public ConfigResponse computeIfAbsent(ConfigCacheKey key, Function<ConfigCacheKey, ConfigResponse> mappingFunction) {
        ConfigResponse config = get(key);
        if (config != null) {
            return config;
        }
        synchronized (stripedLocks[Math.abs(key.hashCode()%stripedLocks.length)]) {
            PayloadChecksum xxhash64 = checksums.get(key);
            if (xxhash64 == null) {
                config = mappingFunction.apply(key);
                put(key, config);
                return config;
            }
            return checksumToConfig.get(xxhash64);
        }
    }
Cache that holds configs and config definitions (builtin and user config definitions).

@author vegardh
configserver/src/main/java/com/yahoo/vespa/config/server/ServerCache.java