Refactoring ; template for block store

1 files changed, 78 insertions, 0 deletions

diff --git a/lib/app/blockstore.ex_ b/lib/app/blockstore.ex_
new file mode 100644
index 0000000..2854161
--- /dev/null
+++ b/lib/app/blockstore.ex_
@@ -0,0 +1,78 @@
+defmodule SApp.BlockStore do
+  @moduledoc """
+  A module that implements a content-adressable storage (blocks, or pages,
+  identified by the hash of their contents).
+
+  Establishes full node connectivity and uses rendez-vous hashing to select
+  which nodes are responsible of a given hash.
+
+  TODO: WIP
+  """
+
+  use GenServer
+
+  defmodule State do
+    defstruct [:name, :id, :manifest,
+               :ncopies,
+               :store, :peers]
+  end
+
+
+  def start_link(name) do
+    GenServer.start_link(__MODULE__, name)
+  end
+
+  def init(name) do
+    manifest = {:blockstore, name}
+    id = SData.term_hash manifest
+
+    GenServer.cast(Shard.Manager, {:register, id, self()})
+    GenServer.cast(self(), :init_pull)
+
+    {:ok, %State{name: name, id: id, manifest: manifest,
+                 ncopies: 3,
+                 store: %{}, peers: %{}}}
+  end
+
+  def handle_call(:manifest, _from, state) do
+    {:reply, state.manifest, state}
+  end
+
+  def handle_call({:get, key}, from, state) do
+    # TODO
+  end
+
+  def handle_call({:put, val}, state) do
+    # TODO
+  end
+
+  def handle_cast({:redundant, _}, _state) do
+    exit :normal
+  end
+
+  def handle_cast(:init_pull, state) do
+    GenServer.call(SNet.Manager, :get_all)
+    |> Enum.each(&(GenServer.cast(&1, {:send_msg, {:interested, [state.id]}})))
+    {:noreply, state}
+  end
+
+  def handle_cast({:interested, peer_id, peer_pid}, state) do
+    new_peers = Map.put(state.peers, peer_id, peer_pid)
+    new_state = %{ state | peers: new_peers }
+    initial_sync(new_state, peer_id, peer_pid)
+    {:noreply, new_state}
+  end
+
+  def handle_cast({:msg, peer_id, peer_pid, msg}, state) do
+    # TODO
+    {:noreply, state}
+  end
+
+  defp initial_sync(state, peer_id, peer_pid) do
+    # TODO
+  end
+
+  defp send(state, to, msg) do
+    GenServer.cast(to, {:send_msg, {state.id, msg}})
+  end
+end