Added batching of multiple updating requests, to improve throughput with many writers. Also removed the couch_batch_save module, now batch requests are simply saved async as immediately, batching with outhr updates if possible.

git-svn-id: https://svn.apache.org/repos/asf/couchdb/trunk@832550 13f79535-47bb-0310-9956-ffa450edef68

1 files changed, 101 insertions, 52 deletions

diff --git a/src/couchdb/couch_db_updater.erl b/src/couchdb/couch_db_updater.erl
index a13f9955..96a59944 100644
--- a/src/couchdb/couch_db_updater.erl
+++ b/src/couchdb/couch_db_updater.erl
@@ -43,19 +43,6 @@ terminate(Reason, _Srv) ->
 
 handle_call(get_db, _From, Db) ->
     {reply, {ok, Db}, Db};
-handle_call({update_docs, GroupedDocs, NonRepDocs, Options}, _From, Db) ->
-    try update_docs_int(Db, GroupedDocs, NonRepDocs, Options) of
-    {ok, Failures, Db2} ->
-        ok = gen_server:call(Db#db.main_pid, {db_updated, Db2}),
-        if Db2#db.update_seq /= Db#db.update_seq ->
-            couch_db_update_notifier:notify({updated, Db2#db.name});
-        true -> ok
-        end,
-        {reply, {ok, Failures}, Db2}
-    catch
-        throw: retry ->
-            {reply, retry, Db}
-    end;
 handle_call(full_commit, _From, #db{waiting_delayed_commit=nil}=Db) ->
     {reply, ok, Db}; % no data waiting, return ok immediately
 handle_call(full_commit, _From,  Db) ->
@@ -192,6 +179,63 @@ handle_cast({compact_done, CompactFilepath}, #db{filepath=Filepath}=Db) ->
         {noreply, Db2}
     end.
 
+
+merge_updates([], RestB, AccOutGroups) ->
+    lists:reverse(AccOutGroups, RestB);
+merge_updates(RestA, [], AccOutGroups) ->
+    lists:reverse(AccOutGroups, RestA);
+merge_updates([[{_, #doc{id=IdA}}|_]=GroupA | RestA],
+        [[{_, #doc{id=IdB}}|_]=GroupB | RestB], AccOutGroups) ->
+    if IdA == IdB ->
+        merge_updates(RestA, RestB, [GroupA ++ GroupB | AccOutGroups]);
+    IdA < IdB ->
+        merge_updates(RestA, [GroupB | RestB], [GroupA | AccOutGroups]);
+    true ->
+        merge_updates([GroupA | RestA], RestB, [GroupB | AccOutGroups])
+    end.
+
+collect_updates(GroupedDocsAcc, ClientsAcc, MergeConflicts, FullCommit) ->
+    receive
+        % only collect updates with the same MergeConflicts flag and without
+        % local docs. Makes it easier to avoid multiple local doc updaters.
+        {update_docs, Client, GroupedDocs, [], MergeConflicts, FullCommit2} ->
+            GroupedDocs2 = [[{Client, Doc} || Doc <- DocGroup]
+                    || DocGroup <- GroupedDocs],
+            GroupedDocsAcc2 = 
+                merge_updates(GroupedDocsAcc, GroupedDocs2, []),
+            collect_updates(GroupedDocsAcc2, [Client | ClientsAcc],
+                    MergeConflicts, (FullCommit or FullCommit2))
+    after 0 ->
+        {GroupedDocsAcc, ClientsAcc, FullCommit}
+    end.
+
+handle_info({update_docs, Client, GroupedDocs, NonRepDocs, MergeConflicts, 
+        FullCommit}, Db) ->
+    GroupedDocs2 = [[{Client, D} || D <- DocGroup] || DocGroup <- GroupedDocs],
+    if NonRepDocs == [] ->
+        {GroupedDocs3, Clients, FullCommit2} = collect_updates(GroupedDocs2, 
+                [Client], MergeConflicts, FullCommit);
+    true ->
+        GroupedDocs3 = GroupedDocs2,
+        FullCommit2 = FullCommit,
+        Clients = [Client]
+    end,
+    NonRepDocs2 = [{Client, NRDoc} || NRDoc <- NonRepDocs],
+    try update_docs_int(Db, GroupedDocs3, NonRepDocs2, MergeConflicts, 
+                FullCommit2) of
+    {ok, Db2} ->
+        ok = gen_server:call(Db#db.main_pid, {db_updated, Db2}),
+        if Db2#db.update_seq /= Db#db.update_seq ->
+            couch_db_update_notifier:notify({updated, Db2#db.name});
+        true -> ok
+        end,
+        [catch(ClientPid ! {done, self()}) || ClientPid <- Clients],
+        {noreply, Db2}
+    catch
+        throw: retry ->
+            [catch(ClientPid ! {retry, self()}) || ClientPid <- Clients],
+            {noreply, Db}
+    end;
 handle_info(delayed_commit, Db) ->
     {noreply, commit_data(Db)}.
 
@@ -399,18 +443,24 @@ flush_trees(#db{fd=Fd,header=Header}=Db,
         end, Unflushed),
     flush_trees(Db, RestUnflushed, [InfoUnflushed#full_doc_info{rev_tree=Flushed} | AccFlushed]).
 
-merge_rev_trees(_MergeConflicts, [], [], AccNewInfos, AccRemoveSeqs, AccConflicts, AccSeq) ->
-    {ok, lists:reverse(AccNewInfos), AccRemoveSeqs, AccConflicts, AccSeq};
+
+send_result(Client, Id, OriginalRevs, NewResult) ->
+    % used to send a result to the client
+    catch(Client ! {result, self(), {{Id, OriginalRevs}, NewResult}}).
+
+merge_rev_trees(_MergeConflicts, [], [], AccNewInfos, AccRemoveSeqs, AccSeq) ->
+    {ok, lists:reverse(AccNewInfos), AccRemoveSeqs, AccSeq};
 merge_rev_trees(MergeConflicts, [NewDocs|RestDocsList],
-        [OldDocInfo|RestOldInfo], AccNewInfos, AccRemoveSeqs, AccConflicts, AccSeq) ->
+        [OldDocInfo|RestOldInfo], AccNewInfos, AccRemoveSeqs, AccSeq) ->
     #full_doc_info{id=Id,rev_tree=OldTree,deleted=OldDeleted,update_seq=OldSeq}
             = OldDocInfo,
-    {NewRevTree, NewConflicts} = lists:foldl(
-        fun(#doc{revs={Pos,[_Rev|PrevRevs]}}=NewDoc, {AccTree, AccConflicts2}) ->
+    NewRevTree = lists:foldl(
+        fun({Client, #doc{revs={Pos,[_Rev|PrevRevs]}}=NewDoc}, AccTree) ->
             if not MergeConflicts ->
                 case couch_key_tree:merge(AccTree, [couch_db:doc_to_tree(NewDoc)]) of
                 {_NewTree, conflicts} when (not OldDeleted) ->
-                    {AccTree, [{{Id, {Pos-1,PrevRevs}}, conflict} | AccConflicts2]};
+                    send_result(Client, Id, {Pos-1,PrevRevs}, conflict),
+                    AccTree;
                 {NewTree, no_conflicts} when  AccTree == NewTree ->
                     % the tree didn't change at all
                     % meaning we are saving a rev that's already
@@ -426,26 +476,28 @@ merge_rev_trees(MergeConflicts, [NewDocs|RestDocsList],
                         NewDoc2 = NewDoc#doc{revs={OldPos + 1, [NewRevId, OldRev]}},
                         {NewTree2, _} = couch_key_tree:merge(AccTree,
                                 [couch_db:doc_to_tree(NewDoc2)]),
-                        % we changed the rev id, this tells the caller we did.
-                        {NewTree2, [{{Id, {Pos-1,PrevRevs}}, {ok, {OldPos + 1, NewRevId}}}
-                                | AccConflicts2]};
+                        % we changed the rev id, this tells the caller we did
+                        send_result(Client, Id, {Pos-1,PrevRevs}, 
+                                {ok, {OldPos + 1, NewRevId}}),
+                        NewTree2;
                     true ->
-                        {AccTree, [{{Id, {Pos-1,PrevRevs}}, conflict} | AccConflicts2]}
+                        send_result(Client, Id, {Pos-1,PrevRevs}, conflict),
+                        AccTree
                     end;
                 {NewTree, _} ->
-                    {NewTree, AccConflicts2}
+                    NewTree
                 end;
             true ->
                 {NewTree, _} = couch_key_tree:merge(AccTree,
                             [couch_db:doc_to_tree(NewDoc)]),
-                {NewTree, AccConflicts2}
+                NewTree
             end 
         end,
-        {OldTree, AccConflicts}, NewDocs),
+        OldTree, NewDocs),
     if NewRevTree == OldTree ->
         % nothing changed
         merge_rev_trees(MergeConflicts, RestDocsList, RestOldInfo, AccNewInfos,
-                AccRemoveSeqs, NewConflicts, AccSeq);
+                AccRemoveSeqs, AccSeq);
     true ->
         % we have updated the document, give it a new seq #
         NewInfo = #full_doc_info{id=Id,update_seq=AccSeq+1,rev_tree=NewRevTree},
@@ -454,7 +506,7 @@ merge_rev_trees(MergeConflicts, [NewDocs|RestDocsList],
             _ -> [OldSeq | AccRemoveSeqs]
         end,
         merge_rev_trees(MergeConflicts, RestDocsList, RestOldInfo,
-                [NewInfo|AccNewInfos], RemoveSeqs, NewConflicts, AccSeq+1)
+                [NewInfo|AccNewInfos], RemoveSeqs, AccSeq+1)
     end.
 
 
@@ -473,13 +525,13 @@ stem_full_doc_infos(#db{revs_limit=Limit}, DocInfos) ->
     [Info#full_doc_info{rev_tree=couch_key_tree:stem(Tree, Limit)} ||
             #full_doc_info{rev_tree=Tree}=Info <- DocInfos].
 
-update_docs_int(Db, DocsList, NonRepDocs, Options) ->
+update_docs_int(Db, DocsList, NonRepDocs, MergeConflicts, FullCommit) ->
     #db{
         fulldocinfo_by_id_btree = DocInfoByIdBTree,
         docinfo_by_seq_btree = DocInfoBySeqBTree,
         update_seq = LastSeq
         } = Db,
-    Ids = [Id || [#doc{id=Id}|_] <- DocsList],
+    Ids = [Id || [{_Client, #doc{id=Id}}|_] <- DocsList],
     % lookup up the old documents, if they exist.
     OldDocLookups = couch_btree:lookup(DocInfoByIdBTree, Ids),
     OldDocInfos = lists:zipwith(
@@ -489,17 +541,15 @@ update_docs_int(Db, DocsList, NonRepDocs, Options) ->
             #full_doc_info{id=Id}
         end,
         Ids, OldDocLookups),
-
     % Merge the new docs into the revision trees.
-    {ok, NewDocInfos0, RemoveSeqs, Conflicts, NewSeq} = merge_rev_trees(
-            lists:member(merge_conflicts, Options),
-            DocsList, OldDocInfos, [], [], [], LastSeq),
+    {ok, NewDocInfos0, RemoveSeqs, NewSeq} = merge_rev_trees(
+            MergeConflicts, DocsList, OldDocInfos, [], [], LastSeq),
 
     NewFullDocInfos = stem_full_doc_infos(Db, NewDocInfos0),
 
     % All documents are now ready to write.
 
-    {ok, LocalConflicts, Db2}  = update_local_docs(Db, NonRepDocs),
+    {ok, Db2}  = update_local_docs(Db, NonRepDocs),
 
     % Write out the document summaries (the bodies are stored in the nodes of
     % the trees, the attachments are already written to disk)
@@ -526,15 +576,14 @@ update_docs_int(Db, DocsList, NonRepDocs, Options) ->
         Db4 = refresh_validate_doc_funs(Db3)
     end,
 
-    {ok, LocalConflicts ++ Conflicts,
-            commit_data(Db4, not lists:member(full_commit, Options))}.
+    {ok, commit_data(Db4, not FullCommit)}.
 
 
 update_local_docs(#db{local_docs_btree=Btree}=Db, Docs) ->
-    Ids = [Id || #doc{id=Id} <- Docs],
+    Ids = [Id || {_Client, #doc{id=Id}} <- Docs],
     OldDocLookups = couch_btree:lookup(Btree, Ids),
     BtreeEntries = lists:zipwith(
-        fun(#doc{id=Id,deleted=Delete,revs={0,PrevRevs},body=Body}, OldDocLookup) ->
+        fun({Client, #doc{id=Id,deleted=Delete,revs={0,PrevRevs},body=Body}}, OldDocLookup) ->
             case PrevRevs of
             [RevStr|_] ->
                 PrevRev = list_to_integer(?b2l(RevStr));
@@ -549,28 +598,28 @@ update_local_docs(#db{local_docs_btree=Btree}=Db, Docs) ->
             case OldRev == PrevRev of
             true ->
                 case Delete of
-                    false -> {update, {Id, {PrevRev + 1, PrevRevs, Body}}};
-                    true  -> {remove, Id, PrevRevs}
+                    false ->
+                        send_result(Client, Id, {0, PrevRevs}, {ok,
+                                {0, ?l2b(integer_to_list(PrevRev + 1))}}),
+                        {update, {Id, {PrevRev + 1, Body}}};
+                    true  ->
+                        send_result(Client, Id, {0, PrevRevs},
+                                {ok, {0, <<"0">>}}),
+                        {remove, Id}
                 end;
             false ->
-                {conflict, {Id, {0, PrevRevs}}}
+                send_result(Client, Id, {0, PrevRevs}, conflict),
+                ignore
             end
         end, Docs, OldDocLookups),
 
-    BtreeIdsRemove = [Id || {remove, Id, _PrevRevs} <- BtreeEntries],
-    BtreeIdsUpdate = [{Id, {NewRev, Body}} || {update, {Id, {NewRev, _OldRevs, Body}}} <- BtreeEntries],
-    Results = 
-            [{{Id, {0, PrevRevs}}, {ok, {0, <<"0">>}}}
-                || {remove, Id, PrevRevs} <- BtreeEntries] ++
-            [{{Id, {0, PrevRevs}}, {ok, {0, ?l2b(integer_to_list(NewRev))}}}
-                || {update, {Id, {NewRev, PrevRevs, _Body}}} <- BtreeEntries] ++
-            [{IdRevs, conflict}
-                || {conflict, IdRevs} <- BtreeEntries],
+    BtreeIdsRemove = [Id || {remove, Id} <- BtreeEntries],
+    BtreeIdsUpdate = [{Key, Val} || {update, {Key, Val}} <- BtreeEntries],
 
     {ok, Btree2} =
         couch_btree:add_remove(Btree, BtreeIdsUpdate, BtreeIdsRemove),
 
-    {ok, Results, Db#db{local_docs_btree = Btree2}}.
+    {ok, Db#db{local_docs_btree = Btree2}}.
 
 
 commit_data(Db) ->