asmhatre/java-core-examples
1
0
Fork 0
Code Activity

bufferedreader: read a file line by line module (BufferedReader vs Scanner vs Files.lines vs readAllLines on a 1 GB file; heap at -Xmx64m, timings, read-call counts, one-huge-line OOM, charset/BOM/line-terminator pitfalls, Scanner swallowing IOException), 10 contract tests

Browse Source 
Co-Authored-By: Claude Sonnet 5.5 <[email protected]>
Claude-Session: https://claude.ai/code/session_017ic4b3pDoGLiWk6LLBeHjW
This commit is contained in:
Claude
2026-11-15 01:20:37 +05:30
parent 5faa57bb2d
commit f8c9e244a3
25 changed files with 809 additions and 0 deletions
Download Patch File Download Diff File Expand all files Collapse all files
bufferedreader/output/04-timing.txt
+19
View File
@@ -0,0 +1,19 @@
$ java -Xmx5g LineCount <approach> big.log (round-robin, 3 rounds, fresh JVM each)
-- round 1
reader lines=9,623,347 chars=990,376,717 time=1,334 ms gc=18 collections / 21 ms (-Xmx5120 MB)
reader64k lines=9,623,347 chars=990,376,717 time=1,260 ms gc=18 collections / 21 ms (-Xmx5120 MB)
scanner lines=9,623,347 chars=990,376,717 time=5,367 ms gc=49 collections / 49 ms (-Xmx5120 MB)
lines lines=9,623,347 chars=990,376,717 time=1,311 ms gc=18 collections / 24 ms (-Xmx5120 MB)
readAllLines lines=9,623,347 chars=990,376,717 time=2,892 ms gc=23 collections / 1048 ms (-Xmx5120 MB)
-- round 2
reader lines=9,623,347 chars=990,376,717 time=1,216 ms gc=19 collections / 20 ms (-Xmx5120 MB)
reader64k lines=9,623,347 chars=990,376,717 time=1,233 ms gc=18 collections / 21 ms (-Xmx5120 MB)
scanner lines=9,623,347 chars=990,376,717 time=5,645 ms gc=50 collections / 51 ms (-Xmx5120 MB)
lines lines=9,623,347 chars=990,376,717 time=1,341 ms gc=17 collections / 26 ms (-Xmx5120 MB)
readAllLines lines=9,623,347 chars=990,376,717 time=2,788 ms gc=23 collections / 955 ms (-Xmx5120 MB)
-- round 3
reader lines=9,623,347 chars=990,376,717 time=1,254 ms gc=18 collections / 21 ms (-Xmx5120 MB)
reader64k lines=9,623,347 chars=990,376,717 time=1,325 ms gc=18 collections / 21 ms (-Xmx5120 MB)
scanner lines=9,623,347 chars=990,376,717 time=5,300 ms gc=49 collections / 45 ms (-Xmx5120 MB)
lines lines=9,623,347 chars=990,376,717 time=1,398 ms gc=18 collections / 25 ms (-Xmx5120 MB)
readAllLines lines=9,623,347 chars=990,376,717 time=2,985 ms gc=24 collections / 1236 ms (-Xmx5120 MB)