tree c524951169166f05b61e470a47eafab73dfc0240
parent 223ed93582dbb730eb92c80cc6350dcec116ec0a
author tomlu <tomlu@google.com> 1517426300 -0800
committer Copybara-Service <copybara-piper@google.com> 1517426414 -0800

Add memory-efficient map for storing nested set -> digest.

Instead of using ConcurrentHashMap, we use a dead-simple open addressed hash hable with a giant byte array with 16-byte slots. We then read or write fingerprints straight into and out of the array, obviating the need to generate intermediate garbage.

Locking mechanism is a read-write lock. This should be faster than full synchronisation for read-heavy loads.

RELNOTES: None
PiperOrigin-RevId: 184019301