switch to multi collection, change readme

weed/filer/arangodb/helpers.go

@@ -1,10 +1,15 @@
 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
@@ -42,3 +47,90 @@ func arrayToBytes(xs []uint64) []byte {
 	}
 	return out[:first]
 }
+
+// gets the bucket name out of filepath
+func extractBucket(fullpath util.FullPath) (string, string) {
+	if !strings.HasPrefix(string(fullpath), BUCKET_PREFIX+"/") {
+		return "", string(fullpath)
+	}
+	if strings.Count(string(fullpath), "/") < 2 {
+		return "", string(fullpath)
+	}
+	bucketAndObjectKey := string(fullpath)[len("/buckets/"):]
+	t := strings.Index(bucketAndObjectKey, "/")
+	bucket := bucketAndObjectKey
+	shortPath := "/"
+	if t > 0 {
+		bucket = bucketAndObjectKey[:t]
+		shortPath = string(util.FullPath(bucketAndObjectKey[t:]))
+	}
+	return bucket, shortPath
+}
+
+// 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
+}
+
+// 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
+}