Merge branch 'v4' into hasql

Signed-off-by: Vasiliy Tolstov <v.tolstov@unistack.org>

README.md

@@ -1,5 +1,5 @@
 # Micro
-![Coverage](https://img.shields.io/badge/Coverage-33.6%25-yellow)
+![Coverage](https://img.shields.io/badge/Coverage-33.8%25-yellow)
 [![License](https://img.shields.io/:license-apache-blue.svg)](https://opensource.org/licenses/Apache-2.0)
 [![Doc](https://img.shields.io/badge/go.dev-reference-007d9c?logo=go&logoColor=white&style=flat-square)](https://pkg.go.dev/go.unistack.org/micro/v4?tab=overview)
 [![Status](https://git.unistack.org/unistack-org/micro/actions/workflows/job_tests.yml/badge.svg?branch=v4)](https://git.unistack.org/unistack-org/micro/actions?query=workflow%3Abuild+branch%3Av4+event%3Apush)

broker/broker.go

@@ -41,7 +41,7 @@ type Broker interface {
 	// Disconnect disconnect from broker
 	Disconnect(ctx context.Context) error
 	// NewMessage create new broker message to publish.
-	NewMessage(ctx context.Context, hdr metadata.Metadata, body interface{}, opts ...PublishOption) (Message, error)
+	NewMessage(ctx context.Context, hdr metadata.Metadata, body interface{}, opts ...MessageOption) (Message, error)
 	// Publish message to broker topic
 	Publish(ctx context.Context, topic string, messages ...Message) error
 	// Subscribe subscribes to topic message via handler

broker/context.go

@@ -42,9 +42,9 @@ func SetSubscribeOption(k, v interface{}) SubscribeOption {
 	}
 }
 
-// SetPublishOption returns a function to setup a context with given value
+// SetMessageOption returns a function to setup a context with given value
-func SetPublishOption(k, v interface{}) PublishOption {
+func SetMessageOption(k, v interface{}) MessageOption {
-	return func(o *PublishOptions) {
+	return func(o *MessageOptions) {
 		if o.Context == nil {
 			o.Context = context.Background()
 		}

broker/memory/memory.go

@@ -32,7 +32,7 @@ type memoryMessage struct {
 	ctx   context.Context
 	body  []byte
 	hdr   metadata.Metadata
-	opts  broker.PublishOptions
+	opts  broker.MessageOptions
 }
 
 func (m *memoryMessage) Ack() error {
@@ -157,8 +157,8 @@ func (b *Broker) Init(opts ...broker.Option) error {
 	return nil
 }
 
-func (b *Broker) NewMessage(ctx context.Context, hdr metadata.Metadata, body interface{}, opts ...broker.PublishOption) (broker.Message, error) {
+func (b *Broker) NewMessage(ctx context.Context, hdr metadata.Metadata, body interface{}, opts ...broker.MessageOption) (broker.Message, error) {
-	options := broker.NewPublishOptions(opts...)
+	options := broker.NewMessageOptions(opts...)
 	if options.ContentType == "" {
 		options.ContentType = b.opts.ContentType
 	}

broker/memory/memory_test.go

@@ -49,7 +49,7 @@ func TestMemoryBroker(t *testing.T) {
 				"id", fmt.Sprintf("%d", i),
 			),
 			[]byte(`"hello world"`),
-			broker.PublishContentType("application/octet-stream"),
+			broker.MessageContentType("application/octet-stream"),
 		)
 		if err != nil {
 			t.Fatal(err)

broker/noop.go

@@ -99,7 +99,7 @@ type noopMessage struct {
 	ctx  context.Context
 	body []byte
 	hdr  metadata.Metadata
-	opts PublishOptions
+	opts MessageOptions
 }
 
 func (m *noopMessage) Ack() error {
@@ -126,8 +126,8 @@ func (m *noopMessage) Unmarshal(dst interface{}, opts ...codec.Option) error {
 	return m.c.Unmarshal(m.body, dst)
 }
 
-func (b *NoopBroker) NewMessage(ctx context.Context, hdr metadata.Metadata, body interface{}, opts ...PublishOption) (Message, error) {
+func (b *NoopBroker) NewMessage(ctx context.Context, hdr metadata.Metadata, body interface{}, opts ...MessageOption) (Message, error) {
-	options := NewPublishOptions(opts...)
+	options := NewMessageOptions(opts...)
 	if options.ContentType == "" {
 		options.ContentType = b.opts.ContentType
 	}

broker/options.go

@@ -87,8 +87,8 @@ func ContentType(ct string) Option {
 	}
 }
 
-// PublishOptions struct
+// MessageOptions struct
-type PublishOptions struct {
+type MessageOptions struct {
 	// ContentType for message body
 	ContentType string
 	// BodyOnly flag says the message contains raw body bytes and don't need
@@ -98,9 +98,9 @@ type PublishOptions struct {
 	Context context.Context
 }
 
-// NewPublishOptions creates PublishOptions struct
+// NewMessageOptions creates MessageOptions struct
-func NewPublishOptions(opts ...PublishOption) PublishOptions {
+func NewMessageOptions(opts ...MessageOption) MessageOptions {
-	options := PublishOptions{
+	options := MessageOptions{
 		Context: context.Background(),
 	}
 	for _, o := range opts {
@@ -128,19 +128,19 @@ type SubscribeOptions struct {
 // Option func
 type Option func(*Options)
 
-// PublishOption func
+// MessageOption func
-type PublishOption func(*PublishOptions)
+type MessageOption func(*MessageOptions)
 
-// PublishContentType sets message content-type that used to Marshal
+// MessageContentType sets message content-type that used to Marshal
-func PublishContentType(ct string) PublishOption {
+func MessageContentType(ct string) MessageOption {
-	return func(o *PublishOptions) {
+	return func(o *MessageOptions) {
 		o.ContentType = ct
 	}
 }
 
-// PublishBodyOnly publish only body of the message
+// MessageBodyOnly publish only body of the message
-func PublishBodyOnly(b bool) PublishOption {
+func MessageBodyOnly(b bool) MessageOption {
-	return func(o *PublishOptions) {
+	return func(o *MessageOptions) {
 		o.BodyOnly = b
 	}
 }

go.mod

@@ -1,6 +1,6 @@
 module go.unistack.org/micro/v4
 
-go 1.22.0
+go 1.24
 
 require (
 	dario.cat/mergo v1.0.1
@@ -17,6 +17,7 @@ require (
 	go.uber.org/automaxprocs v1.6.0
 	go.unistack.org/micro-proto/v4 v4.1.0
 	golang.org/x/sync v0.10.0
+	golang.yandex/hasql/v2 v2.1.0
 	google.golang.org/grpc v1.69.4
 	google.golang.org/protobuf v1.36.3
 )

go.sum

@@ -56,6 +56,8 @@ golang.org/x/sys v0.29.0 h1:TPYlXGxvx1MGTn2GiZDhnjPA9wZzZeGKHHmKhHYvgaU=
 golang.org/x/sys v0.29.0/go.mod h1:/VUhepiaJMQUp4+oa/7Zr1D23ma6VTLIYjOOTFZPUcA=
 golang.org/x/text v0.21.0 h1:zyQAAkrwaneQ066sspRyJaG9VNi/YJ1NfzcGB3hZ/qo=
 golang.org/x/text v0.21.0/go.mod h1:4IBbMaMmOPCJ8SecivzSH54+73PCFmPWxNTLm+vZkEQ=
+golang.yandex/hasql/v2 v2.1.0 h1:7CaFFWeHoK5TvA+QvZzlKHlIN5sqNpqM8NSrXskZD/k=
+golang.yandex/hasql/v2 v2.1.0/go.mod h1:3Au1AxuJDCTXmS117BpbI6e+70kGWeyLR1qJAH6HdtA=
 google.golang.org/genproto/googleapis/rpc v0.0.0-20241216192217-9240e9c98484 h1:Z7FRVJPSMaHQxD0uXU8WdgFh8PseLM8Q8NzhnpMrBhQ=
 google.golang.org/genproto/googleapis/rpc v0.0.0-20241216192217-9240e9c98484/go.mod h1:lcTa1sDdWEIHMWlITnIczmw5w60CF9ffkb8Z+DVmmjA=
 google.golang.org/grpc v1.69.4 h1:MF5TftSMkd8GLw/m0KM6V8CMOCY6NZ1NQDPGFgbTt4A=

hooks/sql/cluster.go

@@ -0,0 +1,504 @@
+package sql
+
+import (
+	"context"
+	"database/sql"
+	"errors"
+	"fmt"
+	"math"
+	"reflect"
+	"time"
+	"unsafe"
+
+	"golang.yandex/hasql/v2"
+)
+
+var errNoAliveNodes = errors.New("no alive nodes")
+
+func newSQLRowError() *sql.Row {
+	row := &sql.Row{}
+	t := reflect.TypeOf(row).Elem()
+	field, _ := t.FieldByName("err")
+	rowPtr := unsafe.Pointer(row)
+	errFieldPtr := unsafe.Pointer(uintptr(rowPtr) + field.Offset)
+	errPtr := (*error)(errFieldPtr)
+	*errPtr = errNoAliveNodes
+	return row
+}
+
+func newSQLRowsError() *sql.Rows {
+	rows := &sql.Rows{}
+	t := reflect.TypeOf(rows).Elem()
+	field, _ := t.FieldByName("lasterr")
+	rowPtr := unsafe.Pointer(rows)
+	errFieldPtr := unsafe.Pointer(uintptr(rowPtr) + field.Offset)
+	errPtr := (*error)(errFieldPtr)
+	*errPtr = errNoAliveNodes
+	return rows
+}
+
+type ClusterQuerier interface {
+	Querier
+	WaitForNodes(ctx context.Context, criterion ...hasql.NodeStateCriterion) error
+}
+
+type Querier interface {
+	// Basic connection methods
+	PingContext(ctx context.Context) error
+	Close() error
+
+	// Query methods with context
+	ExecContext(ctx context.Context, query string, args ...interface{}) (sql.Result, error)
+	QueryContext(ctx context.Context, query string, args ...interface{}) (*sql.Rows, error)
+	QueryRowContext(ctx context.Context, query string, args ...interface{}) *sql.Row
+
+	// Prepared statements with context
+	PrepareContext(ctx context.Context, query string) (*sql.Stmt, error)
+
+	// Transaction management with context
+	BeginTx(ctx context.Context, opts *sql.TxOptions) (*sql.Tx, error)
+
+	// Connection pool management
+	SetConnMaxLifetime(d time.Duration)
+	SetConnMaxIdleTime(d time.Duration)
+	SetMaxOpenConns(n int)
+	SetMaxIdleConns(n int)
+	Stats() sql.DBStats
+
+	Conn(ctx context.Context) (*sql.Conn, error)
+}
+
+var (
+	ErrClusterChecker    = errors.New("cluster node checker required")
+	ErrClusterDiscoverer = errors.New("cluster node discoverer required")
+	ErrClusterPicker     = errors.New("cluster node picker required")
+)
+
+type Cluster struct {
+	hasql   *hasql.Cluster[Querier]
+	options ClusterOptions
+}
+
+// NewCluster returns Querier that provides cluster of nodes
+func NewCluster[T Querier](opts ...ClusterOption) (ClusterQuerier, error) {
+	options := ClusterOptions{Context: context.Background()}
+	for _, opt := range opts {
+		opt(&options)
+	}
+	if options.NodeChecker == nil {
+		return nil, ErrClusterChecker
+	}
+	if options.NodeDiscoverer == nil {
+		return nil, ErrClusterDiscoverer
+	}
+	if options.NodePicker == nil {
+		return nil, ErrClusterPicker
+	}
+
+	options.Options = append(options.Options, hasql.WithNodePicker(options.NodePicker))
+	if p, ok := options.NodePicker.(*CustomPicker[Querier]); ok {
+		p.opts.Priority = options.NodePriority
+	}
+
+	c, err := hasql.NewCluster(
+		options.NodeDiscoverer,
+		options.NodeChecker,
+		options.Options...,
+	)
+	if err != nil {
+		return nil, err
+	}
+
+	return &Cluster{hasql: c, options: options}, nil
+}
+
+// compile time guard
+var _ hasql.NodePicker[Querier] = (*CustomPicker[Querier])(nil)
+
+type nodeStateCriterionKey struct{}
+
+// NodeStateCriterion inject hasql.NodeStateCriterion to context
+func NodeStateCriterion(ctx context.Context, c hasql.NodeStateCriterion) context.Context {
+	return context.WithValue(ctx, nodeStateCriterionKey{}, c)
+}
+
+func getNodeStateCriterion(ctx context.Context) hasql.NodeStateCriterion {
+	if v, ok := ctx.Value(nodeStateCriterionKey{}).(hasql.NodeStateCriterion); ok {
+		return v
+	}
+	return hasql.PreferPrimary
+}
+
+// CustomPickerOptions holds options to pick nodes
+type CustomPickerOptions struct {
+	MaxLag       int
+	Priority     map[string]int32
+	RetryOnError bool
+}
+
+// CustomPickerOption func apply option to CustomPickerOptions
+type CustomPickerOption func(*CustomPickerOptions)
+
+// CustomPickerMaxLag specifies max lag for which node can be used
+func CustomPickerMaxLag(n int) CustomPickerOption {
+	return func(o *CustomPickerOptions) {
+		o.MaxLag = n
+	}
+}
+
+// NewCustomPicker creates new node picker
+func NewCustomPicker[T Querier](opts ...CustomPickerOption) *CustomPicker[Querier] {
+	options := CustomPickerOptions{}
+	for _, o := range opts {
+		o(&options)
+	}
+	return &CustomPicker[Querier]{opts: options}
+}
+
+// CustomPicker holds node picker options
+type CustomPicker[T Querier] struct {
+	opts CustomPickerOptions
+}
+
+// PickNode used to return specific node
+func (p *CustomPicker[T]) PickNode(cnodes []hasql.CheckedNode[T]) hasql.CheckedNode[T] {
+	for _, n := range cnodes {
+		fmt.Printf("node %s\n", n.Node.String())
+	}
+	return cnodes[0]
+}
+
+func (p *CustomPicker[T]) getPriority(nodeName string) int32 {
+	if prio, ok := p.opts.Priority[nodeName]; ok {
+		return prio
+	}
+	return math.MaxInt32 // Default to lowest priority
+}
+
+// CompareNodes used to sort nodes
+func (p *CustomPicker[T]) CompareNodes(a, b hasql.CheckedNode[T]) int {
+	fmt.Printf("CompareNodes %s %s\n", a.Node.String(), b.Node.String())
+	// Get replication lag values
+	aLag := a.Info.(interface{ ReplicationLag() int }).ReplicationLag()
+	bLag := b.Info.(interface{ ReplicationLag() int }).ReplicationLag()
+
+	// First check that lag lower then MaxLag
+	if aLag > p.opts.MaxLag && bLag > p.opts.MaxLag {
+		fmt.Printf("CompareNodes aLag > p.opts.MaxLag && bLag > p.opts.MaxLag\n")
+		return 0 // both are equal
+	}
+
+	// If one node exceeds MaxLag and the other doesn't, prefer the one that doesn't
+	if aLag > p.opts.MaxLag {
+		fmt.Printf("CompareNodes aLag > p.opts.MaxLag\n")
+		return 1 // b is better
+	}
+	if bLag > p.opts.MaxLag {
+		fmt.Printf("CompareNodes bLag > p.opts.MaxLag\n")
+		return -1 // a is better
+	}
+
+	// Get node priorities
+	aPrio := p.getPriority(a.Node.String())
+	bPrio := p.getPriority(b.Node.String())
+
+	// if both priority equals
+	if aPrio == bPrio {
+		fmt.Printf("CompareNodes aPrio == bPrio\n")
+		// First compare by replication lag
+		if aLag < bLag {
+			fmt.Printf("CompareNodes aLag < bLag\n")
+			return -1
+		}
+		if aLag > bLag {
+			fmt.Printf("CompareNodes aLag > bLag\n")
+			return 1
+		}
+		// If replication lag is equal, compare by latency
+		aLatency := a.Info.(interface{ Latency() time.Duration }).Latency()
+		bLatency := b.Info.(interface{ Latency() time.Duration }).Latency()
+
+		if aLatency < bLatency {
+			return -1
+		}
+		if aLatency > bLatency {
+			return 1
+		}
+
+		// If lag and latency is equal
+		return 0
+	}
+
+	// If priorities are different, prefer the node with lower priority value
+	if aPrio < bPrio {
+		return -1
+	}
+
+	return 1
+}
+
+// ClusterOptions contains cluster specific options
+type ClusterOptions struct {
+	NodeChecker    hasql.NodeChecker
+	NodePicker     hasql.NodePicker[Querier]
+	NodeDiscoverer hasql.NodeDiscoverer[Querier]
+	Options        []hasql.ClusterOpt[Querier]
+	Context        context.Context
+	RetryOnError   bool
+	NodePriority   map[string]int32
+}
+
+// ClusterOption apply cluster options to ClusterOptions
+type ClusterOption func(*ClusterOptions)
+
+// WithClusterNodeChecker pass hasql.NodeChecker to cluster options
+func WithClusterNodeChecker(c hasql.NodeChecker) ClusterOption {
+	return func(o *ClusterOptions) {
+		o.NodeChecker = c
+	}
+}
+
+// WithClusterNodePicker pass hasql.NodePicker to cluster options
+func WithClusterNodePicker(p hasql.NodePicker[Querier]) ClusterOption {
+	return func(o *ClusterOptions) {
+		o.NodePicker = p
+	}
+}
+
+// WithClusterNodeDiscoverer pass hasql.NodeDiscoverer to cluster options
+func WithClusterNodeDiscoverer(d hasql.NodeDiscoverer[Querier]) ClusterOption {
+	return func(o *ClusterOptions) {
+		o.NodeDiscoverer = d
+	}
+}
+
+// WithRetryOnError retry on other nodes on error
+func WithRetryOnError(b bool) ClusterOption {
+	return func(o *ClusterOptions) {
+		o.RetryOnError = b
+	}
+}
+
+// WithClusterContext pass context.Context to cluster options and used for checks
+func WithClusterContext(ctx context.Context) ClusterOption {
+	return func(o *ClusterOptions) {
+		o.Context = ctx
+	}
+}
+
+// WithClusterOptions pass hasql.ClusterOpt
+func WithClusterOptions(opts ...hasql.ClusterOpt[Querier]) ClusterOption {
+	return func(o *ClusterOptions) {
+		o.Options = append(o.Options, opts...)
+	}
+}
+
+type ClusterNode struct {
+	Name     string
+	DB       Querier
+	Priority int32
+}
+
+// WithClusterNodes create cluster with static NodeDiscoverer
+func WithClusterNodes(cns ...ClusterNode) ClusterOption {
+	return func(o *ClusterOptions) {
+		nodes := make([]*hasql.Node[Querier], 0, len(cns))
+		if o.NodePriority == nil {
+			o.NodePriority = make(map[string]int32, len(cns))
+		}
+		for _, cn := range cns {
+			nodes = append(nodes, hasql.NewNode(cn.Name, cn.DB))
+			if cn.Priority == 0 {
+				cn.Priority = math.MaxInt32
+			}
+			o.NodePriority[cn.Name] = cn.Priority
+		}
+		o.NodeDiscoverer = hasql.NewStaticNodeDiscoverer(nodes...)
+	}
+}
+
+func (c *Cluster) BeginTx(ctx context.Context, opts *sql.TxOptions) (*sql.Tx, error) {
+	var tx *sql.Tx
+	var err error
+
+	c.hasql.NodesIter(getNodeStateCriterion(ctx))(func(n *hasql.Node[Querier]) bool {
+		if tx, err = n.DB().BeginTx(ctx, opts); err != nil && !c.options.RetryOnError {
+			return true
+		}
+		return false
+	})
+
+	if tx == nil && err == nil {
+		err = errNoAliveNodes
+	}
+
+	return tx, err
+}
+
+func (c *Cluster) Close() error {
+	return c.hasql.Close()
+}
+
+func (c *Cluster) Conn(ctx context.Context) (*sql.Conn, error) {
+	var conn *sql.Conn
+	var err error
+
+	c.hasql.NodesIter(getNodeStateCriterion(ctx))(func(n *hasql.Node[Querier]) bool {
+		if conn, err = n.DB().Conn(ctx); err != nil && !c.options.RetryOnError {
+			return true
+		}
+		return false
+	})
+
+	if conn == nil && err == nil {
+		err = errNoAliveNodes
+	}
+
+	return conn, err
+}
+
+func (c *Cluster) ExecContext(ctx context.Context, query string, args ...interface{}) (sql.Result, error) {
+	var res sql.Result
+	var err error
+
+	c.hasql.NodesIter(getNodeStateCriterion(ctx))(func(n *hasql.Node[Querier]) bool {
+		if res, err = n.DB().ExecContext(ctx, query, args...); err != nil && !c.options.RetryOnError {
+			return true
+		}
+		return false
+	})
+
+	if res == nil && err == nil {
+		err = errNoAliveNodes
+	}
+
+	return res, err
+}
+
+func (c *Cluster) PrepareContext(ctx context.Context, query string) (*sql.Stmt, error) {
+	var res *sql.Stmt
+	var err error
+
+	c.hasql.NodesIter(getNodeStateCriterion(ctx))(func(n *hasql.Node[Querier]) bool {
+		if res, err = n.DB().PrepareContext(ctx, query); err != nil && !c.options.RetryOnError {
+			return true
+		}
+		return false
+	})
+
+	if res == nil && err == nil {
+		err = errNoAliveNodes
+	}
+
+	return res, err
+}
+
+func (c *Cluster) QueryContext(ctx context.Context, query string, args ...interface{}) (*sql.Rows, error) {
+	var res *sql.Rows
+	var err error
+
+	c.hasql.NodesIter(getNodeStateCriterion(ctx))(func(n *hasql.Node[Querier]) bool {
+		if res, err = n.DB().QueryContext(ctx, query); err != nil && err != sql.ErrNoRows && !c.options.RetryOnError {
+			return true
+		}
+		return false
+	})
+
+	if res == nil && err == nil {
+		err = errNoAliveNodes
+	}
+
+	return res, err
+}
+
+func (c *Cluster) QueryRowContext(ctx context.Context, query string, args ...interface{}) *sql.Row {
+	var res *sql.Row
+	c.hasql.NodesIter(getNodeStateCriterion(ctx))(func(n *hasql.Node[Querier]) bool {
+		res = n.DB().QueryRowContext(ctx, query, args...)
+		if res.Err() == nil {
+			return false
+		} else if res.Err() != nil && !c.options.RetryOnError {
+			return false
+		}
+		return true
+	})
+
+	if res == nil {
+		res = newSQLRowError()
+	}
+
+	return res
+}
+
+func (c *Cluster) PingContext(ctx context.Context) error {
+	var err error
+	var ok bool
+
+	c.hasql.NodesIter(getNodeStateCriterion(ctx))(func(n *hasql.Node[Querier]) bool {
+		ok = true
+		if err = n.DB().PingContext(ctx); err != nil && !c.options.RetryOnError {
+			return true
+		}
+		return false
+	})
+
+	if !ok {
+		err = errNoAliveNodes
+	}
+
+	return err
+}
+
+func (c *Cluster) WaitForNodes(ctx context.Context, criterions ...hasql.NodeStateCriterion) error {
+	for _, criterion := range criterions {
+		if _, err := c.hasql.WaitForNode(ctx, criterion); err != nil {
+			return err
+		}
+	}
+	return nil
+}
+
+func (c *Cluster) SetConnMaxLifetime(td time.Duration) {
+	c.hasql.NodesIter(hasql.NodeStateCriterion(hasql.Alive))(func(n *hasql.Node[Querier]) bool {
+		n.DB().SetConnMaxIdleTime(td)
+		return false
+	})
+}
+
+func (c *Cluster) SetConnMaxIdleTime(td time.Duration) {
+	c.hasql.NodesIter(hasql.NodeStateCriterion(hasql.Alive))(func(n *hasql.Node[Querier]) bool {
+		n.DB().SetConnMaxIdleTime(td)
+		return false
+	})
+}
+
+func (c *Cluster) SetMaxOpenConns(nc int) {
+	c.hasql.NodesIter(hasql.NodeStateCriterion(hasql.Alive))(func(n *hasql.Node[Querier]) bool {
+		n.DB().SetMaxOpenConns(nc)
+		return false
+	})
+}
+
+func (c *Cluster) SetMaxIdleConns(nc int) {
+	c.hasql.NodesIter(hasql.NodeStateCriterion(hasql.Alive))(func(n *hasql.Node[Querier]) bool {
+		n.DB().SetMaxIdleConns(nc)
+		return false
+	})
+}
+
+func (c *Cluster) Stats() sql.DBStats {
+	s := sql.DBStats{}
+	c.hasql.NodesIter(hasql.NodeStateCriterion(hasql.Alive))(func(n *hasql.Node[Querier]) bool {
+		st := n.DB().Stats()
+		s.Idle += st.Idle
+		s.InUse += st.InUse
+		s.MaxIdleClosed += st.MaxIdleClosed
+		s.MaxIdleTimeClosed += st.MaxIdleTimeClosed
+		s.MaxOpenConnections += st.MaxOpenConnections
+		s.OpenConnections += st.OpenConnections
+		s.WaitCount += st.WaitCount
+		s.WaitDuration += st.WaitDuration
+		return false
+	})
+	return s
+}

hooks/sql/cluster_test.go

@@ -0,0 +1,171 @@
+package sql
+
+import (
+	"context"
+	"fmt"
+	"testing"
+	"time"
+
+	"github.com/DATA-DOG/go-sqlmock"
+	"golang.yandex/hasql/v2"
+)
+
+func TestNewCluster(t *testing.T) {
+	dbMaster, dbMasterMock, err := sqlmock.New(sqlmock.MonitorPingsOption(true))
+	if err != nil {
+		t.Fatal(err)
+	}
+	defer dbMaster.Close()
+	dbMasterMock.MatchExpectationsInOrder(false)
+
+	dbMasterMock.ExpectQuery(`.*pg_is_in_recovery.*`).WillReturnRows(
+		sqlmock.NewRowsWithColumnDefinition(
+			sqlmock.NewColumn("role").OfType("int8", 0),
+			sqlmock.NewColumn("replication_lag").OfType("int8", 0)).
+			AddRow(1, 0)).
+		RowsWillBeClosed().
+		WithoutArgs()
+
+	dbMasterMock.ExpectQuery(`SELECT node_name as name`).WillReturnRows(
+		sqlmock.NewRows([]string{"name"}).
+			AddRow("master-dc1"))
+
+	dbDRMaster, dbDRMasterMock, err := sqlmock.New(sqlmock.MonitorPingsOption(true))
+	if err != nil {
+		t.Fatal(err)
+	}
+	defer dbDRMaster.Close()
+	dbDRMasterMock.MatchExpectationsInOrder(false)
+
+	dbDRMasterMock.ExpectQuery(`.*pg_is_in_recovery.*`).WillReturnRows(
+		sqlmock.NewRowsWithColumnDefinition(
+			sqlmock.NewColumn("role").OfType("int8", 0),
+			sqlmock.NewColumn("replication_lag").OfType("int8", 0)).
+			AddRow(2, 40)).
+		RowsWillBeClosed().
+		WithoutArgs()
+
+	dbDRMasterMock.ExpectQuery(`SELECT node_name as name`).WillReturnRows(
+		sqlmock.NewRows([]string{"name"}).
+			AddRow("drmaster1-dc2"))
+
+	dbDRMasterMock.ExpectQuery(`SELECT node_name as name`).WillReturnRows(
+		sqlmock.NewRows([]string{"name"}).
+			AddRow("drmaster"))
+
+	dbSlaveDC1, dbSlaveDC1Mock, err := sqlmock.New(sqlmock.MonitorPingsOption(true))
+	if err != nil {
+		t.Fatal(err)
+	}
+	defer dbSlaveDC1.Close()
+	dbSlaveDC1Mock.MatchExpectationsInOrder(false)
+
+	dbSlaveDC1Mock.ExpectQuery(`.*pg_is_in_recovery.*`).WillReturnRows(
+		sqlmock.NewRowsWithColumnDefinition(
+			sqlmock.NewColumn("role").OfType("int8", 0),
+			sqlmock.NewColumn("replication_lag").OfType("int8", 0)).
+			AddRow(2, 50)).
+		RowsWillBeClosed().
+		WithoutArgs()
+
+	dbSlaveDC1Mock.ExpectQuery(`SELECT node_name as name`).WillReturnRows(
+		sqlmock.NewRows([]string{"name"}).
+			AddRow("slave-dc1"))
+
+	dbSlaveDC2, dbSlaveDC2Mock, err := sqlmock.New(sqlmock.MonitorPingsOption(true))
+	if err != nil {
+		t.Fatal(err)
+	}
+	defer dbSlaveDC2.Close()
+	dbSlaveDC1Mock.MatchExpectationsInOrder(false)
+
+	dbSlaveDC2Mock.ExpectQuery(`.*pg_is_in_recovery.*`).WillReturnRows(
+		sqlmock.NewRowsWithColumnDefinition(
+			sqlmock.NewColumn("role").OfType("int8", 0),
+			sqlmock.NewColumn("replication_lag").OfType("int8", 0)).
+			AddRow(2, 50)).
+		RowsWillBeClosed().
+		WithoutArgs()
+
+	dbSlaveDC2Mock.ExpectQuery(`SELECT node_name as name`).WillReturnRows(
+		sqlmock.NewRows([]string{"name"}).
+			AddRow("slave-dc1"))
+
+	tctx, cancel := context.WithTimeout(t.Context(), 10*time.Second)
+	defer cancel()
+
+	c, err := NewCluster[Querier](
+		WithClusterContext(tctx),
+		WithClusterNodeChecker(hasql.PostgreSQLChecker),
+		WithClusterNodePicker(NewCustomPicker[Querier](
+			CustomPickerMaxLag(100),
+		)),
+		WithClusterNodes(
+			ClusterNode{"slave-dc1", dbSlaveDC1, 1},
+			ClusterNode{"master-dc1", dbMaster, 1},
+			ClusterNode{"slave-dc2", dbSlaveDC2, 2},
+			ClusterNode{"drmaster1-dc2", dbDRMaster, 0},
+		),
+		WithClusterOptions(
+			hasql.WithUpdateInterval[Querier](2*time.Second),
+			hasql.WithUpdateTimeout[Querier](1*time.Second),
+		),
+	)
+	if err != nil {
+		t.Fatal(err)
+	}
+	defer c.Close()
+
+	if err = c.WaitForNodes(tctx, hasql.Primary, hasql.Standby); err != nil {
+		t.Fatal(err)
+	}
+
+	time.Sleep(500 * time.Millisecond)
+
+	node1Name := ""
+	fmt.Printf("check for Standby\n")
+	if row := c.QueryRowContext(NodeStateCriterion(tctx, hasql.Standby), "SELECT node_name as name"); row.Err() != nil {
+		t.Fatal(row.Err())
+	} else if err = row.Scan(&node1Name); err != nil {
+		t.Fatal(err)
+	} else if "slave-dc1" != node1Name {
+		t.Fatalf("invalid node name %s != %s", "slave-dc1", node1Name)
+	}
+
+	dbSlaveDC1Mock.ExpectQuery(`SELECT node_name as name`).WillReturnRows(
+		sqlmock.NewRows([]string{"name"}).
+			AddRow("slave-dc1"))
+
+	node2Name := ""
+	fmt.Printf("check for PreferStandby\n")
+	if row := c.QueryRowContext(NodeStateCriterion(tctx, hasql.PreferStandby), "SELECT node_name as name"); row.Err() != nil {
+		t.Fatal(row.Err())
+	} else if err = row.Scan(&node2Name); err != nil {
+		t.Fatal(err)
+	} else if "slave-dc1" != node2Name {
+		t.Fatalf("invalid node name %s != %s", "slave-dc1", node2Name)
+	}
+
+	node3Name := ""
+	fmt.Printf("check for PreferPrimary\n")
+	if row := c.QueryRowContext(NodeStateCriterion(tctx, hasql.PreferPrimary), "SELECT node_name as name"); row.Err() != nil {
+		t.Fatal(row.Err())
+	} else if err = row.Scan(&node3Name); err != nil {
+		t.Fatal(err)
+	} else if "master-dc1" != node3Name {
+		t.Fatalf("invalid node name %s != %s", "master-dc1", node3Name)
+	}
+
+	dbSlaveDC1Mock.ExpectQuery(`.*`).WillReturnRows(sqlmock.NewRows([]string{"role"}).RowError(1, fmt.Errorf("row error")))
+
+	time.Sleep(2 * time.Second)
+
+	fmt.Printf("check for PreferStandby\n")
+	if row := c.QueryRowContext(NodeStateCriterion(tctx, hasql.PreferStandby), "SELECT node_name as name"); row.Err() == nil {
+		t.Fatal("must return error")
+	}
+
+	if dbMasterErr := dbMasterMock.ExpectationsWereMet(); dbMasterErr != nil {
+		t.Error(dbMasterErr)
+	}
+}

logger/slog/slog_test.go

@@ -80,7 +80,7 @@ func TestTime(t *testing.T) {
 		WithHandlerFunc(slog.NewTextHandler),
 		logger.WithAddStacktrace(true),
 		logger.WithTimeFunc(func() time.Time {
-			return time.Unix(0, 0)
+			return time.Unix(0, 0).UTC()
 		}),
 	)
 	if err := l.Init(logger.WithFields("key1", "val1")); err != nil {
@@ -89,8 +89,7 @@ func TestTime(t *testing.T) {
 
 	l.Error(ctx, "msg1", errors.New("err"))
 
-	if !bytes.Contains(buf.Bytes(), []byte(`timestamp=1970-01-01T03:00:00.000000000+03:00`)) &&
+	if !bytes.Contains(buf.Bytes(), []byte(`timestamp=1970-01-01T00:00:00.000000000Z`)) {
-		!bytes.Contains(buf.Bytes(), []byte(`timestamp=1970-01-01T00:00:00.000000000Z`)) {
 		t.Fatalf("logger error not works, buf contains: %s", buf.Bytes())
 	}
 }

meter/meter.go

@@ -4,8 +4,8 @@ package meter
 import (
 	"io"
 	"sort"
-	"strconv"
 	"strings"
+	"sync"
 	"time"
 )
 
@@ -117,6 +117,39 @@ func BuildLabels(labels ...string) []string {
 	return labels
 }
 
+var spool = newStringsPool(500)
+
+type stringsPool struct {
+	p *sync.Pool
+	c int
+}
+
+func newStringsPool(size int) *stringsPool {
+	p := &stringsPool{c: size}
+	p.p = &sync.Pool{
+		New: func() interface{} {
+			return &strings.Builder{}
+		},
+	}
+	return p
+}
+
+func (p *stringsPool) Cap() int {
+	return p.c
+}
+
+func (p *stringsPool) Get() *strings.Builder {
+	return p.p.Get().(*strings.Builder)
+}
+
+func (p *stringsPool) Put(b *strings.Builder) {
+	if b.Cap() > p.c {
+		return
+	}
+	b.Reset()
+	p.p.Put(b)
+}
+
 // BuildName used to combine metric with labels.
 // If labels count is odd, drop last element
 func BuildName(name string, labels ...string) string {
@@ -125,8 +158,6 @@ func BuildName(name string, labels ...string) string {
 	}
 
 	if len(labels) > 2 {
-		sort.Sort(byKey(labels))
-
 		idx := 0
 		for {
 			if labels[idx] == labels[idx+2] {
@@ -141,7 +172,9 @@ func BuildName(name string, labels ...string) string {
 		}
 	}
 
-	var b strings.Builder
+	b := spool.Get()
+	defer spool.Put(b)
+
 	_, _ = b.WriteString(name)
 	_, _ = b.WriteRune('{')
 	for idx := 0; idx < len(labels); idx += 2 {
@@ -149,8 +182,9 @@ func BuildName(name string, labels ...string) string {
 			_, _ = b.WriteRune(',')
 		}
 		_, _ = b.WriteString(labels[idx])
-		_, _ = b.WriteString(`=`)
+		_, _ = b.WriteString(`="`)
-		_, _ = b.WriteString(strconv.Quote(labels[idx+1]))
+		_, _ = b.WriteString(labels[idx+1])
+		_, _ = b.WriteRune('"')
 	}
 	_, _ = b.WriteRune('}')
 

meter/meter_test.go

@@ -50,11 +50,12 @@ func TestBuildName(t *testing.T) {
 	data := map[string][]string{
 		`my_metric{firstlabel="value2",zerolabel="value3"}`: {
 			"my_metric",
-			"zerolabel", "value3", "firstlabel", "value2",
+			"firstlabel", "value2",
+			"zerolabel", "value3",
 		},
 		`my_metric{broker="broker2",register="mdns",server="tcp"}`: {
 			"my_metric",
-			"broker", "broker1", "broker", "broker2", "server", "http", "server", "tcp", "register", "mdns",
+			"broker", "broker1", "broker", "broker2", "register", "mdns", "server", "http", "server", "tcp",
 		},
 		`my_metric{aaa="aaa"}`: {
 			"my_metric",

micro_test.go

@@ -91,7 +91,7 @@ func (p *bro) Connect(_ context.Context) error { return nil }
 func (p *bro) Disconnect(_ context.Context) error { return nil }
 
 // NewMessage creates new message
-func (p *bro) NewMessage(_ context.Context, _ metadata.Metadata, _ interface{}, _ ...broker.PublishOption) (broker.Message, error) {
+func (p *bro) NewMessage(_ context.Context, _ metadata.Metadata, _ interface{}, _ ...broker.MessageOption) (broker.Message, error) {
 	return nil, nil
 }
 

store/noop_test.go

@@ -2,6 +2,7 @@ package store
 
 import (
 	"context"
+	"errors"
 	"testing"
 )
 
@@ -25,7 +26,8 @@ func TestHook(t *testing.T) {
 		t.Fatal(err)
 	}
 
-	if err := s.Exists(context.TODO(), "test"); err != nil {
+	err := s.Exists(context.TODO(), "test")
+	if !errors.Is(err, ErrNotFound) {
 		t.Fatal(err)
 	}
 

tracer/tracer.go

@@ -29,10 +29,10 @@ type ContextAttrFunc func(ctx context.Context) []interface{}
 func init() {
 	logger.DefaultContextAttrFuncs = append(logger.DefaultContextAttrFuncs,
 		func(ctx context.Context) []interface{} {
-			if span, ok := SpanFromContext(ctx); ok {
+			if sp, ok := SpanFromContext(ctx); ok && sp != nil && sp.IsRecording() {
 				return []interface{}{
-					TraceIDKey, span.TraceID(),
+					TraceIDKey, sp.TraceID(),
-					SpanIDKey, span.SpanID(),
+					SpanIDKey, sp.SpanID(),
 				}
 			}
 			return nil

util/buffer/seeker_buffer.go

@@ -1,13 +1,16 @@
 package buffer
 
-import "io"
+import (
+	"fmt"
+	"io"
+)
 
 var _ interface {
 	io.ReadCloser
 	io.ReadSeeker
 } = (*SeekerBuffer)(nil)
 
-// Buffer is a ReadWriteCloser that supports seeking. It's intended to
+// SeekerBuffer is a ReadWriteCloser that supports seeking. It's intended to
 // replicate the functionality of bytes.Buffer that I use in my projects.
 //
 // Note that the seeking is limited to the read marker; all writes are
@@ -23,6 +26,7 @@ func NewSeekerBuffer(data []byte) *SeekerBuffer {
 	}
 }
 
+// Read reads up to len(p) bytes into p from the current read position.
 func (b *SeekerBuffer) Read(p []byte) (int, error) {
 	if b.pos >= int64(len(b.data)) {
 		return 0, io.EOF
@@ -30,29 +34,51 @@ func (b *SeekerBuffer) Read(p []byte) (int, error) {
 
 	n := copy(p, b.data[b.pos:])
 	b.pos += int64(n)
+
 	return n, nil
 }
 
+// Write appends the contents of p to the end of the buffer. It does not affect the read position.
 func (b *SeekerBuffer) Write(p []byte) (int, error) {
+	if len(p) == 0 {
+		return 0, nil
+	}
+
 	b.data = append(b.data, p...)
+
 	return len(p), nil
 }
 
-// Seek sets the read pointer to pos.
+// Seek sets the offset for the next Read operation.
+// The offset is interpreted according to whence:
+// - io.SeekStart: relative to the beginning of the buffer
+// - io.SeekCurrent: relative to the current position
+// - io.SeekEnd: relative to the end of the buffer
+//
+// Returns an error if the resulting position is negative or if whence is invalid.
 func (b *SeekerBuffer) Seek(offset int64, whence int) (int64, error) {
+	var newPos int64
+
 	switch whence {
 	case io.SeekStart:
-		b.pos = offset
+		newPos = offset
 	case io.SeekEnd:
-		b.pos = int64(len(b.data)) + offset
+		newPos = int64(len(b.data)) + offset
 	case io.SeekCurrent:
-		b.pos += offset
+		newPos = b.pos + offset
+	default:
+		return 0, fmt.Errorf("invalid whence: %d", whence)
 	}
 
+	if newPos < 0 {
+		return 0, fmt.Errorf("invalid seek: resulting position %d is negative", newPos)
+	}
+
+	b.pos = newPos
 	return b.pos, nil
 }
 
-// Rewind resets the read pointer to 0.
+// Rewind resets the read position to 0.
 func (b *SeekerBuffer) Rewind() error {
 	if _, err := b.Seek(0, io.SeekStart); err != nil {
 		return err
@@ -75,10 +101,16 @@ func (b *SeekerBuffer) Reset() {
 
 // Len returns the length of data remaining to be read.
 func (b *SeekerBuffer) Len() int {
+	if b.pos >= int64(len(b.data)) {
+		return 0
+	}
 	return len(b.data[b.pos:])
 }
 
 // Bytes returns the underlying bytes from the current position.
 func (b *SeekerBuffer) Bytes() []byte {
+	if b.pos >= int64(len(b.data)) {
+		return []byte{}
+	}
 	return b.data[b.pos:]
 }

util/buffer/seeker_buffer_test.go

@@ -2,54 +2,384 @@ package buffer
 
 import (
 	"fmt"
-	"strings"
+	"io"
 	"testing"
+
+	"github.com/stretchr/testify/require"
 )
 
-func noErrorT(t *testing.T, err error) {
+func TestNewSeekerBuffer(t *testing.T) {
-	if nil != err {
+	input := []byte{'a', 'b', 'c', 'd', 'e'}
-		t.Fatalf("%s", err)
+	expected := &SeekerBuffer{data: []byte{'a', 'b', 'c', 'd', 'e'}, pos: 0}
+	require.Equal(t, expected, NewSeekerBuffer(input))
+}
+
+func TestSeekerBuffer_Read(t *testing.T) {
+	tests := []struct {
+		name         string
+		data         []byte
+		initPos      int64
+		readBuf      []byte
+		expectedN    int
+		expectedData []byte
+		expectedErr  error
+		expectedPos  int64
+	}{
+		{
+			name:         "read with empty buffer",
+			data:         []byte("hello"),
+			initPos:      0,
+			readBuf:      []byte{},
+			expectedN:    0,
+			expectedData: []byte{},
+			expectedErr:  nil,
+			expectedPos:  0,
+		},
+		{
+			name:         "read with nil buffer",
+			data:         []byte("hello"),
+			initPos:      0,
+			readBuf:      nil,
+			expectedN:    0,
+			expectedData: nil,
+			expectedErr:  nil,
+			expectedPos:  0,
+		},
+		{
+			name:         "read full buffer",
+			data:         []byte("hello"),
+			initPos:      0,
+			readBuf:      make([]byte, 5),
+			expectedN:    5,
+			expectedData: []byte("hello"),
+			expectedErr:  nil,
+			expectedPos:  5,
+		},
+		{
+			name:         "read partial buffer",
+			data:         []byte("hello"),
+			initPos:      2,
+			readBuf:      make([]byte, 2),
+			expectedN:    2,
+			expectedData: []byte("ll"),
+			expectedErr:  nil,
+			expectedPos:  4,
+		},
+		{
+			name:         "read after end",
+			data:         []byte("hello"),
+			initPos:      5,
+			readBuf:      make([]byte, 5),
+			expectedN:    0,
+			expectedData: make([]byte, 5),
+			expectedErr:  io.EOF,
+			expectedPos:  5,
+		},
+	}
+
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			sb := NewSeekerBuffer(tt.data)
+			sb.pos = tt.initPos
+
+			n, err := sb.Read(tt.readBuf)
+
+			if tt.expectedErr != nil {
+				require.Equal(t, err, tt.expectedErr)
+			} else {
+				require.NoError(t, err)
+			}
+
+			require.Equal(t, tt.expectedN, n)
+			require.Equal(t, tt.expectedData, tt.readBuf)
+			require.Equal(t, tt.expectedPos, sb.pos)
+		})
 	}
 }
 
-func boolT(t *testing.T, cond bool, s ...string) {
+func TestSeekerBuffer_Write(t *testing.T) {
-	if !cond {
+	tests := []struct {
-		what := strings.Join(s, ", ")
+		name         string
-		if len(what) > 0 {
+		initialData  []byte
-			what = ": " + what
+		initialPos   int64
-		}
+		writeData    []byte
-		t.Fatalf("assert.Bool failed%s", what)
+		expectedData []byte
+		expectedN    int
+	}{
+		{
+			name:         "write empty slice",
+			initialData:  []byte("data"),
+			initialPos:   0,
+			writeData:    []byte{},
+			expectedData: []byte("data"),
+			expectedN:    0,
+		},
+		{
+			name:         "write nil slice",
+			initialData:  []byte("data"),
+			initialPos:   0,
+			writeData:    nil,
+			expectedData: []byte("data"),
+			expectedN:    0,
+		},
+		{
+			name:         "write to empty buffer",
+			initialData:  nil,
+			initialPos:   0,
+			writeData:    []byte("abc"),
+			expectedData: []byte("abc"),
+			expectedN:    3,
+		},
+		{
+			name:         "write to existing buffer",
+			initialData:  []byte("hello"),
+			initialPos:   0,
+			writeData:    []byte(" world"),
+			expectedData: []byte("hello world"),
+			expectedN:    6,
+		},
+		{
+			name:         "write after read",
+			initialData:  []byte("abc"),
+			initialPos:   2,
+			writeData:    []byte("XYZ"),
+			expectedData: []byte("abcXYZ"),
+			expectedN:    3,
+		},
+	}
+
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			sb := NewSeekerBuffer(tt.initialData)
+			sb.pos = tt.initialPos
+
+			n, err := sb.Write(tt.writeData)
+			require.NoError(t, err)
+			require.Equal(t, tt.expectedN, n)
+			require.Equal(t, tt.expectedData, sb.data)
+			require.Equal(t, tt.initialPos, sb.pos)
+		})
 	}
 }
 
-func TestSeeking(t *testing.T) {
+func TestSeekerBuffer_Seek(t *testing.T) {
-	partA := []byte("hello, ")
+	tests := []struct {
-	partB := []byte("world!")
+		name        string
+		initialData []byte
+		initialPos  int64
+		offset      int64
+		whence      int
+		expectedPos int64
+		expectedErr error
+	}{
+		{
+			name:        "seek with invalid whence",
+			initialData: []byte("abcdef"),
+			initialPos:  0,
+			offset:      1,
+			whence:      12345,
+			expectedPos: 0,
+			expectedErr: fmt.Errorf("invalid whence: %d", 12345),
+		},
+		{
+			name:        "seek negative from start",
+			initialData: []byte("abcdef"),
+			initialPos:  0,
+			offset:      -1,
+			whence:      io.SeekStart,
+			expectedPos: 0,
+			expectedErr: fmt.Errorf("invalid seek: resulting position %d is negative", -1),
+		},
+		{
+			name:        "seek from start to 0",
+			initialData: []byte("abcdef"),
+			initialPos:  0,
+			offset:      0,
+			whence:      io.SeekStart,
+			expectedPos: 0,
+			expectedErr: nil,
+		},
+		{
+			name:        "seek from start to 3",
+			initialData: []byte("abcdef"),
+			initialPos:  0,
+			offset:      3,
+			whence:      io.SeekStart,
+			expectedPos: 3,
+			expectedErr: nil,
+		},
+		{
+			name:        "seek from end to -1 (last byte)",
+			initialData: []byte("abcdef"),
+			initialPos:  0,
+			offset:      -1,
+			whence:      io.SeekEnd,
+			expectedPos: 5,
+			expectedErr: nil,
+		},
+		{
+			name:        "seek from current forward",
+			initialData: []byte("abcdef"),
+			initialPos:  2,
+			offset:      2,
+			whence:      io.SeekCurrent,
+			expectedPos: 4,
+			expectedErr: nil,
+		},
+		{
+			name:        "seek from current backward",
+			initialData: []byte("abcdef"),
+			initialPos:  4,
+			offset:      -2,
+			whence:      io.SeekCurrent,
+			expectedPos: 2,
+			expectedErr: nil,
+		},
+		{
+			name:        "seek to end exactly",
+			initialData: []byte("abcdef"),
+			initialPos:  0,
+			offset:      0,
+			whence:      io.SeekEnd,
+			expectedPos: 6,
+			expectedErr: nil,
+		},
+		{
+			name:        "seek to out of range",
+			initialData: []byte("abcdef"),
+			initialPos:  0,
+			offset:      2,
+			whence:      io.SeekEnd,
+			expectedPos: 8,
+			expectedErr: nil,
+		},
+	}
 
-	buf := NewSeekerBuffer(partA)
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			sb := NewSeekerBuffer(tt.initialData)
+			sb.pos = tt.initialPos
 
-	boolT(t, buf.Len() == len(partA), fmt.Sprintf("on init: have length %d, want length %d", buf.Len(), len(partA)))
+			newPos, err := sb.Seek(tt.offset, tt.whence)
 
-	b := make([]byte, 32)
+			if tt.expectedErr != nil {
-
+				require.Equal(t, tt.expectedErr, err)
-	n, err := buf.Read(b)
+			} else {
-	noErrorT(t, err)
+				require.NoError(t, err)
-	boolT(t, buf.Len() == 0, fmt.Sprintf("after reading 1: have length %d, want length 0", buf.Len()))
+				require.Equal(t, tt.expectedPos, newPos)
-	boolT(t, n == len(partA), fmt.Sprintf("after reading 2: have length %d, want length %d", n, len(partA)))
+				require.Equal(t, tt.expectedPos, sb.pos)
-
+			}
-	n, err = buf.Write(partB)
+		})
-	noErrorT(t, err)
+	}
-	boolT(t, n == len(partB), fmt.Sprintf("after writing: have length %d, want length %d", n, len(partB)))
+}
-
+
-	n, err = buf.Read(b)
+func TestSeekerBuffer_Rewind(t *testing.T) {
-	noErrorT(t, err)
+	buf := NewSeekerBuffer([]byte("hello world"))
-	boolT(t, buf.Len() == 0, fmt.Sprintf("after rereading 1: have length %d, want length 0", buf.Len()))
+	buf.pos = 4
-	boolT(t, n == len(partB), fmt.Sprintf("after rereading 2: have length %d, want length %d", n, len(partB)))
+
-
+	require.NoError(t, buf.Rewind())
-	partsLen := len(partA) + len(partB)
+	require.Equal(t, []byte("hello world"), buf.data)
-	_ = buf.Rewind()
+	require.Equal(t, int64(0), buf.pos)
-	boolT(t, buf.Len() == partsLen, fmt.Sprintf("after rewinding: have length %d, want length %d", buf.Len(), partsLen))
+}
-
+
-	buf.Close()
+func TestSeekerBuffer_Close(t *testing.T) {
-	boolT(t, buf.Len() == 0, fmt.Sprintf("after closing, have length %d, want length 0", buf.Len()))
+	buf := NewSeekerBuffer([]byte("hello world"))
+	buf.pos = 2
+
+	require.NoError(t, buf.Close())
+	require.Nil(t, buf.data)
+	require.Equal(t, int64(0), buf.pos)
+}
+
+func TestSeekerBuffer_Reset(t *testing.T) {
+	buf := NewSeekerBuffer([]byte("hello world"))
+	buf.pos = 2
+
+	buf.Reset()
+	require.Nil(t, buf.data)
+	require.Equal(t, int64(0), buf.pos)
+}
+
+func TestSeekerBuffer_Len(t *testing.T) {
+	tests := []struct {
+		name     string
+		data     []byte
+		pos      int64
+		expected int
+	}{
+		{
+			name:     "full buffer",
+			data:     []byte("abcde"),
+			pos:      0,
+			expected: 5,
+		},
+		{
+			name:     "partial read",
+			data:     []byte("abcde"),
+			pos:      2,
+			expected: 3,
+		},
+		{
+			name:     "fully read",
+			data:     []byte("abcde"),
+			pos:      5,
+			expected: 0,
+		},
+		{
+			name:     "pos > len",
+			data:     []byte("abcde"),
+			pos:      10,
+			expected: 0,
+		},
+	}
+
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			buf := NewSeekerBuffer(tt.data)
+			buf.pos = tt.pos
+			require.Equal(t, tt.expected, buf.Len())
+		})
+	}
+}
+
+func TestSeekerBuffer_Bytes(t *testing.T) {
+	tests := []struct {
+		name     string
+		data     []byte
+		pos      int64
+		expected []byte
+	}{
+		{
+			name:     "start of buffer",
+			data:     []byte("abcde"),
+			pos:      0,
+			expected: []byte("abcde"),
+		},
+		{
+			name:     "middle of buffer",
+			data:     []byte("abcde"),
+			pos:      2,
+			expected: []byte("cde"),
+		},
+		{
+			name:     "end of buffer",
+			data:     []byte("abcde"),
+			pos:      5,
+			expected: []byte{},
+		},
+		{
+			name:     "pos beyond end",
+			data:     []byte("abcde"),
+			pos:      10,
+			expected: []byte{},
+		},
+	}
+
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			buf := NewSeekerBuffer(tt.data)
+			buf.pos = tt.pos
+			require.Equal(t, tt.expected, buf.Bytes())
+		})
+	}
 }