5 files changed, 629 insertions, 0 deletions
diff --git a/weed/filer/arangodb/arangodb_store.go b/weed/filer/arangodb/arangodb_store.go
new file mode 100644
index 000000000..9fd1fffb3
--- /dev/null
+++ b/weed/filer/arangodb/arangodb_store.go
@@ -0,0 +1,347 @@
+package arangodb
+
+import (
+	"context"
+	"crypto/tls"
+	"fmt"
+	"strconv"
+	"strings"
+	"sync"
+	"time"
+
+	"github.com/arangodb/go-driver"
+	"github.com/arangodb/go-driver/http"
+	"github.com/chrislusf/seaweedfs/weed/filer"
+	"github.com/chrislusf/seaweedfs/weed/glog"
+	"github.com/chrislusf/seaweedfs/weed/pb/filer_pb"
+	"github.com/chrislusf/seaweedfs/weed/util"
+)
+
+func init() {
+	filer.Stores = append(filer.Stores, &ArangodbStore{})
+}
+
+var (
+	BUCKET_PREFIX      = "/buckets"
+	DEFAULT_COLLECTION = "seaweed_no_bucket"
+	KVMETA_COLLECTION  = "seaweed_kvmeta"
+)
+
+type ArangodbStore struct {
+	connect      driver.Connection
+	client       driver.Client
+	database     driver.Database
+	kvCollection driver.Collection
+
+	buckets map[string]driver.Collection
+	mu      sync.RWMutex
+
+	databaseName string
+}
+
+type Model struct {
+	Key       string `json:"_key"`
+	Directory string `json:"directory,omitempty"`
+	Name      string `json:"name,omitempty"`
+	Ttl       string `json:"ttl,omitempty"`
+
+	//arangodb does not support binary blobs
+	//we encode byte slice into uint64 slice
+	//see helpers.go
+	Meta []uint64 `json:"meta"`
+}
+
+func (store *ArangodbStore) GetName() string {
+	return "arangodb"
+}
+
+func (store *ArangodbStore) Initialize(configuration util.Configuration, prefix string) (err error) {
+	store.buckets = make(map[string]driver.Collection, 3)
+	store.databaseName = configuration.GetString(prefix + "db_name")
+	return store.connection(configuration.GetStringSlice(prefix+"servers"),
+		configuration.GetString(prefix+"username"),
+		configuration.GetString(prefix+"password"),
+		configuration.GetBool(prefix+"insecure_skip_verify"),
+	)
+}
+
+func (store *ArangodbStore) connection(uris []string, user string, pass string, insecure bool) (err error) {
+	ctx, _ := context.WithTimeout(context.Background(), 10*time.Second)
+
+	store.connect, err = http.NewConnection(http.ConnectionConfig{
+		Endpoints: uris,
+		TLSConfig: &tls.Config{
+			InsecureSkipVerify: insecure,
+		},
+	})
+	if err != nil {
+		return err
+	}
+	store.client, err = driver.NewClient(driver.ClientConfig{
+		Connection:     store.connect,
+		Authentication: driver.BasicAuthentication(user, pass),
+	})
+	if err != nil {
+		return err
+	}
+	ok, err := store.client.DatabaseExists(ctx, store.databaseName)
+	if err != nil {
+		return err
+	}
+	if ok {
+		store.database, err = store.client.Database(ctx, store.databaseName)
+	} else {
+		store.database, err = store.client.CreateDatabase(ctx, store.databaseName, &driver.CreateDatabaseOptions{})
+	}
+	if err != nil {
+		return err
+	}
+	if store.kvCollection, err = store.ensureCollection(ctx, KVMETA_COLLECTION); err != nil {
+		return err
+	}
+	return err
+}
+
+type key int
+
+const (
+	transactionKey key = 0
+)
+
+func (store *ArangodbStore) BeginTransaction(ctx context.Context) (context.Context, error) {
+	keys := make([]string, 0, len(store.buckets)+1)
+	for k := range store.buckets {
+		keys = append(keys, k)
+	}
+	keys = append(keys, store.kvCollection.Name())
+	txn, err := store.database.BeginTransaction(ctx, driver.TransactionCollections{
+		Exclusive: keys,
+	}, &driver.BeginTransactionOptions{})
+	if err != nil {
+		return nil, err
+	}
+
+	return context.WithValue(ctx, transactionKey, txn), nil
+}
+
+func (store *ArangodbStore) CommitTransaction(ctx context.Context) error {
+	val := ctx.Value(transactionKey)
+	cast, ok := val.(driver.TransactionID)
+	if !ok {
+		return fmt.Errorf("txn cast fail %s:", val)
+	}
+	err := store.database.CommitTransaction(ctx, cast, &driver.CommitTransactionOptions{})
+	if err != nil {
+		return err
+	}
+	return nil
+}
+
+func (store *ArangodbStore) RollbackTransaction(ctx context.Context) error {
+	val := ctx.Value(transactionKey)
+	cast, ok := val.(driver.TransactionID)
+	if !ok {
+		return fmt.Errorf("txn cast fail %s:", val)
+	}
+	err := store.database.AbortTransaction(ctx, cast, &driver.AbortTransactionOptions{})
+	if err != nil {
+		return err
+	}
+	return nil
+}
+
+func (store *ArangodbStore) InsertEntry(ctx context.Context, entry *filer.Entry) (err error) {
+	dir, name := entry.FullPath.DirAndName()
+	meta, err := entry.EncodeAttributesAndChunks()
+	if err != nil {
+		return fmt.Errorf("encode %s: %s", entry.FullPath, err)
+	}
+
+	if len(entry.Chunks) > 50 {
+		meta = util.MaybeGzipData(meta)
+	}
+	model := &Model{
+		Key:       hashString(string(entry.FullPath)),
+		Directory: dir,
+		Name:      name,
+		Meta:      bytesToArray(meta),
+	}
+	if entry.TtlSec > 0 {
+		model.Ttl = time.Now().Add(time.Second * time.Duration(entry.TtlSec)).Format(time.RFC3339)
+	} else {
+		model.Ttl = ""
+	}
+
+	targetCollection, err := store.extractBucketCollection(ctx, entry.FullPath)
+	if err != nil {
+		return err
+	}
+	_, err = targetCollection.CreateDocument(ctx, model)
+	if driver.IsConflict(err) {
+		return store.UpdateEntry(ctx, entry)
+	}
+
+	if err != nil {
+		return fmt.Errorf("InsertEntry %s: %v", entry.FullPath, err)
+	}
+
+	return nil
+
+}
+
+func (store *ArangodbStore) UpdateEntry(ctx context.Context, entry *filer.Entry) (err error) {
+	dir, name := entry.FullPath.DirAndName()
+	meta, err := entry.EncodeAttributesAndChunks()
+	if err != nil {
+		return fmt.Errorf("encode %s: %s", entry.FullPath, err)
+	}
+
+	if len(entry.Chunks) > 50 {
+		meta = util.MaybeGzipData(meta)
+	}
+	model := &Model{
+		Key:       hashString(string(entry.FullPath)),
+		Directory: dir,
+		Name:      name,
+		Meta:      bytesToArray(meta),
+	}
+	if entry.TtlSec > 0 {
+		model.Ttl = time.Now().Add(time.Duration(entry.TtlSec) * time.Second).Format(time.RFC3339)
+	} else {
+		model.Ttl = "none"
+	}
+	targetCollection, err := store.extractBucketCollection(ctx, entry.FullPath)
+	if err != nil {
+		return err
+	}
+	_, err = targetCollection.UpdateDocument(ctx, model.Key, model)
+	if err != nil {
+		return fmt.Errorf("UpdateEntry %s: %v", entry.FullPath, err)
+	}
+
+	return nil
+}
+
+func (store *ArangodbStore) FindEntry(ctx context.Context, fullpath util.FullPath) (entry *filer.Entry, err error) {
+	var data Model
+	targetCollection, err := store.extractBucketCollection(ctx, fullpath)
+	if err != nil {
+		return nil, err
+	}
+	_, err = targetCollection.ReadDocument(ctx, hashString(string(fullpath)), &data)
+	if err != nil {
+		if driver.IsNotFound(err) {
+			return nil, filer_pb.ErrNotFound
+		}
+		glog.Errorf("find %s: %v", fullpath, err)
+		return nil, filer_pb.ErrNotFound
+	}
+	if len(data.Meta) == 0 {
+		return nil, filer_pb.ErrNotFound
+	}
+	entry = &filer.Entry{
+		FullPath: fullpath,
+	}
+	err = entry.DecodeAttributesAndChunks(util.MaybeDecompressData(arrayToBytes(data.Meta)))
+	if err != nil {
+		return entry, fmt.Errorf("decode %s : %v", entry.FullPath, err)
+	}
+
+	return entry, nil
+}
+
+func (store *ArangodbStore) DeleteEntry(ctx context.Context, fullpath util.FullPath) (err error) {
+	targetCollection, err := store.extractBucketCollection(ctx, fullpath)
+	if err != nil {
+		return err
+	}
+	_, err = targetCollection.RemoveDocument(ctx, hashString(string(fullpath)))
+	if err != nil && !driver.IsNotFound(err) {
+		glog.Errorf("find %s: %v", fullpath, err)
+		return fmt.Errorf("delete %s : %v", fullpath, err)
+	}
+	return nil
+}
+
+// this runs in log time
+func (store *ArangodbStore) DeleteFolderChildren(ctx context.Context, fullpath util.FullPath) (err error) {
+	var query string
+	targetCollection, err := store.extractBucketCollection(ctx, fullpath)
+	if err != nil {
+		return err
+	}
+	query = query + fmt.Sprintf(`
+	for d in %s
+	filter starts_with(d.directory, "%s/")  || d.directory == "%s"
+	remove d._key in %s`,
+		targetCollection.Name(),
+		strings.Join(strings.Split(string(fullpath), "/"), ","),
+		string(fullpath),
+		targetCollection.Name(),
+	)
+	cur, err := store.database.Query(ctx, query, nil)
+	if err != nil {
+		return fmt.Errorf("delete %s : %v", fullpath, err)
+	}
+	defer cur.Close()
+	return nil
+}
+
+func (store *ArangodbStore) ListDirectoryEntries(ctx context.Context, dirPath util.FullPath, startFileName string, includeStartFile bool, limit int64, eachEntryFunc filer.ListEachEntryFunc) (lastFileName string, err error) {
+	return store.ListDirectoryPrefixedEntries(ctx, dirPath, startFileName, includeStartFile, limit, "", eachEntryFunc)
+}
+
+func (store *ArangodbStore) ListDirectoryPrefixedEntries(ctx context.Context, dirPath util.FullPath, startFileName string, includeStartFile bool, limit int64, prefix string, eachEntryFunc filer.ListEachEntryFunc) (lastFileName string, err error) {
+	targetCollection, err := store.extractBucketCollection(ctx, dirPath+"/")
+	if err != nil {
+		return lastFileName, err
+	}
+	query := "for d in " + targetCollection.Name()
+	if includeStartFile {
+		query = query + " filter d.name >= \"" + startFileName + "\" "
+	} else {
+		query = query + " filter d.name > \"" + startFileName + "\" "
+	}
+	if prefix != "" {
+		query = query + fmt.Sprintf(`&& starts_with(d.name, "%s")`, prefix)
+	}
+	query = query + `
+filter d.directory == @dir
+sort d.name asc
+`
+	if limit > 0 {
+		query = query + "limit " + strconv.Itoa(int(limit))
+	}
+	query = query + "\n return d"
+	cur, err := store.database.Query(ctx, query, map[string]interface{}{"dir": dirPath})
+	if err != nil {
+		return lastFileName, fmt.Errorf("failed to list directory entries: find error: %w", err)
+	}
+	defer cur.Close()
+	for cur.HasMore() {
+		var data Model
+		_, err = cur.ReadDocument(ctx, &data)
+		if err != nil {
+			break
+		}
+		entry := &filer.Entry{
+			FullPath: util.NewFullPath(data.Directory, data.Name),
+		}
+		lastFileName = data.Name
+		converted := arrayToBytes(data.Meta)
+		if decodeErr := entry.DecodeAttributesAndChunks(util.MaybeDecompressData(converted)); decodeErr != nil {
+			err = decodeErr
+			glog.V(0).Infof("list %s : %v", entry.FullPath, err)
+			break
+		}
+
+		if !eachEntryFunc(entry) {
+			break
+		}
+
+	}
+	return lastFileName, err
+}
+
+func (store *ArangodbStore) Shutdown() {
+}
diff --git a/weed/filer/arangodb/arangodb_store_bucket.go b/weed/filer/arangodb/arangodb_store_bucket.go
new file mode 100644
index 000000000..810d639a7
--- /dev/null
+++ b/weed/filer/arangodb/arangodb_store_bucket.go
@@ -0,0 +1,40 @@
+package arangodb
+
+import (
+	"context"
+	"github.com/arangodb/go-driver"
+	"time"
+
+	"github.com/chrislusf/seaweedfs/weed/filer"
+
+	"github.com/chrislusf/seaweedfs/weed/glog"
+)
+
+var _ filer.BucketAware = (*ArangodbStore)(nil)
+
+func (store *ArangodbStore) OnBucketCreation(bucket string) {
+	timeout, cancel := context.WithTimeout(context.Background(), 10*time.Second)
+	defer cancel()
+	// create the collection && add to cache
+	_, err := store.ensureBucket(timeout, bucket)
+	if err != nil {
+		glog.Errorf("bucket create %s: %v", bucket, err)
+	}
+}
+func (store *ArangodbStore) OnBucketDeletion(bucket string) {
+	timeout, cancel := context.WithTimeout(context.Background(), 10*time.Second)
+	defer cancel()
+	collection, err := store.ensureBucket(timeout, bucket)
+	if err != nil {
+		glog.Errorf("bucket delete %s: %v", bucket, err)
+		return
+	}
+	err = collection.Remove(timeout)
+	if err != nil && !driver.IsNotFound(err) {
+		glog.Errorf("bucket delete %s: %v", bucket, err)
+		return
+	}
+}
+func (store *ArangodbStore) CanDropWholeBucket() bool {
+	return true
+}
diff --git a/weed/filer/arangodb/arangodb_store_kv.go b/weed/filer/arangodb/arangodb_store_kv.go
new file mode 100644
index 000000000..c1307e78d
--- /dev/null
+++ b/weed/filer/arangodb/arangodb_store_kv.go
@@ -0,0 +1,54 @@
+package arangodb
+
+import (
+	"context"
+	"fmt"
+
+	"github.com/arangodb/go-driver"
+	"github.com/chrislusf/seaweedfs/weed/filer"
+	"github.com/chrislusf/seaweedfs/weed/glog"
+)
+
+func (store *ArangodbStore) KvPut(ctx context.Context, key []byte, value []byte) (err error) {
+	model := &Model{
+		Key:       hashString(".kvstore." + string(key)),
+		Directory: ".kvstore." + string(key),
+		Meta:      bytesToArray(value),
+	}
+
+	exists, err := store.kvCollection.DocumentExists(ctx, model.Key)
+	if err != nil {
+		return fmt.Errorf("kv put: %v", err)
+	}
+	if exists {
+		_, err = store.kvCollection.UpdateDocument(ctx, model.Key, model)
+	} else {
+		_, err = store.kvCollection.CreateDocument(ctx, model)
+	}
+	if err != nil {
+		return fmt.Errorf("kv put: %v", err)
+	}
+
+	return nil
+}
+func (store *ArangodbStore) KvGet(ctx context.Context, key []byte) (value []byte, err error) {
+	var model Model
+	_, err = store.kvCollection.ReadDocument(ctx, hashString(".kvstore."+string(key)), &model)
+	if driver.IsNotFound(err) {
+		return nil, filer.ErrKvNotFound
+	}
+	if err != nil {
+		glog.Errorf("kv get: %s %v", string(key), err)
+		return nil, filer.ErrKvNotFound
+	}
+	return arrayToBytes(model.Meta), nil
+}
+
+func (store *ArangodbStore) KvDelete(ctx context.Context, key []byte) (err error) {
+	_, err = store.kvCollection.RemoveDocument(ctx, hashString(".kvstore."+string(key)))
+	if err != nil {
+		glog.Errorf("kv del: %v", err)
+		return filer.ErrKvNotFound
+	}
+	return nil
+}
diff --git a/weed/filer/arangodb/helpers.go b/weed/filer/arangodb/helpers.go
new file mode 100644
index 000000000..943189781
--- /dev/null
+++ b/weed/filer/arangodb/helpers.go
@@ -0,0 +1,136 @@
+package arangodb
+
+import (
+	"context"
+	"crypto/md5"
+	"encoding/binary"
+	"encoding/hex"
+	"io"
+	"strings"
+
+	"github.com/arangodb/go-driver"
+	"github.com/chrislusf/seaweedfs/weed/util"
+)
+
+//convert a string into arango-key safe hex bytes hash
+func hashString(dir string) string {
+	h := md5.New()
+	io.WriteString(h, dir)
+	b := h.Sum(nil)
+	return hex.EncodeToString(b)
+}
+
+// convert slice of bytes into slice of uint64
+// the first uint64 indicates the length in bytes
+func bytesToArray(bs []byte) []uint64 {
+	out := make([]uint64, 0, 2+len(bs)/8)
+	out = append(out, uint64(len(bs)))
+	for len(bs)%8 != 0 {
+		bs = append(bs, 0)
+	}
+	for i := 0; i < len(bs); i = i + 8 {
+		out = append(out, binary.BigEndian.Uint64(bs[i:]))
+	}
+	return out
+}
+
+// convert from slice of uint64 back to bytes
+// if input length is 0 or 1, will return nil
+func arrayToBytes(xs []uint64) []byte {
+	if len(xs) < 2 {
+		return nil
+	}
+	first := xs[0]
+	out := make([]byte, len(xs)*8) // i think this can actually be len(xs)*8-8, but i dont think an extra 8 bytes hurts...
+	for i := 1; i < len(xs); i = i + 1 {
+		binary.BigEndian.PutUint64(out[((i-1)*8):], xs[i])
+	}
+	return out[:first]
+}
+
+// gets the collection the bucket points to from filepath
+func (store *ArangodbStore) extractBucketCollection(ctx context.Context, fullpath util.FullPath) (c driver.Collection, err error) {
+	bucket, _ := extractBucket(fullpath)
+	if bucket == "" {
+		bucket = DEFAULT_COLLECTION
+	}
+	c, err = store.ensureBucket(ctx, bucket)
+	if err != nil {
+		return nil, err
+	}
+	return c, err
+}
+
+// called by extractBucketCollection
+func extractBucket(fullpath util.FullPath) (string, string) {
+	if !strings.HasPrefix(string(fullpath), BUCKET_PREFIX+"/") {
+		return "", string(fullpath)
+	}
+	if strings.Count(string(fullpath), "/") < 3 {
+		return "", string(fullpath)
+	}
+	bucketAndObjectKey := string(fullpath)[len(BUCKET_PREFIX+"/"):]
+	t := strings.Index(bucketAndObjectKey, "/")
+	bucket := bucketAndObjectKey
+	shortPath := "/"
+	if t > 0 {
+		bucket = bucketAndObjectKey[:t]
+		shortPath = string(util.FullPath(bucketAndObjectKey[t:]))
+	}
+	return bucket, shortPath
+}
+
+// get bucket collection from cache. if not exist, creates the buckets collection and grab it
+func (store *ArangodbStore) ensureBucket(ctx context.Context, bucket string) (bc driver.Collection, err error) {
+	var ok bool
+	store.mu.RLock()
+	bc, ok = store.buckets[bucket]
+	store.mu.RUnlock()
+	if ok {
+		return bc, nil
+	}
+	store.mu.Lock()
+	defer store.mu.Unlock()
+	store.buckets[bucket], err = store.ensureCollection(ctx, bucket)
+	if err != nil {
+		return nil, err
+	}
+	return store.buckets[bucket], nil
+}
+
+// creates collection if not exist, ensures indices if not exist
+func (store *ArangodbStore) ensureCollection(ctx context.Context, name string) (c driver.Collection, err error) {
+	ok, err := store.database.CollectionExists(ctx, name)
+	if err != nil {
+		return
+	}
+	if ok {
+		c, err = store.database.Collection(ctx, name)
+	} else {
+		c, err = store.database.CreateCollection(ctx, name, &driver.CreateCollectionOptions{})
+	}
+	if err != nil {
+		return
+	}
+	// ensure indices
+	if _, _, err = c.EnsurePersistentIndex(ctx, []string{"directory", "name"},
+		&driver.EnsurePersistentIndexOptions{
+			Name: "directory_name_multi", Unique: true,
+		}); err != nil {
+		return
+	}
+	if _, _, err = c.EnsurePersistentIndex(ctx, []string{"directory"},
+		&driver.EnsurePersistentIndexOptions{Name: "IDX_directory"}); err != nil {
+		return
+	}
+	if _, _, err = c.EnsureTTLIndex(ctx, "ttl", 1,
+		&driver.EnsureTTLIndexOptions{Name: "IDX_TTL"}); err != nil {
+		return
+	}
+	if _, _, err = c.EnsurePersistentIndex(ctx, []string{"name"}, &driver.EnsurePersistentIndexOptions{
+		Name: "IDX_name",
+	}); err != nil {
+		return
+	}
+	return c, nil
+}
diff --git a/weed/filer/arangodb/readme.md b/weed/filer/arangodb/readme.md
new file mode 100644
index 000000000..e189811fb
--- /dev/null
+++ b/weed/filer/arangodb/readme.md
@@ -0,0 +1,52 @@
+##arangodb
+
+database: https://github.com/arangodb/arangodb
+go driver: https://github.com/arangodb/go-driver
+
+options:
+
+```
+[arangodb]
+enabled=true
+db_name="seaweedfs"
+servers=["http://localhost:8529"]
+#basic auth
+user="root"
+pass="test"
+
+# tls settings
+insecure_skip_verify=true
+```
+
+i test using this dev database:
+`docker run -p 8529:8529 -e ARANGO_ROOT_PASSWORD=test arangodb/arangodb:3.9.0`
+
+
+## features i don't personally need but are missing
+ [ ] provide tls cert to arango
+ [ ] authentication that is not basic auth
+ [ ] synchronise endpoint interval config
+ [ ] automatic creation of custom index
+ [ ] configure default arangodb collection sharding rules
+ [ ] configure default arangodb collection replication rules
+
+
+## complexity
+
+ok, so if https://www.arangodb.com/docs/stable/indexing-index-basics.html#persistent-index is correct
+
+O(1)
+- InsertEntry
+- UpdateEntry
+- FindEntry
+- DeleteEntry
+- KvPut
+- KvGet
+- KvDelete
+
+O(log(BUCKET_SIZE))
+- DeleteFolderChildren
+
+O(log(DIRECTORY_SIZE))
+- ListDirectoryEntries
+- ListDirectoryPrefixedEntries