[core] Avoid building the LookupFile cache repeatedly when the cache …

[Aitozi]

…is nearly full.

Purpose

Linked issue: close #3855

Tests

API and Format

Documentation

[JingsongLi]

I completely don't understand why just marking a boolean can save disk space

[Aitozi]

Marking the boolean is to make the weight to zero while this file is using. This could avoid the lookup file being evicted when putting it to a nearly full cache.

[JingsongLi]

Can we just:

LookupFile lookupFile = lookupFileCache.getIfPresent(file.fileName());
boolean newLookupFile = false;
if (lookupFile is null or lookupFile is closed) {
     lookupFile = createLookupFile();
     newLookupFile = true;
}
try {
     ..... use lookup file
} finally {
    if (newLookupFile) {
           lookupFileCache.put(file.fileName(), lookupFile);
    }
}

[Aitozi]

lookupFileCache.put(file.fileName(), newLookupFile); This still could evict this new create file out directly?

[Aitozi]

@JingsongLi Have updated to lookup the file before putting to cache

We may update to above 3.1.2 later to solve this strange evicting behavior according to this. (In test, it's better). But, the 3.x version requires JDK11 build.

[JingsongLi]

@JingsongLi Have updated to lookup the file before putting to cache

We may update to above 3.1.2 later to solve this strange evicting behavior according to this. (In test, it's better). But, the 3.x version requires JDK11 build.

Thanks!

[JingsongLi]

+1