Uniqid in PHP in the case of duplication in high concurrency

Duplication of uniqid in PHP with high concurrency

The most recent project has been useful to generate token validation issues. First consider using PHP's uniqid () function to generate a random string, but since the function seems to be based on the microsecond time level. In the case of high concurrency, it is possible to generate the same value.

Solution 1:uniqid (rand (1,10000)), the first parameter of the function can be used as a prefix for the number of builds, thus greatly reducing the repetition rate of the build number. But the possibility of repetition is still there.

Solution 2:md5 (Uniqid ()), use the MD5 () function to generate an absolutely unique value

1 floor Ranxiedao53 minutes ago

Before doing the back end of the time also found this problem, a short period of time quickly generated when the repetition rate is very high, or even reached 20%, so write their own method of generation, the array of letters randomly generated, such as the generation of 8-bit, so that the probability of repetition is much lower than the PHP self-brought, feel this method is a pit Random seed generators and time-dependent

