Rename restapi to api (#3176)

Signed-off-by: Daniel Valdivia <18384552+dvaldivia@users.noreply.github.com>

api/user_watch.go

@@ -0,0 +1,108 @@
+// This file is part of MinIO Console Server
+// Copyright (c) 2021 MinIO, Inc.
+//
+// This program is free software: you can redistribute it and/or modify
+// it under the terms of the GNU Affero General Public License as published by
+// the Free Software Foundation, either version 3 of the License, or
+// (at your option) any later version.
+//
+// This program is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+// GNU Affero General Public License for more details.
+//
+// You should have received a copy of the GNU Affero General Public License
+// along with this program.  If not, see <http://www.gnu.org/licenses/>.
+
+package api
+
+import (
+	"context"
+	"encoding/json"
+	"fmt"
+	"net/http"
+	"regexp"
+	"strings"
+
+	mc "github.com/minio/mc/cmd"
+	"github.com/minio/websocket"
+)
+
+type watchOptions struct {
+	BucketName string
+	mc.WatchOptions
+}
+
+func startWatch(ctx context.Context, conn WSConn, wsc MCClient, options *watchOptions) error {
+	wo, pErr := wsc.watch(ctx, options.WatchOptions)
+	if pErr != nil {
+		LogError("error initializing watch: %v", pErr.Cause)
+		return pErr.Cause
+	}
+	for {
+		select {
+		case <-ctx.Done():
+			close(wo.DoneChan)
+			return nil
+		case events, ok := <-wo.Events():
+			// zero value returned because the channel is closed and empty
+			if !ok {
+				return nil
+			}
+			for _, event := range events {
+				// Serialize message to be sent
+				bytes, err := json.Marshal(event)
+				if err != nil {
+					LogError("error on json.Marshal: %v", err)
+					return err
+				}
+				// Send Message through websocket connection
+				err = conn.writeMessage(websocket.TextMessage, bytes)
+				if err != nil {
+					LogError("error writeMessage: %v", err)
+					return err
+				}
+			}
+		case pErr, ok := <-wo.Errors():
+			// zero value returned because the channel is closed and empty
+			if !ok {
+				return nil
+			}
+			if pErr != nil {
+				LogError("error on watch: %v", pErr.Cause)
+				return pErr.Cause
+
+			}
+		}
+	}
+}
+
+// getWatchOptionsFromReq gets bucket name, events, prefix, suffix from a websocket
+// watch path if defined.
+// path come as : `/watch/bucket1` and query
+// params come on request form
+func getWatchOptionsFromReq(req *http.Request) (*watchOptions, error) {
+	wOptions := watchOptions{}
+	// Default Events if not defined
+	wOptions.Events = []string{"put", "get", "delete"}
+
+	re := regexp.MustCompile(`(/watch/)(.*?$)`)
+	matches := re.FindAllSubmatch([]byte(req.URL.Path), -1)
+	// matches comes as e.g.
+	// [["...", "/watch/", "bucket1"]]
+	// [["/watch/" "/watch/" ""]]
+
+	if len(matches) == 0 || len(matches[0]) < 3 {
+		return nil, fmt.Errorf("invalid url: %s", req.URL.Path)
+	}
+
+	wOptions.BucketName = strings.TrimSpace(string(matches[0][2]))
+
+	events := req.FormValue("events")
+	if strings.TrimSpace(events) != "" {
+		wOptions.Events = strings.Split(events, ",")
+	}
+	wOptions.Prefix = req.FormValue("prefix")
+	wOptions.Suffix = req.FormValue("suffix")
+	return &wOptions, nil
+}