timestamp identifier under enhance mode #146
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| """ | ||
| in enhanced mode, send_notification may return error response from APNs if any | ||
| """ | ||
| if self.enhanced: | ||
| self._last_activity_time = time.time() | ||
| if identifier is None: | ||
| identifier = int(time.time() * 1e5) |
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There are a few conditions that could cause time.time() to return the same value for multiple invocations. Might be better to use something like random.getrandbits(32)
(+1 for this fix in-general though. Missing this detail in implementation has nasty results)
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Are you thinking about multiple processes that execute this module at the same time? int(time.time()) returns epoch in seconds, and it could have the same value. But if we increase time precision to 1e5, which is 10 micro-seconds, it would be unikely, given the sending rate in the document (1 sent per 1000 micro-seconds).
I am good with using random.getrandbits(32) also. I am more curious about the condition, where timestamp would not give unique value, that I haven't thought about.
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Two conditions: 1) time is changed (e.g. if the server updates/synchronizes it's time in the middle of sending pushes) and 2) low precision values for some systems. From the docs:
Note that even though the time is always returned as a floating point number, not all systems provide time with a better precision than 1 second. While this function normally returns non-decreasing values, it can return a lower value than a previous call if the system clock has been set back between the two calls.
Probably rare conditions, but you never know...
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Thank you very taking time pointing that out and enlightening my knowledge! :)
This is mentioned in the README, but extra step can be done in the code to help preventing duplications are being re-sent in enhance mode.