getAndPut method

@override Future getAndPut(String key, dynamic value, { Duration? expiryDuration, })

Associates the specified value with the specified key in this cache, returning an existing value if one existed. If the cache previously contained a mapping for the key, the old value is replaced by the specified value

• key: key with which the specified value is to be associated
• value: value to be associated with the specified key

The previous value is returned, or null if there was no value associated with the key previously.

Implementation

@override
Future<dynamic> getAndPut(String key, dynamic value,
    {Duration? expiryDuration}) {
  // Try to get the entry from the cache
  return _getStorageEntry(key).then((entry) {
    final now = clock.now();
    var expired = entry != null && entry.isExpired(now);

    // If the entry exists on cache but is already expired we remove it first
    final pre = expired
        ? _removeStorageEntry(key, ExpiredEntryEvent(this, entry!))
        : Future.value();

    // If the entry is expired or non existent
    if (entry == null || expired) {
      return pre.then((_) =>
          _putEntry(key, value, now, expiryDuration).then((v) => null));
    } else {
      return pre.then((_) => _updateEntry(entry, value, now, expiryDuration));
    }
  });
}