Avoid calling safe_realloc unnecessarily from ODesc::Grow() #2244
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rsmmr
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This is a silly bug in
ODesc::Grow(), where we callsafe_realloceven if the buffer size doesn't change. This theoretically shouldn't cause arealloc, but on some extremely pathological cases I've seen significant performance improvements by avoiding calling it (think ~50x reductions in time spent).On more normal-looking traffic, it's looking like up to 2% improvement in CPU used (tcpreplay of data-center-like traffic at 500mbps for 5 minutes) and up to 2.5% improvement in pcap read times (pcap file with a very large number of http sessions).