1 files changed, 57 insertions, 7 deletions

diff --git a/src/mem3/src/mem3_util.erl b/src/mem3/src/mem3_util.erl
index 28cb17778..005a6b1bc 100644
--- a/src/mem3/src/mem3_util.erl
+++ b/src/mem3/src/mem3_util.erl
@@ -14,7 +14,8 @@
 
 -export([name_shard/2, create_partition_map/5, build_shards/2,
     n_val/2, q_val/1, to_atom/1, to_integer/1, write_db_doc/1, delete_db_doc/1,
-    shard_info/1, ensure_exists/1, open_db_doc/1, get_or_create_db/2]).
+    shard_info/1, ensure_exists/1, open_db_doc/1, update_db_doc/1]).
+-export([get_or_create_db/2, get_or_create_db_int/2]).
 -export([is_deleted/1, rotate_list/2]).
 -export([get_shard_opts/1, get_engine_opt/1, get_props_opt/1]).
 -export([get_shard_props/1, find_dirty_shards/0]).
@@ -116,6 +117,34 @@ write_db_doc(DbName, #doc{id=Id, body=Body} = Doc, ShouldMutate) ->
         couch_db:close(Db)
     end.
 
+update_db_doc(Doc) ->
+    update_db_doc(mem3_sync:shards_db(), Doc, true).
+
+update_db_doc(DbName, #doc{id=Id, body=Body} = Doc, ShouldMutate) ->
+    {ok, Db} = couch_db:open(DbName, [?ADMIN_CTX]),
+    try couch_db:open_doc(Db, Id, [ejson_body]) of
+    {ok, #doc{body = Body}} ->
+        % the doc is already in the desired state, we're done here
+        ok;
+    {ok, #doc{body = Body1}} ->
+        % the doc has a new body to be written
+        {ok, _} = couch_db:update_doc(Db, Doc#doc{body=Body1}, []),
+        ok;
+    {not_found, _} when ShouldMutate ->
+        try couch_db:update_doc(Db, Doc, []) of
+        {ok, _} ->
+            ok
+        catch conflict ->
+            % check to see if this was a replication race or a different edit
+            update_db_doc(DbName, Doc, false)
+        end;
+    _ ->
+        % the doc already exists in a different state
+        conflict
+    after
+        couch_db:close(Db)
+    end.
+
 delete_db_doc(DocId) ->
     gen_server:cast(mem3_shards, {cache_remove, DocId}),
     delete_db_doc(mem3_sync:shards_db(), DocId, true).
@@ -240,7 +269,7 @@ db_props_from_json([{K, V} | Rest]) ->
     [{K, V} | db_props_from_json(Rest)].
 
 n_val(undefined, NodeCount) ->
-    n_val(config:get("cluster", "n", "3"), NodeCount);
+    n_val(config:get_integer("cluster", "n", 3), NodeCount);
 n_val(N, NodeCount) when is_list(N) ->
     n_val(list_to_integer(N), NodeCount);
 n_val(N, NodeCount) when is_integer(NodeCount), N > NodeCount ->
@@ -508,18 +537,39 @@ sort_ranges_fun({B1, _}, {B2, _}) ->
     B1 =< B2.
 
 
+add_db_config_options(DbName, Options) ->
+    DbOpts = case mem3:dbname(DbName) of
+        DbName  -> [];
+        MDbName -> mem3_shards:opts_for_db(MDbName)
+    end,
+    merge_opts(DbOpts, Options).
+
+
 get_or_create_db(DbName, Options) ->
+    case couch_db:open(DbName, Options) of
+        {ok, _} = OkDb ->
+            OkDb;
+        {not_found, no_db_file} ->
+            try
+                Options1 = [{create_if_missing, true} | Options],
+                Options2 = add_db_config_options(DbName, Options1),
+                couch_db:open(DbName, Options2)
+            catch error:database_does_not_exist ->
+                throw({error, missing_target})
+            end;
+        Else ->
+            Else
+    end.
+
+
+get_or_create_db_int(DbName, Options) ->
     case couch_db:open_int(DbName, Options) of
         {ok, _} = OkDb ->
             OkDb;
         {not_found, no_db_file} ->
             try
-                DbOpts = case mem3:dbname(DbName) of
-                    DbName  -> [];
-                    MDbName -> mem3_shards:opts_for_db(MDbName)
-                end,
                 Options1 = [{create_if_missing, true} | Options],
-                Options2 = merge_opts(DbOpts, Options1),
+                Options2 = add_db_config_options(DbName, Options1),
                 couch_db:open_int(DbName, Options2)
             catch error:database_does_not_exist ->
                 throw({error, missing_target})