- CGFloat time;
- NSString *thing1 = @"hi";
- NSString *thing2 = @"hello there";
- time = BNRTimeBlock(^{
- for (int i = 0; i < LOOPAGE; i++) {
- [thing1 isEqual: thing2];
- }
- });
- printf ("isEqual: time: %f\n", time);
- time = BNRTimeBlock(^{
- for (int i = 0; i < LOOPAGE; i++) {
- [thing1 isEqualToString: thing2];
- }
- });
- printf ("isEqualToString: time: %f\n", time);
- return 0;
- } // main
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