1 files changed, 99 insertions, 0 deletions
diff --git a/src/nouveau/src/nouveau_fabric_info.erl b/src/nouveau/src/nouveau_fabric_info.erl
new file mode 100644
index 000000000..59e47094f
--- /dev/null
+++ b/src/nouveau/src/nouveau_fabric_info.erl
@@ -0,0 +1,99 @@
+%%
+%% Licensed under the Apache License, Version 2.0 (the "License");
+%% you may not use this file except in compliance with the License.
+%% You may obtain a copy of the License at
+%%
+%%     http://www.apache.org/licenses/LICENSE-2.0
+%%
+%% Unless required by applicable law or agreed to in writing, software
+%% distributed under the License is distributed on an "AS IS" BASIS,
+%% WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+%% See the License for the specific language governing permissions and
+%% limitations under the License.
+
+%% -*- erlang-indent-level: 4;indent-tabs-mode: nil -*-
+
+-module(nouveau_fabric_info).
+
+-export([go/3]).
+
+-include_lib("mem3/include/mem3.hrl").
+
+go(DbName, DDocId, IndexName) when is_binary(DDocId) ->
+    {ok, DDoc} = fabric:open_doc(DbName, <<"_design/", DDocId/binary>>, [ejson_body]),
+    go(DbName, DDoc, IndexName);
+go(DbName, DDoc, IndexName) ->
+    {ok, Index} = nouveau_util:design_doc_to_index(DbName, DDoc, IndexName),
+    Shards = mem3:shards(DbName),
+    Counters0 = lists:map(
+        fun(#shard{} = Shard) ->
+            Ref = rexi:cast(
+                Shard#shard.node,
+                {nouveau_rpc, info, [Shard#shard.name, Index]}
+            ),
+            Shard#shard{ref = Ref}
+        end,
+        Shards
+    ),
+    Counters = fabric_dict:init(Counters0, nil),
+    Workers = fabric_dict:fetch_keys(Counters),
+    RexiMon = fabric_util:create_monitors(Workers),
+
+    Acc0 = {fabric_dict:init(Workers, nil), #{}},
+    try
+        fabric_util:recv(Workers, #shard.ref, fun handle_message/3, Acc0)
+    after
+        rexi_monitor:stop(RexiMon),
+        fabric_util:cleanup(Workers)
+    end.
+
+handle_message({rexi_DOWN, _, {_, NodeRef}, _}, _Worker, {Counters, Acc}) ->
+    case fabric_util:remove_down_workers(Counters, NodeRef) of
+        {ok, NewCounters} ->
+            {ok, {NewCounters, Acc}};
+        error ->
+            {error, {nodedown, <<"progress not possible">>}}
+    end;
+handle_message({rexi_EXIT, Reason}, Worker, {Counters, Acc}) ->
+    NewCounters = fabric_dict:erase(Worker, Counters),
+    case fabric_ring:is_progress_possible(NewCounters) of
+        true ->
+            {ok, {NewCounters, Acc}};
+        false ->
+            {error, Reason}
+    end;
+handle_message({ok, Info}, Worker, {Counters, Acc0}) ->
+    case fabric_dict:lookup_element(Worker, Counters) of
+        undefined ->
+            % already heard from someone else in this range
+            {ok, {Counters, Acc0}};
+        nil ->
+            C1 = fabric_dict:store(Worker, ok, Counters),
+            C2 = fabric_view:remove_overlapping_shards(Worker, C1),
+            Acc1 = maps:merge_with(fun merge_info/3, Info, Acc0),
+            case fabric_dict:any(nil, C2) of
+                true ->
+                    {ok, {C2, Acc1}};
+                false ->
+                    {stop, Acc1}
+            end
+    end;
+handle_message({error, Reason}, Worker, {Counters, Acc}) ->
+    NewCounters = fabric_dict:erase(Worker, Counters),
+    case fabric_ring:is_progress_possible(NewCounters) of
+        true ->
+            {ok, {NewCounters, Acc}};
+        false ->
+            {error, Reason}
+    end;
+handle_message({'EXIT', _}, Worker, {Counters, Acc}) ->
+    NewCounters = fabric_dict:erase(Worker, Counters),
+    case fabric_ring:is_progress_possible(NewCounters) of
+        true ->
+            {ok, {NewCounters, Acc}};
+        false ->
+            {error, {nodedown, <<"progress not possible">>}}
+    end.
+
+merge_info(_Key, Val1, Val2) ->
+    Val1 + Val2.