Chronicle Map usage suggestions

[benalexau]

I sent @leventov an email and asked for any usage suggestions. Two changes were suggested:

1. Change readKey to use map.getUsing(r.wkb.byteArray(), r.wvb.byteArray())
2. Change the map initialization to use constant(Key|Value)SizeBySample(..) as the sizes are fixed

I'll apply these shortly.

[benalexau]

When run withjava -jar target/benchmarks.jar -rf csv -foe true -p sequential=true,false -p valSize=4000 Chronicle:

$ cat before.csv
"Benchmark","Mode","Threads","Samples","Score","Score Error (99.9%)","Unit","Param: intKey","Param: num","Param: sequential","Param: valRandom","Param: valSize"
"org.lmdbjava.bench.Chronicle.readKey","sample",1,3,4862.596437,42257.271469,"ms/op",true,1000000,true,false,4000
"org.lmdbjava.bench.Chronicle.readKey","sample",1,3,10134.836565,260810.593293,"ms/op",true,1000000,false,false,4000
"org.lmdbjava.bench.Chronicle.write","sample",1,3,3437.931179,116.885801,"ms/op",true,1000000,true,false,4000
"org.lmdbjava.bench.Chronicle.write","sample",1,3,3533.002069,650.792600,"ms/op",true,1000000,false,false,4000

$ cat after.csv
"Benchmark","Mode","Threads","Samples","Score","Score Error (99.9%)","Unit","Param: intKey","Param: num","Param: sequential","Param: valRandom","Param: valSize"
"org.lmdbjava.bench.Chronicle.readKey","sample",1,3,2255.137451,220.893402,"ms/op",true,1000000,true,false,4000
"org.lmdbjava.bench.Chronicle.readKey","sample",1,3,2186.630485,971.930967,"ms/op",true,1000000,false,false,4000
"org.lmdbjava.bench.Chronicle.write","sample",1,3,3474.281813,1061.208318,"ms/op",true,1000000,true,false,4000
"org.lmdbjava.bench.Chronicle.write","sample",1,3,3383.405227,842.875501,"ms/op",true,1000000,false,false,4000

$ grep Bytes before.txt
Bytes   4107702272  org.lmdbjava.bench.Chronicle.readKey-SampleTime-intKey-true-num-1000000-sequential-true-valRandom-false-valSize-4000
Bytes   4107702272  org.lmdbjava.bench.Chronicle.readKey-SampleTime-intKey-true-num-1000000-sequential-false-valRandom-false-valSize-4000

$ grep Bytes after.txt
Bytes   4017057792  org.lmdbjava.bench.Chronicle.readKey-SampleTime-intKey-true-num-1000000-sequential-true-valRandom-false-valSize-4000
Bytes   4017082368  org.lmdbjava.bench.Chronicle.readKey-SampleTime-intKey-true-num-1000000-sequential-false-valRandom-false-valSize-4000

Thanks @leventov! A nice readKey improvement, and even slightly more space efficient on disk.