sharded-gotify/api/stream/stream.go

322 lines
8.4 KiB
Go

package stream
import (
"net/http"
"net/url"
"regexp"
"strings"
"sync"
"time"
"github.com/gin-gonic/gin"
"github.com/gorilla/websocket"
"github.com/gotify/server/v2/auth"
"github.com/gotify/server/v2/mode"
"github.com/gotify/server/v2/model"
)
// shard holds clients for a subset of users to reduce lock contention.
type shard struct {
clients map[uint]map[string][]*client // userID -> token -> []client (multiple clients can share same token)
lock sync.RWMutex
}
// The API provides a handler for a WebSocket stream API.
type API struct {
shards []*shard
shardCount int
pingPeriod time.Duration
pongTimeout time.Duration
upgrader *websocket.Upgrader
channelBuf int // Buffer size for client write channels
}
// New creates a new instance of API.
// pingPeriod: is the interval, in which is server sends the a ping to the client.
// pongTimeout: is the duration after the connection will be terminated, when the client does not respond with the
// pong command.
// shardCount: number of shards for client storage (should be power of 2 for optimal distribution).
// readBufferSize: WebSocket read buffer size in bytes.
// writeBufferSize: WebSocket write buffer size in bytes.
// channelBufferSize: buffer size for client write channels in messages.
func New(pingPeriod, pongTimeout time.Duration, allowedWebSocketOrigins []string, shardCount, readBufferSize, writeBufferSize, channelBufferSize int) *API {
// Ensure shardCount is at least 1 and is a power of 2 for optimal hashing
if shardCount < 1 {
shardCount = 256
}
// Round up to next power of 2
shardCount = nextPowerOf2(shardCount)
shards := make([]*shard, shardCount)
for i := range shards {
shards[i] = &shard{
clients: make(map[uint]map[string][]*client),
}
}
return &API{
shards: shards,
shardCount: shardCount,
pingPeriod: pingPeriod,
pongTimeout: pingPeriod + pongTimeout,
upgrader: newUpgrader(allowedWebSocketOrigins, readBufferSize, writeBufferSize),
channelBuf: channelBufferSize,
}
}
// nextPowerOf2 returns the next power of 2 >= n.
func nextPowerOf2(n int) int {
if n <= 0 {
return 1
}
n--
n |= n >> 1
n |= n >> 2
n |= n >> 4
n |= n >> 8
n |= n >> 16
n++
return n
}
// getShard returns the shard for a given userID using fast modulo operation.
func (a *API) getShard(userID uint) *shard {
return a.shards[userID%uint(a.shardCount)]
}
// CollectConnectedClientTokens returns all tokens of the connected clients.
func (a *API) CollectConnectedClientTokens() []string {
var allClients []string
for _, shard := range a.shards {
shard.lock.RLock()
for _, userClients := range shard.clients {
for _, tokenClients := range userClients {
for _, c := range tokenClients {
allClients = append(allClients, c.token)
}
}
}
shard.lock.RUnlock()
}
return uniq(allClients)
}
// NotifyDeletedUser closes existing connections for the given user.
func (a *API) NotifyDeletedUser(userID uint) error {
shard := a.getShard(userID)
shard.lock.Lock()
defer shard.lock.Unlock()
if userClients, ok := shard.clients[userID]; ok {
for _, tokenClients := range userClients {
for _, client := range tokenClients {
client.Close()
}
}
delete(shard.clients, userID)
}
return nil
}
// NotifyDeletedClient closes existing connections with the given token.
func (a *API) NotifyDeletedClient(userID uint, token string) {
shard := a.getShard(userID)
shard.lock.Lock()
defer shard.lock.Unlock()
if userClients, ok := shard.clients[userID]; ok {
if tokenClients, exists := userClients[token]; exists {
for _, client := range tokenClients {
client.Close()
}
delete(userClients, token)
// Clean up empty user map
if len(userClients) == 0 {
delete(shard.clients, userID)
}
}
}
}
// Notify notifies the clients with the given userID that a new messages was created.
func (a *API) Notify(userID uint, msg *model.MessageExternal) {
shard := a.getShard(userID)
shard.lock.RLock()
userClients, ok := shard.clients[userID]
if !ok {
shard.lock.RUnlock()
return
}
// Create a snapshot of clients to avoid holding lock during send
clients := make([]*client, 0)
for _, tokenClients := range userClients {
for _, c := range tokenClients {
clients = append(clients, c)
}
}
shard.lock.RUnlock()
// Send messages without holding the lock to prevent blocking other shards
// The channel buffer (default 10) helps prevent blocking in most cases
for _, c := range clients {
c.write <- msg
}
}
func (a *API) remove(c *client) {
shard := a.getShard(c.userID)
shard.lock.Lock()
defer shard.lock.Unlock()
if userClients, ok := shard.clients[c.userID]; ok {
if tokenClients, exists := userClients[c.token]; exists {
// Remove the specific client from the slice
for i, client := range tokenClients {
if client == c {
userClients[c.token] = append(tokenClients[:i], tokenClients[i+1:]...)
// Clean up empty token slice
if len(userClients[c.token]) == 0 {
delete(userClients, c.token)
}
// Clean up empty user map
if len(userClients) == 0 {
delete(shard.clients, c.userID)
}
break
}
}
}
}
}
func (a *API) register(c *client) {
shard := a.getShard(c.userID)
shard.lock.Lock()
defer shard.lock.Unlock()
if shard.clients[c.userID] == nil {
shard.clients[c.userID] = make(map[string][]*client)
}
if shard.clients[c.userID][c.token] == nil {
shard.clients[c.userID][c.token] = make([]*client, 0, 1)
}
shard.clients[c.userID][c.token] = append(shard.clients[c.userID][c.token], c)
}
// Handle handles incoming requests. First it upgrades the protocol to the WebSocket protocol and then starts listening
// for read and writes.
// swagger:operation GET /stream message streamMessages
//
// Websocket, return newly created messages.
//
// ---
// schema: ws, wss
// produces: [application/json]
// security: [clientTokenAuthorizationHeader: [], clientTokenHeader: [], clientTokenQuery: [], basicAuth: []]
// responses:
// 200:
// description: Ok
// schema:
// $ref: "#/definitions/Message"
// 400:
// description: Bad Request
// schema:
// $ref: "#/definitions/Error"
// 401:
// description: Unauthorized
// schema:
// $ref: "#/definitions/Error"
// 403:
// description: Forbidden
// schema:
// $ref: "#/definitions/Error"
// 500:
// description: Server Error
// schema:
// $ref: "#/definitions/Error"
func (a *API) Handle(ctx *gin.Context) {
conn, err := a.upgrader.Upgrade(ctx.Writer, ctx.Request, nil)
if err != nil {
ctx.Error(err)
return
}
client := newClient(conn, auth.GetUserID(ctx), auth.GetTokenID(ctx), a.remove, a.channelBuf)
a.register(client)
go client.startReading(a.pongTimeout)
go client.startWriteHandler(a.pingPeriod)
}
// Close closes all client connections and stops answering new connections.
func (a *API) Close() {
for _, shard := range a.shards {
shard.lock.Lock()
for _, userClients := range shard.clients {
for _, tokenClients := range userClients {
for _, client := range tokenClients {
client.Close()
}
}
}
for k := range shard.clients {
delete(shard.clients, k)
}
shard.lock.Unlock()
}
}
func uniq[T comparable](s []T) []T {
m := make(map[T]struct{}, len(s))
r := make([]T, 0, len(s))
for _, v := range s {
if _, ok := m[v]; !ok {
m[v] = struct{}{}
r = append(r, v)
}
}
return r
}
func isAllowedOrigin(r *http.Request, allowedOrigins []*regexp.Regexp) bool {
origin := r.Header.Get("origin")
if origin == "" {
return true
}
u, err := url.Parse(origin)
if err != nil {
return false
}
if strings.EqualFold(u.Host, r.Host) {
return true
}
for _, allowedOrigin := range allowedOrigins {
if allowedOrigin.MatchString(strings.ToLower(u.Hostname())) {
return true
}
}
return false
}
func newUpgrader(allowedWebSocketOrigins []string, readBufferSize, writeBufferSize int) *websocket.Upgrader {
compiledAllowedOrigins := compileAllowedWebSocketOrigins(allowedWebSocketOrigins)
return &websocket.Upgrader{
ReadBufferSize: readBufferSize,
WriteBufferSize: writeBufferSize,
CheckOrigin: func(r *http.Request) bool {
if mode.IsDev() {
return true
}
return isAllowedOrigin(r, compiledAllowedOrigins)
},
}
}
func compileAllowedWebSocketOrigins(allowedOrigins []string) []*regexp.Regexp {
var compiledAllowedOrigins []*regexp.Regexp
for _, origin := range allowedOrigins {
compiledAllowedOrigins = append(compiledAllowedOrigins, regexp.MustCompile(origin))
}
return compiledAllowedOrigins
}