Casting cas_token to double fails for large cas values

[tachu]

Given a key with a cas_token value of 9941891035036819 the cas operation will fail as casting the cas_token to double will round it up to 9941891035036820.

We tested casting the cas_token to long and was sucesful in casing the value in memcached.

Running php 5.3.24
memcached support => enabled
Version => 1.0.2
libmemcached version => 0.44
Session support => yes

sample code

printf("cas %ld, dbl cas: %f\n", 9941891035036819, (double)9941891035036819);

[mkoppanen]

The cas token should probably overflow to string rather than double.

[axisK]

I'm not very familiar with PHP internals etc. but would it make sense to change the cas_token to a string instead of a double and always treating it as such?

[mkoppanen]

@axisK, yes. that would be ideal if it was done from the beginning. I assume now it would break backwards compatibility. Overflowing to string would work because it would only happen on cas tokens that wont work anyway.

[sqmk]

Just noticed this issue was already created. #159

BC could be addressed by a new option via Memcached::setOption. By default, it would handle the current broken implementation by passing down a float. The new option could return as a string for 64-bit support.

[sodabrew]

This is fixed in the upcoming 3.0.0 release.