Use DETS to store shard & peer list to disk

2 files changed, 17 insertions, 6 deletions

diff --git a/shard/lib/app/blockstore.ex b/shard/lib/app/blockstore.ex
index 8e4fddc..5e93135 100644
--- a/shard/lib/app/blockstore.ex
+++ b/shard/lib/app/blockstore.ex
@@ -109,10 +109,10 @@ defmodule SApp.BlockStore do
   end
 
   def ask_random_peers(state, key) do
-    peers = :ets.lookup(:shard_peer_db, state.shard_id)
+    peers = Shard.Manager.get_shard_peers(state.shard_id)
       |> Enum.shuffle
       |> Enum.take(3)
-    for {_, peer} <- peers do
+    for peer <- peers do
       Shard.Manager.send(peer, {state.shard_id, state.path, {:get, key}})
     end
   end
diff --git a/shard/lib/app/chat.ex b/shard/lib/app/chat.ex
index 051fab6..471d8f7 100644
--- a/shard/lib/app/chat.ex
+++ b/shard/lib/app/chat.ex
@@ -10,7 +10,6 @@ defmodule SApp.Chat do
   Future improvements:
   - message signing
   - storage of the chatroom messages to disk
-  - storage of the known peers that have this channel to disk
   - use a DHT to find peers that are interested in this channel
   - epidemic broadcast (carefull not to be too costly,
     maybe by limiting the number of peers we talk to)
@@ -22,6 +21,18 @@ defmodule SApp.Chat do
   require Logger
   alias SData.MerkleSearchTree, as: MST
 
+
+  defmodule Manifest do
+    defstruct [:channel]
+  end
+
+  defimpl Shard.Manifest, for: Manifest do
+    def start(m) do
+      SApp.Chat.start_link(m.channel)
+    end
+  end
+
+
   @doc """
   Start a process that connects to a given channel
   """
@@ -33,7 +44,7 @@ defmodule SApp.Chat do
   Initialize channel process.
   """
   def init(channel) do
-    manifest = {:chat, channel}
+    manifest = %Manifest{channel: channel}
     id = SData.term_hash manifest
 
     case Shard.Manager.register(id, manifest, self()) do
@@ -75,7 +86,7 @@ defmodule SApp.Chat do
   send data for this channel if they have some.
   """
   def handle_cast(:init_pull, state) do
-    for {_, pid, _, _} <- :ets.tab2list(:peer_db) do
+    for {_, pid, _, _} <- Shard.Manager.list_peers do
       GenServer.cast(pid, {:send_msg, {:interested, [state.id]}})
     end
     {:noreply, state}
@@ -101,7 +112,7 @@ defmodule SApp.Chat do
     end
 
     notif = {:append, prev_root, msgitem, mst.root}
-    for {_, peer_id} <- :ets.lookup(:shard_peer_db, state.id) do
+    for peer_id <- Shard.Manager.get_shard_peers(state.id) do
       Shard.Manager.send(peer_id, {state.id, nil, notif})
     end