Method compute

guava/src/com/google/common/cache/LocalCache.java:2213–2297

(
        K key,
        int hash,
        BiFunction<? super K, ? super @Nullable V, ? extends @Nullable V> function)

    }

    @Nullable V compute(
        K key,
        int hash,
        BiFunction<? super K, ? super @Nullable V, ? extends @Nullable V> function) {
      ReferenceEntry<K, V> e;
      ValueReference<K, V> valueReference = null;
      ComputingValueReference<K, V> computingValueReference = null;
      boolean createNewEntry = true;
      V newValue;

      lock();
      try {
        // re-read ticker once inside the lock
        long now = map.ticker.read();
        preWriteCleanup(now);

        AtomicReferenceArray<ReferenceEntry<K, V>> table = this.table;
        int index = hash & (table.length() - 1);
        ReferenceEntry<K, V> first = table.get(index);

        for (e = first; e != null; e = e.getNext()) {
          K entryKey = e.getKey();
          if (e.getHash() == hash
              && entryKey != null
              && map.keyEquivalence.equivalent(key, entryKey)) {
            valueReference = e.getValueReference();
            if (map.isExpired(e, now)) {
              // This is a duplicate check, as preWriteCleanup already purged expired
              // entries, but let's accommodate an incorrect expiration queue.
              enqueueNotification(
                  entryKey,
                  hash,
                  valueReference.get(),
                  valueReference.getWeight(),
                  RemovalCause.EXPIRED);
            }

            // immediately reuse invalid entries
            writeQueue.remove(e);
            accessQueue.remove(e);
            createNewEntry = false;
            break;
          }
        }

        // note valueReference can be an existing value or even itself another loading value if
        // the value for the key is already being computed.
        computingValueReference = new ComputingValueReference<>(valueReference);

        // Compute the value now, so if it throws an exception we don't change anything.
        newValue = computingValueReference.compute(key, function);

        if (e == null) {
          createNewEntry = true;
          e = newEntry(key, hash, first);
          e.setValueReference(computingValueReference);
          table.set(index, e);
        } else {