Backport new /_active_tasks API

Improved _active_tasks API

Tasks are now free to set any properties they wish (as an
Erlang proplist). Different tasks can have different properties
and the status string doesn't exist anymore - instead client
applications can build it using more granular properties from
_active_tasks. Some of these properties are:

1) "progress" (an integer percentage, for all tasks)
2) "database" (for compactions and indexer tasks)
3) "design_document" (for indexer and view compaction tasks)
4) "source" and "target" (for replications)
5) "docs_read", "docs_written", "doc_write_failures",
   "missing_revs_found", "missing_revs_checked", "source_seq",
   "checkpointed_source_seq" and "continuous" for replications

BugzID: 14269

Conflicts:
	apps/couch/src/couch_db_updater.erl
	apps/couch/src/couch_rep.erl
	apps/couch/src/couch_task_status.erl
	apps/couch/src/couch_view_compactor.erl
	apps/couch/src/couch_view_updater.erl

1 files changed, 12 insertions, 11 deletions

diff --git a/apps/couch/src/couch_view_updater.erl b/apps/couch/src/couch_view_updater.erl
index 8238e3e5..ca144149 100644
--- a/apps/couch/src/couch_view_updater.erl
+++ b/apps/couch/src/couch_view_updater.erl
@@ -32,17 +32,25 @@ update(Owner, Group, #db{name = DbName} = Db) ->
         current_seq = Seq,
         purge_seq = PurgeSeq
     } = Group,
-    couch_task_status:add_task(<<"View Group Indexer">>, <<DbName/binary," ",GroupName/binary>>, <<"Starting index update">>),
+    % compute on all docs modified since we last computed.
+    TotalChanges = couch_db:count_changes_since(Db, Seq),
+    couch_task_status:add_task([
+        {type, indexer},
+        {database, DbName},
+        {design_document, GroupName},
+        {progress, 0},
+        {changes_done, 0},
+        {total_changes, TotalChanges}
+    ]),
+    couch_task_status:set_update_frequency(500),
 
     DbPurgeSeq = couch_db:get_purge_seq(Db),
     Group2 =
     if DbPurgeSeq == PurgeSeq ->
         Group;
     DbPurgeSeq == PurgeSeq + 1 ->
-        couch_task_status:update(<<"Removing purged entries from view index.">>),
         purge_index(Group, Db);
     true ->
-        couch_task_status:update(<<"Resetting view index due to lost purge entries.">>),
         exit(reset)
     end,
     {ok, MapQueue} = couch_work_queue:new(
@@ -53,10 +61,6 @@ update(Owner, Group, #db{name = DbName} = Db) ->
     ViewEmptyKVs = [{View, []} || View <- Group2#group.views],
     spawn_link(?MODULE, do_maps, [Group, MapQueue, WriteQueue, ViewEmptyKVs]),
     spawn_link(?MODULE, do_writes, [Self, Owner, Group2, WriteQueue, Seq == 0]),
-    % compute on all docs modified since we last computed.
-    TotalChanges = couch_db:count_changes_since(Db, Seq),
-    % update status every half second
-    couch_task_status:set_update_frequency(500),
     #group{ design_options = DesignOptions } = Group,
     IncludeDesign = couch_util:get_value(<<"include_design">>,
         DesignOptions, false),
@@ -69,8 +73,6 @@ update(Owner, Group, #db{name = DbName} = Db) ->
     EnumFun = fun ?MODULE:load_docs/3,
     Acc0 = {0, Db, MapQueue, DocOpts, IncludeDesign, TotalChanges},
     {ok, _, _} = couch_db:enum_docs_since(Db, Seq, EnumFun, Acc0, []),
-    couch_task_status:set_update_frequency(0),
-    couch_task_status:update("Finishing."),
     couch_work_queue:close(MapQueue),
     receive {new_group, NewGroup} ->
         exit({new_group,
@@ -78,8 +80,7 @@ update(Owner, Group, #db{name = DbName} = Db) ->
     end.
 
 load_docs(DocInfo, _, {I, Db, MapQueue, DocOpts, IncludeDesign, Total} = Acc) ->
-    couch_task_status:update("Processed ~p of ~p changes (~p%)", [I, Total,
-        (I*100) div Total]),
+    couch_task_status:update([{changes_done, I}, {progress, (I * 100) div Total}]),
     load_doc(Db, DocInfo, MapQueue, DocOpts, IncludeDesign),
     {ok, setelement(1, Acc, I+1)}.