Reduce memory footprint of IO::Socket::SSL

[atoomic]

Avoid import of Carp, only load it when required. Avoid importing everything from IO::Socket / Socket. Hide to the compiler the regexp with \w when using SSL_fingerprint. This is bringing some extra memory for no real advantages.

(master) > export A='use IO::Socket::SSL (); print qx{grep VmRSS /proc/$$/status}'; p14 -Ilib -e "$A"; p22 -Ilib -e "$A" VmRSS: 5940 kB VmRSS: 7460 kB

(devel/memory-improvement) > export A='use IO::Socket::SSL (); print qx{grep VmRSS /proc/$$/status}'; p14 -Ilib -e "$A"; p22 -Ilib -e "$A" VmRSS: 5856 kB VmRSS: 6752 kB

[noxxi]

Thanks for the participating. But I think that these are micro optimizations which are only relevant for minimal programs. With typical programs the effect will be minimal. And they might even cause harm for more complex programs or lead to increased memory usage:

• For more complex programs Carp is often used already, so deferring the load will not help. If Carp is not loaded but you have an application using fork or threads (very common with sockets) then this deferred loading will cause it to load the module multiple times (in different processes) which in effect increases the memory usage because contrary to early use the memory used by this module is not shared with copy on write. Threads are even more difficult and at least with some modules dynamically loading from inside multiple threads can cause serious and hard to debug/reproduce problems.
• Deferring the compilation of a regex from compile time to run time might be a tiny bit more effective if the regex is never used. But compiling the regex on each use again and again just costs more performance. Additionally we have again more memory usage in case of forks or threads. And we don't get a compile time error if the regex is bad, thus making the code harder to maintain.
• Reducing the amount of imported symbols will probably not save much memory. But it impacts the readability of the code if one needs to use fully qualified names all the times. At least it impacts the readability for me and I am the one working most with the code :) At most one might reduce the import to the symbols which are actually needed.