feat: added convenient state groups api

v1/fsm/memory/memory.go

@@ -0,0 +1,129 @@
+package memory
+
+import (
+	"context"
+	"github.com/abelith/gomax/v1/fsm/state"
+	"github.com/abelith/gomax/v1/isolation"
+	"github.com/google/uuid"
+	"sync"
+	"time"
+)
+
+type FSMStorage struct {
+	m sync.Map
+}
+
+type EventIsolation struct {
+	mu    sync.Mutex
+	locks map[isolation.Scope]*lockEntry
+	ttl   time.Duration
+}
+
+type fsmKey struct {
+	userID int64
+	chatID int64
+}
+
+type eventIsolationKey struct {
+	userID int
+	chatID int
+}
+
+type lockEntry struct {
+	owner uuid.UUID
+	timer *time.Timer
+	done  chan struct{}
+}
+
+func NewFSMStorage() *FSMStorage {
+	return &FSMStorage{}
+}
+
+func (f *FSMStorage) Get(_ context.Context, scope isolation.Scope) (state.Snapshot, error) {
+	st, ok := f.m.Load(fsmKey{
+		userID: scope.UserID,
+		chatID: scope.ChatID,
+	})
+	if !ok {
+		return state.Snapshot{}, state.ErrStateNotFound
+	}
+
+	return st.(state.Snapshot), nil
+}
+
+func (f *FSMStorage) Put(_ context.Context, snapshot state.Snapshot) error {
+	f.m.Store(fsmKey{
+		userID: snapshot.Scope.UserID,
+		chatID: snapshot.Scope.ChatID,
+	}, snapshot)
+	return nil
+}
+
+func (f *FSMStorage) Delete(_ context.Context, scope isolation.Scope) error {
+	f.m.Delete(fsmKey{
+		userID: scope.UserID,
+		chatID: scope.ChatID,
+	})
+	return nil
+}
+
+func NewEventIsolation(ttl time.Duration) *EventIsolation {
+	return &EventIsolation{
+		locks: make(map[isolation.Scope]*lockEntry),
+		ttl:   ttl,
+	}
+}
+
+func (ei *EventIsolation) Lock(ctx context.Context, key isolation.Key) error {
+	scope := key.Scope()
+
+	for {
+		ei.mu.Lock()
+		entry, busy := ei.locks[scope]
+		if !busy {
+			ei.acquireLocked(scope, key.UpdateID)
+			ei.mu.Unlock()
+			return nil
+		}
+		done := entry.done
+		ei.mu.Unlock()
+
+		select {
+		case <-done:
+		case <-ctx.Done():
+			return ctx.Err()
+		}
+	}
+}
+
+func (ei *EventIsolation) Unlock(_ context.Context, key isolation.Key) error {
+	scope := key.Scope()
+
+	ei.mu.Lock()
+	defer ei.mu.Unlock()
+
+	entry, ok := ei.locks[scope]
+	if !ok || entry.owner != key.UpdateID {
+		return isolation.ErrNotOwner
+	}
+	ei.releaseLocked(scope, entry)
+	return nil
+}
+
+func (ei *EventIsolation) acquireLocked(scope isolation.Scope, owner uuid.UUID) {
+	entry := &lockEntry{owner: owner, done: make(chan struct{})}
+	entry.timer = time.AfterFunc(ei.ttl, func() {
+		ei.mu.Lock()
+		defer ei.mu.Unlock()
+		if cur, ok := ei.locks[scope]; ok && cur == entry {
+			ei.releaseLocked(scope, entry)
+		}
+	})
+	ei.locks[scope] = entry
+}
+
+func (ei *EventIsolation) releaseLocked(scope isolation.Scope, entry *lockEntry) {
+	entry.timer.Stop()
+	delete(ei.locks, scope)
+	close(entry.done)
+}