mirror of
https://github.com/coder/coder.git
synced 2026-06-03 04:58:23 +00:00
Spike Curtis
bddb808b25
Fixes all our Go file imports to match the preferred spec that we've _mostly_ been using. For example: ``` import ( "context" "time" "github.com/prometheus/client_golang/prometheus" "golang.org/x/xerrors" "gopkg.in/natefinch/lumberjack.v2" "cdr.dev/slog/v3" "github.com/coder/coder/v2/codersdk/agentsdk" "github.com/coder/serpent" ) ``` 3 groups: standard library, 3rd partly libs, Coder libs. This PR makes the change across the codebase. The PR in the stack above modifies our formatting to maintain this state of affairs, and is a separate PR so it's possible to review that one in detail.
78 lines
2.1 KiB
Go
78 lines
2.1 KiB
Go
package wsjson
|
|
|
|
import (
|
|
"context"
|
|
"encoding/json"
|
|
"sync/atomic"
|
|
|
|
"cdr.dev/slog/v3"
|
|
"github.com/coder/websocket"
|
|
)
|
|
|
|
type Decoder[T any] struct {
|
|
conn *websocket.Conn
|
|
typ websocket.MessageType
|
|
ctx context.Context
|
|
cancel context.CancelFunc
|
|
chanCalled atomic.Bool
|
|
logger slog.Logger
|
|
}
|
|
|
|
// Chan returns a `chan` that you can read incoming messages from. The returned
|
|
// `chan` will be closed when the WebSocket connection is closed. If there is an
|
|
// error reading from the WebSocket or decoding a value the WebSocket will be
|
|
// closed.
|
|
//
|
|
// Safety: Chan must only be called once. Successive calls will panic.
|
|
func (d *Decoder[T]) Chan() <-chan T {
|
|
if !d.chanCalled.CompareAndSwap(false, true) {
|
|
panic("chan called more than once")
|
|
}
|
|
values := make(chan T, 1)
|
|
go func() {
|
|
defer close(values)
|
|
defer d.conn.Close(websocket.StatusGoingAway, "")
|
|
for {
|
|
// we don't use d.ctx here because it only gets canceled after closing the connection
|
|
// and a "connection closed" type error is more clear than context canceled.
|
|
typ, b, err := d.conn.Read(context.Background())
|
|
if err != nil {
|
|
// might be benign like EOF, so just log at debug
|
|
d.logger.Debug(d.ctx, "error reading from websocket", slog.Error(err))
|
|
return
|
|
}
|
|
if typ != d.typ {
|
|
d.logger.Error(d.ctx, "websocket type mismatch while decoding")
|
|
return
|
|
}
|
|
var value T
|
|
err = json.Unmarshal(b, &value)
|
|
if err != nil {
|
|
d.logger.Error(d.ctx, "error unmarshalling", slog.Error(err))
|
|
return
|
|
}
|
|
select {
|
|
case values <- value:
|
|
// OK
|
|
case <-d.ctx.Done():
|
|
return
|
|
}
|
|
}
|
|
}()
|
|
return values
|
|
}
|
|
|
|
// nolint: revive // complains that Encoder has the same function name
|
|
func (d *Decoder[T]) Close() error {
|
|
err := d.conn.Close(websocket.StatusNormalClosure, "")
|
|
d.cancel()
|
|
return err
|
|
}
|
|
|
|
// NewDecoder creates a JSON-over-websocket decoder for type T, which must be deserializable from
|
|
// JSON.
|
|
func NewDecoder[T any](conn *websocket.Conn, typ websocket.MessageType, logger slog.Logger) *Decoder[T] {
|
|
ctx, cancel := context.WithCancel(context.Background())
|
|
return &Decoder[T]{conn: conn, ctx: ctx, cancel: cancel, typ: typ, logger: logger}
|
|
}
|