[chore] local instance count query caching, improved status context endpoint logging, don't log ErrHideStatus when timelining (#3330)

* ensure that errors checking status visibility / converting aren't dropped

* add some more context to error messages

* include calling function name in log entries

* don't error on timelining hidden status

* further code to ignore statusfilter.ErrHideStatus type errors

* remove unused error type

* add local instance status / domain / user counts

* add checks for localhost

* rename from InstanceCounts to LocalInstance

* improved code comment

2 files changed, 28 insertions, 3 deletions

diff --git a/internal/cache/db.go b/internal/cache/db.go
index fe9085613..dd4e8b212 100644
--- a/internal/cache/db.go
+++ b/internal/cache/db.go
@@ -18,6 +18,8 @@
 package cache
 
 import (
+	"sync/atomic"
+
 	"codeberg.org/gruf/go-structr"
 	"github.com/superseriousbusiness/gotosocial/internal/cache/domain"
 	"github.com/superseriousbusiness/gotosocial/internal/config"
@@ -136,6 +138,14 @@ type DBCaches struct {
 	// Instance provides access to the gtsmodel Instance database cache.
 	Instance StructCache[*gtsmodel.Instance]
 
+	// LocalInstance provides caching for
+	// simple + common local instance queries.
+	LocalInstance struct {
+		Domains  atomic.Pointer[int]
+		Statuses atomic.Pointer[int]
+		Users    atomic.Pointer[int]
+	}
+
 	// InteractionRequest provides access to the gtsmodel InteractionRequest database cache.
 	InteractionRequest StructCache[*gtsmodel.InteractionRequest]
 
@@ -849,9 +859,10 @@ func (c *Caches) initInstance() {
 			{Fields: "ID"},
 			{Fields: "Domain"},
 		},
-		MaxSize:   cap,
-		IgnoreErr: ignoreErrors,
-		Copy:      copyF,
+		MaxSize:    cap,
+		IgnoreErr:  ignoreErrors,
+		Copy:       copyF,
+		Invalidate: c.OnInvalidateInstance,
 	})
 }
 
diff --git a/internal/cache/invalidate.go b/internal/cache/invalidate.go
index ca12e412c..9b42e88f6 100644
--- a/internal/cache/invalidate.go
+++ b/internal/cache/invalidate.go
@@ -19,6 +19,7 @@ package cache
 
 import (
 	"github.com/superseriousbusiness/gotosocial/internal/gtsmodel"
+	"github.com/superseriousbusiness/gotosocial/internal/util"
 )
 
 // Below are cache invalidation hooks between other caches,
@@ -178,6 +179,11 @@ func (c *Caches) OnInvalidateFollowRequest(followReq *gtsmodel.FollowRequest) {
 	)
 }
 
+func (c *Caches) OnInvalidateInstance(instance *gtsmodel.Instance) {
+	// Invalidate the local domains count.
+	c.DB.LocalInstance.Domains.Store(nil)
+}
+
 func (c *Caches) OnInvalidateList(list *gtsmodel.List) {
 	// Invalidate list IDs cache.
 	c.DB.ListIDs.Invalidate(
@@ -255,6 +261,11 @@ func (c *Caches) OnInvalidateStatus(status *gtsmodel.Status) {
 		// Invalidate cache of attached poll ID.
 		c.DB.Poll.Invalidate("ID", status.PollID)
 	}
+
+	if util.PtrOrZero(status.Local) {
+		// Invalidate the local statuses count.
+		c.DB.LocalInstance.Statuses.Store(nil)
+	}
 }
 
 func (c *Caches) OnInvalidateStatusBookmark(bookmark *gtsmodel.StatusBookmark) {
@@ -271,6 +282,9 @@ func (c *Caches) OnInvalidateUser(user *gtsmodel.User) {
 	// Invalidate local account ID cached visibility.
 	c.Visibility.Invalidate("ItemID", user.AccountID)
 	c.Visibility.Invalidate("RequesterID", user.AccountID)
+
+	// Invalidate the local users count.
+	c.DB.LocalInstance.Users.Store(nil)
 }
 
 func (c *Caches) OnInvalidateUserMute(mute *gtsmodel.UserMute) {