org.httpkit.server

accept

deprecated in v2.4.0 (2020-07-30)

DEPRECATED: prefer `sec-websocket-accept`

as-channel

(as-channel ring-req {:keys [on-receive on-ping on-close on-open init on-handshake-error], :or {on-handshake-error (fn [ch] (send! ch bad-ring-websocket-resp true))}})
Returns `{:body ch}`, where `ch` is the request's underlying
asynchronous HTTP or WebSocket `AsyncChannel`.

Main options:
  :init       - (fn [ch])             for misc pre-handshake setup.
  :on-receive - (fn [ch message])     called for client WebSocket messages.
  :on-ping    - (fn [ch data])        called for client WebSocket pings.
  :on-close   - (fn [ch status-code]) called when AsyncChannel is closed.
  :on-open    - (fn [ch])             called when AsyncChannel is ready for `send!`, etc.

See `Channel` protocol for more info on handlers and `AsyncChannel`s.
See `org.httpkit.timer` ns for optional timeout utils.

---

Example - Async HTTP response:

  (def clients_ (atom #{}))
  (defn my-async-handler [ring-req]
    (as-channel ring-req
      {:on-open (fn [ch] (swap! clients_ conj ch))}))

  ;; Somewhere else in your code
  (doseq [ch @clients_]
    (swap! clients_ disj ch)
    (send! ch {:status 200 :headers {"Content-Type" "text/html"}
               :body "Your async response"}
      ;; false ; Uncomment to use chunk encoding for HTTP streaming
      ))

Example - WebSocket response:

  (defn my-chatroom-handler [ring-req]
    (if-not (:websocket? ring-req)
      {:status 200 :body "Welcome to the chatroom! JS client connecting..."}
      (as-channel ring-req
        {:on-receive (fn [ch message]     (println "on-receive:" message))
         :on-close   (fn [ch status-code] (println "on-close:"   status-code))
         :on-open    (fn [ch]             (println "on-open:"    ch))})))

Channel

protocol

Unified asynchronous channel interface for HTTP (streaming or long-polling)
and WebSocket.

members

close

(close ch)
Closes the channel. Idempotent: returns true if the channel was actually
closed, or false if it was already closed.

on-close

(on-close ch callback)
Sets handler (fn [status-code]) for notification of channel being closed by
the server or client. Handler will be invoked at most once. Useful for clean-up.

Callback status argument:
  :server-close   : Channel closed by sever
  :client-close   : HTTP channel closed by client
  :normal         : WebSocket closed by client (CLOSE_NORMAL)
  :going-away     : WebSocket closed by client (CLOSE_GOING_AWAY)
  :protocol-error : WebSocket closed by client (CLOSE_PROTOCOL_ERROR)
  :unsupported    : WebSocket closed by client (CLOSE_UNSUPPORTED)
  :unknown        : WebSocket closed by client (unknown reason)

on-ping

(on-ping ch callback)
Sets handler (fn [data]) for notification of client WebSocket pings. The
data param represents application data and will by a byte[].

on-receive

(on-receive ch callback)
Sets handler (fn [message]) for notification of client WebSocket
messages. Message ordering is guaranteed by server.

The message argument could be a string or a byte[].

open?

(open? ch)
Returns true iff channel is open.

send!

(send! ch data)(send! ch data close-after-send?)
Sends data to client and returns true if the data was successfully sent,
or false if the channel is closed. Data is sent directly to the client,
NO RING MIDDLEWARE IS APPLIED.

When unspecified, `close-after-send?` defaults to true for HTTP channels
and false for WebSocket.

Data form: {:headers _ :status _ :body _} or just body. Note that :headers
and :status will be stripped for WebSocket and for HTTP streaming responses
after the first.

For WebSocket, a text frame is sent to client if data is String,
a binary frame when data is byte[] or InputStream. For for HTTP streaming
responses, data can be one of the type defined by Ring spec

websocket?

(websocket? ch)
Returns true iff channel is a WebSocket.

IHttpServer

protocol

members

-server-stop!

(-server-stop! http-server opts)

server-port

(server-port http-server)
Given an HttpServer, returns server's local port.

server-status

(server-status http-server)
Given an HttpServer, returns server's status e/o #{:stopped :running :stopping}.

new-worker

(new-worker {:keys [queue-size n-min-threads n-max-threads prefix allow-virtual?], :as opts})
Returns {:keys [n-cores type pool ...]} where `:pool` is a new
`java.util.concurrent.ExecutorService` for handling server requests.

When on JVM 21+, uses `newVirtualThreadPerTaskExecutor` by default.
Otherwise creates a standard `ThreadPoolExecutor` with default min and max
thread count auto-selected based on currently available processor count.

run-server

(run-server handler & [{:keys [ip port max-body max-ws max-line proxy-protocol worker-pool error-logger warn-logger event-logger event-names legacy-return-value? server-header address-finder channel-factory ring-async?], :as opts, :or {max-ws 4194304, ring-async? false, max-body 8388608, max-line 8192, server-header "http-kit", ip "0.0.0.0", proxy-protocol :disable, port 8090, legacy-return-value? true}}])
Starts a mostly[1] Ring-compatible HttpServer with options:

  :ip                 ; Which IP to bind (default: 0.0.0.0)
  :port               ; Which port to listen to for incoming requests

  :worker-pool        ; `java.util.concurrent.ExecutorService` or delay to use
                      ; for handling requests. Defaults to (:pool (new-worker {})).
                      ; See `new-worker` for details.

  :max-body           ; Max HTTP body size in bytes (default: 8MB)
  :max-ws             ; Max WebSocket message size in bytes (default: 4MB)
  :max-line           ; Max HTTP header line size in bytes (default: 8KB)

  :proxy-protocol     ; Proxy protocol e/o #{:disable :enable :optional}

  :server-header      ; The "Server" header, disabled if nil. Default: "http-kit".

  :error-logger       ; (fn [msg ex])  -> log errors
  :warn-logger        ; (fn [msg ex])  -> log warnings
  :event-logger       ; (fn [ev-name]) -> log events
  :event-names        ; Map of http-kit event names to loggable event names

  ;; These opts may be used for Unix Domain Socket (UDS) support, see README:
  :address-finder     ; (fn []) -> `java.net.SocketAddress` (ip/port ignored)
  :channel-factory    ; (fn [java.net.SocketAddress]) -> `java.nio.channels.SocketChannel`

If :legacy-return-value? is
  true  (default)     ; Returns a (fn stop-server [& {:keys [timeout] :or {timeout 100}}])
  false (recommended) ; Returns the `HttpServer` which can be used with `server-port`,
                      ; `server-status`, `server-stop!`, etc.

The server also supports the following JVM properties:

   `org.http-kit.memmap-file-threshold`
     Files above this size (in MB) are mapped into memory for efficiency when served.
     Memory mapping could result to file locking. Defaults to 20 (MB).

[1] Ref. http://http-kit.org/migration.html for differences.

sec-websocket-accept

(sec-websocket-accept sec-websocket-key)

send-checked-websocket-handshake!

(send-checked-websocket-handshake! ch sec-ws-accept)
Given an AsyncChannel and `sec-ws-accept` string, unconditionally
sends handshake to upgrade given AsyncChannel to a WebSocket.
See also `websocket-handshake-check`.

send-websocket-handshake!

(send-websocket-handshake! ch ring-req)
Returns true iff successfully upgraded a valid WebSocket request.

server-stop!

(server-stop! http-server)(server-stop! http-server opts)
Signals given HttpServer to stop.

If     already stopping: returns nil.
If not already stopping: returns a Promise that will be delivered once
server thread actually completes.

Options:
  :timeout ; Max msecs to allow existing requests to complete before attempting
           ; interrupt (default 100).

websocket-handshake-check

(websocket-handshake-check ring-req)
Returns `sec-ws-accept` string iff given Ring request is a valid
WebSocket handshake.

with-channel

macro

deprecated in v2.4.0 (2020-07-30)

(with-channel ring-req ch-name & body)
DEPRECATED: this macro has potential race conditions, Ref. #318.
Prefer `as-channel` instead.