feat: add optional GORM pool and SQL logging adapter

database/gormx/gorm.go

@@ -0,0 +1,121 @@
+// Package gormx optionally attaches GORM to a pool owned by GoOmni. It never
+// creates a pool, changes pool limits, migrates tables or closes the owner.
+package gormx
+
+import (
+	"context"
+	"errors"
+	"maps"
+	"reflect"
+	"time"
+
+	"git.yuntuo.hk/k2safe/go-omni/database"
+	"git.yuntuo.hk/k2safe/go-omni/logx"
+	gormmysql "gorm.io/driver/mysql"
+	"gorm.io/gorm"
+)
+
+// DialectorFactory must use the supplied connection pool. It must not create a
+// pool or retain/use the ORM before Open succeeds. For example, return
+// mysql.New(mysql.Config{Conn: conn}). Other dialects can use the same contract.
+type DialectorFactory func(conn gorm.ConnPool) gorm.Dialector
+
+type options struct {
+	config    gorm.Config
+	logger    *logx.Logger
+	logConfig LogConfig
+	timeout   time.Duration
+}
+type Option func(*options)
+
+// WithConfig preserves native GORM behavior, including naming, hooks, prepared
+// statements and transactions. ConnPool/Dialector are supplied by this adapter;
+// automatic Ping is disabled because the owning pool already passed startup Ping.
+// A custom Config.Logger takes precedence over the logx adapter.
+func WithConfig(config gorm.Config) Option         { return func(o *options) { o.config = config } }
+func WithLogger(logger *logx.Logger) Option        { return func(o *options) { o.logger = logger } }
+func WithLogConfig(config LogConfig) Option        { return func(o *options) { o.logConfig = config } }
+func WithInitTimeout(timeout time.Duration) Option { return func(o *options) { o.timeout = timeout } }
+
+// Error exposes a safe initialization summary while preserving errors.Is/As.
+type Error struct{ cause error }
+
+func (e *Error) Error() string { return "gormx: initialization failed" }
+func (e *Error) Unwrap() error { return e.cause }
+
+// MySQL attaches GORM's MySQL dialect, including version negotiation, to the
+// existing pool. Configure TLS, timeouts and connection limits on that pool.
+func MySQL(ctx context.Context, pool *database.DB, opts ...Option) (*gorm.DB, error) {
+	return Open(ctx, pool, func(conn gorm.ConnPool) gorm.Dialector {
+		return gormmysql.New(gormmysql.Config{Conn: conn})
+	}, opts...)
+}
+
+// Open borrows pool. On failure (including dialect initialization failure),
+// the original pool remains owned by the caller. No ORM Close is required.
+// The returned ORM does not retain the startup context: each request should use
+// WithContext(ctx). Never close the sql.DB returned by orm.DB() independently.
+func Open(ctx context.Context, pool *database.DB, factory DialectorFactory, opts ...Option) (*gorm.DB, error) {
+	if ctx == nil {
+		ctx = context.Background()
+	}
+	if err := ctx.Err(); err != nil {
+		return nil, &Error{cause: err}
+	}
+	if pool == nil || pool.DB == nil || factory == nil {
+		return nil, errors.New("gormx: pool and dialector factory are required")
+	}
+	timeout := pool.PoolConfig().PingTimeout
+	if timeout == 0 {
+		timeout = 5 * time.Second
+	}
+	o := options{timeout: timeout, logConfig: DefaultLogConfig(), logger: logx.FromContext(ctx)}
+	for _, option := range opts {
+		if option != nil {
+			option(&o)
+		}
+	}
+	if o.timeout <= 0 {
+		return nil, errors.New("gormx: initialization timeout must be positive")
+	}
+	if o.config.ConnPool != nil || o.config.Dialector != nil {
+		return nil, errors.New("gormx: configure the existing pool through the dialector factory")
+	}
+	logger, err := NewLogger(o.logger, o.logConfig)
+	if err != nil {
+		return nil, err
+	}
+	config := o.config
+	config.Plugins = maps.Clone(config.Plugins)
+	config.ClauseBuilders = maps.Clone(config.ClauseBuilders)
+	if config.Logger == nil {
+		config.Logger = logger
+	}
+	config.DisableAutomaticPing = true
+	startup, cancel := context.WithTimeout(ctx, o.timeout)
+	defer cancel()
+	borrowed := &borrowedPool{db: pool.DB}
+	borrowed.startup.Store(&startupContext{startup})
+	config.ConnPool = borrowed
+	dialect := factory(borrowed)
+	if dialect == nil || (reflect.ValueOf(dialect).Kind() == reflect.Pointer && reflect.ValueOf(dialect).IsNil()) {
+		return nil, errors.New("gormx: dialector factory returned nil")
+	}
+	orm, err := gorm.Open(dialect, &config)
+	if err != nil {
+		return nil, &Error{cause: err}
+	}
+	if err = startup.Err(); err != nil {
+		return nil, &Error{cause: err}
+	}
+	// Prepared statements are GORM's own wrapper over the very same pool.
+	conn := orm.ConnPool
+	if prepared, ok := conn.(*gorm.PreparedStmtDB); ok {
+		conn = prepared.ConnPool
+	}
+	if actual, ok := conn.(*borrowedPool); !ok || actual != borrowed {
+		return nil, errors.New("gormx: dialector or plugin replaced the supplied pool")
+	}
+	borrowed.startup.Store(nil)
+	return orm, nil
+}