From 7517243d6dcb8bd14157786866a23498479fe8c3 Mon Sep 17 00:00:00 2001
From: Wilmer Paulino <wilmer.paulino@gmail.com>
Date: Wed, 14 Apr 2021 17:12:43 -0700
Subject: [PATCH] wtclient: decrement pending tasks stats upon accepted task

We'd never decrement the number of pending backups upon a watchtower
accepting one, making it confusing for users to determine whether their
backups have actually been accepted. Along the way, we also rename
NumTasksReceived to NumTasksPending to better reflect its purpose.
---
 lnrpc/wtclientrpc/wtclient.go |  4 ++--
 watchtower/wtclient/stats.go  | 11 ++++++-----
 2 files changed, 8 insertions(+), 7 deletions(-)

diff --git a/lnrpc/wtclientrpc/wtclient.go b/lnrpc/wtclientrpc/wtclient.go
index 2dafc7c6..683866e4 100644
--- a/lnrpc/wtclientrpc/wtclient.go
+++ b/lnrpc/wtclientrpc/wtclient.go
@@ -336,7 +336,7 @@ func (c *WatchtowerClient) Stats(ctx context.Context,
 
 		stats.NumTasksAccepted += stat.NumTasksAccepted
 		stats.NumTasksIneligible += stat.NumTasksIneligible
-		stats.NumTasksReceived += stat.NumTasksReceived
+		stats.NumTasksPending += stat.NumTasksPending
 		stats.NumSessionsAcquired += stat.NumSessionsAcquired
 		stats.NumSessionsExhausted += stat.NumSessionsExhausted
 	}
@@ -344,7 +344,7 @@ func (c *WatchtowerClient) Stats(ctx context.Context,
 	return &StatsResponse{
 		NumBackups:           uint32(stats.NumTasksAccepted),
 		NumFailedBackups:     uint32(stats.NumTasksIneligible),
-		NumPendingBackups:    uint32(stats.NumTasksReceived),
+		NumPendingBackups:    uint32(stats.NumTasksPending),
 		NumSessionsAcquired:  uint32(stats.NumSessionsAcquired),
 		NumSessionsExhausted: uint32(stats.NumSessionsExhausted),
 	}, nil
diff --git a/watchtower/wtclient/stats.go b/watchtower/wtclient/stats.go
index 174a9d3d..63178ac3 100644
--- a/watchtower/wtclient/stats.go
+++ b/watchtower/wtclient/stats.go
@@ -10,9 +10,9 @@ import (
 type ClientStats struct {
 	mu sync.Mutex
 
-	// NumTasksReceived is the total number of backups that are pending to
+	// NumTasksPending is the total number of backups that are pending to
 	// be acknowledged by all active and exhausted watchtower sessions.
-	NumTasksReceived int
+	NumTasksPending int
 
 	// NumTasksAccepted is the total number of backups made to all active
 	// and exhausted watchtower sessions.
@@ -36,7 +36,7 @@ type ClientStats struct {
 func (s *ClientStats) taskReceived() {
 	s.mu.Lock()
 	defer s.mu.Unlock()
-	s.NumTasksReceived++
+	s.NumTasksPending++
 }
 
 // taskAccepted increments the number of tasks that have been assigned to active
@@ -45,6 +45,7 @@ func (s *ClientStats) taskAccepted() {
 	s.mu.Lock()
 	defer s.mu.Unlock()
 	s.NumTasksAccepted++
+	s.NumTasksPending--
 }
 
 // taskIneligible increments the number of tasks that were unable to satisfy the
@@ -78,7 +79,7 @@ func (s *ClientStats) String() string {
 	s.mu.Lock()
 	defer s.mu.Unlock()
 	return fmt.Sprintf("tasks(received=%d accepted=%d ineligible=%d) "+
-		"sessions(acquired=%d exhausted=%d)", s.NumTasksReceived,
+		"sessions(acquired=%d exhausted=%d)", s.NumTasksPending,
 		s.NumTasksAccepted, s.NumTasksIneligible, s.NumSessionsAcquired,
 		s.NumSessionsExhausted)
 }
@@ -88,7 +89,7 @@ func (s *ClientStats) Copy() ClientStats {
 	s.mu.Lock()
 	defer s.mu.Unlock()
 	return ClientStats{
-		NumTasksReceived:     s.NumTasksReceived,
+		NumTasksPending:      s.NumTasksPending,
 		NumTasksAccepted:     s.NumTasksAccepted,
 		NumTasksIneligible:   s.NumTasksIneligible,
 		NumSessionsAcquired:  s.NumSessionsAcquired,