lazy_db.go Raw History Folder

1package sqlite
2
3import (
4	"context"
5	"database/sql"
6	"fmt"
7	"sync"
8
9	"github.com/bnema/dumber/internal/application/port"
10	"github.com/bnema/dumber/internal/logging"
11)
12
13// LazyDB implements port.DatabaseProvider with lazy initialization.
14// The database connection is created on first access, deferring the ~300-400ms
15// WASM compilation and migration overhead until actually needed.
16//
17// Currently unused: the application uses eager initialization via OpenDatabase
18// in RunParallelDBWebKit. This implementation is kept for potential future use
19// in scenarios where deferring database initialization past first paint provides
20// additional latency benefits, or for CLI commands that may not need DB access.
21type LazyDB struct {
22	dbPath string
23	db     *sql.DB
24	err    error
25	once   sync.Once
26	mu     sync.RWMutex
27}
28
29// Compile-time interface check.
30var _ port.DatabaseProvider = (*LazyDB)(nil)
31
32// NewLazyDB creates a new lazy database provider.
33// The actual connection is not established until DB() is called.
34func NewLazyDB(dbPath string) *LazyDB {
35	return &LazyDB{dbPath: dbPath}
36}
37
38// DB returns the database connection, initializing it if necessary.
39// This method is thread-safe and will only initialize once.
40func (l *LazyDB) DB(ctx context.Context) (*sql.DB, error) {
41	l.once.Do(func() {
42		log := logging.FromContext(ctx)
43		log.Debug().Str("path", l.dbPath).Msg("lazy database initialization starting")
44
45		db, err := NewConnection(ctx, l.dbPath)
46
47		// Acquire lock before assigning to ensure IsInitialized() sees
48		// a consistent state when reading l.db under RLock.
49		l.mu.Lock()
50		l.db = db
51		l.err = err
52		l.mu.Unlock()
53
54		if err != nil {
55			log.Error().Err(err).Msg("lazy database initialization failed")
56		} else {
57			log.Debug().Msg("lazy database initialized successfully")
58		}
59	})
60
61	l.mu.RLock()
62	db, err := l.db, l.err
63	l.mu.RUnlock()
64
65	if err != nil {
66		return nil, fmt.Errorf("database initialization failed: %w", err)
67	}
68	return db, nil
69}
70
71// Close closes the database connection if it was initialized.
72func (l *LazyDB) Close() error {
73	l.mu.Lock()
74	defer l.mu.Unlock()
75
76	if l.db != nil {
77		return l.db.Close()
78	}
79	return nil
80}
81
82// IsInitialized returns true if the database has been initialized.
83func (l *LazyDB) IsInitialized() bool {
84	l.mu.RLock()
85	defer l.mu.RUnlock()
86	return l.db != nil
87}
88
89// Path returns the database path.
90func (l *LazyDB) Path() string {
91	return l.dbPath
92}

lazy_db.go RawHistoryFolder

lazy_db.go Raw History Folder