Implemented file system storage

.gitignore

@@ -15,3 +15,5 @@ erl_crash.dump
 
 # Also ignore archive artifacts (built via "mix archive.build").
 *.ez
+
+/test/temp/*.txt

CHANGELOG.md

@@ -1,5 +1,10 @@
 # Simple Bayes Changelog
 
+## master
+
+- Introduced the storage mechanism (defaults to `:memory`)
+- Implemented file system storage
+
 ## v0.7.1 [2016-07-23]
 
 - Adjusted the `:smoothing` option

README.md

@@ -84,6 +84,7 @@ For application wide configuration, in your application's `config/config.exs`:
 
 ```elixir
 config :simple_bayes, model: :multinomial
+config :simple_bayes, storage: :memory
 config :simple_bayes, default_weight: 1
 config :simple_bayes, smoothing: 0
 config :simple_bayes, stem: false
@@ -109,19 +110,51 @@ Alternatively, you may pass in the configuration options when you initialise:
 ```elixir
 SimpleBayes.init(
   model:          :multinomial,
+  storage:        :memory,
   default_weight: 1,
   smoothing:      0,
   stem:           false,
   stop_words:     []
 )
 ```
 
-Available options for `:model` are:
+#### Available options for `:model` are:
 
 - `:multinomial` (default)
 - `:binarized_multinomial`
 - `:bernoulli`
 
+#### Available options for `:storage` are:
+
+- `:memory` (default)
+- `:file_system`
+
+Some storage options have extra configurations available via `:storage_config`:
+
+- `:memory`
+  - `:namespace` - optional, it's only useful when you want to `load` by the namespace
+- `:file_system`
+  - `:file_path`
+
+Please use `:storage_config` when setting application-wide configuration, otherwise you may use the varies configuration options directly. See below for some examples.
+
+```elixir
+config :simple_bayes, storage: :file_system
+config :simple_bayes, storage_config: [file_path: "path/to/the/file.txt"]
+
+SimpleBayes.init(
+  storage: :file_system,
+  storage_config: [
+    file_path: "path/to/the/file.txt"
+  ]
+)
+
+SimpleBayes.init(
+  storage: :file_system,
+  file_path: "path/to/the/file.txt"
+)
+```
+
 ## Changelog
 
 Please see [CHANGELOG.md](CHANGELOG.md).

lib/simple_bayes.ex

@@ -56,6 +56,12 @@ defmodule SimpleBayes do
     @storages[opts[:storage]].init(struct, opts)
   end
 
+  def save(pid) do
+    struct = Agent.get(pid, &(&1))
+
+    @storages[struct.opts[:storage]].save(pid, struct)
+  end
+
   def load(opts \\ []) do
     @storages[opts[:storage]].load(opts)
   end

lib/simple_bayes/data.ex

@@ -0,0 +1,15 @@
+defmodule SimpleBayes.Data do
+  def encode(value, opts \\ []) do
+    value
+    |> Kernel.inspect(limit: 1_000_000_000)
+    |> Base.encode64(opts)
+  end
+
+  def decode(value, opts \\ []) do
+    {struct, _} = value
+    |> Base.decode64!(opts)
+    |> Code.eval_string()
+
+    struct
+  end
+end

lib/simple_bayes/storage/behaviour.ex

@@ -1,4 +1,5 @@
 defmodule SimpleBayes.Storage.Behaviour do
   @callback init(%SimpleBayes{}, Keyword.t) :: pid
-  @callback load(Keyword.t) :: pid
+  @callback save(pid, Keyword.t)            :: {:ok, pid}
+  @callback load(Keyword.t)                 :: pid
 end

lib/simple_bayes/storage/file_system.ex

@@ -0,0 +1,29 @@
+defmodule SimpleBayes.Storage.FileSystem do
+  @behaviour SimpleBayes.Storage.Behaviour
+
+  alias SimpleBayes.Data
+
+  def init(struct, _opts) do
+    {:ok, pid} = Agent.start_link(fn -> struct end)
+
+    pid
+  end
+
+  def save(pid, struct) do
+    File.write!(file_path(struct.opts), Data.encode(struct))
+
+    pid
+  end
+
+  def load(opts) do
+    struct = file_path(opts)
+             |> File.read!()
+             |> Data.decode()
+
+    init(struct, opts)
+  end
+
+  defp file_path(opts) do
+    opts[:file_path] || opts[:storage_config][:file_path]
+  end
+end

lib/simple_bayes/storage/memory.ex

@@ -10,6 +10,10 @@ defmodule SimpleBayes.Storage.Memory do
     pid
   end
 
+  def save(pid, _data) do
+    pid
+  end
+
   def load(opts) do
     namespace(opts)
   end

mix.exs

@@ -19,8 +19,8 @@ defmodule SimpleBayes.Mixfile do
 
   defp deps do
     [
-      {:ex_doc, ">= 0.0.0", only: :dev},
-      {:stemmer, "~> 1.0.0-beta.1"},
+      {:ex_doc,  ">= 0.0.0", only: :dev},
+      {:stemmer, "~> 1.0.0-beta.1"}
     ]
   end
 

mix.lock

@@ -1,3 +1,3 @@
-%{"earmark": {:hex, :earmark, "0.2.1", "ba6d26ceb16106d069b289df66751734802777a3cbb6787026dd800ffeb850f3", [:mix], []},
-  "ex_doc": {:hex, :ex_doc, "0.12.0", "b774aabfede4af31c0301aece12371cbd25995a21bb3d71d66f5c2fe074c603f", [:mix], [{:earmark, "~> 0.2", [hex: :earmark, optional: false]}]},
+%{"earmark": {:hex, :earmark, "1.0.1", "2c2cd903bfdc3de3f189bd9a8d4569a075b88a8981ded9a0d95672f6e2b63141", [:mix], []},
+  "ex_doc": {:hex, :ex_doc, "0.13.0", "aa2f8fe4c6136a2f7cfc0a7e06805f82530e91df00e2bff4b4362002b43ada65", [:mix], [{:earmark, "~> 1.0", [hex: :earmark, optional: false]}]},
   "stemmer": {:hex, :stemmer, "1.0.0-beta.1", "17112a69e72953e80985068ce68a77413de7e9adfe17204f23df1a1dc69fa7de", [:mix], []}}

test/simple_bayes/storage/file_system_test.exs

@@ -0,0 +1,87 @@
+defmodule SimpleBayes.Storage.FileSystemTest do
+  use ExUnit.Case, async: true
+
+  doctest SimpleBayes.Storage.FileSystem
+
+  describe "file system storage" do
+    setup do
+      opts = [
+        storage:        :file_system,
+        storage_config: [file_path: "test/temp/file_sysmte_test.txt"]
+      ]
+
+      SimpleBayes.init(opts)
+      |> SimpleBayes.train(:apple, "red sweet")
+      |> SimpleBayes.train(:apple, "green", weight: 0.5)
+      |> SimpleBayes.train(:apple, "round", weight: 2)
+      |> SimpleBayes.train(:banana, "sweet")
+      |> SimpleBayes.save()
+
+      SimpleBayes.load(opts)
+      |> SimpleBayes.train(:banana, "green", weight: 0.5)
+      |> SimpleBayes.train(:banana, "yellow long", weight: 2)
+      |> SimpleBayes.train(:orange, "red")
+      |> SimpleBayes.train(:orange, "yellow sweet", weight: 0.5)
+      |> SimpleBayes.train(:orange, "round", weight: 2)
+      |> SimpleBayes.save()
+
+      {:ok, opts: opts}
+    end
+
+    test "README example on .classify", meta do
+      result = SimpleBayes.load(meta.opts)
+               |> SimpleBayes.classify("Maybe green maybe red but definitely round and sweet")
+               |> Keyword.keys()
+
+      assert result == [:apple, :orange, :banana]
+    end
+
+    test "README example on .classify_one", meta do
+      result = SimpleBayes.load(meta.opts)
+               |> SimpleBayes.classify_one("Maybe green maybe red but definitely round and sweet")
+
+      assert result == :apple
+    end
+  end
+
+  describe "file system storage with flattened configuration options" do
+    setup do
+      opts = [
+        storage:   :file_system,
+        file_path: "test/temp/file_sysmte_test.txt"
+      ]
+
+      SimpleBayes.init(opts)
+      |> SimpleBayes.train(:apple, "red sweet")
+      |> SimpleBayes.train(:apple, "green", weight: 0.5)
+      |> SimpleBayes.train(:apple, "round", weight: 2)
+      |> SimpleBayes.train(:banana, "sweet")
+      |> SimpleBayes.save()
+
+      SimpleBayes.load(opts)
+      |> SimpleBayes.train(:banana, "green", weight: 0.5)
+      |> SimpleBayes.train(:banana, "yellow long", weight: 2)
+      |> SimpleBayes.train(:orange, "red")
+      |> SimpleBayes.train(:orange, "yellow sweet", weight: 0.5)
+      |> SimpleBayes.train(:orange, "round", weight: 2)
+      |> SimpleBayes.save()
+
+      {:ok, opts: opts}
+    end
+
+    test "README example on .classify", meta do
+      result = SimpleBayes.load(meta.opts)
+               |> SimpleBayes.classify("Maybe green maybe red but definitely round and sweet")
+               |> Keyword.keys()
+
+      assert result == [:apple, :orange, :banana]
+    end
+
+    test "README example on .classify_one", meta do
+      result = SimpleBayes.load(meta.opts)
+               |> SimpleBayes.classify_one("Maybe green maybe red but definitely round and sweet")
+
+      assert result == :apple
+    end
+  end
+end

test/simple_bayes/storage/memory_test.exs

@@ -11,17 +11,19 @@ defmodule SimpleBayes.Storage.MemoryTest do
       ]
 
       SimpleBayes.init(opts)
-               |> SimpleBayes.train(:apple, "red sweet")
-               |> SimpleBayes.train(:apple, "green", weight: 0.5)
-               |> SimpleBayes.train(:apple, "round", weight: 2)
-               |> SimpleBayes.train(:banana, "sweet")
+      |> SimpleBayes.train(:apple, "red sweet")
+      |> SimpleBayes.train(:apple, "green", weight: 0.5)
+      |> SimpleBayes.train(:apple, "round", weight: 2)
+      |> SimpleBayes.train(:banana, "sweet")
+      |> SimpleBayes.save()
 
       SimpleBayes.load(opts)
-               |> SimpleBayes.train(:banana, "green", weight: 0.5)
-               |> SimpleBayes.train(:banana, "yellow long", weight: 2)
-               |> SimpleBayes.train(:orange, "red")
-               |> SimpleBayes.train(:orange, "yellow sweet", weight: 0.5)
-               |> SimpleBayes.train(:orange, "round", weight: 2)
+      |> SimpleBayes.train(:banana, "green", weight: 0.5)
+      |> SimpleBayes.train(:banana, "yellow long", weight: 2)
+      |> SimpleBayes.train(:orange, "red")
+      |> SimpleBayes.train(:orange, "yellow sweet", weight: 0.5)
+      |> SimpleBayes.train(:orange, "round", weight: 2)
+      |> SimpleBayes.save()
 
       {:ok, opts: opts}
     end
@@ -50,17 +52,19 @@ defmodule SimpleBayes.Storage.MemoryTest do
       ]
 
       SimpleBayes.init(opts)
-               |> SimpleBayes.train(:apple, "red sweet")
-               |> SimpleBayes.train(:apple, "green", weight: 0.5)
-               |> SimpleBayes.train(:apple, "round", weight: 2)
-               |> SimpleBayes.train(:banana, "sweet")
+      |> SimpleBayes.train(:apple, "red sweet")
+      |> SimpleBayes.train(:apple, "green", weight: 0.5)
+      |> SimpleBayes.train(:apple, "round", weight: 2)
+      |> SimpleBayes.train(:banana, "sweet")
+      |> SimpleBayes.save()
 
       SimpleBayes.load(opts)
-               |> SimpleBayes.train(:banana, "green", weight: 0.5)
-               |> SimpleBayes.train(:banana, "yellow long", weight: 2)
-               |> SimpleBayes.train(:orange, "red")
-               |> SimpleBayes.train(:orange, "yellow sweet", weight: 0.5)
-               |> SimpleBayes.train(:orange, "round", weight: 2)
+      |> SimpleBayes.train(:banana, "green", weight: 0.5)
+      |> SimpleBayes.train(:banana, "yellow long", weight: 2)
+      |> SimpleBayes.train(:orange, "red")
+      |> SimpleBayes.train(:orange, "yellow sweet", weight: 0.5)
+      |> SimpleBayes.train(:orange, "round", weight: 2)
+      |> SimpleBayes.save()
 
       {:ok, opts: opts}
     end