Maximizing the Performance of Java 8 Streams
summary
Case study implements grep -B with Java 8 streams, using a mapped byte buffer and a custom Spliterator plus a collecting terminal operation to compute byte offsets without mutable accumulators. Microbenchmarking uses the Java Microbenchmark Harness and NetBeans/GC logs; common pitfalls are I/O bottlenecks, GC tuning, dead‑code elimination and a ~100 µs splitting/merge overhead. Sequential streams often beat hand loops; parallel streams reach about 2.5× on a 4‑core machine when the regex work outweighs splitting and collection costs.
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chapters (8)
- 0:00Introduction to streams
- 4:31Streams and parallelism
- 11:17Hardware and performance
- 16:47Micro-benchmarking pitfalls
- 24:35System-level performance
- 33:28JVM and garbage collection
- 41:22Case study: Grep utility
- 51:00Conclusion on parallelism
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