Initial commit: Open sourcing all of the Maple Open Technologies code.

cloud/maplefile-backend/pkg/storage/cache/cassandracache/cassandracache.go

@@ -0,0 +1,108 @@
+// monorepo/cloud/maplefileapps-backend/pkg/storage/cache/cassandracache/cassandaracache.go
+package cassandracache
+
+import (
+	"context"
+	"time"
+
+	"github.com/gocql/gocql"
+	"go.uber.org/zap"
+)
+
+type CassandraCacher interface {
+	Shutdown()
+	Get(ctx context.Context, key string) ([]byte, error)
+	Set(ctx context.Context, key string, val []byte) error
+	SetWithExpiry(ctx context.Context, key string, val []byte, expiry time.Duration) error
+	Delete(ctx context.Context, key string) error
+	PurgeExpired(ctx context.Context) error
+}
+
+type cache struct {
+	Session *gocql.Session
+	Logger  *zap.Logger
+}
+
+func NewCassandraCacher(session *gocql.Session, logger *zap.Logger) CassandraCacher {
+	logger = logger.Named("CassandraCache")
+	logger.Info("cassandra cache initialized")
+	return &cache{
+		Session: session,
+		Logger:  logger,
+	}
+}
+
+func (s *cache) Shutdown() {
+	s.Logger.Info("cassandra cache shutting down...")
+	s.Session.Close()
+}
+
+func (s *cache) Get(ctx context.Context, key string) ([]byte, error) {
+	var value []byte
+	var expiresAt time.Time
+
+	query := `SELECT value, expires_at FROM pkg_cache_by_key_with_asc_expire_at WHERE key=?`
+	err := s.Session.Query(query, key).WithContext(ctx).Consistency(gocql.LocalQuorum).Scan(&value, &expiresAt)
+
+	if err == gocql.ErrNotFound {
+		return nil, nil
+	}
+	if err != nil {
+		return nil, err
+	}
+
+	// Check if expired in application code
+	if time.Now().After(expiresAt) {
+		// Entry is expired, delete it and return nil
+		_ = s.Delete(ctx, key) // Clean up expired entry
+		return nil, nil
+	}
+
+	return value, nil
+}
+
+func (s *cache) Set(ctx context.Context, key string, val []byte) error {
+	expiresAt := time.Now().Add(24 * time.Hour) // Default 24 hour expiry
+	return s.Session.Query(`INSERT INTO pkg_cache_by_key_with_asc_expire_at (key, expires_at, value) VALUES (?, ?, ?)`,
+		key, expiresAt, val).WithContext(ctx).Consistency(gocql.LocalQuorum).Exec()
+}
+
+func (s *cache) SetWithExpiry(ctx context.Context, key string, val []byte, expiry time.Duration) error {
+	expiresAt := time.Now().Add(expiry)
+	return s.Session.Query(`INSERT INTO pkg_cache_by_key_with_asc_expire_at (key, expires_at, value) VALUES (?, ?, ?)`,
+		key, expiresAt, val).WithContext(ctx).Consistency(gocql.LocalQuorum).Exec()
+}
+
+func (s *cache) Delete(ctx context.Context, key string) error {
+	return s.Session.Query(`DELETE FROM pkg_cache_by_key_with_asc_expire_at WHERE key=?`,
+		key).WithContext(ctx).Consistency(gocql.LocalQuorum).Exec()
+}
+
+func (s *cache) PurgeExpired(ctx context.Context) error {
+	now := time.Now()
+
+	// Thanks to the index on expires_at, this query is efficient
+	iter := s.Session.Query(`SELECT key FROM pkg_cache_by_key_with_asc_expire_at WHERE expires_at < ? ALLOW FILTERING`,
+		now).WithContext(ctx).Iter()
+
+	var expiredKeys []string
+	var key string
+	for iter.Scan(&key) {
+		expiredKeys = append(expiredKeys, key)
+	}
+
+	if err := iter.Close(); err != nil {
+		return err
+	}
+
+	// Delete expired keys in batch
+	if len(expiredKeys) > 0 {
+		batch := s.Session.NewBatch(gocql.LoggedBatch).WithContext(ctx)
+		for _, expiredKey := range expiredKeys {
+			batch.Query(`DELETE FROM pkg_cache_by_key_with_asc_expire_at WHERE key=?`, expiredKey)
+		}
+		return s.Session.ExecuteBatch(batch)
+	}
+
+	return nil
+}

cloud/maplefile-backend/pkg/storage/cache/cassandracache/provider.go

@@ -0,0 +1,11 @@
+package cassandracache
+
+import (
+	"github.com/gocql/gocql"
+	"go.uber.org/zap"
+)
+
+// ProvideCassandraCacher provides a Cassandra cache instance for Wire DI
+func ProvideCassandraCacher(session *gocql.Session, logger *zap.Logger) CassandraCacher {
+	return NewCassandraCacher(session, logger)
+}