@callback delete(adapter_meta(), key(), opts()) :: :ok

Deletes a single entry from cache.

See Nebulex.Cache.delete/2.

@callback expire(adapter_meta(), key(), ttl()) :: boolean()

Returns true if the given key exists and the new ttl was successfully updated, otherwise, false is returned.

See Nebulex.Cache.expire/2.

@callback get(adapter_meta(), key(), opts()) :: value()

Gets the value for a specific key in cache.

See Nebulex.Cache.get/2.

@callback get_all(adapter_meta(), [key()], opts()) :: map()

Gets a collection of entries from the Cache, returning them as Map.t() of the values associated with the set of keys requested.

For every key that does not hold a value or does not exist, that key is simply ignored. Because of this, the operation never fails.

See Nebulex.Cache.get_all/2.

@callback has_key?(adapter_meta(), key()) :: boolean()

Returns whether the given key exists in cache.

See Nebulex.Cache.has_key?/1.

@callback put(adapter_meta(), key(), value(), ttl(), on_write(), opts()) :: boolean()

Puts the given value under key into the cache.

Returns true if the value with key key is successfully inserted; otherwise false is returned.

The ttl argument sets the time-to-live for the stored entry. If it is not set, it means the entry hasn't a time-to-live, then it shouldn't expire.

OnWrite

The on_write argument supports the following values:

• :put - If the key already exists, it is overwritten. Any previous time-to-live associated with the key is discarded on successful write operation.

• :put_new - It only stores the entry if the key does not already exist, otherwise, false is returned.

• :replace - Alters the value stored under the given key, but only if the key already exists into the cache, otherwise, false is returned.

See Nebulex.Cache.put/3, Nebulex.Cache.put_new/3, Nebulex.Cache.replace/3.

@callback put_all(adapter_meta(), entries(), ttl(), on_write(), opts()) :: boolean()

Puts the given entries (key/value pairs) into the cache.

Returns true if all the keys were inserted. If no key was inserted (at least one key already existed), false is returned.

The ttl argument sets the time-to-live for the stored entry. If it is not set, it means the entry hasn't a time-to-live, then it shouldn't expire. The given ttl is applied to all keys.

OnWrite

The on_write argument supports the following values:

• :put - If the key already exists, it is overwritten. Any previous time-to-live associated with the key is discarded on successful write operation.

• :put_new - It only stores the entry if the key does not already exist, otherwise, false is returned.

Ideally, this operation should be atomic, so all given keys are set at once. But it depends purely on the adapter's implementation and the backend used internally by the adapter. Hence, it is recommended to checkout the adapter's documentation.

See Nebulex.Cache.put_all/2.

@callback take(adapter_meta(), key(), opts()) :: value()

Returns and removes the entry with key key in the cache.

See Nebulex.Cache.take/2.

@callback touch(adapter_meta(), key()) :: boolean()

Returns true if the given key exists and the last access time was successfully updated, otherwise, false is returned.

See Nebulex.Cache.touch/1.

@callback ttl(adapter_meta(), key()) :: ttl() | nil

Returns the TTL (time-to-live) for the given key. If the key does not exist, then nil is returned.

See Nebulex.Cache.ttl/1.

@callback update_counter(adapter_meta(), key(), amount, ttl(), default, opts()) ::
  integer()
when amount: integer(), default: integer()

Updates the counter mapped to the given key.

If amount > 0, the counter is incremented by the given amount. If amount < 0, the counter is decremented by the given amount. If amount == 0, the counter is not updated.

See Nebulex.Cache.incr/3. See Nebulex.Cache.decr/3.