commit c65fec6a6cda564934a93e91bbb46dbd83445720
Author: Janos Dobronszki <dobronszki@gmail.com>
Date:   Tue Apr 7 13:53:22 2020 +0200

    Disk backed local store (#1491)

diff --git a/file.go b/file.go
new file mode 100644
index 0000000..2c6b609
--- /dev/null
+++ b/file.go
@@ -0,0 +1,351 @@
+// Package local is a file system backed store
+package file
+
+import (
+	"encoding/json"
+	"fmt"
+	"os"
+	"path/filepath"
+	"sort"
+	"strings"
+	"time"
+
+	"github.com/micro/go-micro/v2/store"
+	micro_store "github.com/micro/go-micro/v2/store"
+	bolt "go.etcd.io/bbolt"
+
+	"github.com/pkg/errors"
+)
+
+// NewStore returns a memory store
+func NewStore(opts ...store.Option) store.Store {
+	s := &fileStore{
+		options: store.Options{},
+	}
+	for _, o := range opts {
+		o(&s.options)
+	}
+	return s
+}
+
+type fileStore struct {
+	options      store.Options
+	dir          string
+	fileName     string
+	fullFilePath string
+}
+
+func (m *fileStore) Init(opts ...store.Option) error {
+	// m.store.Flush()
+	for _, o := range opts {
+		o(&m.options)
+	}
+	if m.options.Database == "" {
+		m.options.Database = "default"
+	}
+	if m.options.Table == "" {
+		// bbolt requires bucketname to not be empty
+		m.options.Table = "default"
+	}
+	dir := filepath.Join(os.TempDir(), "micro")
+	fname := m.options.Database + ".db"
+	_ = os.Mkdir(dir, 0700)
+	m.dir = dir
+	m.fileName = fname
+	m.fullFilePath = filepath.Join(dir, fname)
+	return nil
+}
+
+func (m *fileStore) String() string {
+	return "local"
+}
+
+func (m *fileStore) Read(key string, opts ...store.ReadOption) ([]*store.Record, error) {
+	readOpts := store.ReadOptions{}
+	for _, o := range opts {
+		o(&readOpts)
+	}
+
+	var keys []string
+
+	// Handle Prefix / suffix
+	if readOpts.Prefix || readOpts.Suffix {
+		var opts []store.ListOption
+		if readOpts.Prefix {
+			opts = append(opts, store.ListPrefix(key))
+		}
+		if readOpts.Suffix {
+			opts = append(opts, store.ListSuffix(key))
+		}
+		opts = append(opts, store.ListLimit(readOpts.Limit))
+		opts = append(opts, store.ListOffset(readOpts.Offset))
+		k, err := m.List(opts...)
+		if err != nil {
+			return nil, errors.Wrap(err, "FileStore: Read couldn't List()")
+		}
+		keys = k
+	} else {
+		keys = []string{key}
+	}
+
+	var results []*store.Record
+	for _, k := range keys {
+		r, err := m.get(k)
+		if err != nil {
+			return results, err
+		}
+		results = append(results, r)
+	}
+	return results, nil
+}
+
+func (m *fileStore) get(k string) (*store.Record, error) {
+	if len(m.options.Table) > 0 {
+		k = m.options.Table + "/" + k
+	}
+	if len(m.options.Database) > 0 {
+		k = m.options.Database + "/" + k
+	}
+	store, err := bolt.Open(m.fullFilePath, 0700, &bolt.Options{Timeout: 1 * time.Second})
+	if err != nil {
+		return nil, err
+	}
+	defer store.Close()
+	err = store.Update(func(tx *bolt.Tx) error {
+		_, err := tx.CreateBucketIfNotExists([]byte(m.options.Table))
+		if err != nil {
+			return err
+		}
+		return nil
+	})
+	if err != nil {
+		return nil, err
+	}
+	var value []byte
+	store.View(func(tx *bolt.Tx) error {
+		// @todo this is still very experimental...
+		bucket := tx.Bucket([]byte(m.options.Table))
+		value = bucket.Get([]byte(k))
+		return nil
+	})
+	if value == nil {
+		return nil, micro_store.ErrNotFound
+	}
+	storedRecord := &internalRecord{}
+	err = json.Unmarshal(value, storedRecord)
+	if err != nil {
+		return nil, err
+	}
+	newRecord := &micro_store.Record{}
+	newRecord.Key = storedRecord.Key
+	newRecord.Value = storedRecord.Value
+	if !storedRecord.ExpiresAt.IsZero() {
+		if storedRecord.ExpiresAt.Before(time.Now()) {
+			return nil, micro_store.ErrNotFound
+		}
+		newRecord.Expiry = time.Until(storedRecord.ExpiresAt)
+	}
+
+	return newRecord, nil
+}
+
+func (m *fileStore) Write(r *store.Record, opts ...store.WriteOption) error {
+	writeOpts := store.WriteOptions{}
+	for _, o := range opts {
+		o(&writeOpts)
+	}
+
+	if len(opts) > 0 {
+		// Copy the record before applying options, or the incoming record will be mutated
+		newRecord := store.Record{}
+		newRecord.Key = r.Key
+		newRecord.Value = r.Value
+		newRecord.Expiry = r.Expiry
+
+		if !writeOpts.Expiry.IsZero() {
+			newRecord.Expiry = time.Until(writeOpts.Expiry)
+		}
+		if writeOpts.TTL != 0 {
+			newRecord.Expiry = writeOpts.TTL
+		}
+		return m.set(&newRecord)
+	}
+	return m.set(r)
+}
+
+func (m *fileStore) set(r *store.Record) error {
+	key := r.Key
+	if len(m.options.Table) > 0 {
+		key = m.options.Table + "/" + key
+	}
+	if len(m.options.Database) > 0 {
+		key = m.options.Database + "/" + key
+	}
+
+	// copy the incoming record and then
+	// convert the expiry in to a hard timestamp
+	i := &internalRecord{}
+	i.Key = r.Key
+	i.Value = r.Value
+	if r.Expiry != 0 {
+		i.ExpiresAt = time.Now().Add(r.Expiry)
+	}
+
+	iJSON, _ := json.Marshal(i)
+
+	store, err := bolt.Open(m.fullFilePath, 0700, &bolt.Options{Timeout: 1 * time.Second})
+	if err != nil {
+		return err
+	}
+	defer store.Close()
+	return store.Update(func(tx *bolt.Tx) error {
+		b := tx.Bucket([]byte(m.options.Table))
+		if b == nil {
+			var err error
+			b, err = tx.CreateBucketIfNotExists([]byte(m.options.Table))
+			if err != nil {
+				return err
+			}
+		}
+		return b.Put([]byte(key), iJSON)
+	})
+}
+
+func (m *fileStore) Delete(key string, opts ...store.DeleteOption) error {
+	deleteOptions := store.DeleteOptions{}
+	for _, o := range opts {
+		o(&deleteOptions)
+	}
+	return m.delete(key)
+}
+
+func (m *fileStore) delete(key string) error {
+	if len(m.options.Table) > 0 {
+		key = m.options.Table + "/" + key
+	}
+	if len(m.options.Database) > 0 {
+		key = m.options.Database + "/" + key
+	}
+	store, err := bolt.Open(m.fullFilePath, 0700, &bolt.Options{Timeout: 1 * time.Second})
+	if err != nil {
+		return err
+	}
+	defer store.Close()
+	return store.Update(func(tx *bolt.Tx) error {
+		b := tx.Bucket([]byte(m.options.Table))
+		if b == nil {
+			var err error
+			b, err = tx.CreateBucketIfNotExists([]byte(m.options.Table))
+			if err != nil {
+				return err
+			}
+		}
+		err := b.Delete([]byte(key))
+		return err
+	})
+}
+
+func (m *fileStore) deleteAll() error {
+	return os.Remove(m.fullFilePath)
+}
+
+func (m *fileStore) Options() store.Options {
+	return m.options
+}
+
+func (m *fileStore) List(opts ...store.ListOption) ([]string, error) {
+	listOptions := store.ListOptions{}
+
+	for _, o := range opts {
+		o(&listOptions)
+	}
+	allKeys := m.list(listOptions.Limit, listOptions.Offset)
+
+	if len(listOptions.Prefix) > 0 {
+		var prefixKeys []string
+		for _, k := range allKeys {
+			if strings.HasPrefix(k, listOptions.Prefix) {
+				prefixKeys = append(prefixKeys, k)
+			}
+		}
+		allKeys = prefixKeys
+	}
+	if len(listOptions.Suffix) > 0 {
+		var suffixKeys []string
+		for _, k := range allKeys {
+			if strings.HasSuffix(k, listOptions.Suffix) {
+				suffixKeys = append(suffixKeys, k)
+			}
+		}
+		allKeys = suffixKeys
+	}
+
+	return allKeys, nil
+}
+
+func (m *fileStore) list(limit, offset uint) []string {
+	allItems := []string{}
+	store, err := bolt.Open(m.fullFilePath, 0700, &bolt.Options{Timeout: 1 * time.Second})
+	if err != nil {
+		fmt.Println("Error creating file:", err)
+	}
+	defer store.Close()
+	store.Update(func(tx *bolt.Tx) error {
+		b := tx.Bucket([]byte(m.options.Table))
+		if b == nil {
+			var err error
+			b, err = tx.CreateBucketIfNotExists([]byte(m.options.Table))
+			if err != nil {
+				return err
+			}
+		}
+		// @todo very inefficient
+		if err := b.ForEach(func(k, v []byte) error {
+			storedRecord := &internalRecord{}
+			err := json.Unmarshal(v, storedRecord)
+			if err != nil {
+				return err
+			}
+			if !storedRecord.ExpiresAt.IsZero() {
+				if storedRecord.ExpiresAt.Before(time.Now()) {
+					return nil
+				}
+			}
+			allItems = append(allItems, string(k))
+			return nil
+		}); err != nil {
+			return err
+		}
+
+		return nil
+	})
+	allKeys := make([]string, len(allItems))
+	i := 0
+	for _, k := range allItems {
+		if len(m.options.Database) > 0 {
+			k = strings.TrimPrefix(k, m.options.Database+"/")
+		}
+		if len(m.options.Table) > 0 {
+			k = strings.TrimPrefix(k, m.options.Table+"/")
+		}
+		allKeys[i] = k
+		i++
+	}
+	if limit != 0 || offset != 0 {
+		sort.Slice(allKeys, func(i, j int) bool { return allKeys[i] < allKeys[j] })
+		min := func(i, j uint) uint {
+			if i < j {
+				return i
+			}
+			return j
+		}
+		return allKeys[offset:min(limit, uint(len(allKeys)))]
+	}
+	return allKeys
+}
+
+type internalRecord struct {
+	Key       string
+	Value     []byte
+	ExpiresAt time.Time
+}
diff --git a/file_test.go b/file_test.go
new file mode 100644
index 0000000..26a20cd
--- /dev/null
+++ b/file_test.go
@@ -0,0 +1,281 @@
+package file
+
+import (
+	"fmt"
+	"testing"
+	"time"
+
+	"github.com/davecgh/go-spew/spew"
+	"github.com/kr/pretty"
+	"github.com/micro/go-micro/v2/store"
+)
+
+func TestFileReInit(t *testing.T) {
+	s := NewStore(store.Table("aaa"))
+	s.Init(store.Table("bbb"))
+	if s.Options().Table != "bbb" {
+		t.Error("Init didn't reinitialise the store")
+	}
+}
+
+func TestFileBasic(t *testing.T) {
+	s := NewStore()
+	s.Init()
+	if err := s.(*fileStore).deleteAll(); err != nil {
+		t.Logf("Can't delete all: %v", err)
+	}
+	basictest(s, t)
+}
+
+func TestFileTable(t *testing.T) {
+	s := NewStore()
+	s.Init(store.Table("some-Table"))
+	if err := s.(*fileStore).deleteAll(); err != nil {
+		t.Logf("Can't delete all: %v", err)
+	}
+	basictest(s, t)
+}
+
+func TestFileDatabase(t *testing.T) {
+	s := NewStore()
+	s.Init(store.Database("some-Database"))
+	if err := s.(*fileStore).deleteAll(); err != nil {
+		t.Logf("Can't delete all: %v", err)
+	}
+	basictest(s, t)
+}
+
+func TestFileDatabaseTable(t *testing.T) {
+	s := NewStore()
+	s.Init(store.Table("some-Table"), store.Database("some-Database"))
+	if err := s.(*fileStore).deleteAll(); err != nil {
+		t.Logf("Can't delete all: %v", err)
+	}
+	basictest(s, t)
+}
+
+func basictest(s store.Store, t *testing.T) {
+	t.Logf("Testing store %s, with options %# v\n", s.String(), pretty.Formatter(s.Options()))
+	// Read and Write an expiring Record
+	if err := s.Write(&store.Record{
+		Key:    "Hello",
+		Value:  []byte("World"),
+		Expiry: time.Millisecond * 100,
+	}); err != nil {
+		t.Error(err)
+	}
+	if r, err := s.Read("Hello"); err != nil {
+		t.Error(err)
+	} else {
+		if len(r) != 1 {
+			t.Error("Read returned multiple records")
+		}
+		if r[0].Key != "Hello" {
+			t.Errorf("Expected %s, got %s", "Hello", r[0].Key)
+		}
+		if string(r[0].Value) != "World" {
+			t.Errorf("Expected %s, got %s", "World", r[0].Value)
+		}
+	}
+	time.Sleep(time.Millisecond * 200)
+	if _, err := s.Read("Hello"); err != store.ErrNotFound {
+		t.Errorf("Expected %# v, got %# v", store.ErrNotFound, err)
+	}
+
+	// Write 3 records with various expiry and get with Table
+	records := []*store.Record{
+		&store.Record{
+			Key:   "foo",
+			Value: []byte("foofoo"),
+		},
+		&store.Record{
+			Key:    "foobar",
+			Value:  []byte("foobarfoobar"),
+			Expiry: time.Millisecond * 100,
+		},
+		&store.Record{
+			Key:    "foobarbaz",
+			Value:  []byte("foobarbazfoobarbaz"),
+			Expiry: 2 * time.Millisecond * 100,
+		},
+	}
+	for _, r := range records {
+		if err := s.Write(r); err != nil {
+			t.Errorf("Couldn't write k: %s, v: %# v (%s)", r.Key, pretty.Formatter(r.Value), err)
+		}
+	}
+	if results, err := s.Read("foo", store.ReadPrefix()); err != nil {
+		t.Errorf("Couldn't read all \"foo\" keys, got %# v (%s)", spew.Sdump(results), err)
+	} else {
+		if len(results) != 3 {
+			t.Errorf("Expected 3 items, got %d", len(results))
+			t.Logf("Table test: %v\n", spew.Sdump(results))
+		}
+	}
+	time.Sleep(time.Millisecond * 100)
+	if results, err := s.Read("foo", store.ReadPrefix()); err != nil {
+		t.Errorf("Couldn't read all \"foo\" keys, got %# v (%s)", spew.Sdump(results), err)
+	} else {
+		if len(results) != 2 {
+			t.Errorf("Expected 2 items, got %d", len(results))
+			t.Logf("Table test: %v\n", spew.Sdump(results))
+		}
+	}
+	time.Sleep(time.Millisecond * 100)
+	if results, err := s.Read("foo", store.ReadPrefix()); err != nil {
+		t.Errorf("Couldn't read all \"foo\" keys, got %# v (%s)", spew.Sdump(results), err)
+	} else {
+		if len(results) != 1 {
+			t.Errorf("Expected 1 item, got %d", len(results))
+			t.Logf("Table test: %# v\n", spew.Sdump(results))
+		}
+	}
+	if err := s.Delete("foo", func(d *store.DeleteOptions) {}); err != nil {
+		t.Errorf("Delete failed (%v)", err)
+	}
+	if results, err := s.Read("foo", store.ReadPrefix()); err != nil {
+		t.Errorf("Couldn't read all \"foo\" keys, got %# v (%s)", spew.Sdump(results), err)
+	} else {
+		if len(results) != 0 {
+			t.Errorf("Expected 0 items, got %d (%# v)", len(results), spew.Sdump(results))
+		}
+	}
+
+	// Write 3 records with various expiry and get with Suffix
+	records = []*store.Record{
+		&store.Record{
+			Key:   "foo",
+			Value: []byte("foofoo"),
+		},
+		&store.Record{
+			Key:    "barfoo",
+			Value:  []byte("barfoobarfoo"),
+			Expiry: time.Millisecond * 100,
+		},
+		&store.Record{
+			Key:    "bazbarfoo",
+			Value:  []byte("bazbarfoobazbarfoo"),
+			Expiry: 2 * time.Millisecond * 100,
+		},
+	}
+	for _, r := range records {
+		if err := s.Write(r); err != nil {
+			t.Errorf("Couldn't write k: %s, v: %# v (%s)", r.Key, pretty.Formatter(r.Value), err)
+		}
+	}
+	if results, err := s.Read("foo", store.ReadSuffix()); err != nil {
+		t.Errorf("Couldn't read all \"foo\" keys, got %# v (%s)", spew.Sdump(results), err)
+	} else {
+		if len(results) != 3 {
+			t.Errorf("Expected 3 items, got %d", len(results))
+			t.Logf("Table test: %v\n", spew.Sdump(results))
+		}
+
+	}
+	time.Sleep(time.Millisecond * 100)
+	if results, err := s.Read("foo", store.ReadSuffix()); err != nil {
+		t.Errorf("Couldn't read all \"foo\" keys, got %# v (%s)", spew.Sdump(results), err)
+	} else {
+		if len(results) != 2 {
+			t.Errorf("Expected 2 items, got %d", len(results))
+			t.Logf("Table test: %v\n", spew.Sdump(results))
+		}
+
+	}
+	time.Sleep(time.Millisecond * 100)
+	if results, err := s.Read("foo", store.ReadSuffix()); err != nil {
+		t.Errorf("Couldn't read all \"foo\" keys, got %# v (%s)", spew.Sdump(results), err)
+	} else {
+		if len(results) != 1 {
+			t.Errorf("Expected 1 item, got %d", len(results))
+			t.Logf("Table test: %# v\n", spew.Sdump(results))
+		}
+	}
+	if err := s.Delete("foo"); err != nil {
+		t.Errorf("Delete failed (%v)", err)
+	}
+	if results, err := s.Read("foo", store.ReadSuffix()); err != nil {
+		t.Errorf("Couldn't read all \"foo\" keys, got %# v (%s)", spew.Sdump(results), err)
+	} else {
+		if len(results) != 0 {
+			t.Errorf("Expected 0 items, got %d (%# v)", len(results), spew.Sdump(results))
+		}
+	}
+
+	// Test Table, Suffix and WriteOptions
+	if err := s.Write(&store.Record{
+		Key:   "foofoobarbar",
+		Value: []byte("something"),
+	}, store.WriteTTL(time.Millisecond*100)); err != nil {
+		t.Error(err)
+	}
+	if err := s.Write(&store.Record{
+		Key:   "foofoo",
+		Value: []byte("something"),
+	}, store.WriteExpiry(time.Now().Add(time.Millisecond*100))); err != nil {
+		t.Error(err)
+	}
+	if err := s.Write(&store.Record{
+		Key:   "barbar",
+		Value: []byte("something"),
+		// TTL has higher precedence than expiry
+	}, store.WriteExpiry(time.Now().Add(time.Hour)), store.WriteTTL(time.Millisecond*100)); err != nil {
+		t.Error(err)
+	}
+	if results, err := s.Read("foo", store.ReadPrefix(), store.ReadSuffix()); err != nil {
+		t.Error(err)
+	} else {
+		if len(results) != 1 {
+			t.Errorf("Expected 1 results, got %d: %# v", len(results), spew.Sdump(results))
+		}
+	}
+	time.Sleep(time.Millisecond * 100)
+	if results, err := s.List(); err != nil {
+		t.Errorf("List failed: %s", err)
+	} else {
+		if len(results) != 0 {
+			t.Errorf("Expiry options were not effective, results :%v", spew.Sdump(results))
+		}
+	}
+	s.Write(&store.Record{Key: "a", Value: []byte("a")})
+	s.Write(&store.Record{Key: "aa", Value: []byte("aa")})
+	s.Write(&store.Record{Key: "aaa", Value: []byte("aaa")})
+	if results, err := s.Read("b", store.ReadPrefix()); err != nil {
+		t.Error(err)
+	} else {
+		if len(results) != 0 {
+			t.Errorf("Expected 0 results, got %d", len(results))
+		}
+	}
+
+	s.Init()
+	if err := s.(*fileStore).deleteAll(); err != nil {
+		t.Logf("Can't delete all: %v", err)
+	}
+	for i := 0; i < 10; i++ {
+		s.Write(&store.Record{
+			Key:   fmt.Sprintf("a%d", i),
+			Value: []byte{},
+		})
+	}
+	if results, err := s.Read("a", store.ReadLimit(5), store.ReadPrefix()); err != nil {
+		t.Error(err)
+	} else {
+		if len(results) != 5 {
+			t.Error("Expected 5 results, got ", len(results))
+		}
+		if results[0].Key != "a0" {
+			t.Errorf("Expected a0, got %s", results[0].Key)
+		}
+		if results[4].Key != "a4" {
+			t.Errorf("Expected a4, got %s", results[4].Key)
+		}
+	}
+	if results, err := s.Read("a", store.ReadLimit(30), store.ReadOffset(5), store.ReadPrefix()); err != nil {
+		t.Error(err)
+	} else {
+		if len(results) != 5 {
+			t.Error("Expected 5 results, got ", len(results))
+		}
+	}
+}