Method replace

guava/src/com/google/common/cache/LocalCache.java:2938–2997

(K key, int hash, V oldValue, V newValue)

    }

    boolean replace(K key, int hash, V oldValue, V newValue) {
      lock();
      try {
        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 (ReferenceEntry<K, V> e = first; e != null; e = e.getNext()) {
          K entryKey = e.getKey();
          if (e.getHash() == hash
              && entryKey != null
              && map.keyEquivalence.equivalent(key, entryKey)) {
            ValueReference<K, V> valueReference = e.getValueReference();
            V entryValue = valueReference.get();
            if (entryValue == null) {
              if (valueReference.isActive()) {
                // If the value disappeared, this entry is partially collected.
                int newCount = this.count - 1;
                ++modCount;
                ReferenceEntry<K, V> newFirst =
                    removeValueFromChain(
                        first,
                        e,
                        entryKey,
                        hash,
                        entryValue,
                        valueReference,
                        RemovalCause.COLLECTED);
                newCount = this.count - 1;
                table.set(index, newFirst);
                this.count = newCount; // write-volatile
              }
              return false;
            }

            if (map.valueEquivalence.equivalent(oldValue, entryValue)) {
              ++modCount;
              enqueueNotification(
                  key, hash, entryValue, valueReference.getWeight(), RemovalCause.REPLACED);
              setValue(e, key, newValue, now);
              evictEntries(e);
              return true;
            } else {
              // Mimic
              // "if (map.containsKey(key) && map.get(key).equals(oldValue))..."
              recordLockedRead(e, now);
              return false;
            }
          }
        }

        return false;
      } finally {
        unlock();
        postWriteCleanup();