job queue and async oplog-import/export (#395)

- Feature: New http endpoint for background jobs `/admin/jobs/status` which will return a response listing the currently active background jobs and their status
- Feature: New http endpoint for background jobs information `/admin/jobs/status/{jobid}` which will return a response detailing status, pending messages and progress status
  - GET will return a response detailing status, pending messages and progress status
  - DELETE will mark the job for cancelling and return without waiting for completion
  - If status returned is "Complete" or "Aborted" the jobid will be removed from the server and can not be queried again
- Feature: New zen command `jobs` to list, get info about and cancel background jobs
  - If no options are given it will display a list of active background jobs
  - `--jobid` accepts an id (returned from for example `oplog-export` with `--async`) and will return a response detailing status, pending messages and progress status for that job
  - `--cancel` can be added when `--jobid` is given which will request zenserver to cancel the background job
- Feature: oplog import and export http rpc requests are now async operations that will run in the background
- Feature: `oplog-export` and `oplog-import` now reports progress to the console as work progress by default
- Feature: `oplog-export` and `oplog-import` can now be cancelled using Ctrl+C
- Feature: `oplog-export` and `oplog-import` has a new option `--async` which will only trigger the work and report a background job id back

1 files changed, 3 insertions, 1 deletions

diff --git a/src/zenserver/admin/admin.h b/src/zenserver/admin/admin.h
index 9463ffbb3..3152f87ab 100644
--- a/src/zenserver/admin/admin.h
+++ b/src/zenserver/admin/admin.h
@@ -8,11 +8,12 @@
 namespace zen {
 
 class GcScheduler;
+class JobQueue;
 
 class HttpAdminService : public zen::HttpService
 {
 public:
-	HttpAdminService(GcScheduler& Scheduler);
+	HttpAdminService(GcScheduler& Scheduler, JobQueue& BackgroundJobQueue);
 	~HttpAdminService();
 
 	virtual const char* BaseUri() const override;
@@ -21,6 +22,7 @@ public:
 private:
 	HttpRequestRouter m_Router;
 	GcScheduler&	  m_GcScheduler;
+	JobQueue&		  m_BackgroundJobQueue;
 };
 
 }  // namespace zen