WebSocket Deflate extension
Ktor implements Deflate
WebSocket extensions RFC-7692 for the client and server. The extension can transparently compress frame before sending, and decompress after receiving. It's useful to enable this extension if you're sending large amounts of text data.
Installation
To use the extension, it should be installed first. To do that we can use install
method in extensions
block:
Advanced configuration parameters
Context takeover
Specify if the client (and server) should use a compression window. Enabling these parameters reduces the amount of space allocated per single session. Note that the window size cannot be configured due to limitations of java.util.zip.Deflater
API. The value is fixed to 15
.
These parameters are described in RFC-7692 Section 7.1.1
Specify compress condition
To specify a compress condition explicitly, you can use the compressIf
method. For instance, to compress text-only:
All calls to compressIf
will be evaluated before compression takes place.
Fine-tune list of protocols
The list of protocols to send can be edited as needed using the configureProtocols
method: