90 lines
3.1 KiB
Go
90 lines
3.1 KiB
Go
package streaming
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import (
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"fmt"
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"net/http"
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"time"
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"github.com/gin-gonic/gin"
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"github.com/gorilla/websocket"
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)
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// StreamGETHandler handles the creation of a new websocket streaming request.
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func (m *Module) StreamGETHandler(c *gin.Context) {
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l := m.log.WithField("func", "StreamGETHandler")
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streamType := c.Query(StreamQueryKey)
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if streamType == "" {
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c.JSON(http.StatusBadRequest, gin.H{"error": fmt.Sprintf("no stream type provided under query key %s", StreamQueryKey)})
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return
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}
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accessToken := c.Query(AccessTokenQueryKey)
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if accessToken == "" {
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c.JSON(http.StatusUnauthorized, gin.H{"error": fmt.Sprintf("no access token provided under query key %s", AccessTokenQueryKey)})
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return
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}
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// make sure a valid token has been provided and obtain the associated account
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account, err := m.processor.AuthorizeStreamingRequest(accessToken)
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if err != nil {
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c.JSON(http.StatusUnauthorized, gin.H{"error": "could not authorize with given token"})
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return
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}
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// prepare to upgrade the connection to a websocket connection
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upgrader := websocket.Upgrader{
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ReadBufferSize: 1024,
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WriteBufferSize: 1024,
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CheckOrigin: func(r *http.Request) bool {
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// we fully expect cors requests (via something like pinafore.social) so we should be lenient here
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return true
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},
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}
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// do the actual upgrade here
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conn, err := upgrader.Upgrade(c.Writer, c.Request, nil)
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if err != nil {
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l.Infof("error upgrading websocket connection: %s", err)
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return
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}
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defer conn.Close() // whatever happens, when we leave this function we want to close the websocket connection
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// inform the processor that we have a new connection and want a stream for it
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stream, errWithCode := m.processor.OpenStreamForAccount(account, streamType)
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if errWithCode != nil {
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c.JSON(errWithCode.Code(), errWithCode.Safe())
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return
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}
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defer close(stream.Hangup) // closing stream.Hangup indicates that we've finished with the connection (the client has gone), so we want to do this on exiting this handler
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// spawn a new ticker for pinging the connection periodically
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t := time.NewTicker(30 * time.Second)
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// we want to stay in the sendloop as long as possible while the client is connected -- the only thing that should break the loop is if the client leaves or something else goes wrong
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sendLoop:
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for {
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select {
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case m := <-stream.Messages:
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// we've got a streaming message!!
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l.Debug("received message from stream")
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if err := conn.WriteJSON(m); err != nil {
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l.Infof("error writing json to websocket connection: %s", err)
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// if something is wrong we want to bail and drop the connection -- the client will create a new one
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break sendLoop
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}
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l.Debug("wrote message into websocket connection")
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case <-t.C:
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l.Debug("received TICK from ticker")
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if err := conn.WriteMessage(websocket.PingMessage, []byte(": ping")); err != nil {
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l.Infof("error writing ping to websocket connection: %s", err)
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// if something is wrong we want to bail and drop the connection -- the client will create a new one
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break sendLoop
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}
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l.Debug("wrote ping message into websocket connection")
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}
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}
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l.Debug("leaving StreamGETHandler")
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}
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