[performance] Add dereference shortcuts to avoid making http calls to self (#430)

* update transport (controller) to allow shortcuts

* go fmt

* expose underlying sig transport to allow test sigs

1 files changed, 19 insertions, 0 deletions

diff --git a/internal/transport/dereference.go b/internal/transport/dereference.go
index 5ef6db9a7..61d99c5c5 100644
--- a/internal/transport/dereference.go
+++ b/internal/transport/dereference.go
@@ -23,10 +23,29 @@ import (
 	"net/url"
 
 	"github.com/sirupsen/logrus"
+	"github.com/spf13/viper"
+	"github.com/superseriousbusiness/gotosocial/internal/config"
+	"github.com/superseriousbusiness/gotosocial/internal/uris"
 )
 
 func (t *transport) Dereference(ctx context.Context, iri *url.URL) ([]byte, error) {
 	l := logrus.WithField("func", "Dereference")
+
+	// if the request is to us, we can shortcut for certain URIs rather than going through
+	// the normal request flow, thereby saving time and energy
+	if iri.Host == viper.GetString(config.Keys.Host) {
+		if uris.IsFollowersPath(iri) {
+			// the request is for followers of one of our accounts, which we can shortcut
+			return t.dereferenceFollowersShortcut(ctx, iri)
+		}
+
+		if uris.IsUserPath(iri) {
+			// the request is for one of our accounts, which we can shortcut
+			return t.dereferenceUserShortcut(ctx, iri)
+		}
+	}
+
+	// the request is either for a remote host or for us but we don't have a shortcut, so continue as normal
 	l.Debugf("performing GET to %s", iri.String())
 	return t.sigTransport.Dereference(ctx, iri)
 }