parent
1b3ca1af4b
commit
b1641d1af9
@ -1,467 +0,0 @@ |
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// Package chat implements a simple chatroom system.
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package chat |
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import ( |
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"context" |
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"encoding/json" |
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"errors" |
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"fmt" |
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"strconv" |
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"sync" |
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"time" |
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"github.com/mediocregopher/mediocre-go-lib/v2/mctx" |
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"github.com/mediocregopher/mediocre-go-lib/v2/mlog" |
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"github.com/mediocregopher/radix/v4" |
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) |
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// ErrInvalidArg is returned from methods in this package when a call fails due
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// to invalid input.
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type ErrInvalidArg struct { |
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Err error |
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} |
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func (e ErrInvalidArg) Error() string { |
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return fmt.Sprintf("invalid argument: %v", e.Err) |
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} |
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var ( |
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errInvalidMessageID = ErrInvalidArg{Err: errors.New("invalid Message ID")} |
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) |
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// Message describes a message which has been posted to a Room.
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type Message struct { |
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ID string `json:"id"` |
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UserID UserID `json:"userID"` |
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Body string `json:"body"` |
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CreatedAt int64 `json:"createdAt,omitempty"` |
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} |
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func msgFromStreamEntry(entry radix.StreamEntry) (Message, error) { |
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// NOTE this should probably be a shortcut in radix
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var bodyStr string |
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for _, field := range entry.Fields { |
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if field[0] == "json" { |
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bodyStr = field[1] |
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break |
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} |
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} |
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if bodyStr == "" { |
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return Message{}, errors.New("no 'json' field") |
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} |
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var msg Message |
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if err := json.Unmarshal([]byte(bodyStr), &msg); err != nil { |
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return Message{}, fmt.Errorf( |
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"json unmarshaling body %q: %w", bodyStr, err, |
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) |
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} |
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msg.ID = entry.ID.String() |
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msg.CreatedAt = int64(entry.ID.Time / 1000) |
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return msg, nil |
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} |
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// MessageIterator returns a sequence of Messages which may or may not be
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// unbounded.
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type MessageIterator interface { |
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// Next blocks until it returns the next Message in the sequence, or the
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// context error if the context is cancelled, or io.EOF if the sequence has
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// been exhausted.
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Next(context.Context) (Message, error) |
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// Close should always be called once Next has returned an error or the
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// MessageIterator will no longer be used.
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Close() error |
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} |
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// HistoryOpts are passed into Room's History method in order to affect its
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// result. All fields are optional.
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type HistoryOpts struct { |
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Limit int // defaults to, and is capped at, 100.
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Cursor string // If not given then the most recent Messages are returned.
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} |
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func (o HistoryOpts) sanitize() (HistoryOpts, error) { |
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if o.Limit <= 0 || o.Limit > 100 { |
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o.Limit = 100 |
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} |
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if o.Cursor != "" { |
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id, err := parseStreamEntryID(o.Cursor) |
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if err != nil { |
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return HistoryOpts{}, fmt.Errorf("parsing Cursor: %w", err) |
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} |
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o.Cursor = id.String() |
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} |
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return o, nil |
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} |
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// Room implements functionality related to a single, unique chat room.
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type Room interface { |
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// Append accepts a new Message and stores it at the end of the room's
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// history. The original Message is returned with any relevant fields (e.g.
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// ID) updated.
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Append(context.Context, Message) (Message, error) |
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// Returns a cursor and the list of historical Messages in time descending
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// order. The cursor can be passed into the next call to History to receive
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// the next set of Messages.
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History(context.Context, HistoryOpts) (string, []Message, error) |
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// Listen returns a MessageIterator which will return all Messages appended
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// to the Room since the given ID. Once all existing messages are iterated
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// through then the MessageIterator will begin blocking until a new Message
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// is posted.
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Listen(ctx context.Context, sinceID string) (MessageIterator, error) |
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// Delete deletes a Message from the Room.
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Delete(ctx context.Context, id string) error |
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// Close is used to clean up all resources created by the Room.
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Close() error |
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} |
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// RoomParams are used to instantiate a new Room. All fields are required unless
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// otherwise noted.
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type RoomParams struct { |
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Logger *mlog.Logger |
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Redis radix.Client |
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ID string |
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MaxMessages int |
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} |
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func (p RoomParams) streamKey() string { |
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return fmt.Sprintf("chat:{%s}:stream", p.ID) |
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} |
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type room struct { |
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params RoomParams |
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closeCtx context.Context |
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closeCancel context.CancelFunc |
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wg sync.WaitGroup |
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listeningL sync.Mutex |
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listening map[chan Message]struct{} |
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listeningLastID radix.StreamEntryID |
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} |
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// NewRoom initializes and returns a new Room instance.
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func NewRoom(ctx context.Context, params RoomParams) (Room, error) { |
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params.Logger = params.Logger.WithNamespace("chat-room") |
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r := &room{ |
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params: params, |
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listening: map[chan Message]struct{}{}, |
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} |
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r.closeCtx, r.closeCancel = context.WithCancel(context.Background()) |
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// figure out the most recent message, if any.
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lastEntryID, err := r.mostRecentMsgID(ctx) |
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if err != nil { |
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return nil, fmt.Errorf("discovering most recent entry ID in stream: %w", err) |
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} |
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r.listeningLastID = lastEntryID |
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r.wg.Add(1) |
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go func() { |
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defer r.wg.Done() |
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r.readStreamLoop(r.closeCtx) |
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}() |
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return r, nil |
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} |
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func (r *room) Close() error { |
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r.closeCancel() |
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r.wg.Wait() |
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return nil |
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} |
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func (r *room) mostRecentMsgID(ctx context.Context) (radix.StreamEntryID, error) { |
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var entries []radix.StreamEntry |
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err := r.params.Redis.Do(ctx, radix.Cmd( |
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&entries, |
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"XREVRANGE", r.params.streamKey(), "+", "-", "COUNT", "1", |
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)) |
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if err != nil || len(entries) == 0 { |
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return radix.StreamEntryID{}, err |
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} |
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return entries[0].ID, nil |
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} |
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func (r *room) Append(ctx context.Context, msg Message) (Message, error) { |
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msg.ID = "" // just in case
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b, err := json.Marshal(msg) |
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if err != nil { |
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return Message{}, fmt.Errorf("json marshaling Message: %w", err) |
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} |
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key := r.params.streamKey() |
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maxLen := strconv.Itoa(r.params.MaxMessages) |
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body := string(b) |
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var id radix.StreamEntryID |
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err = r.params.Redis.Do(ctx, radix.Cmd( |
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&id, "XADD", key, "MAXLEN", "=", maxLen, "*", "json", body, |
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)) |
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if err != nil { |
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return Message{}, fmt.Errorf("posting message to redis: %w", err) |
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} |
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msg.ID = id.String() |
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msg.CreatedAt = int64(id.Time / 1000) |
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return msg, nil |
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} |
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const zeroCursor = "0-0" |
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func (r *room) History(ctx context.Context, opts HistoryOpts) (string, []Message, error) { |
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opts, err := opts.sanitize() |
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if err != nil { |
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return "", nil, err |
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} |
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key := r.params.streamKey() |
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end := opts.Cursor |
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if end == "" { |
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end = "+" |
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} |
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start := "-" |
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count := strconv.Itoa(opts.Limit) |
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msgs := make([]Message, 0, opts.Limit) |
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streamEntries := make([]radix.StreamEntry, 0, opts.Limit) |
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err = r.params.Redis.Do(ctx, radix.Cmd( |
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&streamEntries, |
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"XREVRANGE", key, end, start, "COUNT", count, |
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)) |
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if err != nil { |
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return "", nil, fmt.Errorf("calling XREVRANGE: %w", err) |
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} |
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var oldestEntryID radix.StreamEntryID |
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for _, entry := range streamEntries { |
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oldestEntryID = entry.ID |
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msg, err := msgFromStreamEntry(entry) |
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if err != nil { |
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return "", nil, fmt.Errorf( |
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"parsing stream entry %q: %w", entry.ID, err, |
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) |
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} |
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msgs = append(msgs, msg) |
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} |
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if len(msgs) < opts.Limit { |
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return zeroCursor, msgs, nil |
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} |
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cursor := oldestEntryID.Prev() |
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return cursor.String(), msgs, nil |
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} |
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func (r *room) readStream(ctx context.Context) error { |
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r.listeningL.Lock() |
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lastEntryID := r.listeningLastID |
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r.listeningL.Unlock() |
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redisAddr := r.params.Redis.Addr() |
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redisConn, err := radix.Dial(ctx, redisAddr.Network(), redisAddr.String()) |
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if err != nil { |
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return fmt.Errorf("creating redis connection: %w", err) |
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} |
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defer redisConn.Close() |
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streamReader := (radix.StreamReaderConfig{}).New( |
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redisConn, |
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map[string]radix.StreamConfig{ |
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r.params.streamKey(): {After: lastEntryID}, |
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}, |
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) |
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for { |
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dlCtx, dlCtxCancel := context.WithTimeout(ctx, 10*time.Second) |
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_, streamEntry, err := streamReader.Next(dlCtx) |
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dlCtxCancel() |
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if errors.Is(err, radix.ErrNoStreamEntries) { |
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continue |
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} else if err != nil { |
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return fmt.Errorf("fetching next entry from stream: %w", err) |
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} |
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msg, err := msgFromStreamEntry(streamEntry) |
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if err != nil { |
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return fmt.Errorf("parsing stream entry %q: %w", streamEntry, err) |
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} |
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r.listeningL.Lock() |
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var dropped int |
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for ch := range r.listening { |
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select { |
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case ch <- msg: |
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default: |
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dropped++ |
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} |
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} |
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if dropped > 0 { |
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ctx := mctx.Annotate(ctx, "msgID", msg.ID, "dropped", dropped) |
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r.params.Logger.WarnString(ctx, "some listening channels full, messages dropped") |
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} |
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r.listeningLastID = streamEntry.ID |
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r.listeningL.Unlock() |
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} |
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} |
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func (r *room) readStreamLoop(ctx context.Context) { |
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for { |
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err := r.readStream(ctx) |
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if errors.Is(err, context.Canceled) { |
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return |
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} else if err != nil { |
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r.params.Logger.Error(ctx, "reading from redis stream", err) |
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} |
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} |
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} |
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type listenMsgIterator struct { |
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ch <-chan Message |
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missedMsgs []Message |
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sinceEntryID radix.StreamEntryID |
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cleanup func() |
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} |
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func (i *listenMsgIterator) Next(ctx context.Context) (Message, error) { |
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if len(i.missedMsgs) > 0 { |
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msg := i.missedMsgs[0] |
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i.missedMsgs = i.missedMsgs[1:] |
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return msg, nil |
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} |
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for { |
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select { |
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case <-ctx.Done(): |
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return Message{}, ctx.Err() |
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case msg := <-i.ch: |
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entryID, err := parseStreamEntryID(msg.ID) |
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if err != nil { |
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return Message{}, fmt.Errorf("parsing Message ID %q: %w", msg.ID, err) |
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} else if !i.sinceEntryID.Before(entryID) { |
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// this can happen if someone Appends a Message at the same time
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// as another calls Listen. The Listener might have already seen
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// the Message by calling History prior to the stream reader
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// having processed it and updating listeningLastID.
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continue |
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} |
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return msg, nil |
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} |
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} |
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} |
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func (i *listenMsgIterator) Close() error { |
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i.cleanup() |
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return nil |
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} |
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func (r *room) Listen( |
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ctx context.Context, sinceID string, |
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) ( |
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MessageIterator, error, |
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) { |
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var sinceEntryID radix.StreamEntryID |
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if sinceID != "" { |
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var err error |
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if sinceEntryID, err = parseStreamEntryID(sinceID); err != nil { |
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return nil, fmt.Errorf("parsing sinceID: %w", err) |
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} |
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} |
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ch := make(chan Message, 32) |
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r.listeningL.Lock() |
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lastEntryID := r.listeningLastID |
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r.listening[ch] = struct{}{} |
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r.listeningL.Unlock() |
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cleanup := func() { |
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r.listeningL.Lock() |
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defer r.listeningL.Unlock() |
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delete(r.listening, ch) |
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} |
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key := r.params.streamKey() |
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start := sinceEntryID.Next().String() |
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end := "+" |
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if lastEntryID != (radix.StreamEntryID{}) { |
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end = lastEntryID.String() |
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} |
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var streamEntries []radix.StreamEntry |
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err := r.params.Redis.Do(ctx, radix.Cmd( |
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&streamEntries, |
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"XRANGE", key, start, end, |
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)) |
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if err != nil { |
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cleanup() |
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return nil, fmt.Errorf("retrieving missed stream entries: %w", err) |
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} |
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missedMsgs := make([]Message, len(streamEntries)) |
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for i := range streamEntries { |
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msg, err := msgFromStreamEntry(streamEntries[i]) |
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if err != nil { |
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cleanup() |
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return nil, fmt.Errorf( |
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"parsing stream entry %q: %w", streamEntries[i].ID, err, |
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) |
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} |
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missedMsgs[i] = msg |
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} |
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return &listenMsgIterator{ |
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ch: ch, |
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missedMsgs: missedMsgs, |
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sinceEntryID: sinceEntryID, |
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cleanup: cleanup, |
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}, nil |
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} |
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func (r *room) Delete(ctx context.Context, id string) error { |
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return r.params.Redis.Do(ctx, radix.Cmd( |
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nil, "XDEL", r.params.streamKey(), id, |
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)) |
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} |
@ -1,213 +0,0 @@ |
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//go:build integration
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// +build integration
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package chat |
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import ( |
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"context" |
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"strconv" |
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"testing" |
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"time" |
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"github.com/google/uuid" |
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cfgpkg "github.com/mediocregopher/blog.mediocregopher.com/srv/cfg" |
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"github.com/mediocregopher/mediocre-go-lib/v2/mlog" |
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"github.com/mediocregopher/radix/v4" |
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"github.com/stretchr/testify/assert" |
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) |
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const roomTestHarnessMaxMsgs = 10 |
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type roomTestHarness struct { |
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ctx context.Context |
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room Room |
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allMsgs []Message |
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} |
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func (h *roomTestHarness) newMsg(t *testing.T) Message { |
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msg, err := h.room.Append(h.ctx, Message{ |
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UserID: UserID{ |
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Name: uuid.New().String(), |
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Hash: "0000", |
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}, |
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Body: uuid.New().String(), |
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}) |
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assert.NoError(t, err) |
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t.Logf("appended message %s", msg.ID) |
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h.allMsgs = append([]Message{msg}, h.allMsgs...) |
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if len(h.allMsgs) > roomTestHarnessMaxMsgs { |
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h.allMsgs = h.allMsgs[:roomTestHarnessMaxMsgs] |
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} |
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return msg |
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} |
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func newRoomTestHarness(t *testing.T) *roomTestHarness { |
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ctx, cancel := context.WithTimeout(context.Background(), 5*time.Second) |
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t.Cleanup(cancel) |
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cfg := cfgpkg.NewBlogCfg(cfgpkg.Params{ |
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Args: []string{}, // prevents the test process args from interfering
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}) |
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var radixClient cfgpkg.RadixClient |
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radixClient.SetupCfg(cfg) |
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t.Cleanup(func() { radixClient.Close() }) |
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if err := cfg.Init(ctx); err != nil { |
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t.Fatal(err) |
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} |
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roomParams := RoomParams{ |
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Logger: mlog.NewLogger(nil), |
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Redis: radixClient.Client, |
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ID: uuid.New().String(), |
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MaxMessages: roomTestHarnessMaxMsgs, |
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} |
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t.Logf("creating test Room %q", roomParams.ID) |
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room, err := NewRoom(ctx, roomParams) |
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assert.NoError(t, err) |
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|
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t.Cleanup(func() { |
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err := radixClient.Client.Do(context.Background(), radix.Cmd( |
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nil, "DEL", roomParams.streamKey(), |
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)) |
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assert.NoError(t, err) |
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}) |
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return &roomTestHarness{ctx: ctx, room: room} |
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} |
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func TestRoom(t *testing.T) { |
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t.Run("history", func(t *testing.T) { |
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tests := []struct { |
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numMsgs int |
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limit int |
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}{ |
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{numMsgs: 0, limit: 1}, |
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{numMsgs: 1, limit: 1}, |
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{numMsgs: 2, limit: 1}, |
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{numMsgs: 2, limit: 10}, |
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{numMsgs: 9, limit: 2}, |
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{numMsgs: 9, limit: 3}, |
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{numMsgs: 9, limit: 4}, |
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{numMsgs: 15, limit: 3}, |
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} |
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|
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for i, test := range tests { |
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t.Run(strconv.Itoa(i), func(t *testing.T) { |
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t.Logf("test: %+v", test) |
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h := newRoomTestHarness(t) |
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for j := 0; j < test.numMsgs; j++ { |
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h.newMsg(t) |
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} |
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var gotMsgs []Message |
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var cursor string |
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for { |
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var msgs []Message |
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var err error |
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cursor, msgs, err = h.room.History(h.ctx, HistoryOpts{ |
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Cursor: cursor, |
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Limit: test.limit, |
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}) |
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assert.NoError(t, err) |
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assert.NotEmpty(t, cursor) |
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if len(msgs) == 0 { |
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break |
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} |
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gotMsgs = append(gotMsgs, msgs...) |
||||
} |
||||
|
||||
assert.Equal(t, h.allMsgs, gotMsgs) |
||||
}) |
||||
} |
||||
}) |
||||
|
||||
assertNextMsg := func( |
||||
t *testing.T, expMsg Message, |
||||
ctx context.Context, it MessageIterator, |
||||
) { |
||||
t.Helper() |
||||
gotMsg, err := it.Next(ctx) |
||||
assert.NoError(t, err) |
||||
assert.Equal(t, expMsg, gotMsg) |
||||
} |
||||
|
||||
t.Run("listen/already_populated", func(t *testing.T) { |
||||
h := newRoomTestHarness(t) |
||||
|
||||
msgA, msgB, msgC := h.newMsg(t), h.newMsg(t), h.newMsg(t) |
||||
_ = msgA |
||||
_ = msgB |
||||
|
||||
itFoo, err := h.room.Listen(h.ctx, msgC.ID) |
||||
assert.NoError(t, err) |
||||
defer itFoo.Close() |
||||
|
||||
itBar, err := h.room.Listen(h.ctx, msgA.ID) |
||||
assert.NoError(t, err) |
||||
defer itBar.Close() |
||||
|
||||
msgD := h.newMsg(t) |
||||
|
||||
// itBar should get msgB and msgC before anything else.
|
||||
assertNextMsg(t, msgB, h.ctx, itBar) |
||||
assertNextMsg(t, msgC, h.ctx, itBar) |
||||
|
||||
// now both iterators should give msgD
|
||||
assertNextMsg(t, msgD, h.ctx, itFoo) |
||||
assertNextMsg(t, msgD, h.ctx, itBar) |
||||
|
||||
// timeout should be honored
|
||||
{ |
||||
timeoutCtx, timeoutCancel := context.WithTimeout(h.ctx, 1*time.Second) |
||||
_, errFoo := itFoo.Next(timeoutCtx) |
||||
_, errBar := itBar.Next(timeoutCtx) |
||||
timeoutCancel() |
||||
|
||||
assert.ErrorIs(t, errFoo, context.DeadlineExceeded) |
||||
assert.ErrorIs(t, errBar, context.DeadlineExceeded) |
||||
} |
||||
|
||||
// new message should work
|
||||
{ |
||||
expMsg := h.newMsg(t) |
||||
|
||||
timeoutCtx, timeoutCancel := context.WithTimeout(h.ctx, 1*time.Second) |
||||
gotFooMsg, errFoo := itFoo.Next(timeoutCtx) |
||||
gotBarMsg, errBar := itBar.Next(timeoutCtx) |
||||
timeoutCancel() |
||||
|
||||
assert.Equal(t, expMsg, gotFooMsg) |
||||
assert.NoError(t, errFoo) |
||||
assert.Equal(t, expMsg, gotBarMsg) |
||||
assert.NoError(t, errBar) |
||||
} |
||||
|
||||
}) |
||||
|
||||
t.Run("listen/empty", func(t *testing.T) { |
||||
h := newRoomTestHarness(t) |
||||
|
||||
it, err := h.room.Listen(h.ctx, "") |
||||
assert.NoError(t, err) |
||||
defer it.Close() |
||||
|
||||
msg := h.newMsg(t) |
||||
assertNextMsg(t, msg, h.ctx, it) |
||||
}) |
||||
} |
@ -1,68 +0,0 @@ |
||||
package chat |
||||
|
||||
import ( |
||||
"encoding/hex" |
||||
"fmt" |
||||
"sync" |
||||
|
||||
"golang.org/x/crypto/argon2" |
||||
) |
||||
|
||||
// UserID uniquely identifies an individual user who has posted a message in a
|
||||
// Room.
|
||||
type UserID struct { |
||||
|
||||
// Name will be the user's chosen display name.
|
||||
Name string `json:"name"` |
||||
|
||||
// Hash will be a hex string generated from a secret only the user knows.
|
||||
Hash string `json:"id"` |
||||
} |
||||
|
||||
// UserIDCalculator is used to calculate UserIDs.
|
||||
type UserIDCalculator struct { |
||||
|
||||
// Secret is used when calculating UserID Hash salts.
|
||||
Secret []byte |
||||
|
||||
// TimeCost, MemoryCost, and Threads are used as inputs to the Argon2id
|
||||
// algorithm which is used to generate the Hash.
|
||||
TimeCost, MemoryCost uint32 |
||||
Threads uint8 |
||||
|
||||
// HashLen specifies the number of bytes the Hash should be.
|
||||
HashLen uint32 |
||||
|
||||
// Lock, if set, forces concurrent Calculate calls to occur sequentially.
|
||||
Lock *sync.Mutex |
||||
} |
||||
|
||||
// NewUserIDCalculator returns a UserIDCalculator with sane defaults.
|
||||
func NewUserIDCalculator(secret []byte) *UserIDCalculator { |
||||
return &UserIDCalculator{ |
||||
Secret: secret, |
||||
TimeCost: 15, |
||||
MemoryCost: 128 * 1024, |
||||
Threads: 2, |
||||
HashLen: 16, |
||||
Lock: new(sync.Mutex), |
||||
} |
||||
} |
||||
|
||||
// Calculate accepts a name and password and returns the calculated UserID.
|
||||
func (c *UserIDCalculator) Calculate(name, password string) UserID { |
||||
|
||||
input := fmt.Sprintf("%q:%q", name, password) |
||||
|
||||
hashB := argon2.IDKey( |
||||
[]byte(input), |
||||
c.Secret, // salt
|
||||
c.TimeCost, c.MemoryCost, c.Threads, |
||||
c.HashLen, |
||||
) |
||||
|
||||
return UserID{ |
||||
Name: name, |
||||
Hash: hex.EncodeToString(hashB), |
||||
} |
||||
} |
@ -1,26 +0,0 @@ |
||||
package chat |
||||
|
||||
import ( |
||||
"testing" |
||||
|
||||
"github.com/stretchr/testify/assert" |
||||
) |
||||
|
||||
func TestUserIDCalculator(t *testing.T) { |
||||
|
||||
const name, password = "name", "password" |
||||
|
||||
c := NewUserIDCalculator([]byte("foo")) |
||||
|
||||
// calculating with same params twice should result in same UserID
|
||||
userID := c.Calculate(name, password) |
||||
assert.Equal(t, userID, c.Calculate(name, password)) |
||||
|
||||
// changing either name or password should result in a different Hash
|
||||
assert.NotEqual(t, userID.Hash, c.Calculate(name+"!", password).Hash) |
||||
assert.NotEqual(t, userID.Hash, c.Calculate(name, password+"!").Hash) |
||||
|
||||
// changing the secret should change the UserID
|
||||
c.Secret = []byte("bar") |
||||
assert.NotEqual(t, userID, c.Calculate(name, password)) |
||||
} |
@ -1,28 +0,0 @@ |
||||
package chat |
||||
|
||||
import ( |
||||
"strconv" |
||||
"strings" |
||||
|
||||
"github.com/mediocregopher/radix/v4" |
||||
) |
||||
|
||||
func parseStreamEntryID(str string) (radix.StreamEntryID, error) { |
||||
|
||||
split := strings.SplitN(str, "-", 2) |
||||
if len(split) != 2 { |
||||
return radix.StreamEntryID{}, errInvalidMessageID |
||||
} |
||||
|
||||
time, err := strconv.ParseUint(split[0], 10, 64) |
||||
if err != nil { |
||||
return radix.StreamEntryID{}, errInvalidMessageID |
||||
} |
||||
|
||||
seq, err := strconv.ParseUint(split[1], 10, 64) |
||||
if err != nil { |
||||
return radix.StreamEntryID{}, errInvalidMessageID |
||||
} |
||||
|
||||
return radix.StreamEntryID{Time: time, Seq: seq}, nil |
||||
} |
@ -1,28 +0,0 @@ |
||||
package main |
||||
|
||||
import ( |
||||
"encoding/json" |
||||
"flag" |
||||
"fmt" |
||||
|
||||
"github.com/mediocregopher/blog.mediocregopher.com/srv/chat" |
||||
) |
||||
|
||||
func main() { |
||||
|
||||
secret := flag.String("secret", "", "Secret to use when calculating UserIDs") |
||||
name := flag.String("name", "", "") |
||||
password := flag.String("password", "", "") |
||||
|
||||
flag.Parse() |
||||
|
||||
calc := chat.NewUserIDCalculator([]byte(*secret)) |
||||
userID := calc.Calculate(*name, *password) |
||||
|
||||
b, err := json.Marshal(userID) |
||||
if err != nil { |
||||
panic(err) |
||||
} |
||||
|
||||
fmt.Println(string(b)) |
||||
} |
@ -1,211 +0,0 @@ |
||||
package http |
||||
|
||||
import ( |
||||
"context" |
||||
"errors" |
||||
"fmt" |
||||
"net/http" |
||||
"strings" |
||||
"unicode" |
||||
|
||||
"github.com/gorilla/websocket" |
||||
"github.com/mediocregopher/blog.mediocregopher.com/srv/chat" |
||||
"github.com/mediocregopher/blog.mediocregopher.com/srv/http/apiutil" |
||||
) |
||||
|
||||
type chatHandler struct { |
||||
*http.ServeMux |
||||
|
||||
room chat.Room |
||||
userIDCalc *chat.UserIDCalculator |
||||
|
||||
wsUpgrader websocket.Upgrader |
||||
} |
||||
|
||||
func newChatHandler( |
||||
room chat.Room, userIDCalc *chat.UserIDCalculator, |
||||
requirePowMiddleware func(http.Handler) http.Handler, |
||||
) http.Handler { |
||||
c := &chatHandler{ |
||||
ServeMux: http.NewServeMux(), |
||||
room: room, |
||||
userIDCalc: userIDCalc, |
||||
|
||||
wsUpgrader: websocket.Upgrader{}, |
||||
} |
||||
|
||||
c.Handle("/history", c.historyHandler()) |
||||
c.Handle("/user-id", requirePowMiddleware(c.userIDHandler())) |
||||
c.Handle("/append", requirePowMiddleware(c.appendHandler())) |
||||
c.Handle("/listen", c.listenHandler()) |
||||
|
||||
return c |
||||
} |
||||
|
||||
func (c *chatHandler) historyHandler() http.Handler { |
||||
return http.HandlerFunc(func(rw http.ResponseWriter, r *http.Request) { |
||||
limit, err := apiutil.StrToInt(r.PostFormValue("limit"), 0) |
||||
if err != nil { |
||||
apiutil.BadRequest(rw, r, fmt.Errorf("invalid limit parameter: %w", err)) |
||||
return |
||||
} |
||||
|
||||
cursor := r.PostFormValue("cursor") |
||||
|
||||
cursor, msgs, err := c.room.History(r.Context(), chat.HistoryOpts{ |
||||
Limit: limit, |
||||
Cursor: cursor, |
||||
}) |
||||
|
||||
if argErr := (chat.ErrInvalidArg{}); errors.As(err, &argErr) { |
||||
apiutil.BadRequest(rw, r, argErr.Err) |
||||
return |
||||
} else if err != nil { |
||||
apiutil.InternalServerError(rw, r, err) |
||||
} |
||||
|
||||
apiutil.JSONResult(rw, r, struct { |
||||
Cursor string `json:"cursor"` |
||||
Messages []chat.Message `json:"messages"` |
||||
}{ |
||||
Cursor: cursor, |
||||
Messages: msgs, |
||||
}) |
||||
}) |
||||
} |
||||
|
||||
func (c *chatHandler) userID(r *http.Request) (chat.UserID, error) { |
||||
name := r.PostFormValue("name") |
||||
if l := len(name); l == 0 { |
||||
return chat.UserID{}, errors.New("name is required") |
||||
} else if l > 16 { |
||||
return chat.UserID{}, errors.New("name too long") |
||||
} |
||||
|
||||
nameClean := strings.Map(func(r rune) rune { |
||||
if !unicode.IsPrint(r) { |
||||
return -1 |
||||
} |
||||
return r |
||||
}, name) |
||||
|
||||
if nameClean != name { |
||||
return chat.UserID{}, errors.New("name contains invalid characters") |
||||
} |
||||
|
||||
password := r.PostFormValue("password") |
||||
if l := len(password); l == 0 { |
||||
return chat.UserID{}, errors.New("password is required") |
||||
} else if l > 128 { |
||||
return chat.UserID{}, errors.New("password too long") |
||||
} |
||||
|
||||
return c.userIDCalc.Calculate(name, password), nil |
||||
} |
||||
|
||||
func (c *chatHandler) userIDHandler() http.Handler { |
||||
return http.HandlerFunc(func(rw http.ResponseWriter, r *http.Request) { |
||||
userID, err := c.userID(r) |
||||
if err != nil { |
||||
apiutil.BadRequest(rw, r, err) |
||||
return |
||||
} |
||||
|
||||
apiutil.JSONResult(rw, r, struct { |
||||
UserID chat.UserID `json:"userID"` |
||||
}{ |
||||
UserID: userID, |
||||
}) |
||||
}) |
||||
} |
||||
|
||||
func (c *chatHandler) appendHandler() http.Handler { |
||||
return http.HandlerFunc(func(rw http.ResponseWriter, r *http.Request) { |
||||
userID, err := c.userID(r) |
||||
if err != nil { |
||||
apiutil.BadRequest(rw, r, err) |
||||
return |
||||
} |
||||
|
||||
body := r.PostFormValue("body") |
||||
|
||||
if l := len(body); l == 0 { |
||||
apiutil.BadRequest(rw, r, errors.New("body is required")) |
||||
return |
||||
|
||||
} else if l > 300 { |
||||
apiutil.BadRequest(rw, r, errors.New("body too long")) |
||||
return |
||||
} |
||||
|
||||
msg, err := c.room.Append(r.Context(), chat.Message{ |
||||
UserID: userID, |
||||
Body: body, |
||||
}) |
||||
|
||||
if err != nil { |
||||
apiutil.InternalServerError(rw, r, err) |
||||
return |
||||
} |
||||
|
||||
apiutil.JSONResult(rw, r, struct { |
||||
MessageID string `json:"messageID"` |
||||
}{ |
||||
MessageID: msg.ID, |
||||
}) |
||||
}) |
||||
} |
||||
|
||||
func (c *chatHandler) listenHandler() http.Handler { |
||||
return http.HandlerFunc(func(rw http.ResponseWriter, r *http.Request) { |
||||
|
||||
ctx := r.Context() |
||||
sinceID := r.FormValue("sinceID") |
||||
|
||||
conn, err := c.wsUpgrader.Upgrade(rw, r, nil) |
||||
if err != nil { |
||||
apiutil.BadRequest(rw, r, err) |
||||
return |
||||
} |
||||
defer conn.Close() |
||||
|
||||
it, err := c.room.Listen(ctx, sinceID) |
||||
|
||||
if errors.As(err, new(chat.ErrInvalidArg)) { |
||||
apiutil.BadRequest(rw, r, err) |
||||
return |
||||
|
||||
} else if errors.Is(err, context.Canceled) { |
||||
return |
||||
|
||||
} else if err != nil { |
||||
apiutil.InternalServerError(rw, r, err) |
||||
return |
||||
} |
||||
|
||||
defer it.Close() |
||||
|
||||
for { |
||||
|
||||
msg, err := it.Next(ctx) |
||||
if errors.Is(err, context.Canceled) { |
||||
return |
||||
|
||||
} else if err != nil { |
||||
apiutil.InternalServerError(rw, r, err) |
||||
return |
||||
} |
||||
|
||||
err = conn.WriteJSON(struct { |
||||
Message chat.Message `json:"message"` |
||||
}{ |
||||
Message: msg, |
||||
}) |
||||
|
||||
if err != nil { |
||||
apiutil.GetRequestLogger(r).Error(ctx, "couldn't write message", err) |
||||
return |
||||
} |
||||
} |
||||
}) |
||||
} |
@ -1,251 +0,0 @@ |
||||
{{ define "body" }} |
||||
|
||||
<script async type="module" src="/assets/api.js"></script> |
||||
|
||||
<style> |
||||
#messages { |
||||
max-height: 65vh; |
||||
overflow: auto; |
||||
padding-right: 2rem; |
||||
} |
||||
|
||||
#messages .message { |
||||
border: 1px solid #AAA; |
||||
border-radius: 10px; |
||||
margin-bottom: 1rem; |
||||
padding: 2rem; |
||||
overflow: auto; |
||||
} |
||||
|
||||
#messages .message .title { |
||||
font-weight: bold; |
||||
font-size: 120%; |
||||
} |
||||
|
||||
#messages .message .secondaryTitle { |
||||
font-family: monospace; |
||||
color: #CCC; |
||||
} |
||||
|
||||
#messages .message p { |
||||
font-family: monospace; |
||||
margin: 1rem 0 0 0; |
||||
} |
||||
|
||||
</style> |
||||
|
||||
<div id="messages"></div> |
||||
|
||||
<span id="fail" style="color: red;"></span> |
||||
|
||||
<script> |
||||
|
||||
const messagesEl = document.getElementById("messages"); |
||||
|
||||
let messagesScrolledToBottom = true; |
||||
messagesEl.onscroll = () => { |
||||
const el = messagesEl; |
||||
messagesScrolledToBottom = el.scrollHeight == el.scrollTop + el.clientHeight; |
||||
}; |
||||
|
||||
function renderMessages(msgs) { |
||||
|
||||
messagesEl.innerHTML = ''; |
||||
|
||||
msgs.forEach((msg) => { |
||||
const el = document.createElement("div"); |
||||
el.className = "row message" |
||||
|
||||
const elWithTextContents = (tag, body) => { |
||||
const el = document.createElement(tag); |
||||
el.appendChild(document.createTextNode(body)); |
||||
return el; |
||||
}; |
||||
|
||||
const titleEl = document.createElement("div"); |
||||
titleEl.className = "title"; |
||||
el.appendChild(titleEl); |
||||
|
||||
const userNameEl = elWithTextContents("span", msg.userID.name); |
||||
titleEl.appendChild(userNameEl); |
||||
|
||||
const secondaryTitleEl = document.createElement("div"); |
||||
secondaryTitleEl.className = "secondaryTitle"; |
||||
el.appendChild(secondaryTitleEl); |
||||
|
||||
const dt = new Date(msg.createdAt*1000); |
||||
const dtStr |
||||
= `${dt.getFullYear()}-${dt.getMonth()+1}-${dt.getDate()}` |
||||
+ ` ${dt.getHours()}:${dt.getMinutes()}:${dt.getSeconds()}`; |
||||
|
||||
const userIDEl = elWithTextContents("span", `userID:${msg.userID.id} @ ${dtStr}`); |
||||
secondaryTitleEl.appendChild(userIDEl); |
||||
|
||||
const bodyEl = document.createElement("p"); |
||||
|
||||
const bodyParts = msg.body.split("\n"); |
||||
for (const i in bodyParts) { |
||||
if (i > 0) bodyEl.appendChild(document.createElement("br")); |
||||
bodyEl.appendChild(document.createTextNode(bodyParts[i])); |
||||
} |
||||
|
||||
el.appendChild(bodyEl); |
||||
|
||||
messagesEl.appendChild(el); |
||||
}); |
||||
} |
||||
|
||||
|
||||
(async () => { |
||||
|
||||
const failEl = document.getElementById("fail"); |
||||
setErr = (msg) => failEl.innerHTML = `${msg} (please refresh the page to retry)`; |
||||
|
||||
try { |
||||
|
||||
const api = await import("/assets/api.js"); |
||||
|
||||
const history = await api.call("/api/chat/global/history"); |
||||
const msgs = history.messages; |
||||
|
||||
// history returns msgs in time descending, but we display them in time |
||||
// ascending. |
||||
msgs.reverse() |
||||
|
||||
const sinceID = (msgs.length > 0) ? msgs[msgs.length-1].id : ""; |
||||
|
||||
const ws = await api.ws("/api/chat/global/listen", { |
||||
params: { sinceID }, |
||||
}); |
||||
|
||||
while (true) { |
||||
renderMessages(msgs); |
||||
|
||||
// If the user was previously scrolled to the bottom then keep them |
||||
// there. |
||||
if (messagesScrolledToBottom) { |
||||
messagesEl.scrollTop = messagesEl.scrollHeight; |
||||
} |
||||
|
||||
const msg = await ws.next(); |
||||
msgs.push(msg.message); |
||||
renderMessages(msgs); |
||||
} |
||||
|
||||
|
||||
} catch (e) { |
||||
e = `Failed to fetch message history: ${e}` |
||||
setErr(e); |
||||
console.error(e); |
||||
return; |
||||
} |
||||
|
||||
})() |
||||
|
||||
</script> |
||||
|
||||
<style> |
||||
#append { |
||||
border: 1px dashed #AAA; |
||||
border-radius: 10px; |
||||
padding: 2rem; |
||||
} |
||||
|
||||
#append #appendBody { |
||||
font-family: monospace; |
||||
} |
||||
|
||||
#append #appendStatus { |
||||
color: red; |
||||
} |
||||
|
||||
</style> |
||||
|
||||
<form id="append"> |
||||
<h5>New Message</h5> |
||||
<div class="row"> |
||||
<div class="columns four"> |
||||
<input class="u-full-width" placeholder="Name" id="appendName" type="text" /> |
||||
<input class="u-full-width" placeholder="Secret" id="appendSecret" type="password" /> |
||||
</div> |
||||
<div class="columns eight"> |
||||
<p> |
||||
Your name is displayed alongside your message. |
||||
|
||||
Your name+secret is used to generate your userID, which is also |
||||
displayed alongside your message. |
||||
|
||||
Other users can validate two messages are from the same person |
||||
by comparing the messages' userID. |
||||
</p> |
||||
</div> |
||||
</div> |
||||
<div class="row"> |
||||
<div class="columns twelve"> |
||||
<textarea |
||||
style="font-family: monospace" |
||||
id="appendBody" |
||||
class="u-full-width" |
||||
placeholder="Well thought out statement goes here..." |
||||
></textarea> |
||||
</div> |
||||
</div> |
||||
<div class="row"> |
||||
<div class="columns four"> |
||||
<input class="u-full-width button-primary" id="appendSubmit" type="button" value="Submit" /> |
||||
</div> |
||||
</div> |
||||
<span id="appendStatus"></span> |
||||
</form> |
||||
|
||||
<script> |
||||
|
||||
const append = document.getElementById("append"); |
||||
const appendName = document.getElementById("appendName"); |
||||
const appendSecret = document.getElementById("appendSecret"); |
||||
const appendBody = document.getElementById("appendBody"); |
||||
const appendSubmit = document.getElementById("appendSubmit"); |
||||
const appendStatus = document.getElementById("appendStatus"); |
||||
|
||||
appendSubmit.onclick = async () => { |
||||
|
||||
const appendSubmitOrigValue = appendSubmit.value; |
||||
|
||||
appendSubmit.disabled = true; |
||||
appendSubmit.className = ""; |
||||
appendSubmit.value = "Please hold..."; |
||||
|
||||
appendStatus.innerHTML = ''; |
||||
|
||||
try { |
||||
|
||||
const api = await import("/assets/api.js"); |
||||
|
||||
await api.call('/api/chat/global/append', { |
||||
body: { |
||||
name: appendName.value, |
||||
password: appendSecret.value, |
||||
body: appendBody.value, |
||||
}, |
||||
requiresPow: true, |
||||
}); |
||||
|
||||
appendBody.value = ''; |
||||
|
||||
} catch (e) { |
||||
|
||||
appendStatus.innerHTML = e; |
||||
|
||||
} finally { |
||||
appendSubmit.disabled = false; |
||||
appendSubmit.className = "button-primary"; |
||||
appendSubmit.value = appendSubmitOrigValue; |
||||
} |
||||
}; |
||||
|
||||
</script> |
||||
|
||||
{{ end }} |
||||
|
||||
{{ template "base.html" . }} |
||||
|
Loading…
Reference in new issue