There are some long loops and sleeps in unit tests, it will cost a
very long time to run all unit tests, especially run in TSAN mode.
This patch speed up unit tests by shortening long loops and sleeps,
on my environment all unit tests finished in 1 minite. It's useful
to do basic functional unit tests.
You can switch to run in this mode by adding a new environment variable
'DORIS_ALLOW_SLOW_TESTS'. For example, you can set:
export DORIS_ALLOW_SLOW_TESTS=1
and also you can disable it by setting:
export DORIS_ALLOW_SLOW_TESTS=0
When LRUCache insert and evict a large number of entries, there are
frequently calls of HandleTable::remove(e->key, e->hash), it will
lookup the entry in the hash table. Now that we know the entry to
remove 'e', we can remove it directly from hash table's collision list
if it's a double linked list.
This patch refactor the collision list to double linked list, the simple
benchmark CacheTest.SimpleBenchmark shows that time cost reduced about
18% in my test environment.
