Initial commit

.formatter.exs

@@ -0,0 +1,4 @@
+[
+  inputs: [".formatter.exs", "mix.exs", "config/.credo.exs", "{config,lib,test}/**/*.{ex,exs}"],
+  line_length: 98
+]

.gitignore

@@ -1,9 +1,15 @@
-/_build
-/cover
-/deps
-/doc
-/.fetch
-erl_crash.dump
-*.ez
+_build
+.DS_Store
+.elixir_ls
+.fetch
+.idea
+.sonarlint
+.vscode
 *.beam
-/config/*.secret.exs
+*.ez
+cover
+deps
+doc
+erl_crash.dump
+mnesiac-*.tar
+mnesiac.iml

README.md

@@ -1,2 +1,17 @@
-# mnesiac
-mnesia autoclustering made easy!
+# Mnesiac
+
+Autoclustering for mnesia made easy! 
+
+Docs can be found at [https://hexdocs.pm/mnesiac](https://hexdocs.pm/mnesiac).
+
+## Installation
+
+Simply add `mnesiac` to your list of dependencies in `mix.exs`:
+
+```elixir
+def deps do
+  [
+    {:mnesiac, "~> 0.1.0"}
+  ]
+end
+```

config/.credo.exs

@@ -0,0 +1,78 @@
+%{
+  configs: [
+    %{
+      name: "default",
+      files: %{
+        included: ["lib/", "src/", "test/", "web/", "apps/"],
+        excluded: [~r"/_build/", ~r"/deps/"]
+      },
+      requires: [],
+      strict: true,
+      color: true,
+      checks: [
+        {Credo.Check.Consistency.ExceptionNames},
+        {Credo.Check.Consistency.LineEndings},
+        {Credo.Check.Consistency.ParameterPatternMatching},
+        {Credo.Check.Consistency.SpaceAroundOperators},
+        {Credo.Check.Consistency.SpaceInParentheses},
+        {Credo.Check.Consistency.TabsOrSpaces},
+        {Credo.Check.Design.AliasUsage, priority: :low},
+        {Credo.Check.Design.DuplicatedCode, excluded_macros: []},
+        {Credo.Check.Design.TagTODO, exit_status: 2},
+        {Credo.Check.Design.TagFIXME},
+        {Credo.Check.Readability.AliasOrder},
+        {Credo.Check.Readability.FunctionNames},
+        {Credo.Check.Readability.LargeNumbers},
+        {Credo.Check.Readability.MaxLineLength, priority: :low, max_length: 98},
+        {Credo.Check.Readability.ModuleAttributeNames},
+        {Credo.Check.Readability.ModuleDoc},
+        {Credo.Check.Readability.ModuleNames},
+        {Credo.Check.Readability.ParenthesesOnZeroArityDefs},
+        {Credo.Check.Readability.ParenthesesInCondition},
+        {Credo.Check.Readability.PredicateFunctionNames},
+        {Credo.Check.Readability.PreferImplicitTry},
+        {Credo.Check.Readability.RedundantBlankLines},
+        {Credo.Check.Readability.StringSigils},
+        {Credo.Check.Readability.TrailingBlankLine},
+        {Credo.Check.Readability.TrailingWhiteSpace},
+        {Credo.Check.Readability.VariableNames},
+        {Credo.Check.Readability.Semicolons},
+        {Credo.Check.Readability.SpaceAfterCommas},
+        {Credo.Check.Refactor.DoubleBooleanNegation},
+        {Credo.Check.Refactor.CondStatements},
+        {Credo.Check.Refactor.CyclomaticComplexity},
+        {Credo.Check.Refactor.FunctionArity},
+        {Credo.Check.Refactor.LongQuoteBlocks},
+        {Credo.Check.Refactor.MatchInCondition},
+        {Credo.Check.Refactor.NegatedConditionsInUnless},
+        {Credo.Check.Refactor.NegatedConditionsWithElse},
+        {Credo.Check.Refactor.Nesting},
+        {Credo.Check.Refactor.PipeChainStart,
+         excluded_argument_types: [:atom, :binary, :fn, :keyword], excluded_functions: []},
+        {Credo.Check.Refactor.UnlessWithElse},
+        {Credo.Check.Warning.BoolOperationOnSameValues},
+        {Credo.Check.Warning.ExpensiveEmptyEnumCheck},
+        {Credo.Check.Warning.IExPry},
+        {Credo.Check.Warning.IoInspect},
+        {Credo.Check.Warning.LazyLogging},
+        {Credo.Check.Warning.OperationOnSameValues},
+        {Credo.Check.Warning.OperationWithConstantResult},
+        {Credo.Check.Warning.UnusedEnumOperation},
+        {Credo.Check.Warning.UnusedFileOperation},
+        {Credo.Check.Warning.UnusedKeywordOperation},
+        {Credo.Check.Warning.UnusedListOperation},
+        {Credo.Check.Warning.UnusedPathOperation},
+        {Credo.Check.Warning.UnusedRegexOperation},
+        {Credo.Check.Warning.UnusedStringOperation},
+        {Credo.Check.Warning.UnusedTupleOperation},
+        {Credo.Check.Warning.RaiseInsideRescue},
+        {Credo.Check.Refactor.ABCSize, false},
+        {Credo.Check.Refactor.AppendSingleItem, false},
+        {Credo.Check.Refactor.VariableRebinding, false},
+        {Credo.Check.Warning.MapGetUnsafePass, false},
+        {Credo.Check.Consistency.MultiAliasImportRequireUse, false},
+        {Credo.Check.Readability.Specs, false}
+      ]
+    }
+  ]
+}

config/config.exs

@@ -0,0 +1 @@
+use Mix.Config

lib/mnesiac.ex

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+defmodule Mnesiac do
+  @moduledoc """
+  Mnesiac Manager
+  """
+  require Logger
+
+  use GenServer
+
+  def start_link(args) do
+    GenServer.start_link(__MODULE__, args, name: __MODULE__)
+  end
+
+  @impl true
+  def init(args) do
+    GenServer.cast(__MODULE__, {:init, args})
+
+    {:ok, []}
+  end
+
+  @impl true
+  def handle_cast({:init, nodes}, _state) do
+    init_mnesia(nodes)
+
+    {:noreply, []}
+  end
+
+  @doc """
+  Start Mnesia with/without a cluster
+  """
+  def init_mnesia(nodes) do
+    nodes =
+      Enum.filter(List.delete(Node.list(), Node.self()), fn node ->
+        node in List.delete(List.flatten(nodes), Node.self())
+      end)
+
+    case nodes do
+      [h | _t] -> join_cluster(h)
+      [] -> start()
+    end
+  end
+
+  @doc """
+  Start Mnesia with/without a cluster. Test helper.
+  """
+  def init_mnesia(nodes, :test) do
+    case List.delete(List.flatten(nodes), Node.self()) do
+      [h | _t] -> join_cluster(h)
+      [] -> start()
+    end
+  end
+
+  @doc """
+  Start Mnesia alone
+  """
+  def start do
+    with :ok <- ensure_dir_exists(),
+         :ok <- start_server(),
+         :ok <- Store.copy_schema(Node.self()),
+         :ok <- Store.init_tables(),
+         :ok <- Store.ensure_tables_loaded() do
+      :ok
+    else
+      {:error, error} -> {:error, error}
+    end
+  end
+
+  @doc """
+  Join to a Mnesia cluster
+  """
+  def join_cluster(cluster_node) do
+    with :ok <- ensure_stopped(),
+         :ok <- Store.delete_schema(),
+         :ok <- ensure_started(),
+         :ok <- connect(cluster_node),
+         :ok <- Store.copy_schema(Node.self()),
+         :ok <- Store.copy_tables(),
+         :ok <- Store.ensure_tables_loaded() do
+      :ok
+    else
+      {:error, reason} ->
+        Logger.log(:debug, fn -> inspect(reason) end)
+        {:error, reason}
+    end
+  end
+
+  @doc """
+  Cluster status
+  """
+  def cluster_status do
+    running = :mnesia.system_info(:running_db_nodes)
+    stopped = :mnesia.system_info(:db_nodes) -- running
+
+    if stopped == [] do
+      [{:running_nodes, running}]
+    else
+      [{:running_nodes, running}, {:stopped_nodes, stopped}]
+    end
+  end
+
+  @doc """
+  Cluster with a node
+  """
+  def connect(cluster_node) do
+    case :mnesia.change_config(:extra_db_nodes, [cluster_node]) do
+      {:ok, [_cluster_node]} -> :ok
+      {:ok, []} -> {:error, {:failed_to_connect_node, cluster_node}}
+      reason -> {:error, reason}
+    end
+  end
+
+  @doc """
+  Running Mnesia nodes
+  """
+  def running_nodes do
+    :mnesia.system_info(:running_db_nodes)
+  end
+
+  @doc """
+  Is node in Mnesia cluster?
+  """
+  def node_in_cluster?(cluster_node) do
+    Enum.member?(:mnesia.system_info(:db_nodes), cluster_node)
+  end
+
+  @doc """
+  Is running Mnesia node?
+  """
+  def running_db_node?(cluster_node) do
+    Enum.member?(running_nodes(), cluster_node)
+  end
+
+  defp ensure_started do
+    with :ok <- start_server(),
+         :ok <- wait_for(:start) do
+      :ok
+    else
+      {:error, reason} -> {:error, reason}
+    end
+  end
+
+  defp ensure_stopped do
+    with :stopped <- stop_server(),
+         :ok <- wait_for(:stop) do
+      :ok
+    else
+      {:error, reason} -> {:error, reason}
+    end
+  end
+
+  defp ensure_dir_exists do
+    mnesia_dir = :mnesia.system_info(:directory)
+
+    with false <- File.exists?(mnesia_dir),
+         :ok <- File.mkdir(mnesia_dir) do
+      :ok
+    else
+      true ->
+        :ok
+
+      {:error, reason} ->
+        Logger.log(:debug, fn -> inspect(reason) end)
+        {:error, reason}
+    end
+  end
+
+  defp start_server do
+    :mnesia.start()
+  end
+
+  defp stop_server do
+    :mnesia.stop()
+  end
+
+  defp wait_for(:start) do
+    case :mnesia.system_info(:is_running) do
+      :yes ->
+        :ok
+
+      :no ->
+        {:error, :mnesia_unexpectedly_stopped}
+
+      :stopping ->
+        {:error, :mnesia_unexpectedly_stopping}
+
+      :starting ->
+        Process.sleep(1_000)
+        wait_for(:start)
+    end
+  end
+
+  defp wait_for(:stop) do
+    case :mnesia.system_info(:is_running) do
+      :no ->
+        :ok
+
+      :yes ->
+        {:error, :mnesia_unexpectedly_running}
+
+      :starting ->
+        {:error, :mnesia_unexpectedly_starting}
+
+      :stopping ->
+        Process.sleep(1_000)
+        wait_for(:stop)
+    end
+  end
+end