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3fbbad7d60
The header file <gm/inet_address.hh> is included, directly or indirectly, from 291 source files in Scylla. It is hard to reduce this number because Scylla relies heavily on IP addresses as keys to different things. So it is important that this header file be fast to include. Unfortunately it wasn't... ClangBuildAnalyzer measurements showed that each inclusion of this header file added a whopping 2 seconds (in dev build mode) to the build. A total of 600 CPU seconds - 10 CPU minutes - were spent just on this header file. It was actually worse because the build also spent additional time on template instantiation (more on this below). So in this patch we: 1. Remove some unnecessary stuff from gms/inet_address.hh, and avoid including it in one place that doesn't need it. This is just cosmetic, and doesn't significantly speed up the build. 2. Move the to_sstring() implementation for the .hh to .cc. This saves a lot of time on template instantiations - previously every source file instantiated this to_sstring(), which was slow (that "format" thing is slow). 3. Do not include <seastar/net/ip.hh> which is a huge file including half the world. All we need from it is the type "ipv4_address", so instead include just the new <seastar/net/ipv4_address.hh>. This change brings most of the performance improvement. So source files forgot to include various Seastar header files because the includes-everything ip.hh did it - so we need to add these missing includes in this patch. After this patch, ClangBuildAnalyzer's reports that the cost of inclusion of <gms/inet_address.hh> is down from 2 seconds to 0.326 seconds. Additionally the format<inet_address> template instantiation 291 times - about half a second each - is also gone. All in all, this patch should reduce around 10 CPU minutes from the build. Refs #1 Signed-off-by: Nadav Har'El <nyh@scylladb.com>