diff options
Diffstat (limited to 'testing/web-platform/tests/tools/third_party/websockets/docs/howto/extensions.rst')
| -rw-r--r-- | testing/web-platform/tests/tools/third_party/websockets/docs/howto/extensions.rst | 30 |
1 files changed, 30 insertions, 0 deletions
diff --git a/testing/web-platform/tests/tools/third_party/websockets/docs/howto/extensions.rst b/testing/web-platform/tests/tools/third_party/websockets/docs/howto/extensions.rst new file mode 100644 index 0000000000..3c8a7d72a6 --- /dev/null +++ b/testing/web-platform/tests/tools/third_party/websockets/docs/howto/extensions.rst @@ -0,0 +1,30 @@ +Write an extension +================== + +.. currentmodule:: websockets.extensions + +During the opening handshake, WebSocket clients and servers negotiate which +extensions_ will be used with which parameters. Then each frame is processed +by extensions before being sent or after being received. + +.. _extensions: https://www.rfc-editor.org/rfc/rfc6455.html#section-9 + +As a consequence, writing an extension requires implementing several classes: + +* Extension Factory: it negotiates parameters and instantiates the extension. + + Clients and servers require separate extension factories with distinct APIs. + + Extension factories are the public API of an extension. + +* Extension: it decodes incoming frames and encodes outgoing frames. + + If the extension is symmetrical, clients and servers can use the same + class. + + Extensions are initialized by extension factories, so they don't need to be + part of the public API of an extension. + +websockets provides base classes for extension factories and extensions. +See :class:`ClientExtensionFactory`, :class:`ServerExtensionFactory`, +and :class:`Extension` for details. |