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

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

@@ -0,0 +1,17 @@
+package twotiercache
+
+import (
+	"go.uber.org/zap"
+
+	"codeberg.org/mapleopentech/monorepo/cloud/maplefile-backend/pkg/storage/cache/cassandracache"
+	"codeberg.org/mapleopentech/monorepo/cloud/maplefile-backend/pkg/storage/memory/redis"
+)
+
+// ProvideTwoTierCache provides a two-tier cache instance for Wire DI
+func ProvideTwoTierCache(
+	redisCache redis.Cacher,
+	cassandraCache cassandracache.CassandraCacher,
+	logger *zap.Logger,
+) TwoTierCacher {
+	return NewTwoTierCache(redisCache, cassandraCache, logger)
+}

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

@@ -0,0 +1,106 @@
+// monorepo/cloud/maplefileapps-backend/pkg/storage/cache/twotiercache/twotiercache.go
+package twotiercache
+
+import (
+	"context"
+	"time"
+
+	"codeberg.org/mapleopentech/monorepo/cloud/maplefile-backend/pkg/storage/cache/cassandracache"
+	"codeberg.org/mapleopentech/monorepo/cloud/maplefile-backend/pkg/storage/memory/redis"
+	"go.uber.org/zap"
+)
+
+type TwoTierCacher interface {
+	Shutdown(ctx context.Context)
+	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
+}
+
+// twoTierCacheImpl: clean 2-layer (read-through write-through) cache
+//
+// L1: Redis (fast, in-memory)
+// L2: Cassandra (persistent)
+//
+// On Get: check Redis → then Cassandra → if found in Cassandra → populate Redis
+// On Set: write to both
+// On SetWithExpiry: write to both with expiry
+// On Delete: remove from both
+type twoTierCacheImpl struct {
+	RedisCache     redis.Cacher
+	CassandraCache cassandracache.CassandraCacher
+	Logger         *zap.Logger
+}
+
+func NewTwoTierCache(redisCache redis.Cacher, cassandraCache cassandracache.CassandraCacher, logger *zap.Logger) TwoTierCacher {
+	logger = logger.Named("TwoTierCache")
+	return &twoTierCacheImpl{
+		RedisCache:     redisCache,
+		CassandraCache: cassandraCache,
+		Logger:         logger,
+	}
+}
+
+func (c *twoTierCacheImpl) Get(ctx context.Context, key string) ([]byte, error) {
+	val, err := c.RedisCache.Get(ctx, key)
+	if err != nil {
+		return nil, err
+	}
+	if val != nil {
+		c.Logger.Debug("cache hit from Redis", zap.String("key", key))
+		return val, nil
+	}
+
+	val, err = c.CassandraCache.Get(ctx, key)
+	if err != nil {
+		return nil, err
+	}
+	if val != nil {
+		c.Logger.Debug("cache hit from Cassandra, writing back to Redis", zap.String("key", key))
+		_ = c.RedisCache.Set(ctx, key, val)
+	}
+	return val, nil
+}
+
+func (c *twoTierCacheImpl) Set(ctx context.Context, key string, val []byte) error {
+	if err := c.RedisCache.Set(ctx, key, val); err != nil {
+		return err
+	}
+	if err := c.CassandraCache.Set(ctx, key, val); err != nil {
+		return err
+	}
+	return nil
+}
+
+func (c *twoTierCacheImpl) SetWithExpiry(ctx context.Context, key string, val []byte, expiry time.Duration) error {
+	if err := c.RedisCache.SetWithExpiry(ctx, key, val, expiry); err != nil {
+		return err
+	}
+	if err := c.CassandraCache.SetWithExpiry(ctx, key, val, expiry); err != nil {
+		return err
+	}
+	return nil
+}
+
+func (c *twoTierCacheImpl) Delete(ctx context.Context, key string) error {
+	if err := c.RedisCache.Delete(ctx, key); err != nil {
+		return err
+	}
+	if err := c.CassandraCache.Delete(ctx, key); err != nil {
+		return err
+	}
+	return nil
+}
+
+func (c *twoTierCacheImpl) PurgeExpired(ctx context.Context) error {
+	return c.CassandraCache.PurgeExpired(ctx)
+}
+
+func (c *twoTierCacheImpl) Shutdown(ctx context.Context) {
+	c.Logger.Info("two-tier cache shutting down...")
+	c.RedisCache.Shutdown(ctx)
+	c.CassandraCache.Shutdown()
+	c.Logger.Info("two-tier cache shutdown complete")
+}