代码整理

hooks/storage/badger/badger.go

@@ -0,0 +1,576 @@
+// SPDX-License-Identifier: MIT
+// SPDX-FileCopyrightText: 2022 mochi-mqtt, mochi-co
+// SPDX-FileContributor: mochi-co, gsagula, werbenhu
+
+package badger
+
+import (
+	"bytes"
+	"errors"
+	"fmt"
+	"strings"
+	"time"
+
+	badgerdb "github.com/dgraph-io/badger/v4"
+	"testmqtt/hooks/storage"
+	"testmqtt/mqtt"
+	"testmqtt/packets"
+	"testmqtt/system"
+)
+
+const (
+	// defaultDbFile is the default file path for the badger db file.
+	defaultDbFile         = ".badger"
+	defaultGcInterval     = 5 * 60 // gc interval in seconds
+	defaultGcDiscardRatio = 0.5
+)
+
+// clientKey returns a primary key for a client.
+func clientKey(cl *mqtt.Client) string {
+	return storage.ClientKey + "_" + cl.ID
+}
+
+// subscriptionKey returns a primary key for a subscription.
+func subscriptionKey(cl *mqtt.Client, filter string) string {
+	return storage.SubscriptionKey + "_" + cl.ID + ":" + filter
+}
+
+// retainedKey returns a primary key for a retained message.
+func retainedKey(topic string) string {
+	return storage.RetainedKey + "_" + topic
+}
+
+// inflightKey returns a primary key for an inflight message.
+func inflightKey(cl *mqtt.Client, pk packets.Packet) string {
+	return storage.InflightKey + "_" + cl.ID + ":" + pk.FormatID()
+}
+
+// sysInfoKey returns a primary key for system info.
+func sysInfoKey() string {
+	return storage.SysInfoKey
+}
+
+// Serializable is an interface for objects that can be serialized and deserialized.
+type Serializable interface {
+	UnmarshalBinary([]byte) error
+	MarshalBinary() (data []byte, err error)
+}
+
+// Options contains configuration settings for the BadgerDB instance.
+type Options struct {
+	Options *badgerdb.Options
+	Path    string `yaml:"path" json:"path"`
+	// GcDiscardRatio specifies the ratio of log discard compared to the maximum possible log discard.
+	// Setting it to a higher value would result in fewer space reclaims, while setting it to a lower value
+	// would result in more space reclaims at the cost of increased activity on the LSM tree.
+	// discardRatio must be in the range (0.0, 1.0), both endpoints excluded, otherwise, it will be set to the default value of 0.5.
+	GcDiscardRatio float64 `yaml:"gc_discard_ratio" json:"gc_discard_ratio"`
+	GcInterval     int64   `yaml:"gc_interval" json:"gc_interval"`
+}
+
+// Hook is a persistent storage hook based using BadgerDB file store as a backend.
+type Hook struct {
+	mqtt.HookBase
+	config   *Options     // options for configuring the BadgerDB instance.
+	gcTicker *time.Ticker // Ticker for BadgerDB garbage collection.
+	db       *badgerdb.DB // the BadgerDB instance.
+}
+
+// ID returns the id of the hook.
+func (h *Hook) ID() string {
+	return "badger-db"
+}
+
+// Provides indicates which hook methods this hook provides.
+func (h *Hook) Provides(b byte) bool {
+	return bytes.Contains([]byte{
+		mqtt.OnSessionEstablished,
+		mqtt.OnDisconnect,
+		mqtt.OnSubscribed,
+		mqtt.OnUnsubscribed,
+		mqtt.OnRetainMessage,
+		mqtt.OnWillSent,
+		mqtt.OnQosPublish,
+		mqtt.OnQosComplete,
+		mqtt.OnQosDropped,
+		mqtt.OnSysInfoTick,
+		mqtt.OnClientExpired,
+		mqtt.OnRetainedExpired,
+		mqtt.StoredClients,
+		mqtt.StoredInflightMessages,
+		mqtt.StoredRetainedMessages,
+		mqtt.StoredSubscriptions,
+		mqtt.StoredSysInfo,
+	}, []byte{b})
+}
+
+// GcLoop periodically runs the garbage collection process to reclaim space in the value log files.
+// It uses a ticker to trigger the garbage collection at regular intervals specified by the configuration.
+// Refer to: https://dgraph.io/docs/badger/get-started/#garbage-collection
+func (h *Hook) gcLoop() {
+	for range h.gcTicker.C {
+	again:
+		// Run the garbage collection process with a threshold.
+		// If the process returns nil (success), repeat the process.
+		err := h.db.RunValueLogGC(h.config.GcDiscardRatio)
+		if err == nil {
+			goto again // Retry garbage collection if successful.
+		}
+	}
+}
+
+// Init initializes and connects to the badger instance.
+func (h *Hook) Init(config any) error {
+	if _, ok := config.(*Options); !ok && config != nil {
+		return mqtt.ErrInvalidConfigType
+	}
+
+	if config == nil {
+		h.config = new(Options)
+	} else {
+		h.config = config.(*Options)
+	}
+
+	if len(h.config.Path) == 0 {
+		h.config.Path = defaultDbFile
+	}
+
+	if h.config.GcInterval == 0 {
+		h.config.GcInterval = defaultGcInterval
+	}
+
+	if h.config.GcDiscardRatio <= 0.0 || h.config.GcDiscardRatio >= 1.0 {
+		h.config.GcDiscardRatio = defaultGcDiscardRatio
+	}
+
+	if h.config.Options == nil {
+		defaultOpts := badgerdb.DefaultOptions(h.config.Path)
+		h.config.Options = &defaultOpts
+	}
+	h.config.Options.Logger = h
+
+	var err error
+	h.db, err = badgerdb.Open(*h.config.Options)
+	if err != nil {
+		return err
+	}
+
+	h.gcTicker = time.NewTicker(time.Duration(h.config.GcInterval) * time.Second)
+	go h.gcLoop()
+
+	return nil
+}
+
+// Stop closes the badger instance.
+func (h *Hook) Stop() error {
+	if h.gcTicker != nil {
+		h.gcTicker.Stop()
+	}
+	return h.db.Close()
+}
+
+// OnSessionEstablished adds a client to the store when their session is established.
+func (h *Hook) OnSessionEstablished(cl *mqtt.Client, pk packets.Packet) {
+	h.updateClient(cl)
+}
+
+// OnWillSent is called when a client sends a Will Message and the Will Message is removed from the client record.
+func (h *Hook) OnWillSent(cl *mqtt.Client, pk packets.Packet) {
+	h.updateClient(cl)
+}
+
+// updateClient writes the client data to the store.
+func (h *Hook) updateClient(cl *mqtt.Client) {
+	if h.db == nil {
+		h.Log.Error("", "error", storage.ErrDBFileNotOpen)
+		return
+	}
+
+	props := cl.Properties.Props.Copy(false)
+	in := &storage.Client{
+		ID:              cl.ID,
+		T:               storage.ClientKey,
+		Remote:          cl.Net.Remote,
+		Listener:        cl.Net.Listener,
+		Username:        cl.Properties.Username,
+		Clean:           cl.Properties.Clean,
+		ProtocolVersion: cl.Properties.ProtocolVersion,
+		Properties: storage.ClientProperties{
+			SessionExpiryInterval: props.SessionExpiryInterval,
+			AuthenticationMethod:  props.AuthenticationMethod,
+			AuthenticationData:    props.AuthenticationData,
+			RequestProblemInfo:    props.RequestProblemInfo,
+			RequestResponseInfo:   props.RequestResponseInfo,
+			ReceiveMaximum:        props.ReceiveMaximum,
+			TopicAliasMaximum:     props.TopicAliasMaximum,
+			User:                  props.User,
+			MaximumPacketSize:     props.MaximumPacketSize,
+		},
+		Will: storage.ClientWill(cl.Properties.Will),
+	}
+
+	err := h.setKv(clientKey(cl), in)
+	if err != nil {
+		h.Log.Error("failed to upsert client data", "error", err, "data", in)
+	}
+}
+
+// OnDisconnect removes a client from the store if their session has expired.
+func (h *Hook) OnDisconnect(cl *mqtt.Client, _ error, expire bool) {
+	if h.db == nil {
+		h.Log.Error("", "error", storage.ErrDBFileNotOpen)
+		return
+	}
+
+	h.updateClient(cl)
+
+	if !expire {
+		return
+	}
+
+	if errors.Is(cl.StopCause(), packets.ErrSessionTakenOver) {
+		return
+	}
+
+	_ = h.delKv(clientKey(cl))
+}
+
+// OnSubscribed adds one or more client subscriptions to the store.
+func (h *Hook) OnSubscribed(cl *mqtt.Client, pk packets.Packet, reasonCodes []byte) {
+	if h.db == nil {
+		h.Log.Error("", "error", storage.ErrDBFileNotOpen)
+		return
+	}
+
+	var in *storage.Subscription
+	for i := 0; i < len(pk.Filters); i++ {
+		in = &storage.Subscription{
+			ID:                subscriptionKey(cl, pk.Filters[i].Filter),
+			T:                 storage.SubscriptionKey,
+			Client:            cl.ID,
+			Qos:               reasonCodes[i],
+			Filter:            pk.Filters[i].Filter,
+			Identifier:        pk.Filters[i].Identifier,
+			NoLocal:           pk.Filters[i].NoLocal,
+			RetainHandling:    pk.Filters[i].RetainHandling,
+			RetainAsPublished: pk.Filters[i].RetainAsPublished,
+		}
+
+		_ = h.setKv(in.ID, in)
+	}
+}
+
+// OnUnsubscribed removes one or more client subscriptions from the store.
+func (h *Hook) OnUnsubscribed(cl *mqtt.Client, pk packets.Packet) {
+	if h.db == nil {
+		h.Log.Error("", "error", storage.ErrDBFileNotOpen)
+		return
+	}
+
+	for i := 0; i < len(pk.Filters); i++ {
+		_ = h.delKv(subscriptionKey(cl, pk.Filters[i].Filter))
+	}
+}
+
+// OnRetainMessage adds a retained message for a topic to the store.
+func (h *Hook) OnRetainMessage(cl *mqtt.Client, pk packets.Packet, r int64) {
+	if h.db == nil {
+		h.Log.Error("", "error", storage.ErrDBFileNotOpen)
+		return
+	}
+
+	if r == -1 {
+		_ = h.delKv(retainedKey(pk.TopicName))
+		return
+	}
+
+	props := pk.Properties.Copy(false)
+	in := &storage.Message{
+		ID:          retainedKey(pk.TopicName),
+		T:           storage.RetainedKey,
+		FixedHeader: pk.FixedHeader,
+		TopicName:   pk.TopicName,
+		Payload:     pk.Payload,
+		Created:     pk.Created,
+		Origin:      pk.Origin,
+		Properties: storage.MessageProperties{
+			PayloadFormat:          props.PayloadFormat,
+			MessageExpiryInterval:  props.MessageExpiryInterval,
+			ContentType:            props.ContentType,
+			ResponseTopic:          props.ResponseTopic,
+			CorrelationData:        props.CorrelationData,
+			SubscriptionIdentifier: props.SubscriptionIdentifier,
+			TopicAlias:             props.TopicAlias,
+			User:                   props.User,
+		},
+	}
+
+	_ = h.setKv(in.ID, in)
+}
+
+// OnQosPublish adds or updates an inflight message in the store.
+func (h *Hook) OnQosPublish(cl *mqtt.Client, pk packets.Packet, sent int64, resends int) {
+	if h.db == nil {
+		h.Log.Error("", "error", storage.ErrDBFileNotOpen)
+		return
+	}
+
+	props := pk.Properties.Copy(false)
+	in := &storage.Message{
+		ID:          inflightKey(cl, pk),
+		T:           storage.InflightKey,
+		Origin:      pk.Origin,
+		PacketID:    pk.PacketID,
+		FixedHeader: pk.FixedHeader,
+		TopicName:   pk.TopicName,
+		Payload:     pk.Payload,
+		Sent:        sent,
+		Created:     pk.Created,
+		Properties: storage.MessageProperties{
+			PayloadFormat:          props.PayloadFormat,
+			MessageExpiryInterval:  props.MessageExpiryInterval,
+			ContentType:            props.ContentType,
+			ResponseTopic:          props.ResponseTopic,
+			CorrelationData:        props.CorrelationData,
+			SubscriptionIdentifier: props.SubscriptionIdentifier,
+			TopicAlias:             props.TopicAlias,
+			User:                   props.User,
+		},
+	}
+
+	_ = h.setKv(in.ID, in)
+}
+
+// OnQosComplete removes a resolved inflight message from the store.
+func (h *Hook) OnQosComplete(cl *mqtt.Client, pk packets.Packet) {
+	if h.db == nil {
+		h.Log.Error("", "error", storage.ErrDBFileNotOpen)
+		return
+	}
+
+	_ = h.delKv(inflightKey(cl, pk))
+}
+
+// OnQosDropped removes a dropped inflight message from the store.
+func (h *Hook) OnQosDropped(cl *mqtt.Client, pk packets.Packet) {
+	if h.db == nil {
+		h.Log.Error("", "error", storage.ErrDBFileNotOpen)
+	}
+
+	h.OnQosComplete(cl, pk)
+}
+
+// OnSysInfoTick stores the latest system info in the store.
+func (h *Hook) OnSysInfoTick(sys *system.Info) {
+	if h.db == nil {
+		h.Log.Error("", "error", storage.ErrDBFileNotOpen)
+		return
+	}
+
+	in := &storage.SystemInfo{
+		ID:   sysInfoKey(),
+		T:    storage.SysInfoKey,
+		Info: *sys.Clone(),
+	}
+
+	_ = h.setKv(in.ID, in)
+}
+
+// OnRetainedExpired deletes expired retained messages from the store.
+func (h *Hook) OnRetainedExpired(filter string) {
+	if h.db == nil {
+		h.Log.Error("", "error", storage.ErrDBFileNotOpen)
+		return
+	}
+
+	_ = h.delKv(retainedKey(filter))
+}
+
+// OnClientExpired deleted expired clients from the store.
+func (h *Hook) OnClientExpired(cl *mqtt.Client) {
+	if h.db == nil {
+		h.Log.Error("", "error", storage.ErrDBFileNotOpen)
+		return
+	}
+
+	_ = h.delKv(clientKey(cl))
+}
+
+// StoredClients returns all stored clients from the store.
+func (h *Hook) StoredClients() (v []storage.Client, err error) {
+	if h.db == nil {
+		h.Log.Error("", "error", storage.ErrDBFileNotOpen)
+		return
+	}
+
+	err = h.iterKv(storage.ClientKey, func(value []byte) error {
+		obj := storage.Client{}
+		err = obj.UnmarshalBinary(value)
+		if err == nil {
+			v = append(v, obj)
+		}
+		return err
+	})
+	return
+}
+
+// StoredSubscriptions returns all stored subscriptions from the store.
+func (h *Hook) StoredSubscriptions() (v []storage.Subscription, err error) {
+	if h.db == nil {
+		h.Log.Error("", "error", storage.ErrDBFileNotOpen)
+		return
+	}
+
+	v = make([]storage.Subscription, 0)
+	err = h.iterKv(storage.SubscriptionKey, func(value []byte) error {
+		obj := storage.Subscription{}
+		err = obj.UnmarshalBinary(value)
+		if err == nil {
+			v = append(v, obj)
+		}
+		return err
+	})
+	return
+}
+
+// StoredRetainedMessages returns all stored retained messages from the store.
+func (h *Hook) StoredRetainedMessages() (v []storage.Message, err error) {
+	if h.db == nil {
+		h.Log.Error("", "error", storage.ErrDBFileNotOpen)
+		return
+	}
+
+	v = make([]storage.Message, 0)
+	err = h.iterKv(storage.RetainedKey, func(value []byte) error {
+		obj := storage.Message{}
+		err = obj.UnmarshalBinary(value)
+		if err == nil {
+			v = append(v, obj)
+		}
+		return err
+	})
+
+	if err != nil && !errors.Is(err, badgerdb.ErrKeyNotFound) {
+		return
+	}
+	return
+}
+
+// StoredInflightMessages returns all stored inflight messages from the store.
+func (h *Hook) StoredInflightMessages() (v []storage.Message, err error) {
+	if h.db == nil {
+		h.Log.Error("", "error", storage.ErrDBFileNotOpen)
+		return
+	}
+
+	v = make([]storage.Message, 0)
+	err = h.iterKv(storage.InflightKey, func(value []byte) error {
+		obj := storage.Message{}
+		err = obj.UnmarshalBinary(value)
+		if err == nil {
+			v = append(v, obj)
+		}
+		return err
+	})
+	return
+}
+
+// StoredSysInfo returns the system info from the store.
+func (h *Hook) StoredSysInfo() (v storage.SystemInfo, err error) {
+	if h.db == nil {
+		h.Log.Error("", "error", storage.ErrDBFileNotOpen)
+		return
+	}
+
+	err = h.getKv(storage.SysInfoKey, &v)
+	if err != nil && !errors.Is(err, badgerdb.ErrKeyNotFound) {
+		return
+	}
+	return v, nil
+}
+
+// Errorf satisfies the badger interface for an error logger.
+func (h *Hook) Errorf(m string, v ...any) {
+	h.Log.Error(fmt.Sprintf(strings.ToLower(strings.Trim(m, "\n")), v...), "v", v)
+
+}
+
+// Warningf satisfies the badger interface for a warning logger.
+func (h *Hook) Warningf(m string, v ...any) {
+	h.Log.Warn(fmt.Sprintf(strings.ToLower(strings.Trim(m, "\n")), v...), "v", v)
+}
+
+// Infof satisfies the badger interface for an info logger.
+func (h *Hook) Infof(m string, v ...any) {
+	h.Log.Info(fmt.Sprintf(strings.ToLower(strings.Trim(m, "\n")), v...), "v", v)
+}
+
+// Debugf satisfies the badger interface for a debug logger.
+func (h *Hook) Debugf(m string, v ...any) {
+	h.Log.Debug(fmt.Sprintf(strings.ToLower(strings.Trim(m, "\n")), v...), "v", v)
+}
+
+// setKv stores a key-value pair in the database.
+func (h *Hook) setKv(k string, v storage.Serializable) error {
+	err := h.db.Update(func(txn *badgerdb.Txn) error {
+		data, _ := v.MarshalBinary()
+		return txn.Set([]byte(k), data)
+	})
+	if err != nil {
+		h.Log.Error("failed to upsert data", "error", err, "key", k)
+	}
+	return err
+}
+
+// delKv deletes a key-value pair from the database.
+func (h *Hook) delKv(k string) error {
+	err := h.db.Update(func(txn *badgerdb.Txn) error {
+		return txn.Delete([]byte(k))
+	})
+
+	if err != nil {
+		h.Log.Error("failed to delete data", "error", err, "key", k)
+	}
+	return err
+}
+
+// getKv retrieves the value associated with a key from the database.
+func (h *Hook) getKv(k string, v storage.Serializable) error {
+	return h.db.View(func(txn *badgerdb.Txn) error {
+		item, err := txn.Get([]byte(k))
+		if err != nil {
+			return err
+		}
+		value, err := item.ValueCopy(nil)
+		if err != nil {
+			return err
+		}
+		return v.UnmarshalBinary(value)
+	})
+}
+
+// iterKv iterates over key-value pairs with keys having the specified prefix in the database.
+func (h *Hook) iterKv(prefix string, visit func([]byte) error) error {
+	err := h.db.View(func(txn *badgerdb.Txn) error {
+		iterator := txn.NewIterator(badgerdb.DefaultIteratorOptions)
+		defer iterator.Close()
+
+		for iterator.Seek([]byte(prefix)); iterator.ValidForPrefix([]byte(prefix)); iterator.Next() {
+			item := iterator.Item()
+			value, err := item.ValueCopy(nil)
+
+			if err != nil {
+				return err
+			}
+
+			if err := visit(value); err != nil {
+				return err
+			}
+		}
+		return nil
+	})
+	if err != nil {
+		h.Log.Error("failed to find data", "error", err, "prefix", prefix)
+	}
+	return err
+}

hooks/storage/badger/badger_test.go

@@ -0,0 +1,809 @@
+// SPDX-License-Identifier: MIT
+// SPDX-FileCopyrightText: 2022 mochi-mqtt, mochi-co
+// SPDX-FileContributor: mochi-co, werbenhu
+
+package badger
+
+import (
+	"errors"
+	"log/slog"
+	"os"
+	"strings"
+	"testing"
+	"time"
+
+	badgerdb "github.com/dgraph-io/badger/v4"
+	"testmqtt/hooks/storage"
+	"testmqtt/mqtt"
+	"testmqtt/packets"
+	"testmqtt/system"
+
+	"github.com/stretchr/testify/require"
+)
+
+var (
+	logger = slog.New(slog.NewTextHandler(os.Stdout, nil))
+
+	client = &mqtt.Client{
+		ID: "test",
+		Net: mqtt.ClientConnection{
+			Remote:   "test.addr",
+			Listener: "listener",
+		},
+		Properties: mqtt.ClientProperties{
+			Username: []byte("username"),
+			Clean:    false,
+		},
+	}
+
+	pkf = packets.Packet{Filters: packets.Subscriptions{{Filter: "a/b/c"}}}
+)
+
+func teardown(t *testing.T, path string, h *Hook) {
+	_ = h.Stop()
+	_ = h.db.Close()
+	err := os.RemoveAll("./" + strings.Replace(path, "..", "", -1))
+	require.NoError(t, err)
+}
+
+func TestSetGetDelKv(t *testing.T) {
+	h := new(Hook)
+	h.SetOpts(logger, nil)
+	h.Init(nil)
+	defer teardown(t, h.config.Path, h)
+
+	key := "testKey"
+	value := &storage.Client{ID: "cl1"}
+	err := h.setKv(key, value)
+	require.NoError(t, err)
+
+	var client storage.Client
+	err = h.getKv(key, &client)
+	require.NoError(t, err)
+	require.Equal(t, "cl1", client.ID)
+
+	err = h.delKv(key)
+	require.NoError(t, err)
+
+	err = h.getKv(key, &client)
+	require.ErrorIs(t, badgerdb.ErrKeyNotFound, err)
+}
+
+func TestClientKey(t *testing.T) {
+	k := clientKey(&mqtt.Client{ID: "cl1"})
+	require.Equal(t, storage.ClientKey+"_cl1", k)
+}
+
+func TestSubscriptionKey(t *testing.T) {
+	k := subscriptionKey(&mqtt.Client{ID: "cl1"}, "a/b/c")
+	require.Equal(t, storage.SubscriptionKey+"_cl1:a/b/c", k)
+}
+
+func TestRetainedKey(t *testing.T) {
+	k := retainedKey("a/b/c")
+	require.Equal(t, storage.RetainedKey+"_a/b/c", k)
+}
+
+func TestInflightKey(t *testing.T) {
+	k := inflightKey(&mqtt.Client{ID: "cl1"}, packets.Packet{PacketID: 1})
+	require.Equal(t, storage.InflightKey+"_cl1:1", k)
+}
+
+func TestSysInfoKey(t *testing.T) {
+	require.Equal(t, storage.SysInfoKey, sysInfoKey())
+}
+
+func TestID(t *testing.T) {
+	h := new(Hook)
+	require.Equal(t, "badger-db", h.ID())
+}
+
+func TestProvides(t *testing.T) {
+	h := new(Hook)
+	require.True(t, h.Provides(mqtt.OnSessionEstablished))
+	require.True(t, h.Provides(mqtt.OnDisconnect))
+	require.True(t, h.Provides(mqtt.OnSubscribed))
+	require.True(t, h.Provides(mqtt.OnUnsubscribed))
+	require.True(t, h.Provides(mqtt.OnRetainMessage))
+	require.True(t, h.Provides(mqtt.OnQosPublish))
+	require.True(t, h.Provides(mqtt.OnQosComplete))
+	require.True(t, h.Provides(mqtt.OnQosDropped))
+	require.True(t, h.Provides(mqtt.OnSysInfoTick))
+	require.True(t, h.Provides(mqtt.StoredClients))
+	require.True(t, h.Provides(mqtt.StoredInflightMessages))
+	require.True(t, h.Provides(mqtt.StoredRetainedMessages))
+	require.True(t, h.Provides(mqtt.StoredSubscriptions))
+	require.True(t, h.Provides(mqtt.StoredSysInfo))
+	require.False(t, h.Provides(mqtt.OnACLCheck))
+	require.False(t, h.Provides(mqtt.OnConnectAuthenticate))
+}
+
+func TestInitBadConfig(t *testing.T) {
+	h := new(Hook)
+	h.SetOpts(logger, nil)
+
+	err := h.Init(map[string]any{})
+	require.Error(t, err)
+}
+
+func TestInitBadOption(t *testing.T) {
+	h := new(Hook)
+	h.SetOpts(logger, nil)
+
+	err := h.Init(&Options{
+		Options: &badgerdb.Options{
+			NumCompactors: 1,
+		},
+	})
+	// Cannot have 1 compactor. Need at least 2
+	require.Error(t, err)
+}
+
+func TestInitUseDefaults(t *testing.T) {
+	h := new(Hook)
+	h.SetOpts(logger, nil)
+	err := h.Init(nil)
+	require.NoError(t, err)
+	defer teardown(t, h.config.Path, h)
+
+	require.Equal(t, defaultDbFile, h.config.Path)
+}
+
+func TestOnSessionEstablishedThenOnDisconnect(t *testing.T) {
+	h := new(Hook)
+	h.SetOpts(logger, nil)
+	err := h.Init(nil)
+	require.NoError(t, err)
+	defer teardown(t, h.config.Path, h)
+
+	h.OnSessionEstablished(client, packets.Packet{})
+
+	r := new(storage.Client)
+	err = h.getKv(clientKey(client), r)
+	require.NoError(t, err)
+	require.Equal(t, client.ID, r.ID)
+	require.Equal(t, client.Properties.Username, r.Username)
+	require.Equal(t, client.Properties.Clean, r.Clean)
+	require.Equal(t, client.Net.Remote, r.Remote)
+	require.Equal(t, client.Net.Listener, r.Listener)
+	require.NotSame(t, client, r)
+
+	h.OnDisconnect(client, nil, false)
+	r2 := new(storage.Client)
+	err = h.getKv(clientKey(client), r2)
+	require.NoError(t, err)
+	require.Equal(t, client.ID, r.ID)
+
+	h.OnDisconnect(client, nil, true)
+	r3 := new(storage.Client)
+	err = h.getKv(clientKey(client), r3)
+	require.Error(t, err)
+	require.ErrorIs(t, badgerdb.ErrKeyNotFound, err)
+	require.Empty(t, r3.ID)
+}
+
+func TestOnClientExpired(t *testing.T) {
+	h := new(Hook)
+	h.SetOpts(logger, nil)
+	err := h.Init(nil)
+	require.NoError(t, err)
+	defer teardown(t, h.config.Path, h)
+
+	cl := &mqtt.Client{ID: "cl1"}
+	clientKey := clientKey(cl)
+
+	err = h.setKv(clientKey, &storage.Client{ID: cl.ID})
+	require.NoError(t, err)
+
+	r := new(storage.Client)
+	err = h.getKv(clientKey, r)
+
+	require.NoError(t, err)
+	require.Equal(t, cl.ID, r.ID)
+
+	h.OnClientExpired(cl)
+	err = h.getKv(clientKey, r)
+	require.Error(t, err)
+	require.ErrorIs(t, badgerdb.ErrKeyNotFound, err)
+}
+
+func TestOnClientExpiredNoDB(t *testing.T) {
+	h := new(Hook)
+	h.SetOpts(logger, nil)
+	h.OnClientExpired(client)
+}
+
+func TestOnClientExpiredClosedDB(t *testing.T) {
+	h := new(Hook)
+	h.SetOpts(logger, nil)
+	err := h.Init(nil)
+	require.NoError(t, err)
+	teardown(t, h.config.Path, h)
+	h.OnClientExpired(client)
+}
+
+func TestOnSessionEstablishedNoDB(t *testing.T) {
+	h := new(Hook)
+	h.SetOpts(logger, nil)
+	h.OnSessionEstablished(client, packets.Packet{})
+}
+
+func TestOnSessionEstablishedClosedDB(t *testing.T) {
+	h := new(Hook)
+	h.SetOpts(logger, nil)
+	err := h.Init(nil)
+	require.NoError(t, err)
+	teardown(t, h.config.Path, h)
+	h.OnSessionEstablished(client, packets.Packet{})
+}
+
+func TestOnWillSent(t *testing.T) {
+	h := new(Hook)
+	h.SetOpts(logger, nil)
+	err := h.Init(nil)
+	require.NoError(t, err)
+	defer teardown(t, h.config.Path, h)
+
+	c1 := client
+	c1.Properties.Will.Flag = 1
+	h.OnWillSent(c1, packets.Packet{})
+
+	r := new(storage.Client)
+	err = h.getKv(clientKey(client), r)
+	require.NoError(t, err)
+
+	require.Equal(t, uint32(1), r.Will.Flag)
+	require.NotSame(t, client, r)
+}
+
+func TestOnDisconnectNoDB(t *testing.T) {
+	h := new(Hook)
+	h.SetOpts(logger, nil)
+	h.OnDisconnect(client, nil, false)
+}
+
+func TestOnDisconnectClosedDB(t *testing.T) {
+	h := new(Hook)
+	h.SetOpts(logger, nil)
+	err := h.Init(nil)
+	require.NoError(t, err)
+	teardown(t, h.config.Path, h)
+	h.OnDisconnect(client, nil, false)
+}
+
+func TestOnDisconnectSessionTakenOver(t *testing.T) {
+	h := new(Hook)
+	h.SetOpts(logger, nil)
+	err := h.Init(nil)
+	require.NoError(t, err)
+
+	testClient := &mqtt.Client{
+		ID: "test",
+		Net: mqtt.ClientConnection{
+			Remote:   "test.addr",
+			Listener: "listener",
+		},
+		Properties: mqtt.ClientProperties{
+			Username: []byte("username"),
+			Clean:    false,
+		},
+	}
+
+	testClient.Stop(packets.ErrSessionTakenOver)
+	teardown(t, h.config.Path, h)
+	h.OnDisconnect(testClient, nil, true)
+}
+
+func TestOnSubscribedThenOnUnsubscribed(t *testing.T) {
+	h := new(Hook)
+	h.SetOpts(logger, nil)
+	err := h.Init(nil)
+	require.NoError(t, err)
+	defer teardown(t, h.config.Path, h)
+
+	h.OnSubscribed(client, pkf, []byte{0})
+	r := new(storage.Subscription)
+
+	err = h.getKv(subscriptionKey(client, pkf.Filters[0].Filter), r)
+	require.NoError(t, err)
+	require.Equal(t, client.ID, r.Client)
+	require.Equal(t, pkf.Filters[0].Filter, r.Filter)
+	require.Equal(t, byte(0), r.Qos)
+
+	h.OnUnsubscribed(client, pkf)
+	err = h.getKv(subscriptionKey(client, pkf.Filters[0].Filter), r)
+	require.Error(t, err)
+	require.Equal(t, badgerdb.ErrKeyNotFound, err)
+}
+
+func TestOnSubscribedNoDB(t *testing.T) {
+	h := new(Hook)
+	h.SetOpts(logger, nil)
+	h.OnSubscribed(client, pkf, []byte{0})
+}
+
+func TestOnSubscribedClosedDB(t *testing.T) {
+	h := new(Hook)
+	h.SetOpts(logger, nil)
+	err := h.Init(nil)
+	require.NoError(t, err)
+	teardown(t, h.config.Path, h)
+	h.OnSubscribed(client, pkf, []byte{0})
+}
+
+func TestOnUnsubscribedNoDB(t *testing.T) {
+	h := new(Hook)
+	h.SetOpts(logger, nil)
+	h.OnUnsubscribed(client, pkf)
+}
+
+func TestOnUnsubscribedClosedDB(t *testing.T) {
+	h := new(Hook)
+	h.SetOpts(logger, nil)
+	err := h.Init(nil)
+	require.NoError(t, err)
+	teardown(t, h.config.Path, h)
+	h.OnUnsubscribed(client, pkf)
+}
+
+func TestOnRetainMessageThenUnset(t *testing.T) {
+	h := new(Hook)
+	h.SetOpts(logger, nil)
+	err := h.Init(nil)
+	require.NoError(t, err)
+	defer teardown(t, h.config.Path, h)
+
+	pk := packets.Packet{
+		FixedHeader: packets.FixedHeader{
+			Retain: true,
+		},
+		Payload:   []byte("hello"),
+		TopicName: "a/b/c",
+	}
+
+	h.OnRetainMessage(client, pk, 1)
+
+	r := new(storage.Message)
+	err = h.getKv(retainedKey(pk.TopicName), r)
+	require.NoError(t, err)
+	require.Equal(t, pk.TopicName, r.TopicName)
+	require.Equal(t, pk.Payload, r.Payload)
+
+	h.OnRetainMessage(client, pk, -1)
+	err = h.getKv(retainedKey(pk.TopicName), r)
+	require.Error(t, err)
+	require.ErrorIs(t, err, badgerdb.ErrKeyNotFound)
+
+	// coverage: delete deleted
+	h.OnRetainMessage(client, pk, -1)
+	err = h.getKv(retainedKey(pk.TopicName), r)
+	require.Error(t, err)
+	require.ErrorIs(t, err, badgerdb.ErrKeyNotFound)
+}
+
+func TestOnRetainedExpired(t *testing.T) {
+	h := new(Hook)
+	h.SetOpts(logger, nil)
+	err := h.Init(nil)
+	require.NoError(t, err)
+	defer teardown(t, h.config.Path, h)
+
+	m := &storage.Message{
+		ID:        retainedKey("a/b/c"),
+		T:         storage.RetainedKey,
+		TopicName: "a/b/c",
+	}
+
+	err = h.setKv(m.ID, m)
+	require.NoError(t, err)
+
+	r := new(storage.Message)
+	err = h.getKv(m.ID, r)
+	require.NoError(t, err)
+	require.Equal(t, m.TopicName, r.TopicName)
+
+	h.OnRetainedExpired(m.TopicName)
+	err = h.getKv(m.ID, r)
+	require.Error(t, err)
+	require.ErrorIs(t, err, badgerdb.ErrKeyNotFound)
+}
+
+func TestOnRetainExpiredNoDB(t *testing.T) {
+	h := new(Hook)
+	h.SetOpts(logger, nil)
+	h.OnRetainedExpired("a/b/c")
+}
+
+func TestOnRetainExpiredClosedDB(t *testing.T) {
+	h := new(Hook)
+	h.SetOpts(logger, nil)
+	err := h.Init(nil)
+	require.NoError(t, err)
+	teardown(t, h.config.Path, h)
+	h.OnRetainedExpired("a/b/c")
+}
+
+func TestOnRetainMessageNoDB(t *testing.T) {
+	h := new(Hook)
+	h.SetOpts(logger, nil)
+	h.OnRetainMessage(client, packets.Packet{}, 0)
+}
+
+func TestOnRetainMessageClosedDB(t *testing.T) {
+	h := new(Hook)
+	h.SetOpts(logger, nil)
+	err := h.Init(nil)
+	require.NoError(t, err)
+	teardown(t, h.config.Path, h)
+	h.OnRetainMessage(client, packets.Packet{}, 0)
+}
+
+func TestOnQosPublishThenQOSComplete(t *testing.T) {
+	h := new(Hook)
+	h.SetOpts(logger, nil)
+	err := h.Init(nil)
+	require.NoError(t, err)
+	defer teardown(t, h.config.Path, h)
+
+	pk := packets.Packet{
+		FixedHeader: packets.FixedHeader{
+			Retain: true,
+			Qos:    2,
+		},
+		Payload:   []byte("hello"),
+		TopicName: "a/b/c",
+	}
+
+	h.OnQosPublish(client, pk, time.Now().Unix(), 0)
+
+	r := new(storage.Message)
+	err = h.getKv(inflightKey(client, pk), r)
+	require.NoError(t, err)
+	require.Equal(t, pk.TopicName, r.TopicName)
+	require.Equal(t, pk.Payload, r.Payload)
+
+	// ensure dates are properly saved
+	require.True(t, r.Sent > 0)
+	require.True(t, time.Now().Unix()-1 < r.Sent)
+
+	// OnQosDropped is a passthrough to OnQosComplete here
+	h.OnQosDropped(client, pk)
+	err = h.getKv(inflightKey(client, pk), r)
+	require.Error(t, err)
+	require.ErrorIs(t, err, badgerdb.ErrKeyNotFound)
+}
+
+func TestOnQosPublishNoDB(t *testing.T) {
+	h := new(Hook)
+	h.SetOpts(logger, nil)
+	h.OnQosPublish(client, packets.Packet{}, time.Now().Unix(), 0)
+}
+
+func TestOnQosPublishClosedDB(t *testing.T) {
+	h := new(Hook)
+	h.SetOpts(logger, nil)
+	err := h.Init(nil)
+	require.NoError(t, err)
+	teardown(t, h.config.Path, h)
+	h.OnQosPublish(client, packets.Packet{}, time.Now().Unix(), 0)
+}
+
+func TestOnQosCompleteNoDB(t *testing.T) {
+	h := new(Hook)
+	h.SetOpts(logger, nil)
+	h.OnQosComplete(client, packets.Packet{})
+}
+
+func TestOnQosCompleteClosedDB(t *testing.T) {
+	h := new(Hook)
+	h.SetOpts(logger, nil)
+	err := h.Init(nil)
+	require.NoError(t, err)
+	teardown(t, h.config.Path, h)
+	h.OnQosComplete(client, packets.Packet{})
+}
+
+func TestOnQosDroppedNoDB(t *testing.T) {
+	h := new(Hook)
+	h.SetOpts(logger, nil)
+	h.OnQosDropped(client, packets.Packet{})
+}
+
+func TestOnSysInfoTick(t *testing.T) {
+	h := new(Hook)
+	h.SetOpts(logger, nil)
+	err := h.Init(nil)
+	require.NoError(t, err)
+	defer teardown(t, h.config.Path, h)
+
+	info := &system.Info{
+		Version:       "2.0.0",
+		BytesReceived: 100,
+	}
+
+	h.OnSysInfoTick(info)
+
+	r := new(storage.SystemInfo)
+	err = h.getKv(storage.SysInfoKey, r)
+	require.NoError(t, err)
+	require.Equal(t, info.Version, r.Version)
+	require.Equal(t, info.BytesReceived, r.BytesReceived)
+	require.NotSame(t, info, r)
+}
+
+func TestOnSysInfoTickNoDB(t *testing.T) {
+	h := new(Hook)
+	h.SetOpts(logger, nil)
+	h.OnSysInfoTick(new(system.Info))
+}
+
+func TestOnSysInfoTickClosedDB(t *testing.T) {
+	h := new(Hook)
+	h.SetOpts(logger, nil)
+	err := h.Init(nil)
+	require.NoError(t, err)
+	teardown(t, h.config.Path, h)
+	h.OnSysInfoTick(new(system.Info))
+}
+
+func TestStoredClients(t *testing.T) {
+	h := new(Hook)
+	h.SetOpts(logger, nil)
+	err := h.Init(nil)
+	require.NoError(t, err)
+	defer teardown(t, h.config.Path, h)
+
+	// populate with clients
+	err = h.setKv(storage.ClientKey+"_cl1", &storage.Client{ID: "cl1", T: storage.ClientKey})
+	require.NoError(t, err)
+
+	err = h.setKv(storage.ClientKey+"_cl2", &storage.Client{ID: "cl2", T: storage.ClientKey})
+	require.NoError(t, err)
+
+	err = h.setKv(storage.ClientKey+"_cl3", &storage.Client{ID: "cl3", T: storage.ClientKey})
+	require.NoError(t, err)
+
+	r, err := h.StoredClients()
+	require.NoError(t, err)
+	require.Len(t, r, 3)
+	require.Equal(t, "cl1", r[0].ID)
+	require.Equal(t, "cl2", r[1].ID)
+	require.Equal(t, "cl3", r[2].ID)
+}
+
+func TestStoredClientsNoDB(t *testing.T) {
+	h := new(Hook)
+	h.SetOpts(logger, nil)
+	v, err := h.StoredClients()
+	require.Empty(t, v)
+	require.NoError(t, err)
+}
+
+func TestStoredSubscriptions(t *testing.T) {
+	h := new(Hook)
+	h.SetOpts(logger, nil)
+	err := h.Init(nil)
+	require.NoError(t, err)
+	defer teardown(t, h.config.Path, h)
+
+	// populate with subscriptions
+	err = h.setKv(storage.SubscriptionKey+"_sub1", &storage.Subscription{ID: "sub1", T: storage.SubscriptionKey})
+	require.NoError(t, err)
+
+	err = h.setKv(storage.SubscriptionKey+"_sub2", &storage.Subscription{ID: "sub2", T: storage.SubscriptionKey})
+	require.NoError(t, err)
+
+	err = h.setKv(storage.SubscriptionKey+"_sub3", &storage.Subscription{ID: "sub3", T: storage.SubscriptionKey})
+	require.NoError(t, err)
+
+	r, err := h.StoredSubscriptions()
+	require.NoError(t, err)
+	require.Len(t, r, 3)
+	require.Equal(t, "sub1", r[0].ID)
+	require.Equal(t, "sub2", r[1].ID)
+	require.Equal(t, "sub3", r[2].ID)
+}
+
+func TestStoredSubscriptionsNoDB(t *testing.T) {
+	h := new(Hook)
+	h.SetOpts(logger, nil)
+	v, err := h.StoredSubscriptions()
+	require.Empty(t, v)
+	require.NoError(t, err)
+}
+
+func TestStoredRetainedMessages(t *testing.T) {
+	h := new(Hook)
+	h.SetOpts(logger, nil)
+	err := h.Init(nil)
+	require.NoError(t, err)
+	defer teardown(t, h.config.Path, h)
+
+	// populate with messages
+	err = h.setKv(storage.RetainedKey+"_m1", &storage.Message{ID: "m1", T: storage.RetainedKey})
+	require.NoError(t, err)
+
+	err = h.setKv(storage.RetainedKey+"_m2", &storage.Message{ID: "m2", T: storage.RetainedKey})
+	require.NoError(t, err)
+
+	err = h.setKv(storage.RetainedKey+"_m3", &storage.Message{ID: "m3", T: storage.RetainedKey})
+	require.NoError(t, err)
+
+	err = h.setKv(storage.InflightKey+"_i3", &storage.Message{ID: "i3", T: storage.InflightKey})
+	require.NoError(t, err)
+
+	r, err := h.StoredRetainedMessages()
+	require.NoError(t, err)
+	require.Len(t, r, 3)
+	require.Equal(t, "m1", r[0].ID)
+	require.Equal(t, "m2", r[1].ID)
+	require.Equal(t, "m3", r[2].ID)
+}
+
+func TestStoredRetainedMessagesNoDB(t *testing.T) {
+	h := new(Hook)
+	h.SetOpts(logger, nil)
+	v, err := h.StoredRetainedMessages()
+	require.Empty(t, v)
+	require.NoError(t, err)
+}
+
+func TestStoredInflightMessages(t *testing.T) {
+	h := new(Hook)
+	h.SetOpts(logger, nil)
+	err := h.Init(nil)
+	require.NoError(t, err)
+	defer teardown(t, h.config.Path, h)
+
+	// populate with messages
+	err = h.setKv(storage.InflightKey+"_i1", &storage.Message{ID: "i1", T: storage.InflightKey})
+	require.NoError(t, err)
+
+	err = h.setKv(storage.InflightKey+"_i2", &storage.Message{ID: "i2", T: storage.InflightKey})
+	require.NoError(t, err)
+
+	err = h.setKv(storage.InflightKey+"_i3", &storage.Message{ID: "i3", T: storage.InflightKey})
+	require.NoError(t, err)
+
+	err = h.setKv(storage.RetainedKey+"_m1", &storage.Message{ID: "m1", T: storage.RetainedKey})
+	require.NoError(t, err)
+
+	r, err := h.StoredInflightMessages()
+	require.NoError(t, err)
+	require.Len(t, r, 3)
+	require.Equal(t, "i1", r[0].ID)
+	require.Equal(t, "i2", r[1].ID)
+	require.Equal(t, "i3", r[2].ID)
+}
+
+func TestStoredInflightMessagesNoDB(t *testing.T) {
+	h := new(Hook)
+	h.SetOpts(logger, nil)
+	v, err := h.StoredInflightMessages()
+	require.Empty(t, v)
+	require.NoError(t, err)
+}
+
+func TestStoredSysInfo(t *testing.T) {
+	h := new(Hook)
+	h.SetOpts(logger, nil)
+	err := h.Init(nil)
+	require.NoError(t, err)
+	defer teardown(t, h.config.Path, h)
+
+	// populate with messages
+	err = h.setKv(storage.SysInfoKey, &storage.SystemInfo{
+		ID: storage.SysInfoKey,
+		Info: system.Info{
+			Version: "2.0.0",
+		},
+		T: storage.SysInfoKey,
+	})
+	require.NoError(t, err)
+
+	r, err := h.StoredSysInfo()
+	require.NoError(t, err)
+	require.Equal(t, "2.0.0", r.Info.Version)
+}
+
+func TestStoredSysInfoNoDB(t *testing.T) {
+	h := new(Hook)
+	h.SetOpts(logger, nil)
+	v, err := h.StoredSysInfo()
+	require.Empty(t, v)
+	require.NoError(t, err)
+}
+
+func TestErrorf(t *testing.T) {
+	// coverage: one day check log hook
+	h := new(Hook)
+	h.SetOpts(logger, nil)
+	h.Errorf("test", 1, 2, 3)
+}
+
+func TestWarningf(t *testing.T) {
+	// coverage: one day check log hook
+	h := new(Hook)
+	h.SetOpts(logger, nil)
+	h.Warningf("test", 1, 2, 3)
+}
+
+func TestInfof(t *testing.T) {
+	// coverage: one day check log hook
+	h := new(Hook)
+	h.SetOpts(logger, nil)
+	h.Infof("test", 1, 2, 3)
+}
+
+func TestDebugf(t *testing.T) {
+	// coverage: one day check log hook
+	h := new(Hook)
+	h.SetOpts(logger, nil)
+	h.Debugf("test", 1, 2, 3)
+}
+
+func TestGcLoop(t *testing.T) {
+	h := new(Hook)
+	h.SetOpts(logger, nil)
+	opts := badgerdb.DefaultOptions(defaultDbFile)
+	opts.ValueLogFileSize = 1 << 20
+	h.Init(&Options{
+		GcInterval: 2, // Set the interval for garbage collection.
+		Options:    &opts,
+	})
+	defer teardown(t, defaultDbFile, h)
+	h.OnSessionEstablished(client, packets.Packet{})
+	h.OnDisconnect(client, nil, true)
+	time.Sleep(3 * time.Second)
+}
+
+func TestGetSetDelKv(t *testing.T) {
+	h := new(Hook)
+	h.SetOpts(logger, nil)
+	err := h.Init(nil)
+	defer teardown(t, h.config.Path, h)
+	require.NoError(t, err)
+
+	err = h.setKv("testKey", &storage.Client{ID: "testId"})
+	require.NoError(t, err)
+
+	var obj storage.Client
+	err = h.getKv("testKey", &obj)
+	require.NoError(t, err)
+
+	err = h.delKv("testKey")
+	require.NoError(t, err)
+
+	err = h.getKv("testKey", &obj)
+	require.Error(t, err)
+	require.ErrorIs(t, badgerdb.ErrKeyNotFound, err)
+}
+
+func TestIterKv(t *testing.T) {
+	h := new(Hook)
+	h.SetOpts(logger, nil)
+
+	err := h.Init(nil)
+	defer teardown(t, h.config.Path, h)
+	require.NoError(t, err)
+
+	h.setKv("prefix_a_1", &storage.Client{ID: "1"})
+	h.setKv("prefix_a_2", &storage.Client{ID: "2"})
+	h.setKv("prefix_b_2", &storage.Client{ID: "3"})
+
+	var clients []storage.Client
+	err = h.iterKv("prefix_a", func(data []byte) error {
+		var item storage.Client
+		item.UnmarshalBinary(data)
+		clients = append(clients, item)
+		return nil
+	})
+	require.Equal(t, 2, len(clients))
+	require.NoError(t, err)
+
+	visitErr := errors.New("iter visit error")
+	err = h.iterKv("prefix_b", func(data []byte) error {
+		return visitErr
+	})
+	require.ErrorIs(t, visitErr, err)
+}