[performance] reduce InboxForward->Create calls by partially implementing Exists() (#3647)

* alphabetical reordering

* keep a cache of activity IDs we have handled creates for

* reduce number of inbox forwarding create calls by partially implementing Exists()

* increase cache size, since all we're storing is string keys

1 files changed, 14 insertions, 14 deletions

diff --git a/internal/cache/cache.go b/internal/cache/cache.go
index 560fbc9f6..6f925e24f 100644
--- a/internal/cache/cache.go
+++ b/internal/cache/cache.go
@@ -40,6 +40,11 @@ type Caches struct {
 	// the block []headerfilter.Filter cache.
 	BlockHeaderFilters headerfilter.Cache
 
+	// TTL cache of statuses -> filterable text fields.
+	// To ensure up-to-date fields, cache is keyed as:
+	// `[status.ID][status.UpdatedAt.Unix()]`
+	StatusesFilterableFields *ttl.Cache[string, []string]
+
 	// Visibility provides access to the item visibility
 	// cache. (used by the visibility filter).
 	Visibility VisibilityCache
@@ -47,11 +52,6 @@ type Caches struct {
 	// Webfinger provides access to the webfinger URL cache.
 	Webfinger *ttl.Cache[string, string] // TTL=24hr, sweep=5min
 
-	// TTL cache of statuses -> filterable text fields.
-	// To ensure up-to-date fields, cache is keyed as:
-	// `[status.ID][status.UpdatedAt.Unix()]`
-	StatusesFilterableFields *ttl.Cache[string, []string]
-
 	// prevent pass-by-value.
 	_ nocopy
 }
@@ -203,6 +203,15 @@ func (c *Caches) Sweep(threshold float64) {
 	c.Visibility.Trim(threshold)
 }
 
+func (c *Caches) initStatusesFilterableFields() {
+	c.StatusesFilterableFields = new(ttl.Cache[string, []string])
+	c.StatusesFilterableFields.Init(
+		0,
+		512,
+		1*time.Hour,
+	)
+}
+
 func (c *Caches) initWebfinger() {
 	// Calculate maximum cache size.
 	cap := calculateCacheMax(
@@ -219,12 +228,3 @@ func (c *Caches) initWebfinger() {
 		24*time.Hour,
 	)
 }
-
-func (c *Caches) initStatusesFilterableFields() {
-	c.StatusesFilterableFields = new(ttl.Cache[string, []string])
-	c.StatusesFilterableFields.Init(
-		0,
-		512,
-		1*time.Hour,
-	)
-}