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, 38 insertions, 3 deletions

diff --git a/rel/overlay/share/www/status.html b/rel/overlay/share/www/status.html
index 2067ab9b..c9fecc60 100644
--- a/rel/overlay/share/www/status.html
+++ b/rel/overlay/share/www/status.html
@@ -65,11 +65,46 @@ specific language governing permissions and limitations under the License.
               .appendTo("#status tbody.content");
           } else {
             $.each(tasks, function(idx, task) {
+              var status, type, object;
+
+              switch (task.type) {
+              case "database_compaction":
+                type = "Database compaction";
+                object = task.database + (task.retry ? " retry" : "");
+                status = "Copied " + task.changes_done + " of " +
+                  task.total_changes + " changes (" + task.progress + "%)";
+                break;
+              case "view_compaction":
+                type = "View compaction";
+                object = task.database + ", " + task.design_document;
+                status = "Progress " + task.progress + "%";
+                break;
+              case "indexer":
+                type = "Indexer";
+                object = task.database + ", " + task.design_document;
+                status = "Processed " + task.changes_done + " of " +
+                  task.total_changes + " changes (" + task.progress + "%)";
+                break;
+              case "replication":
+                type = "Replication";
+                object = task.source + " to " + task.target;
+                status = "Checkpointed source sequence " +
+                  task.checkpointed_source_seq + ", current source sequence " +
+                  task.source_seq + ", progress " + task.progress + "%";
+                break;
+              case "search_indexer":
+                type = "Search Indexer";
+                object = task.database + ", " + task.design_document;
+                status = "Processed " + task.changes_done + " of " +
+                  task.total_changes + " changes (" + task.progress + "%)";
+                break;
+              }
+
               $("<tr><th></th><td class='object'></td><td class='pid'></td><td class='status'></td></tr>")
-                .find("th").text(task.type).end()
-                .find("td.object").text(task.task).end()
+                .find("th").text(type).end()
+                .find("td.object").text(object).end()
                 .find("td.pid").text(task.pid).end()
-                .find("td.status").text(task.status).end()
+                .find("td.status").text(status).end()
                 .appendTo("#status tbody.content");
             });
           }