WIP: starting machi_cr_client:append_chunk*

src/machi_cr_client.erl

@@ -65,6 +65,7 @@
          terminate/2, code_change/3]).
 
 -define(FLU_PC, machi_proxy_flu1_client).
+-define(TIMEOUT, 2*1000).
 
 -record(state, {
           members_dict    :: p_srvr_dict(),
@@ -278,7 +279,46 @@ code_change(_OldVsn, S, _Extra) ->
 %%%%%%%%%%%%%%%%%%%%%%%%%%%
 
 handle_call2({append_chunk_extra, Prefix, Chunk, ChunkExtra}, _From, S) ->
-    {reply, sorry_dude, S}.
+    do_append_chunk_extra1(Prefix, Chunk, ChunkExtra, S).
+
+do_append_chunk_extra1(Prefix, Chunk, ChunkExtra,
+                       #state{epoch_id=EpochID, proj=P,
+                              proxies_dict=PD}=S) ->
+    #projection_v1{upi=[HeadFLU|RestFLUs]} = P,
+    case ?FLU_PC:append_chunk_extra(orddict:fetch(HeadFLU, PD),
+                                    EpochID, Prefix, Chunk, ChunkExtra,
+                                    ?TIMEOUT) of
+        {ok, {Offset, _Size, File}=_X} ->
+            io:format(user, "TODO: X ~p\n", [_X]),
+            do_append_chunk_extra2(RestFLUs, File, Offset, Chunk,
+                                   HeadFLU, 1, S);
+        {error, Change} when Change == bad_epoch; Change == wedged ->
+            S2 = update_proj(S#state{proj=undefined, bad_proj=P}),
+            do_append_chunk_extra1(Prefix, Chunk, ChunkExtra, S2)
+        %% TODO return values here
+    end.
+
+do_append_chunk_extra2([], File, Offset, _Chunk, _OldHeadFLU, _OkCount, S) ->
+    {reply, {ok, {File, Offset}}, S};
+do_append_chunk_extra2([FLU|RestFLUs], File, Offset, Chunk, OldHeadFLU, OkCount,
+                       #state{epoch_id=EpochID, proj=P,
+                              proxies_dict=PD}=S) ->
+    case ?FLU_PC:write_chunk(orddict:fetch(FLU, PD),
+                                    EpochID, File, Offset, Chunk, ?TIMEOUT) of
+        ok ->
+            do_append_chunk_extra2(RestFLUs, File, Offset, Chunk,
+                                   OldHeadFLU, OkCount + 1, S);
+        {error, Change} when Change == bad_epoch; Change == wedged ->
+            S2 = update_proj(S#state{proj=undefined, bad_proj=P}),
+            #projection_v1{upi=[NewHeadFLU|NewRestFLUs]} = S2#state.proj,
+            if OkCount == 1, NewHeadFLU == OldHeadFLU ->
+                    do_append_chunk_extra2(NewRestFLUs, File, Offset, Chunk,
+                                           OldHeadFLU, OkCount, S2);
+               true ->
+                    {error, partition}
+            end
+        %% TODO return values here
+    end.
 
 update_proj(#state{proj=undefined}=S) ->
     update_proj2(1, S);
@@ -287,18 +327,38 @@ update_proj(S) ->
 
 update_proj2(Count, #state{bad_proj=BadProj, proxies_dict=ProxiesDict}=S) ->
     Timeout = 2*1000,
-    PidsMons =
+    Parent = self(),
-        [spawn_monitor(fun() ->
+    Proxies = orddict:to_list(ProxiesDict),
-                               exit(catch ?FLU_PC:read_latest_projection(
+    Worker = spawn(
-                                             Proxy, private, Timeout))
+               fun() ->
-                       end) || {_K, Proxy} <- orddict:to_list(ProxiesDict)],
+                  PidsMons =
-    Rs = gather_worker_statuses(PidsMons, Timeout*2),
+                      [spawn_monitor(fun() ->
+                                      exit(catch ?FLU_PC:read_latest_projection(
+                                                       Proxy, private, Timeout))
+                                      end) || {_K, Proxy} <- Proxies],
+                  Rs = gather_worker_statuses(PidsMons, Timeout*2),
+                  Parent ! {res, self(), Rs},
+                  exit(normal)
+               end),
+    Rs = receive {res, Worker, Results} -> Results
+         after Timeout*2 -> []
+         end,
+    %% TODO: There's a possible bug here when running multiple independent
+    %% Machi clusters/chains.  If our chain used to be [a,b], but our
+    %% sysadmin has changed our cluster to be [a] and a completely seprate
+    %% cluster with [b], and if b is reusing the address & port number,
+    %% then it is possible that choose_best_projs() can incorrectly choose
+    %% b's projection.
     case choose_best_proj(Rs) of
         P when P >= BadProj ->
+            #projection_v1{epoch_number=Epoch, epoch_csum=CSum,
+                           members_dict=NewMembersDict} = P,
             io:format(user, "~s: proj ~P\n", [?MODULE, P, 10]),
-            EpochID = {P#projection_v1.epoch_number,
+            EpochID = {Epoch, CSum},
-                       P#projection_v1.epoch_csum},
+            ?FLU_PC:stop_proxies(ProxiesDict),
-            S#state{bad_proj=undefined, proj=EpochID, epoch_id=EpochID};
+            NewProxiesDict = ?FLU_PC:start_proxies(NewMembersDict),
+            S#state{bad_proj=undefined, proj=P, epoch_id=EpochID,
+                    members_dict=NewMembersDict, proxies_dict=NewProxiesDict};
         _ ->
             timer:sleep(10 + (Count * 20)),
             update_proj2(Count + 1, S)
@@ -315,7 +375,7 @@ gather_worker_statuses([{Pid,Ref}|Rest], Timeout) ->
     end.
 
 choose_best_proj(Rs) ->
-    WorstEpoch = #projection_v1{epoch_number=-1},
+    WorstEpoch = #projection_v1{epoch_number=-1,epoch_csum= <<>>},
     lists:foldl(fun({ok, NewEpoch}, BestEpoch)
                       when NewEpoch > BestEpoch ->
                         NewEpoch;