16992: Merge branch 'master' into 16992-disable-pg-pager

[arvados.git] / services / ws / session.go

diff --git a/services/ws/session.go b/services/ws/session.go
index 98164e354995970e05e8298c4dfb03defebef621..c0cfbd6d02f6ff37083f426c85084effae45f212 100644 (file)
--- a/services/ws/session.go
+++ b/services/ws/session.go
@@ -1,8 +1,37 @@
-package main
+// Copyright (C) The Arvados Authors. All rights reserved.
+//
+// SPDX-License-Identifier: AGPL-3.0
+
+package ws
+
+import (
+       "database/sql"
+
+       "git.arvados.org/arvados.git/sdk/go/arvados"
+)
 
 type session interface {
-       Receive(map[string]interface{}, []byte)
-       EventMessage(*event) ([]byte, error)
+       // Receive processes a message received from the client. If a
+       // non-nil error is returned, the connection will be
+       // terminated.
+       Receive([]byte) error
+
+       // Filter returns true if the event should be queued for
+       // sending to the client. It should return as fast as
+       // possible, and must not block.
        Filter(*event) bool
-       debugLogf(string, ...interface{})
+
+       // EventMessage encodes the given event (from the front of the
+       // queue) into a form suitable to send to the client. If a
+       // non-nil error is returned, the connection is terminated. If
+       // the returned buffer is empty, nothing is sent to the client
+       // and the event is not counted in statistics.
+       //
+       // Unlike Filter, EventMessage can block without affecting
+       // other connections. If EventMessage is slow, additional
+       // incoming events will be queued. If the event queue fills
+       // up, the connection will be dropped.
+       EventMessage(*event) ([]byte, error)
 }
+
+type sessionFactory func(wsConn, chan<- interface{}, *sql.DB, permChecker, *arvados.Client) (session, error)