rgw: data changes log, don't always send new requests

We may piggy back on older entries that hasn't expired yet.

Signed-off-by: Yehuda Sadeh <yehuda@inktank.com>

2 files changed, 84 insertions, 2 deletions

diff --git a/src/rgw/rgw_bucket.cc b/src/rgw/rgw_bucket.cc
index 7d8a3b36e83..e6f985c45e4 100644
--- a/src/rgw/rgw_bucket.cc
+++ b/src/rgw/rgw_bucket.cc
@@ -1056,6 +1056,51 @@ int RGWDataChangesLog::choose_oid(rgw_bucket& bucket) {
 }
 
 int RGWDataChangesLog::add_entry(rgw_bucket& bucket) {
+  lock.Lock();
+  ChangeStatus *& status = changes[bucket.name];
+  if (!status) {
+    status = new ChangeStatus;
+  }
+
+  status->get();
+  lock.Unlock();
+
+  utime_t now = ceph_clock_now(cct);
+
+  status->lock->Lock();
+
+#warning FIXME delta config
+  if (now < status->cur_expiration) {
+    /* no need to send, recently completed */
+    status->lock->Unlock();
+    status->put();
+    return 0;
+  }
+
+  RefCountedCond *cond;
+
+  if (status->pending) {
+    cond = status->cond;
+
+    assert(cond);
+
+    status->cond->get();
+    status->lock->Unlock();
+    status->put();
+
+    cond->wait();
+    cond->put();
+#warning FIXME need to return actual status
+    return 0;
+  }
+
+  status->cond = new RefCountedCond;
+  status->pending = true;
+
+  status->cur_sent = now;
+
+  status->lock->Unlock();
+  
   string& oid = oids[choose_oid(bucket)];
 
   utime_t ut = ceph_clock_now(cct);
@@ -1065,7 +1110,24 @@ int RGWDataChangesLog::add_entry(rgw_bucket& bucket) {
   change.key = bucket.name;
   ::encode(change, bl);
   string section;
-  return store->time_log_add(oid, ut, section, change.key, bl);
+  int ret = store->time_log_add(oid, ut, section, change.key, bl);
+
+  status->lock->Lock();
+
+  cond = status->cond;
+
+  status->pending = false;
+  status->cur_expiration = status->cur_sent; /* time of when operation started, not completed */
+  status->cur_expiration += utime_t(5, 0);
+  status->cond = NULL;
+  status->lock->Unlock();
+
+  status->put();
+
+  cond->done();
+  cond->put();
+
+  return ret;
 }
 
 int RGWDataChangesLog::list_entries(int shard, utime_t& start_time, utime_t& end_time, int max_entries,
diff --git a/src/rgw/rgw_bucket.h b/src/rgw/rgw_bucket.h
index ddca6122efc..7c4c3d3c6cb 100644
--- a/src/rgw/rgw_bucket.h
+++ b/src/rgw/rgw_bucket.h
@@ -256,9 +256,29 @@ class RGWDataChangesLog {
   int num_shards;
   string *oids;
 
+  Mutex lock;
+
+  struct ChangeStatus : public RefCountedObject {
+    utime_t cur_expiration;
+    utime_t cur_sent;
+    bool pending;
+    RefCountedCond *cond;
+    Mutex *lock;
+
+    ChangeStatus() : pending(false), cond(NULL) {
+      lock = new Mutex("RGWDataChangesLog::ChangeStatus");
+    }
+
+    ~ChangeStatus() {
+      delete lock;
+    }
+  };
+
+  map<string, ChangeStatus *> changes;
+
 public:
 
-  RGWDataChangesLog(CephContext *_cct, RGWRados *_store) : cct(_cct), store(_store) {
+  RGWDataChangesLog(CephContext *_cct, RGWRados *_store) : cct(_cct), store(_store), lock("RGWDataChangesLog") {
     num_shards = 128; /* FIXME */
     oids = new string[num_shards];