filer: add API to add/modify/delete tagging

weed/server/common.go

@@ -38,10 +38,12 @@ func init() {
 
 func writeJson(w http.ResponseWriter, r *http.Request, httpStatus int, obj interface{}) (err error) {
 	var bytes []byte
-	if r.FormValue("pretty") != "" {
-		bytes, err = json.MarshalIndent(obj, "", "  ")
-	} else {
-		bytes, err = json.Marshal(obj)
+	if obj != nil {
+		if r.FormValue("pretty") != "" {
+			bytes, err = json.MarshalIndent(obj, "", "  ")
+		} else {
+			bytes, err = json.Marshal(obj)
+		}
 	}
 	if err != nil {
 		return

weed/server/filer_server_handlers.go

@@ -26,11 +26,19 @@ func (fs *FilerServer) filerHandler(w http.ResponseWriter, r *http.Request) {
 		stats.FilerRequestHistogram.WithLabelValues("head").Observe(time.Since(start).Seconds())
 	case "DELETE":
 		stats.FilerRequestCounter.WithLabelValues("delete").Inc()
-		fs.DeleteHandler(w, r)
+		if _, ok := r.URL.Query()["tagging"]; ok {
+			fs.DeleteTaggingHandler(w,r)
+		} else {
+			fs.DeleteHandler(w, r)
+		}
 		stats.FilerRequestHistogram.WithLabelValues("delete").Observe(time.Since(start).Seconds())
 	case "PUT":
 		stats.FilerRequestCounter.WithLabelValues("put").Inc()
-		fs.PostHandler(w, r)
+		if _, ok := r.URL.Query()["tagging"]; ok {
+			fs.PutTaggingHandler(w,r)
+		} else {
+			fs.PostHandler(w, r)
+		}
 		stats.FilerRequestHistogram.WithLabelValues("put").Observe(time.Since(start).Seconds())
 	case "POST":
 		stats.FilerRequestCounter.WithLabelValues("post").Inc()

weed/server/filer_server_handlers_tagging.go

@@ -0,0 +1,102 @@
+package weed_server
+
+import (
+	"context"
+	"net/http"
+	"strings"
+
+	"github.com/chrislusf/seaweedfs/weed/glog"
+	"github.com/chrislusf/seaweedfs/weed/storage/needle"
+	"github.com/chrislusf/seaweedfs/weed/util"
+)
+
+// add or replace one file Seaweed- prefixed attributes
+// curl -X PUT -H "Seaweed-Name1: value1" http://localhost:8888/path/to/a/file?tagging
+func (fs *FilerServer) PutTaggingHandler(w http.ResponseWriter, r *http.Request) {
+
+	ctx := context.Background()
+
+	path := r.URL.Path
+	if strings.HasSuffix(path, "/") {
+		path = path[:len(path)-1]
+	}
+
+	existingEntry, err := fs.filer.FindEntry(ctx, util.FullPath(path))
+	if err != nil {
+		writeJsonError(w, r, http.StatusNotFound, err)
+		return
+	}
+	if existingEntry == nil {
+		writeJsonError(w, r, http.StatusNotFound, err)
+		return
+	}
+
+	if existingEntry.Extended == nil {
+		existingEntry.Extended = make(map[string][]byte)
+	}
+
+	for header, values := range r.Header {
+		if strings.HasPrefix(header, needle.PairNamePrefix) {
+			for _, value := range values {
+				existingEntry.Extended[header] = []byte(value)
+			}
+		}
+	}
+
+	if dbErr := fs.filer.CreateEntry(ctx, existingEntry, false, false, nil); dbErr != nil {
+		glog.V(0).Infof("failing to update %s tagging : %v", path, dbErr)
+		writeJsonError(w, r, http.StatusInternalServerError, err)
+		return
+	}
+
+	writeJsonQuiet(w, r, http.StatusAccepted, nil)
+	return
+}
+
+// remove all Seaweed- prefixed attributes
+// curl -X DELETE http://localhost:8888/path/to/a/file?tagging
+func (fs *FilerServer) DeleteTaggingHandler(w http.ResponseWriter, r *http.Request) {
+
+	ctx := context.Background()
+
+	path := r.URL.Path
+	if strings.HasSuffix(path, "/") {
+		path = path[:len(path)-1]
+	}
+
+	existingEntry, err := fs.filer.FindEntry(ctx, util.FullPath(path))
+	if err != nil {
+		writeJsonError(w, r, http.StatusNotFound, err)
+		return
+	}
+	if existingEntry == nil {
+		writeJsonError(w, r, http.StatusNotFound, err)
+		return
+	}
+
+	if existingEntry.Extended == nil {
+		existingEntry.Extended = make(map[string][]byte)
+	}
+
+	hasDeletion := false
+	for header, _ := range existingEntry.Extended {
+		if strings.HasPrefix(header, needle.PairNamePrefix) {
+			delete(existingEntry.Extended, header)
+			hasDeletion = true
+		}
+	}
+
+	if !hasDeletion {
+		writeJsonQuiet(w, r, http.StatusNotModified, nil)
+		return
+	}
+
+	if dbErr := fs.filer.CreateEntry(ctx, existingEntry, false, false, nil); dbErr != nil {
+		glog.V(0).Infof("failing to delete %s tagging : %v", path, dbErr)
+		writeJsonError(w, r, http.StatusInternalServerError, err)
+		return
+	}
+
+	writeJsonQuiet(w, r, http.StatusAccepted, nil)
+	return
+}