navidrome/db/db.go

package db

import (
	"context"
	"database/sql"
	"embed"
	"errors"
	"fmt"
	"sync"
	"time"

	"github.com/mattn/go-sqlite3"
	"github.com/navidrome/navidrome/conf"
	_ "github.com/navidrome/navidrome/db/migrations"
	"github.com/navidrome/navidrome/log"
	"github.com/navidrome/navidrome/utils/hasher"
	"github.com/navidrome/navidrome/utils/natural"
	"github.com/navidrome/navidrome/utils/singleton"
	"github.com/pressly/goose/v3"
)

// NaturalCollation sorts embedded numbers by value. It is registered on every
// connection, but only referenced when conf.Server.EnableNaturalSorting is on.
const NaturalCollation = "NATSORT"

var (
	Dialect = "sqlite3"
	Driver  = Dialect + "_custom"
	Path    string
)

//go:embed migrations/*.sql
var embedMigrations embed.FS

const migrationsFolder = "migrations"

// sql.Register panics if called twice, so guard it: the singleton instance can be reset
// (tests/benchmarks) and rebuilt, but the driver is process-global and registers only once.
var registerDriverOnce sync.Once

func Db() *sql.DB {
	return singleton.GetInstance(func() *sql.DB {
		registerDriverOnce.Do(func() {
			sql.Register(Driver, &sqlite3.SQLiteDriver{
				ConnectHook: func(conn *sqlite3.SQLiteConn) error {
					if err := conn.RegisterFunc("SEEDEDRAND", hasher.HashFunc(), false); err != nil {
						return err
					}
					return conn.RegisterCollation(NaturalCollation, natural.CompareFold)
				},
			})
		})
		Path = conf.Server.DbPath
		if Path == ":memory:" {
			Path = "file::memory:?cache=shared&_foreign_keys=on"
			conf.Server.DbPath = Path
		} else {
			conf.Server.DataFolder.MustPath()
		}
		log.Debug("Opening DataBase", "dbPath", Path, "driver", Driver)
		db, err := sql.Open(Driver, Path)
		db.SetMaxOpenConns(conf.MaxOpenConns())
		if err != nil {
			log.Fatal("Error opening database", err)
		}
		return db
	})
}

func Close(ctx context.Context) {
	// Ignore cancellations when closing the DB
	ctx = context.WithoutCancel(ctx)

	log.Info(ctx, "Closing Database")
	err := Db().Close()
	if err != nil {
		log.Error(ctx, "Error closing Database", err)
	}
}

func Init(ctx context.Context) func() {
	db := Db()

	// Disable foreign_keys to allow re-creating tables in migrations
	_, err := db.ExecContext(ctx, "PRAGMA foreign_keys=off")
	defer func() {
		_, err := db.ExecContext(ctx, "PRAGMA foreign_keys=on")
		if err != nil {
			log.Error(ctx, "Error re-enabling foreign_keys", err)
		}
	}()
	if err != nil {
		log.Error(ctx, "Error disabling foreign_keys", err)
	}

	goose.SetBaseFS(embedMigrations)
	err = goose.SetDialect(Dialect)
	if err != nil {
		log.Fatal(ctx, "Invalid DB driver", "driver", Driver, err)
	}
	schemaEmpty := isSchemaEmpty(ctx, db)
	hasSchemaChanges := hasPendingMigrations(ctx, db, migrationsFolder)
	if !schemaEmpty && hasSchemaChanges {
		log.Info(ctx, "Upgrading DB Schema to latest version")
	}
	goose.SetLogger(&logAdapter{ctx: ctx, silent: schemaEmpty})
	err = goose.UpContext(ctx, db, migrationsFolder)
	if err != nil {
		log.Fatal(ctx, "Failed to apply new migrations", err)
	}

	if hasSchemaChanges {
		log.Debug(ctx, "Running ANALYZE after schema changes")
		err = optimizeAt(ctx, db, time.Now())
		if err != nil {
			log.Error(ctx, "Error running ANALYZE", err)
		}
	}

	return func() {
		Close(ctx)
	}
}

// ErrorCodes reports the SQLite result code and extended result code carried by err.
// The extended code is what distinguishes errors that share a message: "database is locked"
// is both SQLITE_BUSY, which busy_timeout retries, and SQLITE_BUSY_SNAPSHOT, which it never can.
func ErrorCodes(err error) (code, extended int, ok bool) {
	var se sqlite3.Error
	if !errors.As(err, &se) {
		return 0, 0, false
	}
	return int(se.Code), int(se.ExtendedCode), true
}

// IsBusy reports whether err is SQLITE_BUSY, including BUSY_SNAPSHOT, which only a new transaction clears.
func IsBusy(err error) bool {
	code, _, ok := ErrorCodes(err)
	return ok && code == int(sqlite3.ErrBusy)
}

type statusLogger struct{ numPending int }

func (*statusLogger) Fatalf(format string, v ...any) { log.Fatal(fmt.Sprintf(format, v...)) }
func (l *statusLogger) Printf(format string, v ...any) {
	if len(v) < 1 {
		return
	}
	if v0, ok := v[0].(string); !ok {
		return
	} else if v0 == "Pending" {
		l.numPending++
	}
}

func hasPendingMigrations(ctx context.Context, db *sql.DB, folder string) bool {
	l := &statusLogger{}
	goose.SetLogger(l)
	err := goose.StatusContext(ctx, db, folder)
	if err != nil {
		log.Fatal(ctx, "Failed to check for pending migrations", err)
	}
	return l.numPending > 0
}

// hasGooseTable reports whether goose's bookkeeping table exists, i.e. whether the
// database has ever been migrated.
func hasGooseTable(ctx context.Context, db *sql.DB) (bool, error) {
	var name string
	err := db.QueryRowContext(ctx,
		"SELECT name FROM sqlite_master WHERE type='table' AND name='goose_db_version'").Scan(&name)
	if errors.Is(err, sql.ErrNoRows) {
		return false, nil
	}
	return err == nil, err
}

func isSchemaEmpty(ctx context.Context, db *sql.DB) bool {
	found, err := hasGooseTable(ctx, db)
	if err != nil {
		log.Fatal(ctx, "Database could not be opened!", err)
	}
	return !found
}

type logAdapter struct {
	ctx    context.Context
	silent bool
}

func (l *logAdapter) Fatal(v ...any) {
	log.Fatal(l.ctx, fmt.Sprint(v...))
}

func (l *logAdapter) Fatalf(format string, v ...any) {
	log.Fatal(l.ctx, fmt.Sprintf(format, v...))
}

func (l *logAdapter) Print(v ...any) {
	if !l.silent {
		log.Info(l.ctx, fmt.Sprint(v...))
	}
}

func (l *logAdapter) Println(v ...any) {
	if !l.silent {
		log.Info(l.ctx, fmt.Sprintln(v...))
	}
}

func (l *logAdapter) Printf(format string, v ...any) {
	if !l.silent {
		log.Info(l.ctx, fmt.Sprintf(format, v...))
	}
}