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|
package main
import (
"context"
"database/sql"
"encoding/json"
"flag"
"html/template"
"io"
"log"
"net/http"
"net/url"
"os"
"os/signal"
"slices"
"strconv"
"strings"
"sync"
"sync/atomic"
"syscall"
"time"
"github.com/rs/zerolog"
"maunium.net/go/mautrix/event"
"maunium.net/go/mautrix/id"
"go.mau.fi/gomuks/pkg/hicli"
"go.mau.fi/gomuks/pkg/hicli/database"
"go.mau.fi/gomuks/pkg/hicli/jsoncmd"
)
// ---------------------------------------------------------------------------
// tuning
// ---------------------------------------------------------------------------
const (
// backlogTarget is how many timeline rows a freshly loaded page walks back
// to. Rows already in SQLite are essentially free; beyond that hicli
// backfills from the homeserver, so the first walk of a long-lived room does
// real /messages requests while later ones are local.
backlogTarget = 1000
// paginateBatch is the batch size for backfill requests to the homeserver.
paginateBatch = 500
// chunkSize is how many messages go into one SSE frame. Chunking (rather
// than one frame per message) keeps framing overhead down on a large
// backlog, while letting the browser paint the newest chunk immediately.
chunkSize = 200
// liveQueueSize bounds the per-subscriber queue for *live* events. Live
// sends must never block, because they run on hicli's syncer goroutine.
// Overflowing it means the client's view is missing events, which is
// unrecoverable without a resync — see subscriber.overflow.
liveQueueSize = 1024
)
// ---------------------------------------------------------------------------
// SSE fan-out hub
// ---------------------------------------------------------------------------
// subscriber is one connected browser tab, watching one room.
//
// Only *live* traffic goes through this channel. History is written straight to
// the HTTP response before the subscriber's drain loop starts (see
// handleEvents), so there is exactly one discipline here: never block, because
// these sends run on hicli's syncer goroutine and a stalled write would stall
// the whole sync loop.
//
// A full queue therefore cannot be papered over. Dropping a live event would
// leave a hole the client can never learn about — its cursor advances past the
// gap on the next event that *does* get through. So overflow is recorded and
// the stream is reset instead, which is the only honest recovery.
//
// Note there is no de-duplication here. A message committing between subscribe
// and the history snapshot is delivered twice, and that is deliberately fine:
// the client keys rows by event ID and updates in place, so a repeat delivery
// re-renders one row rather than adding a second. Suppressing it server-side
// would mean tracking a boundary per subscriber to fix something the client
// already handles.
type subscriber struct {
ch chan []byte
// overflow is set when a live event had to be dropped. The drain loop
// notices and resets the client.
overflow atomic.Bool
// tabID identifies the browser tab this subscription belongs to, so the
// tab can update its own visibility over a separate request. It is
// generated by the client and only has to be unique among live streams.
tabID string
// visible is true while this tab is actually on screen showing this room.
//
// It exists so notifications can be suppressed for a conversation the user
// is already looking at. Deciding that here rather than in the browser is
// not an optimisation but a correctness requirement: the server sends each
// notification to exactly one tab (see notifyHub), which is generally *not*
// the tab displaying the room, so no single client has enough information
// to make the call.
//
// Tying it to the subscription is what keeps it honest — a closed tab takes
// its flag with it, so a crashed or navigated-away browser cannot leave a
// room permanently muted.
visible atomic.Bool
}
// hub is the set of tabs watching one room; there is one per roomView.
type hub struct {
mu sync.Mutex
subs map[*subscriber]struct{}
}
func newHub() *hub {
return &hub{subs: map[*subscriber]struct{}{}}
}
// subscribe registers a subscriber. Callers must subscribe *before* reading
// history, so that an event arriving mid-read is queued rather than lost.
//
// tabID lets the tab update its visibility later; visible is its state at
// connect time, which the client sends as a query parameter so a tab opened in
// the background never counts as on screen.
func (h *hub) subscribe(tabID string, visible bool) *subscriber {
sub := &subscriber{ch: make(chan []byte, liveQueueSize), tabID: tabID}
sub.visible.Store(visible)
h.mu.Lock()
h.subs[sub] = struct{}{}
h.mu.Unlock()
return sub
}
func (h *hub) unsubscribe(sub *subscriber) {
h.mu.Lock()
delete(h.subs, sub)
h.mu.Unlock()
}
// anyVisible reports whether some tab currently has this room on screen.
func (h *hub) anyVisible() bool {
h.mu.Lock()
defer h.mu.Unlock()
for sub := range h.subs {
if sub.visible.Load() {
return true
}
}
return false
}
// setVisible updates the visibility of the subscription belonging to tabID.
//
// The tab is identified by an ID it made up rather than by its connection,
// because visibility arrives on a separate HTTP request from the SSE stream it
// applies to. An unknown ID is ignored: it means the stream has already gone,
// which is exactly when the flag no longer matters.
func (h *hub) setVisible(tabID string, visible bool) {
h.mu.Lock()
defer h.mu.Unlock()
for sub := range h.subs {
if sub.tabID == tabID {
sub.visible.Store(visible)
}
}
}
// ---------------------------------------------------------------------------
// notification fan-out
// ---------------------------------------------------------------------------
// notifyHub delivers desktop notifications to exactly one open tab.
//
// Unlike hub, this is process-wide (notifications are not scoped to a room) and
// delivers to a *single* subscriber rather than all of them. Showing the same
// notification once per open tab is the obvious failure mode here, and the
// alternatives to fixing it server-side are all worse: a SharedWorker holding
// the one connection, or client-side coordination over BroadcastChannel /
// navigator.locks. Both put consensus in the browser to solve something the
// server already knows the answer to — it can simply write the frame once.
//
// Leadership is "longest connected", which is why subs is a slice and not a
// map: it needs an order. When the leader disconnects it is removed and the
// next tab inherits, so the feature keeps working as long as any tab is open
// and stops when the last one closes, with no lifecycle code anywhere.
//
// Caveat: a backgrounded tab is still a live subscriber even when the browser
// throttles it, so it can hold the lease while draining slowly. That is bounded
// by the same overflow path as hub — a full queue marks the subscriber, whose
// drain loop then resets and disconnects it, handing leadership on.
type notifyHub struct {
mu sync.Mutex
subs []*subscriber
}
func newNotifyHub() *notifyHub {
return ¬ifyHub{}
}
func (n *notifyHub) subscribe() *subscriber {
sub := &subscriber{ch: make(chan []byte, liveQueueSize)}
n.mu.Lock()
n.subs = append(n.subs, sub)
n.mu.Unlock()
return sub
}
func (n *notifyHub) unsubscribe(sub *subscriber) {
n.mu.Lock()
defer n.mu.Unlock()
n.subs = slices.DeleteFunc(n.subs, func(s *subscriber) bool { return s == sub })
}
// hasSubscribers reports whether any tab is listening for notifications.
//
// handleEvent checks this before doing any notification work at all, so an
// account with no webchat tab open pays nothing beyond this lock for the
// feature — which matters because that path runs on hicli's syncer goroutine
// for every room in every sync.
func (n *notifyHub) hasSubscribers() bool {
n.mu.Lock()
defer n.mu.Unlock()
return len(n.subs) > 0
}
// send delivers a notification to the leader (the longest-connected tab) only.
//
// Like hub.broadcastLive this must never block: it runs on hicli's syncer
// goroutine. A full queue means that tab has stopped reading, so the
// notification is dropped for it — and unlike a timeline event, it is not
// retried against another subscriber. A notification is a transient alert; the
// message itself is still in the timeline either way, and re-routing a stale
// alert to a different tab is worse than not showing it.
func (n *notifyHub) send(logger zerolog.Logger, payload any) {
frame, err := sseFrame(sseNotify, payload, "")
if err != nil {
logger.Err(err).Msg("marshal notification")
return
}
n.mu.Lock()
defer n.mu.Unlock()
if len(n.subs) == 0 {
return
}
leader := n.subs[0]
select {
case leader.ch <- frame:
default:
leader.overflow.Store(true)
logger.Warn().Msg("notification subscriber queue full, dropping notification")
}
}
// SSE event names. Each one maps to exactly one O(1) DOM operation in the
// frontend, which is the whole point of the protocol: the server always knows
// whether a batch belongs above or below what the client holds, so the client
// never has to sort or compare anything.
const (
// sseAppend adds messages to the bottom (live events, gap replay).
sseAppend = "append"
// ssePrepend adds messages to the top (walking back through history).
ssePrepend = "prepend"
// sseUpdate re-renders existing messages in place, keyed by event ID.
// Unknown IDs are dropped by the client — an update for a message outside
// its window is not an insert.
sseUpdate = "update"
// sseReset tells the client to throw away everything and reload.
sseReset = "reset"
// sseTyping carries typing notifications; not a message operation.
sseTyping = "typing"
// sseNotify carries a desktop notification. It is the only event name that
// travels on /notifications rather than a room's stream.
sseNotify = "notify"
)
// sseFrame renders one SSE frame. A non-empty id sets the stream's Last-Event-ID,
// which the browser echoes back on reconnect.
//
// The id is always an event ID, never a timeline row ID: see resolveCursorSQL
// for why row IDs cannot survive a round trip through the client.
func sseFrame(eventName string, payload any, lastEventID string) ([]byte, error) {
b, err := json.Marshal(payload)
if err != nil {
return nil, err
}
frame := make([]byte, 0, len(b)+64)
if lastEventID != "" {
frame = append(frame, "id: "...)
frame = append(frame, lastEventID...)
frame = append(frame, '\n')
}
frame = append(frame, "event: "...)
frame = append(frame, eventName...)
frame = append(frame, "\ndata: "...)
frame = append(frame, b...)
frame = append(frame, '\n', '\n')
return frame, nil
}
// broadcastLive fans a live event out to every subscriber without blocking.
func (h *hub) broadcastLive(logger zerolog.Logger, eventName string, payload any, lastEventID string) {
frame, err := sseFrame(eventName, payload, lastEventID)
if err != nil {
logger.Err(err).Str("event", eventName).Msg("marshal sse event")
return
}
h.mu.Lock()
defer h.mu.Unlock()
for sub := range h.subs {
select {
case sub.ch <- frame:
default:
// Only a browser that has stopped reading entirely can get here.
// The event is genuinely lost for this subscriber, so mark it and
// let the drain loop reset the client rather than leave a silent
// hole in its log.
sub.overflow.Store(true)
logger.Warn().Msg("subscriber queue full, resetting client")
}
}
}
// ---------------------------------------------------------------------------
// wire format
// ---------------------------------------------------------------------------
// mediaInfo describes an attachment for the frontend. The URL points at
// webchat's own media proxy, never at the homeserver.
type mediaInfo struct {
URL string `json:"url"`
MimeType string `json:"mimetype,omitempty"`
Size int `json:"size,omitempty"`
// Width/Height let the frontend reserve layout space, which is what makes
// lazy loading usable: without them every not-yet-loaded image has zero
// height and the scroll position jumps around as images arrive.
Width int `json:"w,omitempty"`
Height int `json:"h,omitempty"`
FileName string `json:"filename,omitempty"`
// Duration is in milliseconds, for audio/video.
Duration int `json:"duration,omitempty"`
}
// edit is one revision of a message, in the order the revisions were made.
type edit struct {
Body string `json:"body"`
Timestamp int64 `json:"timestamp"`
}
// message is the trimmed-down view of a Matrix event that the frontend needs.
//
// It carries no sort key. Ordering is decided entirely by which frame a message
// arrives in (prepend/append), so the frontend never compares two messages —
// see the SSE event name constants above.
//
// Edits and redaction state are *fields of the message they affect*, not
// separate entries. That is what keeps the protocol to four operations: an edit
// is not a new row to be positioned, it is a changed rendering of an existing
// one, delivered as an `update`.
type message struct {
// EventID is the identity, the dedup key and the SSE resume cursor. It is
// UNIQUE in hicli's schema, server-assigned and never reused.
EventID id.EventID `json:"event_id"`
Sender id.UserID `json:"sender"`
// Display is the sender's room display name, falling back to the MXID
// localpart. The full MXID stays in Sender for the hover title.
Display string `json:"display"`
Body string `json:"body"`
Timestamp int64 `json:"timestamp"`
IsOwn bool `json:"is_own"`
// MsgType distinguishes m.text/m.image/m.video/m.audio/m.file so the
// frontend can pick an element.
MsgType string `json:"msgtype,omitempty"`
Media *mediaInfo `json:"media,omitempty"`
// Redacted marks a deleted message. The body is kept when we still have it
// cached (hicli never deletes event rows, so a redaction seen live leaves
// the original text in place) and the frontend shows it behind a marker.
// After a database rebuild the homeserver only serves the stripped event,
// so the same message then renders as the marker alone.
Redacted bool `json:"redacted,omitempty"`
// Edits are the successive revisions of this message, oldest first.
Edits []edit `json:"edits,omitempty"`
// Set when the event could not be decrypted; Body is then a placeholder.
Error string `json:"error,omitempty"`
}
// notification is one desktop notification for the frontend.
//
// Crucially, webchat decides *nothing* about which messages get one. hicli
// evaluates the account's Matrix push rules on every sync
// (hicli/pushrules.go, evaluatePushRules) and reports the result as
// SyncRoom.Notifications; this type is just that decision on the wire.
//
// That is not laziness, it is the only way to get it right: those rules are
// what already express "notify for direct messages and mentions, stay quiet in
// busy public rooms", they are edited from any Matrix client, and they include
// per-room mutes. Reimplementing the policy here would duplicate spec-defined
// logic and silently drift from every other client on the account.
type notification struct {
RoomID id.RoomID `json:"room_id"`
RoomName string `json:"room_name"`
// Path is where the frontend should navigate when the notification is
// clicked.
Path string `json:"path"`
Sender id.UserID `json:"sender"`
// Display is the sender's room display name, as in message.Display.
Display string `json:"display"`
Body string `json:"body"`
// Highlight marks a mention (or anything else the push rules highlight, in
// practice mostly the user's name); the frontend renders these more loudly.
Highlight bool `json:"highlight"`
// Sound is the push rules' sound tweak. The frontend maps it to the
// Notification `silent` option rather than playing audio itself.
Sound bool `json:"sound"`
}
// messageContent is the subset of m.room.message content webchat understands.
type messageContent struct {
Body string `json:"body"`
MsgType event.MessageType `json:"msgtype"`
FileName string `json:"filename"`
URL id.ContentURIString `json:"url"`
File *event.EncryptedFileInfo `json:"file"`
Info *event.FileInfo `json:"info"`
NewContent *struct {
Body string `json:"body"`
} `json:"m.new_content"`
}
// displayName picks the nicest available name for a sender: the room display
// name if the member event has one, otherwise the MXID localpart.
//
// Dropping the server name can in principle make two users from different
// homeservers look alike. The full MXID is kept in the message's Sender field
// and shown on hover, so the ambiguity is always resolvable; a nick column full
// of @user:server.tld is the worse trade.
func displayName(sender id.UserID, roomDisplayName string) string {
if roomDisplayName != "" {
return roomDisplayName
}
if lp := sender.Localpart(); lp != "" {
return lp
}
return string(sender)
}
// toMessage converts a joined timeline row into a wire message, returning false
// for events the UI does not display.
//
// Dropped here: state events, reactions, and edits. Edits are dropped as
// *timeline rows* because they are re-attached to the message they replace by
// loadEdits — showing them standalone is what made an edit appear as a
// duplicate message at the bottom of the log.
//
// Redacted events are deliberately kept: they render with a marker instead of
// vanishing, so a deletion is visible without a reload.
func (s *server) toMessage(row timelineRow) (message, bool) {
if row.StateKey.Valid {
return message{}, false
}
// Edits are folded into their target, never shown on their own.
if row.RelationType.String == string(event.RelReplace) {
return message{}, false
}
msg := message{
EventID: row.EventID,
Sender: row.Sender,
Display: displayName(row.Sender, row.Displayname.String),
Timestamp: row.Timestamp,
IsOwn: row.Sender == s.userID,
Redacted: row.RedactedBy.Valid,
}
// An encrypted event that hicli could not decrypt (yet) still deserves a
// placeholder, otherwise messages would silently vanish from the log. A
// later `decrypted` event replaces it in place, keyed by event ID.
if row.DecryptionError != "" {
msg.Error = row.DecryptionError
msg.Body = "[unable to decrypt]"
return msg, true
}
if row.Type != event.EventMessage.Type && row.Type != event.EventSticker.Type {
return message{}, false
}
var content messageContent
if err := json.Unmarshal(row.Content, &content); err != nil {
return message{}, false
}
// Edits carry the replacement text in m.new_content.
if content.NewContent != nil && content.NewContent.Body != "" {
msg.Body = content.NewContent.Body
} else {
msg.Body = content.Body
}
msg.MsgType = string(content.MsgType)
// Attachments: the URL lives in `file` for encrypted rooms and `url` for
// plaintext ones.
uri := content.URL
if content.File != nil {
uri = content.File.URL
}
if url := mediaURL(uri); url != "" {
msg.Media = &mediaInfo{
URL: url,
FileName: content.FileName,
}
if msg.Media.FileName == "" {
msg.Media.FileName = content.Body
}
if info := content.Info; info != nil {
msg.Media.MimeType = info.MimeType
msg.Media.Size = info.Size
msg.Media.Width = info.Width
msg.Media.Height = info.Height
msg.Media.Duration = info.Duration
}
}
// A message with neither text nor an attachment has nothing to render —
// except a redacted one, whose emptiness is exactly what we want to show
// (the homeserver strips content on redaction, so a redacted event fetched
// after a database rebuild arrives with an empty body).
if msg.Body == "" && msg.Media == nil && !msg.Redacted {
return message{}, false
}
return msg, true
}
// toMessages converts timeline rows to wire messages and attaches each one's
// edits, in one batched query rather than one per message.
//
// order is preserved: callers rely on it to decide prepend vs append.
func (v *roomView) toMessages(ctx context.Context, rows []timelineRow) []message {
msgs := make([]message, 0, len(rows))
for _, row := range rows {
if msg, ok := v.s.toMessage(row); ok {
msgs = append(msgs, msg)
}
}
if len(msgs) == 0 {
return msgs
}
ids := make([]id.EventID, len(msgs))
for i, msg := range msgs {
ids[i] = msg.EventID
}
edits, err := v.loadEdits(ctx, ids)
if err != nil {
// Edits are an enhancement; failing to load them should not cost us the
// messages themselves.
v.s.log.Err(err).Msg("load edits")
return msgs
}
for i := range msgs {
for _, e := range edits[msgs[i].EventID] {
msgs[i].Edits = append(msgs[i].Edits, edit{Body: e.Body, Timestamp: e.Timestamp})
}
}
return msgs
}
// ---------------------------------------------------------------------------
// server
// ---------------------------------------------------------------------------
// server is the process-wide state: one Matrix client, one account, and the
// set of rooms that currently have a browser attached.
//
// Everything room-specific lives in a roomView instead. The split exists
// because hicli already syncs *every* joined room — its sync filter has no
// room restriction (hicli/syncwrap.go, GetFilterJSON) — so serving more rooms
// is purely a matter of routing, not of fetching more.
type server struct {
cli *hicli.HiClient
userID id.UserID
log zerolog.Logger
// uploadLimit is the homeserver's m.upload.size, i.e. the largest
// attachment it will accept. The browser shrinks oversized images down to
// this before uploading, and handleUpload enforces it server-side too.
uploadLimit int64
// notify fans desktop notifications out to a single tab, for every room
// rather than just the open ones — see notifyHub.
notify *notifyHub
// views holds one roomView per room that has been opened since startup.
// Created lazily rather than upfront: an account can be in hundreds of
// rooms and all but a couple of them will never be looked at.
//
// Entries are never removed. A view holds a hub with no subscribers and a
// mutex — a few dozen bytes — so reclaiming them would buy nothing but a
// lifetime problem, since the syncer goroutine and HTTP handlers both reach
// for them concurrently.
viewsMu sync.RWMutex
views map[id.RoomID]*roomView
}
// roomView is the per-room state: one SSE fan-out hub and one pagination lock.
//
// Both are per-room by necessity, not by preference. Subscribers must be
// per-room because a browser tab is showing exactly one room's timeline, and
// hicli's paginator refuses concurrent pagination *for the same room*
// (ErrPaginationAlreadyInProgress, hicli/paginate.go) — a single global lock
// would serialise unrelated rooms' backfills for no reason.
type roomView struct {
s *server
roomID id.RoomID
hub *hub
// backfillMu serializes calls into hicli's paginator for this room. It is
// held for the duration of that call only — see backfill.
backfillMu sync.Mutex
}
// view returns the roomView for a room, creating it if this is the first time
// the room has been opened.
func (s *server) view(roomID id.RoomID) *roomView {
s.viewsMu.RLock()
v, ok := s.views[roomID]
s.viewsMu.RUnlock()
if ok {
return v
}
s.viewsMu.Lock()
defer s.viewsMu.Unlock()
// Re-check: another request may have created it while we were upgrading.
if v, ok := s.views[roomID]; ok {
return v
}
v = &roomView{s: s, roomID: roomID, hub: newHub()}
s.views[roomID] = v
return v
}
// viewIfOpen returns the roomView for a room only if one already exists.
//
// This is what the sync event handler uses, and it is the reason serving every
// joined room costs no more than serving one: a sync touching a room nobody is
// looking at does no work beyond this map lookup. Creating views here instead
// would allocate a hub for every room in the account on the first sync.
func (s *server) viewIfOpen(roomID id.RoomID) *roomView {
s.viewsMu.RLock()
defer s.viewsMu.RUnlock()
return s.views[roomID]
}
// senderDisplayName looks up a sender's current room display name. Used for
// typing notifications and desktop notifications, which carry user IDs rather
// than joined event rows; timeline display names are resolved by the SQL join
// in eventColumns instead.
// A name is never worth failing over: every lookup problem — no client, no
// member event, a database error — falls back to the MXID localpart, which is
// always available and always recognisable.
func (s *server) senderDisplayName(ctx context.Context, roomID id.RoomID, sender id.UserID) string {
if s.cli == nil {
return displayName(sender, "")
}
memberEvt, err := s.cli.DB.CurrentState.Get(ctx, roomID, event.StateMember, string(sender))
if err != nil || memberEvt == nil {
return displayName(sender, "")
}
var content struct {
Displayname string `json:"displayname"`
}
_ = json.Unmarshal(memberEvt.Content, &content)
return displayName(sender, content.Displayname)
}
// nullString converts an optional string to the sql.NullString that
// timelineRow uses, so events pushed by hicli can be fed through the same
// conversion as rows read back from SQLite.
func nullString(s *string) sql.NullString {
if s == nil {
return sql.NullString{}
}
return sql.NullString{String: *s, Valid: true}
}
// ptrIfSet returns a pointer to s, or nil if s is empty. hicli uses "" for
// absent in several event fields where the database column is NULL.
func ptrIfSet(s string) *string {
if s == "" {
return nil
}
return &s
}
// handleEvent is hicli's EventHandler: it runs on the syncer's goroutine for
// every push event, and classifies each one into the four-operation protocol.
//
// The classification is the heart of the design: a timeline row is either a new
// message (append), or a modification of an existing one (update). Edits and
// redactions are the latter, which is why they never need a position.
//
// Timeline handling dispatches through viewIfOpen, so a sync for a room no
// browser has open is dropped after one map lookup. That is what keeps syncing
// the whole account as cheap as syncing a single room.
//
// Notifications are the one thing that deliberately does *not* work that way:
// the whole point is to hear about rooms you are not looking at, so they are
// handled for every room in the sync. That extra pass is skipped entirely when
// no tab is listening.
func (s *server) handleEvent(rawEvt any) {
ctx := context.Background()
switch evt := rawEvt.(type) {
case *jsoncmd.SyncComplete:
notifying := s.notify.hasSubscribers()
for roomID, room := range evt.Rooms {
if notifying {
s.handleNotifications(ctx, room)
}
v := s.viewIfOpen(roomID)
if v == nil {
continue
}
// A limited sync makes hicli wipe the room's timeline and restart
// row IDs (see resolveCursorSQL). Every connected client is now
// holding a view that cannot be reconciled, so tell them to start
// over. hicli reports this and webchat used to ignore it, which
// left connected tabs silently stitching pre- and post-reset
// history together.
if room.Reset {
v.s.log.Info().Stringer("room", roomID).
Msg("timeline reset, telling clients to reload")
v.hub.broadcastLive(v.s.log, sseReset, map[string]any{}, "")
continue
}
v.handleTimeline(ctx, room)
}
case *jsoncmd.EventsDecrypted:
v := s.viewIfOpen(evt.RoomID)
if v == nil {
return
}
// Late decryption replaces the "[unable to decrypt]" placeholder. This
// is an update keyed by event ID, so — unlike before — it needs no
// timeline row ID, which is just as well: the query hicli uses to find
// these events does not join the timeline table, so the row IDs it
// reports are always zero.
ids := make([]id.EventID, 0, len(evt.Events))
for _, e := range evt.Events {
ids = append(ids, e.ID)
}
v.broadcastUpdate(ctx, ids)
case *jsoncmd.Typing:
v := s.viewIfOpen(evt.RoomID)
if v == nil {
return
}
others := make([]string, 0, len(evt.UserIDs))
for _, u := range evt.UserIDs {
if u != s.userID {
others = append(others, s.senderDisplayName(ctx, evt.RoomID, u))
}
}
v.hub.broadcastLive(s.log, sseTyping, map[string]any{"users": others}, "")
}
}
// handleTimeline turns one sync's worth of new timeline rows into append and
// update frames.
func (v *roomView) handleTimeline(ctx context.Context, room *jsoncmd.SyncRoom) {
// The timeline lists row IDs; the actual event bodies are in .Events.
byRowID := make(map[database.EventRowID]*database.Event, len(room.Events))
for _, e := range room.Events {
byRowID[e.RowID] = e
}
var appendIDs []id.EventID
var updateIDs []id.EventID
for _, tuple := range room.Timeline {
evtData, ok := byRowID[tuple.Event]
if !ok {
// Not included in this payload (e.g. already known); fetch it.
var err error
evtData, err = v.s.cli.DB.Event.GetByRowID(ctx, tuple.Event)
if err != nil || evtData == nil {
continue
}
}
switch {
case evtData.RelationType == event.RelReplace:
// An edit: re-render the message it replaces, not the edit itself.
if evtData.RelatesTo != "" {
updateIDs = append(updateIDs, evtData.RelatesTo)
}
case evtData.Type == event.EventRedaction.Type:
// A redaction: re-render its target. hicli's schema has an AFTER
// INSERT trigger that sets redacted_by on the target row, and it
// runs inside the sync transaction, which has already committed by
// the time we get here — so re-reading the target now sees it.
if target := redactionTarget(evtData); target != "" {
updateIDs = append(updateIDs, target)
}
default:
appendIDs = append(appendIDs, evtData.ID)
}
}
if len(appendIDs) > 0 {
v.broadcastMessages(ctx, sseAppend, appendIDs)
}
if len(updateIDs) > 0 {
v.broadcastUpdate(ctx, updateIDs)
}
}
// handleNotifications turns one room's push-rule matches into notify frames.
//
// room.Notifications is hicli's output, not ours: it has already run the
// account's push rules over each new event (evaluatePushRules) and listed only
// those that should notify. So there is no policy here — no DM check, no
// mention matching, no mute list — just formatting.
//
// hicli also suppresses these until the first sync has completed
// (firstSyncReceived, hicli/sync.go), so starting webchat after a week away
// does not produce a week of notifications.
func (s *server) handleNotifications(ctx context.Context, room *jsoncmd.SyncRoom) {
if len(room.Notifications) == 0 {
return
}
// Suppress notifications for a room the user is already watching. This is
// decided here, not in the browser, because the notification goes to
// exactly one tab (notifyHub) and that tab is usually not the one showing
// the room — it cannot know whether some other tab has it on screen. A tab
// only counts while it is actually visible, so a room left open in a
// background window still notifies.
if v := s.viewIfOpen(room.Meta.ID); v != nil && v.hub.anyVisible() {
return
}
for _, notif := range room.Notifications {
if notif.Event == nil {
continue
}
// Never notify for our own messages. hicli's push rules normally take
// care of this, but a rule set edited by hand could let one through,
// and being pinged by your own message is pure noise.
if notif.Event.Sender == s.userID {
continue
}
// Reuse the timeline's own conversion so a notification says exactly
// what the message row will say — same body, same attachment handling,
// same "not something we render" rejections (state events, reactions,
// edits). Content/type mirror eventColumns' COALESCE: the cleartext
// when the event was encrypted, the raw content when it was not.
evt := notif.Event
content, evtType := evt.Content, evt.Type
if evt.Decrypted != nil {
content, evtType = evt.Decrypted, evt.DecryptedType
}
msg, ok := s.toMessage(timelineRow{
EventID: evt.ID,
Sender: evt.Sender,
Timestamp: evt.Timestamp.UnixMilli(),
Content: content,
Type: evtType,
StateKey: nullString(evt.StateKey),
RedactedBy: nullString(ptrIfSet(string(evt.RedactedBy))),
RelationType: nullString(ptrIfSet(string(evt.RelationType))),
})
if !ok {
continue
}
// A message that was redacted before we got here is not worth an alert.
if msg.Redacted {
continue
}
s.notify.send(s.log, notification{
RoomID: room.Meta.ID,
RoomName: roomDisplayName(room.Meta),
Path: roomPath(room.Meta.ID),
Sender: msg.Sender,
Display: s.senderDisplayName(ctx, room.Meta.ID, msg.Sender),
Body: notificationBody(msg),
Highlight: notif.Highlight,
Sound: notif.Sound,
})
}
}
// notificationBody is the one-line summary shown in the notification.
//
// An attachment has no useful text body (for an image it is just the filename),
// so it gets a placeholder instead. Long messages are truncated: notification
// daemons cut them off anyway, and doing it here keeps the frame small.
func notificationBody(msg message) string {
body := msg.Body
if msg.Media != nil && msg.MsgType != "m.text" {
switch msg.MsgType {
case "m.image":
body = "[image]"
case "m.video":
body = "[video]"
case "m.audio":
body = "[audio]"
default:
body = "[file]"
}
}
const maxBody = 200
if len(body) > maxBody {
// Trim on a rune boundary so the snippet cannot end mid-character.
body = strings.ToValidUTF8(body[:maxBody], "") + "…"
}
return body
}
// roomDisplayName is the room's name, falling back to its ID. Rooms that hicli
// has not named yet (no m.room.name, no canonical alias, member list not
// loaded) would otherwise show an empty title.
func roomDisplayName(room *database.Room) string {
if room == nil {
return ""
}
if room.Name != nil && *room.Name != "" {
return *room.Name
}
return string(room.ID)
}
// redactionTarget extracts the event a redaction applies to.
//
// Matrix moved `redacts` from the top level of the event into its content in
// room version 11. hicli normalises this while processing the event, copying
// the top-level field into content when only the former is present (see
// processEvent in hicli/sync.go), so reading content alone covers both.
func redactionTarget(evt *database.Event) id.EventID {
var content struct {
Redacts id.EventID `json:"redacts"`
}
if err := json.Unmarshal(evt.Content, &content); err != nil {
return ""
}
return content.Redacts
}
// broadcastMessages re-reads the given events from SQLite and sends them as one
// frame under the given operation.
//
// Re-reading rather than converting the pushed database.Event structs directly
// is what collapses the two conversion paths into one: display names, edits and
// redaction state all come from the same joined query the history path uses, so
// a message renders identically no matter which path delivered it.
func (v *roomView) broadcastMessages(ctx context.Context, op string, ids []id.EventID) {
rows, err := v.queryByEventIDs(ctx, ids)
if err != nil {
v.s.log.Err(err).Str("op", op).Msg("read events for broadcast")
return
}
msgs := v.toMessages(ctx, rows)
if len(msgs) == 0 {
return
}
// The resume cursor is the newest event in the frame. Only append frames
// set it: they are the only ones that extend the client's newest-known
// message. (Frames are built oldest-first, so that is the last element.)
cursor := ""
if op == sseAppend {
cursor = string(msgs[len(msgs)-1].EventID)
}
v.hub.broadcastLive(v.s.log, op, map[string]any{"messages": msgs}, cursor)
}
// broadcastUpdate re-renders existing messages in place. Updates never carry a
// resume cursor (they do not extend the timeline) and are never positional, so
// they go to every subscriber regardless of its history boundary.
func (v *roomView) broadcastUpdate(ctx context.Context, ids []id.EventID) {
v.broadcastMessages(ctx, sseUpdate, ids)
}
// handleRooms serves the room list, which is the landing page.
//
// Deliberately a plain rendered page rather than another live stream: keeping
// it static is what lets handleEvent early-out on rooms nobody has open. The
// list is re-sorted on every load, which is as fresh as it needs to be for
// something you look at for a second before clicking through.
func (s *server) handleRooms(w http.ResponseWriter, r *http.Request) {
if r.URL.Path != "/" {
http.NotFound(w, r)
return
}
rooms, err := listRooms(r.Context(), s.cli)
if err != nil {
s.log.Err(err).Msg("list rooms")
http.Error(w, "could not list rooms", http.StatusInternalServerError)
return
}
w.Header().Set("Content-Type", "text/html; charset=utf-8")
if err := roomsTmpl.Execute(w, map[string]any{
"UserID": s.userID,
"Rooms": rooms,
}); err != nil {
s.log.Err(err).Msg("render room list")
}
}
// handleIndex serves the single-page UI for one room, with the backlog already
// in it.
//
// Embedding the backlog rather than streaming it is what makes the scrolling
// sane. When the log starts empty, every message arrives as a prepend into a
// container whose scrollTop is 0 — and scroll anchoring is specified not to
// engage there (css-scroll-anchoring §2.1: no anchor node is selected for a
// scrolling box that is not scrolled away from its origin; §2.2.2 lists a zero
// scroll offset as a suppression trigger). So the view could only be held still
// by measuring and re-applying scroll offsets by hand, which is what used to be
// here and what jumped. With the rows already present at first paint there is
// nothing to hold still: the page is simply scrolled to the bottom once.
//
// The messages are embedded as JSON and rendered by the same mk() the live
// stream uses, rather than as server-rendered <li>s. Update frames re-render
// arbitrary rows in place (edits, redactions, late decryption), so that
// renderer has to exist in the browser regardless; a second server-side one
// would have to produce byte-identical markup forever or an edited message
// would visibly change shape as it was revised.
func (v *roomView) handleIndex(w http.ResponseWriter, r *http.Request) {
// The room name is read per request rather than cached on the view: it can
// change at any time (an m.room.name event, or a DM whose name is derived
// from its members), and a page load is not a hot path.
roomName := ""
if room, err := v.s.cli.DB.Room.Get(r.Context(), v.roomID); err == nil && room != nil && room.Name != nil {
roomName = *room.Name
}
msgs, newest, oldest, have := v.pageBacklog(r.Context())
// json.Marshal escapes <, > and & as \u003c, \u003e and \u0026, so the
// payload cannot terminate the <script> element it is embedded in.
backlog, err := json.Marshal(msgs)
if err != nil {
v.s.log.Err(err).Msg("marshal page backlog")
backlog = []byte("[]")
newest, oldest, have = "", "", 0
}
w.Header().Set("Content-Type", "text/html; charset=utf-8")
if err := tmpl.Execute(w, map[string]any{
"RoomID": v.roomID,
// Base is the prefix every API call in the page is built from, so the
// frontend needs no knowledge of the routing scheme beyond "prepend
// this". Escaped once here rather than in JS.
"Base": roomPath(v.roomID),
"UserID": v.s.userID,
"RoomName": roomName,
"UploadLimit": v.s.uploadLimit,
"Backlog": template.JS(backlog),
// The stream resumes forward from Newest and continues backwards from
// Oldest, so it neither replays nor skips what is already on the page.
"Newest": newest,
"Oldest": oldest,
"Have": have,
}); err != nil {
v.s.log.Err(err).Msg("render index")
}
}
// handleEvents is the SSE stream. It is the *only* way messages reach the
// browser: backlog, gap replay after a reconnect, and live events all arrive
// here, so the frontend has a single idempotent rendering path.
//
// History is written directly to the response *before* the live drain loop
// starts. That ordering is what lets the protocol drop its sort key: history
// and live events can no longer interleave, so every frame is either strictly
// above or strictly below what the client already holds, and the server always
// knows which.
func (v *roomView) handleEvents(w http.ResponseWriter, r *http.Request) {
flusher, ok := startSSE(w)
if !ok {
http.Error(w, "streaming unsupported", http.StatusInternalServerError)
return
}
ctx := r.Context()
// Subscribe *before* reading history, so an event committing while we read
// is queued rather than lost. It may then also appear in the history we are
// about to send; the client renders by event ID, so the repeat collapses
// onto the row it already has.
// The tab reports whether it is on screen right now, so a room opened in a
// background tab does not start out suppressing its own notifications.
sub := v.hub.subscribe(r.URL.Query().Get("tab"), r.URL.Query().Get("visible") == "1")
defer v.hub.unsubscribe(sub)
// The cursor comes from Last-Event-ID on a reconnect and from ?since on the
// first connect, where the page rendered its own backlog and the browser
// has no header to send yet. The header wins when both are present: it is
// necessarily the newer of the two, since ?since is fixed at page load.
cursor := r.Header.Get("Last-Event-ID")
if cursor == "" {
cursor = r.URL.Query().Get("since")
}
have, _ := strconv.Atoi(r.URL.Query().Get("have"))
if !v.sendHistory(ctx, w, flusher, cursor, r.URL.Query().Get("before"), have) {
return
}
// Keepalive comments stop intermediaries from dropping an idle stream.
ticker := time.NewTicker(25 * time.Second)
defer ticker.Stop()
for {
// A dropped live event leaves a hole this client cannot discover on its
// own, so the only correct recovery is to make it start over.
if sub.overflow.Load() {
frame, err := sseFrame(sseReset, map[string]any{}, "")
if err == nil {
_, _ = w.Write(frame)
flusher.Flush()
}
return
}
select {
case <-ctx.Done():
return
case <-ticker.C:
if _, err := w.Write([]byte(": keepalive\n\n")); err != nil {
return
}
flusher.Flush()
case frame := <-sub.ch:
if _, err := w.Write(frame); err != nil {
return
}
flusher.Flush()
}
}
}
// startSSE writes the event-stream headers and flushes them, so the browser
// treats the response as open rather than waiting for a complete body.
func startSSE(w http.ResponseWriter) (http.Flusher, bool) {
flusher, ok := w.(http.Flusher)
if !ok {
return nil, false
}
w.Header().Set("Content-Type", "text/event-stream")
w.Header().Set("Cache-Control", "no-cache")
w.Header().Set("Connection", "keep-alive")
// nginx buffers proxied responses by default, which would hold frames back
// until the buffer fills — fatal for a stream that is mostly idle.
w.Header().Set("X-Accel-Buffering", "no")
w.WriteHeader(http.StatusOK)
flusher.Flush()
return flusher, true
}
// handleNotifications is the notification stream, subscribed by every page.
//
// Unlike a room's /events stream this has no history and no resume cursor. A
// notification is a transient alert about something that happened while you
// were not looking; replaying a missed one after a reconnect would announce
// old news, and the message itself is in the timeline regardless. So there is
// nothing to send on connect and nothing to catch up on — only live frames.
//
// Note the stream is opened by every tab even though only one of them will be
// sent anything: subscribing is what makes a tab eligible to become the leader
// when the current one closes (see notifyHub).
func (s *server) handleNotificationStream(w http.ResponseWriter, r *http.Request) {
flusher, ok := startSSE(w)
if !ok {
http.Error(w, "streaming unsupported", http.StatusInternalServerError)
return
}
sub := s.notify.subscribe()
defer s.notify.unsubscribe(sub)
ctx := r.Context()
ticker := time.NewTicker(25 * time.Second)
defer ticker.Stop()
for {
// Overflow means this tab stopped reading. There is no "reset" for a
// stream with no state, so just drop the connection: the tab is
// removed from the subscriber list and leadership passes to the next.
if sub.overflow.Load() {
return
}
select {
case <-ctx.Done():
return
case <-ticker.C:
if _, err := w.Write([]byte(": keepalive\n\n")); err != nil {
return
}
flusher.Flush()
case frame := <-sub.ch:
if _, err := w.Write(frame); err != nil {
return
}
flusher.Flush()
}
}
}
// sendHistory delivers everything the client is missing, returning false if the
// connection died partway.
//
// There are three cases, distinguished by what the client already holds:
//
// - Nothing (no cursor): walk backwards to backlogTarget rows, backfilling
// from the homeserver when the local cache runs out. This is now the cold
// path — a fresh page load arrives with its backlog already rendered.
// - A cursor and a pre-rendered backlog (`since`+`before`+`have`): send the
// gap above it, then top the backlog up to backlogTarget from `before`.
// - A cursor alone (a reconnect, via Last-Event-ID): send only the gap.
//
// oldest/have describe the *bottom* of what the page rendered: the oldest
// timeline row it covered, and how many rows that was. They are what let the
// backfill continue from where the page stopped instead of duplicating it.
func (v *roomView) sendHistory(ctx context.Context, w io.Writer, flusher http.Flusher, lastEventID, oldest string, have int) bool {
if lastEventID == "" {
return v.sendBacklog(ctx, w, flusher, 0, backlogTarget, true)
}
// Event IDs are resolved against the *current* timeline on every reconnect,
// so a recycled or renumbered row ID can never be misread — see
// resolveCursorSQL.
cursor, found, err := v.resolveCursor(ctx, id.EventID(lastEventID))
if err != nil {
v.s.log.Err(err).Str("last_event_id", lastEventID).Msg("resolve cursor")
return v.sendBacklog(ctx, w, flusher, 0, backlogTarget, true)
}
if !found {
// The event is no longer on the timeline: it was cleared by a limited
// sync. The client's view cannot be extended, only replaced.
v.s.log.Info().Str("last_event_id", lastEventID).
Msg("cursor no longer on timeline, resetting client")
if !writeFrame(w, flusher, sseReset, map[string]any{}, "") {
return false
}
return v.sendBacklog(ctx, w, flusher, 0, backlogTarget, true)
}
if !v.sendGap(ctx, w, flusher, cursor) {
return false
}
if oldest == "" || have >= backlogTarget {
return true
}
// The page rendered a short backlog (the local cache ran out), so continue
// below it. The client already holds a newer cursor from the gap above, so
// these prepends must not carry one of their own.
bottom, found, err := v.resolveCursor(ctx, id.EventID(oldest))
if err != nil || !found {
return true // the boundary is gone; the client keeps what it has
}
return v.sendBacklog(ctx, w, flusher, bottom, backlogTarget-have, false)
}
// sendGap replays everything newer than the client's cursor. Deliberately
// uncapped: after a long disconnect we would rather push a large gap than
// silently skip messages.
func (v *roomView) sendGap(ctx context.Context, w io.Writer, flusher http.Flusher, cursor database.TimelineRowID) bool {
rows, err := v.queryForward(ctx, cursor)
if err != nil {
v.s.log.Err(err).Msg("query timeline gap")
return false
}
if len(rows) == 0 {
return true
}
// Oldest-first and all newer than what the client holds: an append.
return v.sendChunks(ctx, w, flusher, sseAppend, rows, "")
}
// pageBacklog reads the backlog that handleIndex embeds directly into the HTML,
// returning messages oldest-first along with the newest and oldest timeline row
// event IDs it covered.
//
// Unlike sendBacklog this reads *only what SQLite already has*: it never calls
// backfill. That is the whole point of pre-rendering. A cold room's backfill
// does real /messages round trips against the homeserver, and doing that inline
// would hold the page load — and therefore a blank screen — for as long as it
// takes. Whatever is missing is streamed in afterwards as prepends, which by
// then land in a log that is scrolled away from the origin, the one case where
// scroll anchoring is specified to hold the view still.
//
// The returned event IDs are timeline row IDs, not message IDs: they are only
// ever resolved back to a timeline position (see resolveCursorSQL), never
// displayed, so a state event serves as a boundary just as well as a message.
func (v *roomView) pageBacklog(ctx context.Context) (msgs []message, newest, oldest id.EventID, rowCount int) {
var cursor database.TimelineRowID // 0 = start from the newest row
var all []timelineRow
for rowCount < backlogTarget {
batch, err := v.queryBackward(ctx, cursor, paginateBatch)
if err != nil {
v.s.log.Err(err).Msg("query timeline for page backlog")
break
}
if len(batch) == 0 {
break // nothing more cached; the stream backfills the rest
}
// The cursor advances over every row read, not just displayable ones —
// see queryBackward.
cursor = batch[len(batch)-1].RowID
rowCount += len(batch)
all = append(all, batch...) // accumulated newest-first
}
if len(all) == 0 {
return nil, "", "", 0
}
newest, oldest = all[0].EventID, all[len(all)-1].EventID
slices.Reverse(all) // flip to oldest-first for rendering
return v.toMessages(ctx, all), newest, oldest, rowCount
}
// sendBacklog walks backwards from cursor (0 = the newest message), emitting
// chunks as it goes so the bottom of the log paints immediately, and
// backfilling from the homeserver once the local cache is exhausted.
//
// setCursor says whether the first frame carries the SSE resume cursor. It is
// false when continuing below a backlog the page already rendered: the client
// then already holds a *newer* cursor, and overwriting it with an older one
// would make the next reconnect replay everything in between.
func (v *roomView) sendBacklog(ctx context.Context, w io.Writer, flusher http.Flusher, cursor database.TimelineRowID, target int, setCursor bool) bool {
// The resume cursor is established from the *first* batch, which is the
// newest one. So a client that disconnects halfway through the walk still
// has a valid cursor and resumes forward correctly — how much history it
// managed to load has no bearing on staying up to date.
cursorSent := !setCursor
sent := 0
for sent < target {
rows, err := v.queryBackward(ctx, cursor, paginateBatch)
if err != nil {
v.s.log.Err(err).Msg("query timeline backlog")
return false
}
if len(rows) == 0 {
// Nothing cached below the cursor: ask hicli to backfill from the
// homeserver, then re-read. Paginate writes the fetched events into
// SQLite, so the next queryBackward picks them up.
more, err := v.backfill(ctx, cursor)
if err != nil {
v.s.log.Err(err).Msg("backfill from homeserver")
return false
}
if !more {
return true // start of the room
}
rows, err = v.queryBackward(ctx, cursor, paginateBatch)
if err != nil {
v.s.log.Err(err).Msg("query timeline after backfill")
return false
}
if len(rows) == 0 {
return true
}
}
// The cursor advances over *every* row read, not just the displayable
// ones. Advancing only past rendered messages would let a window of
// nothing but state events leave the cursor unchanged and spin forever.
cursor = rows[len(rows)-1].RowID
// Rows come back newest-first; flip to oldest-first for rendering.
slices.Reverse(rows)
// The newest row of the first batch is the resume point. It need not be
// a row the client renders — a state event works just as well — because
// the cursor is only ever resolved back to a timeline position, never
// displayed.
resumeFrom := id.EventID("")
if !cursorSent {
resumeFrom = rows[len(rows)-1].EventID
cursorSent = true
}
if !v.sendChunks(ctx, w, flusher, ssePrepend, rows, resumeFrom) {
return false
}
sent += len(rows)
if ctx.Err() != nil {
return false
}
}
return true
}
// backfill asks hicli to fetch older events from the homeserver. It reports
// whether more history may exist.
//
// The lock covers only this call, not the surrounding walk: hicli refuses
// concurrent pagination for one room, but holding it across the SSE writes
// would let one stalled browser block every other tab's first paint.
func (v *roomView) backfill(ctx context.Context, cursor database.TimelineRowID) (bool, error) {
v.backfillMu.Lock()
defer v.backfillMu.Unlock()
resp, err := v.s.cli.API.Paginate(ctx, &jsoncmd.PaginateParams{
RoomID: v.roomID,
MaxTimelineID: cursor,
Limit: paginateBatch,
})
if err != nil {
return false, err
}
return resp.HasMore, nil
}
// writeFrame writes one SSE frame straight to the response.
func writeFrame(w io.Writer, flusher http.Flusher, eventName string, payload any, lastEventID string) bool {
frame, err := sseFrame(eventName, payload, lastEventID)
if err != nil {
return false
}
if _, err := w.Write(frame); err != nil {
return false
}
flusher.Flush()
return true
}
// sendChunks converts rows (oldest-first) to messages and writes them out in
// chunks under the given operation.
//
// Chunking preserves order in both directions. For a prepend the caller walks
// backwards batch by batch, so batches arrive newest-first while each batch is
// internally oldest-first; chunks within a batch must therefore be emitted
// newest-chunk-first so that successive prepends stack up correctly. Worked
// example, rows [a,b,c,d] (oldest to newest) with chunkSize 2: this sends [c,d]
// then [a,b], and prepending each in turn yields [c,d] -> [a,b,c,d].
//
// resumeFrom, when set, is attached to the first frame written. It is emitted
// even for a batch that renders nothing, so that a window of state events does
// not cost the client its resume point.
func (v *roomView) sendChunks(ctx context.Context, w io.Writer, flusher http.Flusher, op string, rows []timelineRow, resumeFrom id.EventID) bool {
msgs := v.toMessages(ctx, rows)
if len(msgs) == 0 {
if resumeFrom != "" {
return writeFrame(w, flusher, op, map[string]any{"messages": []message{}}, string(resumeFrom))
}
return true
}
type chunk struct{ start, end int }
var chunks []chunk
for start := 0; start < len(msgs); start += chunkSize {
chunks = append(chunks, chunk{start, min(start+chunkSize, len(msgs))})
}
// Prepends paint from the bottom up, so the newest chunk goes first.
if op == ssePrepend {
slices.Reverse(chunks)
}
for i, c := range chunks {
cursor := ""
if i == 0 {
cursor = string(resumeFrom)
}
if !writeFrame(w, flusher, op, map[string]any{"messages": msgs[c.start:c.end]}, cursor) {
return false
}
if ctx.Err() != nil {
return false
}
}
return true
}
// handleSend sends a text message to this room. hicli takes care of encrypting
// it and sharing the megolm session as needed.
func (v *roomView) handleSend(w http.ResponseWriter, r *http.Request) {
var req struct {
Text string `json:"text"`
}
if err := json.NewDecoder(http.MaxBytesReader(w, r.Body, 1<<20)).Decode(&req); err != nil {
http.Error(w, "bad request", http.StatusBadRequest)
return
}
if req.Text == "" {
http.Error(w, "text required", http.StatusBadRequest)
return
}
evt, err := v.s.cli.API.SendMessage(r.Context(), &jsoncmd.SendMessageParams{
RoomID: v.roomID,
Text: req.Text,
})
if err != nil {
v.s.log.Err(err).Msg("send message")
http.Error(w, "send failed", http.StatusInternalServerError)
return
}
// The echo back through /events is what actually renders the message, so
// here we only confirm acceptance.
writeJSON(w, map[string]any{"ok": true, "event_id": evt.ID})
}
// handleTyping forwards typing notifications so the other side sees them.
// handleVisibility records whether a tab currently has this room on screen, so
// the server can skip notifications for a conversation the user is watching.
//
// This is a separate request rather than a message on the SSE stream because
// SSE is one-directional; the alternative would be a WebSocket, which is a lot
// of machinery for one boolean.
//
// Kept deliberately forgiving: an unknown tab ID is a no-op rather than an
// error, since the natural race — the stream dropping just as the tab reports
// going hidden — is harmless and would otherwise log noise on every reconnect.
func (v *roomView) handleVisibility(w http.ResponseWriter, r *http.Request) {
var req struct {
Tab string `json:"tab"`
Visible bool `json:"visible"`
}
if err := json.NewDecoder(http.MaxBytesReader(w, r.Body, 4096)).Decode(&req); err != nil {
http.Error(w, "bad request", http.StatusBadRequest)
return
}
if req.Tab == "" {
http.Error(w, "tab required", http.StatusBadRequest)
return
}
v.hub.setVisible(req.Tab, req.Visible)
w.WriteHeader(http.StatusNoContent)
}
func (v *roomView) handleTyping(w http.ResponseWriter, r *http.Request) {
var req struct {
Typing bool `json:"typing"`
}
if err := json.NewDecoder(http.MaxBytesReader(w, r.Body, 4096)).Decode(&req); err != nil {
http.Error(w, "bad request", http.StatusBadRequest)
return
}
timeout := 0
if req.Typing {
timeout = 10000
}
if err := v.s.cli.API.SetTyping(r.Context(), &jsoncmd.SetTypingParams{
RoomID: v.roomID,
Timeout: timeout,
}); err != nil {
v.s.log.Debug().Err(err).Msg("set typing")
}
w.WriteHeader(http.StatusNoContent)
}
func writeJSON(w http.ResponseWriter, v any) {
w.Header().Set("Content-Type", "application/json")
if err := json.NewEncoder(w).Encode(v); err != nil {
log.Printf("encode json: %v", err)
}
}
// roomInfo is a minimal room listing entry, used both by the `rooms` command
// and by the room list page.
type roomInfo struct {
ID id.RoomID
Name string
// Path is the URL of this room's chat page.
Path string
// Activity is the timestamp of the room's last activity, in milliseconds,
// as hicli's sorting_timestamp. Rendered as a relative time by the page.
Activity int64
}
// listRooms returns joined rooms, most recently active first.
//
// hicli's GetBySortTS excludes spaces (`room_type<>'m.space'`) and rooms that
// have never had activity (`sorting_timestamp > 0`), which is exactly the set
// worth listing — so no filtering is needed here.
func listRooms(ctx context.Context, cli *hicli.HiClient) ([]roomInfo, error) {
rooms, err := cli.DB.Room.GetBySortTS(ctx, time.Now().Add(1*time.Hour), 500)
if err != nil {
return nil, err
}
out := make([]roomInfo, 0, len(rooms))
for _, r := range rooms {
name := "(unnamed)"
if r.Name != nil && *r.Name != "" {
name = *r.Name
}
out = append(out, roomInfo{
ID: r.ID,
Name: name,
Path: roomPath(r.ID),
Activity: r.SortingTimestamp.UnixMilli(),
})
}
return out, nil
}
// roomPath is the URL prefix for a room's page and its API endpoints.
//
// Room IDs contain no characters that are special in a path segment
// (`!localpart:server`), but they are escaped anyway: the ID comes from the
// homeserver, and constructing URLs from remote data without escaping is a
// habit worth not having.
func roomPath(roomID id.RoomID) string {
return "/room/" + url.PathEscape(string(roomID))
}
// withRoom resolves the {roomID} path parameter to a roomView before handing
// off to a room-scoped handler.
//
// The database lookup is the access control for every room route, and it is
// the same shape the media proxy uses (see handleMedia): hicli only has a room
// row for rooms this account is actually in, so "is it in the DB" answers "may
// this be served". Without it, any room ID typed into the URL bar would create
// a view and start paginating a room we may not be in.
func (s *server) withRoom(h func(*roomView, http.ResponseWriter, *http.Request)) http.HandlerFunc {
return func(w http.ResponseWriter, r *http.Request) {
roomID := id.RoomID(r.PathValue("roomID"))
room, err := s.cli.DB.Room.Get(r.Context(), roomID)
if err != nil {
s.log.Err(err).Stringer("room", roomID).Msg("look up room")
http.Error(w, "room lookup failed", http.StatusInternalServerError)
return
}
if room == nil {
http.NotFound(w, r)
return
}
h(s.view(roomID), w, r)
}
}
// ---------------------------------------------------------------------------
// serve command
// ---------------------------------------------------------------------------
func cmdServe(args []string) {
fs := flag.NewFlagSet("serve", flag.ExitOnError)
addr := fs.String("addr", "127.0.0.1:8775", "listen address")
dbPath := fs.String("db", defaultDBPath(), "path to the webchat database")
debug := fs.Bool("debug", false, "verbose logging")
fs.Parse(args)
logger := newLogger(*debug)
ctx := logger.WithContext(context.Background())
s := &server{
views: map[id.RoomID]*roomView{},
notify: newNotifyHub(),
log: logger,
}
cli, err := startClient(ctx, *dbPath, logger, s.handleEvent)
if err != nil {
fatalf("%v", err)
}
s.cli = cli
s.userID = cli.Account.UserID
if !cli.VerificationState.IsVerified {
logger.Warn().Msg("device is not cross-signing verified; encrypted history may not decrypt — re-run `webchat login`")
}
s.uploadLimit = fetchUploadLimit(ctx, cli, logger)
mux := http.NewServeMux()
// The room list is the landing page; every room lives under /room/{id}, so
// each one gets its own SSE stream and its own Last-Event-ID cursor. That
// is what lets the single-timeline protocol carry over unchanged.
mux.HandleFunc("GET /{$}", s.handleRooms)
// Notifications are process-wide, not per room: the point is to hear about
// rooms you do *not* have open. Every page subscribes; only one is sent to.
mux.HandleFunc("GET /notifications", s.handleNotificationStream)
mux.HandleFunc("GET /room/{roomID}", s.withRoom((*roomView).handleIndex))
mux.HandleFunc("GET /room/{roomID}/events", s.withRoom((*roomView).handleEvents))
mux.HandleFunc("POST /room/{roomID}/send", s.withRoom((*roomView).handleSend))
mux.HandleFunc("POST /room/{roomID}/typing", s.withRoom((*roomView).handleTyping))
mux.HandleFunc("POST /room/{roomID}/visibility", s.withRoom((*roomView).handleVisibility))
mux.HandleFunc("POST /room/{roomID}/upload", s.withRoom((*roomView).handleUpload))
// Media stays global: it is keyed by mxc URI and access-controlled against
// hicli's media table, which is already room-agnostic.
mux.HandleFunc("GET /media/{server}/{fileID}", s.handleMedia)
srv := &http.Server{Addr: *addr, Handler: mux}
// Shut down cleanly so the sqlite WAL is checkpointed and olm state flushed.
stop := make(chan os.Signal, 1)
signal.Notify(stop, os.Interrupt, syscall.SIGTERM)
go func() {
<-stop
logger.Info().Msg("shutting down")
shutdownCtx, cancel := context.WithTimeout(context.Background(), 5*time.Second)
defer cancel()
_ = srv.Shutdown(shutdownCtx)
cli.Stop()
}()
logger.Info().
Str("addr", *addr).
Stringer("user", s.userID).
Msg("webchat listening")
if err := srv.ListenAndServe(); err != nil && err != http.ErrServerClosed {
logPanic("listen: %v", err)
}
}
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