84 lines
1.9 KiB
Go
84 lines
1.9 KiB
Go
// Package events broadcasts vault changes to all connected clients over WebSocket.
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package events
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import (
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"encoding/json"
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"log/slog"
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"sync"
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)
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// Event is a message pushed to clients.
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//
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// tree Directory structure changed (create/delete/move); clients reload the tree.
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// changed Note contents changed; Rev contains the new revision.
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// deleted A note was deleted.
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// moved A file or folder moved (From -> Path); folder events include child path mappings.
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// settings Application settings changed; clients reload them.
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type Event struct {
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Type string `json:"type"`
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Path string `json:"path,omitempty"`
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From string `json:"from,omitempty"`
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Rev string `json:"rev,omitempty"`
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}
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type Hub struct {
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mu sync.Mutex
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clients map[chan []byte]struct{}
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closed bool
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}
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func NewHub() *Hub { return &Hub{clients: map[chan []byte]struct{}{}} }
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// Subscribe returns a message channel and cancel function. Slow clients are disconnected and must reconnect and fully sync.
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func (h *Hub) Subscribe() (<-chan []byte, func()) {
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ch := make(chan []byte, 64)
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h.mu.Lock()
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if h.closed {
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close(ch)
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h.mu.Unlock()
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return ch, func() {}
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}
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h.clients[ch] = struct{}{}
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h.mu.Unlock()
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return ch, func() {
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h.mu.Lock()
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if _, ok := h.clients[ch]; ok {
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delete(h.clients, ch)
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close(ch)
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}
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h.mu.Unlock()
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}
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}
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func (h *Hub) Broadcast(events ...Event) {
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if len(events) == 0 {
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return
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}
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msg, err := json.Marshal(events)
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if err != nil {
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slog.Error("序列化事件失败", "err", err)
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return
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}
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h.mu.Lock()
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defer h.mu.Unlock()
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for ch := range h.clients {
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select {
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case ch <- msg:
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default:
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delete(h.clients, ch)
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close(ch)
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}
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}
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}
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// Close rejects new subscriptions and closes existing connections so instance recovery can reopen databases.
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func (h *Hub) Close() {
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h.mu.Lock()
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defer h.mu.Unlock()
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h.closed = true
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for ch := range h.clients {
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delete(h.clients, ch)
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close(ch)
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}
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}
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