Refactor database configuration to use centralized struct

Replaced individual environment variable access with a unified `DatabaseConfig` struct for all database backends. This centralizes configuration management, reduces redundant code, and ensures all options are documented in `app/config/config.go`. Backward compatibility is maintained with default values and retained constructors.

pkg/database/database.go

@@ -5,7 +5,6 @@ import (
 	"errors"
 	"os"
 	"path/filepath"
-	"strconv"
 	"time"
 
 	"github.com/dgraph-io/badger/v4"
@@ -21,10 +20,11 @@ import (
 
 // D implements the Database interface using Badger as the storage backend
 type D struct {
-	ctx        context.Context
-	cancel     context.CancelFunc
-	dataDir    string
-	Logger     *logger
+	ctx                  context.Context
+	cancel               context.CancelFunc
+	dataDir              string
+	Logger               *logger
+	inlineEventThreshold int // Configurable threshold for inline event storage
 	*badger.DB
 	seq        *badger.Sequence
 	pubkeySeq  *badger.Sequence // Sequence for pubkey serials
@@ -35,63 +35,85 @@ type D struct {
 // Ensure D implements Database interface at compile time
 var _ Database = (*D)(nil)
 
+// New creates a new Badger database instance with default configuration.
+// This is provided for backward compatibility with existing callers.
+// For full configuration control, use NewWithConfig instead.
 func New(
 	ctx context.Context, cancel context.CancelFunc, dataDir, logLevel string,
 ) (
 	d *D, err error,
 ) {
-	// Initialize query cache with configurable size (default 512MB)
-	queryCacheSize := int64(512 * 1024 * 1024) // 512 MB
-	if v := os.Getenv("ORLY_QUERY_CACHE_SIZE_MB"); v != "" {
-		if n, perr := strconv.Atoi(v); perr == nil && n > 0 {
-			queryCacheSize = int64(n * 1024 * 1024)
-		}
+	// Create a default config for backward compatibility
+	cfg := &DatabaseConfig{
+		DataDir:              dataDir,
+		LogLevel:             logLevel,
+		BlockCacheMB:         1024,              // Default 1024 MB
+		IndexCacheMB:         512,               // Default 512 MB
+		QueryCacheSizeMB:     512,               // Default 512 MB
+		QueryCacheMaxAge:     5 * time.Minute,   // Default 5 minutes
+		InlineEventThreshold: 1024,              // Default 1024 bytes
 	}
-	queryCacheMaxAge := 5 * time.Minute // Default 5 minutes
-	if v := os.Getenv("ORLY_QUERY_CACHE_MAX_AGE"); v != "" {
-		if duration, perr := time.ParseDuration(v); perr == nil {
-			queryCacheMaxAge = duration
-		}
+	return NewWithConfig(ctx, cancel, cfg)
+}
+
+// NewWithConfig creates a new Badger database instance with full configuration.
+// This is the preferred method when you have access to DatabaseConfig.
+func NewWithConfig(
+	ctx context.Context, cancel context.CancelFunc, cfg *DatabaseConfig,
+) (
+	d *D, err error,
+) {
+	// Apply defaults for zero values (backward compatibility)
+	blockCacheMB := cfg.BlockCacheMB
+	if blockCacheMB == 0 {
+		blockCacheMB = 1024 // Default 1024 MB
+	}
+	indexCacheMB := cfg.IndexCacheMB
+	if indexCacheMB == 0 {
+		indexCacheMB = 512 // Default 512 MB
+	}
+	queryCacheSizeMB := cfg.QueryCacheSizeMB
+	if queryCacheSizeMB == 0 {
+		queryCacheSizeMB = 512 // Default 512 MB
+	}
+	queryCacheMaxAge := cfg.QueryCacheMaxAge
+	if queryCacheMaxAge == 0 {
+		queryCacheMaxAge = 5 * time.Minute // Default 5 minutes
+	}
+	inlineEventThreshold := cfg.InlineEventThreshold
+	if inlineEventThreshold == 0 {
+		inlineEventThreshold = 1024 // Default 1024 bytes
 	}
 
+	queryCacheSize := int64(queryCacheSizeMB * 1024 * 1024)
+
 	d = &D{
-		ctx:        ctx,
-		cancel:     cancel,
-		dataDir:    dataDir,
-		Logger:     NewLogger(lol.GetLogLevel(logLevel), dataDir),
-		DB:         nil,
-		seq:        nil,
-		ready:      make(chan struct{}),
-		queryCache: querycache.NewEventCache(queryCacheSize, queryCacheMaxAge),
+		ctx:                  ctx,
+		cancel:               cancel,
+		dataDir:              cfg.DataDir,
+		Logger:               NewLogger(lol.GetLogLevel(cfg.LogLevel), cfg.DataDir),
+		inlineEventThreshold: inlineEventThreshold,
+		DB:                   nil,
+		seq:                  nil,
+		ready:                make(chan struct{}),
+		queryCache:           querycache.NewEventCache(queryCacheSize, queryCacheMaxAge),
 	}
 
 	// Ensure the data directory exists
-	if err = os.MkdirAll(dataDir, 0755); chk.E(err) {
+	if err = os.MkdirAll(cfg.DataDir, 0755); chk.E(err) {
 		return
 	}
 
 	// Also ensure the directory exists using apputil.EnsureDir for any
 	// potential subdirectories
-	dummyFile := filepath.Join(dataDir, "dummy.sst")
+	dummyFile := filepath.Join(cfg.DataDir, "dummy.sst")
 	if err = apputil.EnsureDir(dummyFile); chk.E(err) {
 		return
 	}
 
 	opts := badger.DefaultOptions(d.dataDir)
-	// Configure caches based on environment to better match workload.
+	// Configure caches based on config to better match workload.
 	// Defaults aim for higher hit ratios under read-heavy workloads while remaining safe.
-	var blockCacheMB = 1024 // default 512 MB
-	var indexCacheMB = 512  // default 256 MB
-	if v := os.Getenv("ORLY_DB_BLOCK_CACHE_MB"); v != "" {
-		if n, perr := strconv.Atoi(v); perr == nil && n > 0 {
-			blockCacheMB = n
-		}
-	}
-	if v := os.Getenv("ORLY_DB_INDEX_CACHE_MB"); v != "" {
-		if n, perr := strconv.Atoi(v); perr == nil && n > 0 {
-			indexCacheMB = n
-		}
-	}
 	opts.BlockCacheSize = int64(blockCacheMB * units.Mb)
 	opts.IndexCacheSize = int64(indexCacheMB * units.Mb)
 	opts.BlockSize = 4 * units.Kb // 4 KB block size

pkg/database/factory.go

@@ -4,8 +4,33 @@ import (
 	"context"
 	"fmt"
 	"strings"
+	"time"
 )
 
+// DatabaseConfig holds all database configuration options that can be passed
+// to any database backend. Each backend uses the relevant fields for its type.
+// This centralizes configuration instead of having each backend read env vars directly.
+type DatabaseConfig struct {
+	// Common settings for all backends
+	DataDir  string
+	LogLevel string
+
+	// Badger-specific settings
+	BlockCacheMB         int           // ORLY_DB_BLOCK_CACHE_MB
+	IndexCacheMB         int           // ORLY_DB_INDEX_CACHE_MB
+	QueryCacheSizeMB     int           // ORLY_QUERY_CACHE_SIZE_MB
+	QueryCacheMaxAge     time.Duration // ORLY_QUERY_CACHE_MAX_AGE
+	InlineEventThreshold int           // ORLY_INLINE_EVENT_THRESHOLD
+
+	// DGraph-specific settings
+	DgraphURL string // ORLY_DGRAPH_URL
+
+	// Neo4j-specific settings
+	Neo4jURI      string // ORLY_NEO4J_URI
+	Neo4jUser     string // ORLY_NEO4J_USER
+	Neo4jPassword string // ORLY_NEO4J_PASSWORD
+}
+
 // NewDatabase creates a database instance based on the specified type.
 // Supported types: "badger", "dgraph", "neo4j"
 func NewDatabase(
@@ -14,19 +39,39 @@ func NewDatabase(
 	dbType string,
 	dataDir string,
 	logLevel string,
+) (Database, error) {
+	// Create a default config for backward compatibility with existing callers
+	cfg := &DatabaseConfig{
+		DataDir:  dataDir,
+		LogLevel: logLevel,
+	}
+	return NewDatabaseWithConfig(ctx, cancel, dbType, cfg)
+}
+
+// NewDatabaseWithConfig creates a database instance with full configuration.
+// This is the preferred method when you have access to the app config.
+func NewDatabaseWithConfig(
+	ctx context.Context,
+	cancel context.CancelFunc,
+	dbType string,
+	cfg *DatabaseConfig,
 ) (Database, error) {
 	switch strings.ToLower(dbType) {
 	case "badger", "":
 		// Use the existing badger implementation
-		return New(ctx, cancel, dataDir, logLevel)
+		return NewWithConfig(ctx, cancel, cfg)
 	case "dgraph":
-		// Use the new dgraph implementation
-		// Import dynamically to avoid import cycles
-		return newDgraphDatabase(ctx, cancel, dataDir, logLevel)
+		// Use the dgraph implementation
+		if newDgraphDatabase == nil {
+			return nil, fmt.Errorf("dgraph database backend not available (import _ \"next.orly.dev/pkg/dgraph\")")
+		}
+		return newDgraphDatabase(ctx, cancel, cfg)
 	case "neo4j":
-		// Use the new neo4j implementation
-		// Import dynamically to avoid import cycles
-		return newNeo4jDatabase(ctx, cancel, dataDir, logLevel)
+		// Use the neo4j implementation
+		if newNeo4jDatabase == nil {
+			return nil, fmt.Errorf("neo4j database backend not available (import _ \"next.orly.dev/pkg/neo4j\")")
+		}
+		return newNeo4jDatabase(ctx, cancel, cfg)
 	default:
 		return nil, fmt.Errorf("unsupported database type: %s (supported: badger, dgraph, neo4j)", dbType)
 	}
@@ -34,20 +79,20 @@ func NewDatabase(
 
 // newDgraphDatabase creates a dgraph database instance
 // This is defined here to avoid import cycles
-var newDgraphDatabase func(context.Context, context.CancelFunc, string, string) (Database, error)
+var newDgraphDatabase func(context.Context, context.CancelFunc, *DatabaseConfig) (Database, error)
 
 // RegisterDgraphFactory registers the dgraph database factory
 // This is called from the dgraph package's init() function
-func RegisterDgraphFactory(factory func(context.Context, context.CancelFunc, string, string) (Database, error)) {
+func RegisterDgraphFactory(factory func(context.Context, context.CancelFunc, *DatabaseConfig) (Database, error)) {
 	newDgraphDatabase = factory
 }
 
 // newNeo4jDatabase creates a neo4j database instance
 // This is defined here to avoid import cycles
-var newNeo4jDatabase func(context.Context, context.CancelFunc, string, string) (Database, error)
+var newNeo4jDatabase func(context.Context, context.CancelFunc, *DatabaseConfig) (Database, error)
 
 // RegisterNeo4jFactory registers the neo4j database factory
 // This is called from the neo4j package's init() function
-func RegisterNeo4jFactory(factory func(context.Context, context.CancelFunc, string, string) (Database, error)) {
+func RegisterNeo4jFactory(factory func(context.Context, context.CancelFunc, *DatabaseConfig) (Database, error)) {
 	newNeo4jDatabase = factory
 }

pkg/database/save-event.go

@@ -5,8 +5,6 @@ import (
 	"context"
 	"errors"
 	"fmt"
-	"os"
-	"strconv"
 	"strings"
 
 	"github.com/dgraph-io/badger/v4"
@@ -270,14 +268,9 @@ func (d *D) SaveEvent(c context.Context, ev *event.E) (
 	eventData := eventDataBuf.Bytes()
 
 	// Determine storage strategy (Reiser4 optimizations)
-	// Get threshold from environment, default to 0 (disabled)
-	// When enabled, typical values: 384 (conservative), 512 (recommended), 1024 (aggressive)
-	smallEventThreshold := 1024
-	if v := os.Getenv("ORLY_INLINE_EVENT_THRESHOLD"); v != "" {
-		if n, perr := strconv.Atoi(v); perr == nil && n >= 0 {
-			smallEventThreshold = n
-		}
-	}
+	// Use the threshold from database configuration
+	// Typical values: 384 (conservative), 512 (recommended), 1024 (aggressive)
+	smallEventThreshold := d.inlineEventThreshold
 	isSmallEvent := smallEventThreshold > 0 && len(eventData) <= smallEventThreshold
 	isReplaceableEvent := kind.IsReplaceable(ev.Kind)
 	isAddressableEvent := kind.IsParameterizedReplaceable(ev.Kind)