Mnemonix v0.10.0 Mnemonix View Source

Provides easy access to a store through a Map-like interface.

Rather than a map, you can use the GenServer.server/0 reference returned by Mnemonix.Features.Supervision.start_link/2 to perform operations on Mnemonix stores.

All functions defined in the Mnemonix.Features modules are available on the Mnemonix module:

Map Features

Mnemonix.Features.Map lets you manipulate a store just like a Map.

The new/0, new/1, and new/2 functions start links to a Mnemonix.Stores.Map (mimicking Map.new) and make it easy to play with the Mnemonix functions:

iex> store = Mnemonix.new(fizz: 1)
iex> Mnemonix.get(store, :foo)
nil
iex> Mnemonix.get(store, :fizz)
1
iex> Mnemonix.put_new(store, :foo, "bar")
iex> Mnemonix.get(store, :foo)
"bar"
iex> Mnemonix.put_new(store, :foo, "baz")
iex> Mnemonix.get(store, :foo)
"bar"
iex> Mnemonix.put(store, :foo, "baz")
iex> Mnemonix.get(store, :foo)
"baz"
iex> Mnemonix.get(store, :fizz)
1
iex> Mnemonix.get_and_update(store, :fizz, &({&1, &1 * 2}))
iex> Mnemonix.get_and_update(store, :fizz, &({&1, &1 * 2}))
iex> Mnemonix.get(store, :fizz)
4

These functions behave exactly like their Map counterparts. Mnemonix doesn’t supply analogs for only a few Map functions:

Map functions that traverse every entry in a store are handled a little differently, in the Enumerable feature below.

Bump Features

Mnemonix.Features.Bump lets you perform increment/decrement operations on any store.

iex> store = Mnemonix.new(fizz: 1)
iex> Mnemonix.increment(store, :fizz)
iex> Mnemonix.get(store, :fizz)
2
iex> Mnemonix.decrement(store, :fizz)
iex> Mnemonix.get(store, :fizz)
1

Expiry Features

Mnemonix.Features.Expiry lets you set entries to expire after a given time-to-live on any store.

iex> store = Mnemonix.new(fizz: 1)
iex> Mnemonix.expire(store, :fizz, 100)
iex> :timer.sleep(1000)
iex> Mnemonix.get(store, :fizz)
nil

Enumerable Features

Mnemonix.Features.Enumerable enables functions that try to iterate over a store’s contents. These functions keep parity with the Map API, but be warned: they are only implemented for a subset of stores, and may be very inefficient. Consult your store’s specific documentation for more details.

These Map equivalents will raise Mnemonix.Features.Enumerable.Error if your store doesn’t support them:

Any store can be checked for enumerable support via Mnemonix.enumerable?/1.

Supervision Features

Mnemonix.Features.Supervision allows all stores to fit into Mnemonix supervision tools out of the box. If you know what you’re doing and really want to customize them, you can always override them.

Link to this section Summary

Types

key()

Keys allowed in Mnemonix entries

store()

Values representing a store that Mnemonix functions can operate on

value()

Values allowed in Mnemonix entries

Functions

new()

Starts a new empty in-memory store

new(enumerable)

Starts a new in-memory store using enumerable for initial data

new(enumerable, transform)

Starts a new store applying a transformation to enumerable for initial data

start(type, list)

Starts the :mnemonix application

Link to this section Types

key()

key() :: term()

Keys allowed in Mnemonix entries.

store()

store() :: pid() | GenServer.name()

Values representing a store that Mnemonix functions can operate on.

value()

value() :: term()

Values allowed in Mnemonix entries.

Link to this section Functions

new()

new() :: store()

Starts a new empty in-memory store.

Examples

iex> store = Mnemonix.new
iex> Mnemonix.get(store, :a)
nil
iex> Mnemonix.get(store, :b)
nil

new(enumerable)

new(Enum.t()) :: store()

Starts a new in-memory store using enumerable for initial data.

Duplicated keys in the enumerable are removed; the last mentioned one prevails.

Examples

iex> store = Mnemonix.new(a: 1)
iex> Mnemonix.get(store, :a)
1
iex> Mnemonix.get(store, :b)
nil

new(enumerable, transform)

new(Enum.t(), (term() -> {key(), value()})) :: store()

Starts a new store applying a transformation to enumerable for initial data.

Duplicated keys are removed; the last mentioned one prevails.

Examples

iex> store = Mnemonix.new(%{"A" => 0}, fn {key, value} ->
...>  { String.downcase(key), value + 1 }
...> end )
iex> Mnemonix.get(store, "a")
1
iex> Mnemonix.get(store, "A")
nil

start(type, list)

start(Application.start_type(), Mnemonix.Application.options()) ::
  {:ok, store()} |
  {:error, reason :: term()}

Starts the :mnemonix application.

Finds stores in your application configuration and brings them up when your app starts with the specified start type.

See Mnemonix.Application for more on how the options are consumed.