IPv4 address counter

Counts unique ipv4 addresses passed to application as file or stdin.

Build

 ./gradlew clean build

Application's jar will be located at build/libs/ip-addr-counter-1.0.jar

Launch with pipe

art4noir$ time cat ~/ips | java -Xmn10m -Xmx530m -jar build/libs/ip-addr-counter-1.0.jar 
1000000000

real    1m6.941s
user    0m55.239s
sys     0m20.588s

Launch with file

art4noir$ time java -Xmn10m -Xmx530m -jar build/libs/ip-addr-counter-1.0.jar ~/ips
1000000000

real    1m0.370s
user    0m49.927s
sys     0m9.026s

Memory usage

Main memory consumer is IPv4Counter which takes more than 512Mb of heap constantly. All other allocations are insignificant - a dozen Mbs for young generation and old generation will be enough.

About dataset and read speed used for tests above