Minikv

Minikv: A lightweight Elixir library for building distributed key-value stores (:ets) featuring asynchronous replication between nodes, offering a simple way to store and retrieve key-value pairs, with advanced features like key expiration, locking, and persistence.

Installation

To use Minikv in your Elixir project, add it as a dependency in your mix.exs file:

defp deps do
  [
    {:minikv, "~> 0.1.1"}
  ]
end

Then run mix deps.get to fetch the dependency.

Example Usage

Storing a value

To store a value in the registry, you can use the Minikv.Registry.put/3 function:

iex> Minikv.Registry.put(WalletExKv, :my_balance, "100$")
%Minikv.Kv{value: "100$"}

Retrieving a value

To retrieve a value from the registry, you can use the Minikv.Registry.get/2 function:

iex> Minikv.Registry.get(WalletExKv, :my_balance)
%Minikv.Kv{value: "100$", node: :node1, time: 123456789}

Deleting a value

To delete a value from the registry, you can use the Minikv.Registry.delete/2 function:

iex> Minikv.Registry.delete(WalletExKv, :my_balance)
%Minikv.Kv{value: "100$"}

Locking a key

Minikv allows you to lock a key in the registry, preventing other nodes from modifying it. To lock a key, you can use the Minikv.Registry.lock/2 function:

iex> Minikv.Registry.lock(WalletExKv, :my_balance)
%Minikv.Kv{value: "100$", lock: true}

Unlocking a key

To unlock a key in the registry, you can use the Minikv.Registry.unlock/2 function:

iex> Minikv.Registry.unlock(WalletExKv, :my_balance)
%Minikv.Kv{value: "100$", lock: nil}

Persisting a key-value

To persist a key-value in the registry, you can use the Minikv.Registry.persist/2 function:

iex> Minikv.Registry.persist(WalletExKv, :my_balance)
%Minikv.Kv{value: "100$", exp: nil}

Advanced Usage

Customizing key-value options

When storing a value in the registry, you can customize the options associated with the key-value pair. The Minikv.Registry.put/3 function accepts a list of options as the third argument:

iex> Minikv.Registry.put(WalletExKv, :my_balance, [value: "100$", ttl: 1000])
%Minikv.Kv{value: "100$", exp: 123_456_789_100}

In the above example, we've set the ttl (time-to-live) of the key-value pair to 1000 milliseconds. Other available options include:

• :lock - A boolean value indicating whether the key should be locked.
• :persist - A boolean value indicating whether the key-value should be persisted.

Handling errors

The functions provided by Minikv can return errors in certain situations. For example, if you try to retrieve a value for a key that doesn't exist, the Minikv.Registry.get/2 function will return nil.

iex> Minikv.Registry.get(WalletExKv, :nonexistent_key)
nil

Similarly, if you try to lock a key that's already locked by another process, the Minikv.Registry.lock/2 function will return {:error, :locked}.

iex> Minikv.Registry.lock(WalletExKv, :my_balance)
%Minikv.Kv{value: "100$", lock: true}
iex> Minikv.Registry.lock(WalletExKv, :my_balance)
{:error, :locked}