From 48c8fde34591f782be7af77575eaa02dab8659b3 Mon Sep 17 00:00:00 2001
From: Adam Kocoloski <adam@cloudant.com>
Date: Wed, 30 Jun 2010 16:23:38 -0400
Subject: standardize mem3 naming.  app is horribly broken for now

---
 src/mem3_cache.erl | 91 ++++++++++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 91 insertions(+)
 create mode 100644 src/mem3_cache.erl

(limited to 'src/mem3_cache.erl')

diff --git a/src/mem3_cache.erl b/src/mem3_cache.erl
new file mode 100644
index 00000000..8f5c372a
--- /dev/null
+++ b/src/mem3_cache.erl
@@ -0,0 +1,91 @@
+-module(mem3_cache).
+-behaviour(gen_server).
+-export([init/1, handle_call/3, handle_cast/2, handle_info/2, terminate/2,
+    code_change/3]).
+
+-export([start_link/0]).
+
+-include("mem3.hrl").
+
+start_link() ->
+    gen_server:start_link({local, ?MODULE}, ?MODULE, [], []).
+
+init([]) ->
+    ets:new(partitions, [bag, protected, named_table, {keypos,#shard.dbname}]),
+    ets:new(memnodes, [bag, protected, named_table]),
+    cache_dbs(),
+    Self = self(),
+    couch_db_update_notifier:start_link(fun({updated, <<"dbs">>}) ->
+        Self ! rebuild_dbs_cache;
+    (_) -> ok end),
+    {ok, nil}.
+
+handle_call(_Msg, _From, State) ->
+    {reply, ok, State}.
+
+handle_cast(_Msg, State) ->
+    {noreply, State}.
+
+handle_info(rebuild_dbs_cache, State) ->
+    receive rebuild_dbs_cache ->
+        handle_info(rebuild_dbs_cache, State)
+    after 0 -> ok end,
+    T0 = now(),
+    ?LOG_INFO("rebuilding dbs DB cache", []),
+    ets:delete_all_objects(partitions),
+    ets:delete_all_objects(memnodes),
+    cache_dbs(),
+    ?LOG_INFO("rebuild of dbs DB cache complete in ~p ms",
+        [round(timer:now_diff(now(),T0)/1000)]),
+    {noreply, State}.
+
+terminate(_Reason, _State) ->
+    ok.
+
+code_change(_OldVsn, State, _Extra) ->
+    {ok, State}.
+
+cache_dbs() ->
+    try couch_db:open(<<"dbs">>, []) of
+    {ok, Db} ->
+        Bt = Db#db.id_tree,
+        FoldFun = fun(#full_doc_info{id=Id, deleted=false} = FullDocInfo, _, _) ->
+            {ok, Doc} = couch_db:open_doc_int(Db, FullDocInfo, []),
+            {Props} = couch_doc:to_json_obj(Doc, []),
+            cache_map(Id, Props),
+            cache_nodes(Id, Props),
+            {ok, true};
+        (_, _, _) ->
+            {ok, nil}
+        end,
+        couch_btree:foldl(Bt, FoldFun, nil),
+        couch_db:close(Db)
+    catch exit:{noproc,{gen_server,call,[couch_server|_]}} ->
+        timer:sleep(1000),
+        exit(couch_server_is_dead)
+    end.
+
+cache_map(Id, Props) ->
+    Map = couch_util:get_value(<<"map">>, Props, []),
+    lists:foreach(fun({[{<<"node">>,Node},{<<"b">>,Beg},{<<"e">>,End}]}) ->
+        Part = #shard{
+            name = partitions:shard_name(Beg, Id),
+            dbname = Id,
+            node = to_atom(Node),
+            range = [Beg,End]
+        },
+        ets:insert(partitions, Part)
+    end, Map).
+
+cache_nodes(Id, Props) ->
+    Nodes = couch_util:get_value(<<"nodes">>, Props, []),
+    lists:foreach(fun({[{<<"order">>,Order},{<<"node">>, Node},{<<"options">>,Opts}]}) ->
+        ets:insert(memnodes, {Id, {Order, to_atom(Node), Opts}})
+    end, Nodes).
+
+to_atom(Node) when is_binary(Node) ->
+    list_to_atom(binary_to_list(Node));
+to_atom(Node) when is_atom(Node) ->
+    Node.
+
+%{ok, ets:insert(dbs_cache, {Id, Props})};
-- 
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