Changes wrt govet/golint suggestions; client code refactoring

client/client.go

@@ -18,9 +18,32 @@ import (
 	"github.com/vkuznet/transfer2go/utils"
 )
 
-// Transfer client function is responsible to initiate transfer request from
-// source to destination.
-func Transfer(agent, src, dst string) error {
+type UserRequest struct {
+	SrcUrl   string
+	SrcAlias string
+	SrcFile  string
+	DstUrl   string
+	DstAlias string
+	DstFile  string
+	Transfer bool
+	Upload   bool
+}
+
+// String returns string representation of UserRequest struct
+func (u *UserRequest) String() string {
+	var action string
+	if u.Transfer {
+		action = "transfer"
+	}
+	if u.Upload {
+		action = "upload"
+	}
+	return fmt.Sprintf("<UserRequest %s %s(%s) %s => %s(%s) %s>", action, u.SrcAlias, u.SrcUrl, u.SrcFile, u.DstAlias, u.DstUrl, u.DstFile)
+}
+
+// helper function to parse source and destination parameters
+func parse(agent, src, dst string) (UserRequest, error) {
+	var req UserRequest
 	var transfer, upload bool
 	var srcFile, srcAlias, srcUrl, dstFile, dstAlias, dstUrl string
 	if stat, err := os.Stat(src); err == nil && !stat.IsDir() {
@@ -50,12 +73,12 @@ func Transfer(agent, src, dst string) error {
 	url := fmt.Sprintf("%s/agents", agent)
 	resp := utils.FetchResponse(url, []byte{})
 	if resp.Error != nil {
-		return resp.Error
+		return req, resp.Error
 	}
 	var remoteAgents map[string]string
 	e := json.Unmarshal(resp.Data, &remoteAgents)
 	if e != nil {
-		return e
+		return req, e
 	}
 
 	// get source agent alias name
@@ -81,59 +104,79 @@ func Transfer(agent, src, dst string) error {
 	if !ok {
 		log.Println("Unable to resolve destination", dst)
 		log.Println("Map of known agents", remoteAgents)
-		return fmt.Errorf("Unknown destination")
+		return req, fmt.Errorf("Unknown destination")
 	}
+	req = UserRequest{SrcUrl: srcUrl, SrcAlias: srcAlias, SrcFile: srcFile, DstUrl: dstUrl, DstAlias: dstAlias, DstFile: dstFile, Transfer: transfer, Upload: upload}
+	log.Println(req.String())
+	return req, nil
+}
 
-	if transfer {
-		log.Println("### Transfer", srcAlias, srcUrl, srcFile, "=>", dstAlias, dstUrl, dstFile)
+// helper function to perform user request transfer
+func transfer(req UserRequest) error {
 
-		// Read data from source agent
-		url = fmt.Sprintf("%s/files?pattern=%s", srcUrl, srcFile)
-		resp = utils.FetchResponse(url, []byte{})
-		if resp.Error != nil {
-			return resp.Error
-		}
-		var files []string
-		err := json.Unmarshal(resp.Data, &files)
-		if err != nil {
-			return err
-		}
+	// Read data from source agent
+	url := fmt.Sprintf("%s/files?pattern=%s", req.SrcUrl, req.SrcFile)
+	resp := utils.FetchResponse(url, []byte{})
+	if resp.Error != nil {
+		return resp.Error
+	}
+	var files []string
+	err := json.Unmarshal(resp.Data, &files)
+	if err != nil {
+		return err
+	}
 
-		// form transfer request
-		var requests []model.TransferRequest
-		for _, fname := range files {
-			ts := time.Now().Unix()
-			requests = append(requests, model.TransferRequest{SrcUrl: srcUrl, SrcAlias: srcAlias, DstUrl: dstUrl, DstAlias: dst, File: fname, TimeStamp: ts})
-		}
+	// form transfer request
+	var requests []model.TransferRequest
+	for _, fname := range files {
 		ts := time.Now().Unix()
-		transferCollection := model.TransferCollection{TimeStamp: ts, Requests: requests}
+		requests = append(requests, model.TransferRequest{SrcUrl: req.SrcUrl, SrcAlias: req.SrcAlias, DstUrl: req.DstUrl, DstAlias: req.DstAlias, File: fname, TimeStamp: ts})
+	}
+	ts := time.Now().Unix()
+	transferCollection := model.TransferCollection{TimeStamp: ts, Requests: requests}
 
-		url = fmt.Sprintf("%s/request", srcUrl)
-		d, e := json.Marshal(transferCollection)
-		if e != nil {
-			return e
-		}
-		resp = utils.FetchResponse(url, d)
-		return resp.Error
+	url = fmt.Sprintf("%s/request", req.SrcUrl)
+	d, e := json.Marshal(transferCollection)
+	if e != nil {
+		return e
 	}
+	resp = utils.FetchResponse(url, d)
+	return resp.Error
+}
 
-	if upload {
-		log.Println("### Upload", src, "to site", dstAlias, dstUrl, "as", dstFile)
-		data, err := ioutil.ReadFile(srcFile)
-		if err != nil {
-			return err
-		}
-		hash, bytes := utils.Hash(data)
-		d := "/a/b/c" // dataset name
-		b := "123"    // block name
-		transferData := model.TransferData{File: dstFile, Dataset: d, Block: b, SrcUrl: srcUrl, SrcAlias: srcAlias, DstUrl: dstUrl, DstAlias: dstAlias, Data: data, Hash: hash, Bytes: bytes}
-		url = fmt.Sprintf("%s/transfer", dstUrl)
-		data, err = json.Marshal(transferData)
-		if err != nil {
-			return err
-		}
-		resp = utils.FetchResponse(url, data)
-		return resp.Error
+// helper function to perform user request upload to the agent
+func upload(req UserRequest) error {
+	data, err := ioutil.ReadFile(req.SrcFile)
+	if err != nil {
+		return err
+	}
+	hash, bytes := utils.Hash(data)
+	d := "/a/b/c" // dataset name
+	b := "123"    // block name
+	transferData := model.TransferData{File: req.DstFile, Dataset: d, Block: b, SrcUrl: req.SrcUrl, SrcAlias: req.SrcAlias, DstUrl: req.DstUrl, DstAlias: req.DstAlias, Data: data, Hash: hash, Bytes: bytes}
+	url := fmt.Sprintf("%s/transfer", req.DstUrl)
+	data, err = json.Marshal(transferData)
+	if err != nil {
+		return err
+	}
+	resp := utils.FetchResponse(url, data)
+	return resp.Error
+}
+
+// Transfer client function is responsible to initiate transfer request from
+// source to destination.
+func Transfer(agent, src, dst string) error {
+	req, err := parse(agent, src, dst)
+	if err != nil {
+		return err
+	}
+
+	if req.Transfer {
+		return transfer(req)
+	}
+
+	if req.Upload {
+		return upload(req)
 	}
 
 	return fmt.Errorf("Unable to understand client request, src=%v to dst=%v", src, dst)
@@ -142,6 +185,6 @@ func Transfer(agent, src, dst string) error {
 // Status function provides status about given agent
 func Status(agent string) error {
 	resp := utils.FetchResponse(agent+"/status", []byte{})
-	log.Println("### Status", agent, string(resp.Data))
+	log.Println("Status", agent, string(resp.Data))
 	return resp.Error
 }

model/catalog.go

@@ -17,7 +17,7 @@ import (
 	_ "github.com/mattn/go-sqlite3"
 )
 
-// global pointer to DB
+// DB is global pointer to sql database object, it is initialized once when server starts
 var DB *sql.DB
 
 func check(msg string, err error) {
@@ -54,9 +54,8 @@ func (c *Catalog) Dump() []byte {
 			log.Println("ERROR c.Dump", err)
 		}
 		return out
-	} else {
-		log.Println("Catalog Dump method is not implemented yet for", c.Type)
 	}
+	log.Println("Catalog Dump method is not implemented yet for", c.Type)
 	return nil
 
 }
@@ -156,7 +155,7 @@ func (c *Catalog) Files(pattern string) []string {
 		// fetch data from DB
 		rows, err := DB.Query(stm, pattern)
 		if err != nil {
-			log.Println("ERROR DB.Query, query='%s' error=%v", stm, err)
+			log.Printf("ERROR DB.Query, query='%s' error=%v\n", stm, err)
 			return files
 		}
 		defer rows.Close()
@@ -196,7 +195,7 @@ func (c *Catalog) FileInfo(fileEntry string) CatalogEntry {
 		// fetch data from DB
 		rows, err := DB.Query(stm, fileEntry)
 		if err != nil {
-			log.Println("ERROR DB.Query, query='%s' error=%v", stm, err)
+			log.Printf("ERROR DB.Query, query='%s' error=%v\n", stm, err)
 			return CatalogEntry{}
 		}
 		defer rows.Close()

server/handlers.go

@@ -185,13 +185,10 @@ func RegisterProtocolHandler(w http.ResponseWriter, r *http.Request) {
 		_protocol = protocolParams.Protocol
 		_backend = protocolParams.Backend
 		_tool = protocolParams.Tool
-		log.Printf("INFO RegisterHandler switched to protocol=%s backend=%s tool=%s\n", _protocol, _backend, _tool)
+		log.Printf("INFO RegisterProtocolHandler switched to protocol=%s backend=%s tool=%s\n", _protocol, _backend, _tool)
 		w.WriteHeader(http.StatusOK)
 		return
-	} else {
-		log.Println("ERROR RegisterHandler", err)
 	}
-	w.WriteHeader(http.StatusInternalServerError)
 }
 
 // RequestHandler initiate transfer work for given request

server/server.go

@@ -40,7 +40,7 @@ type AgentInfo struct {
 	Alias string
 }
 
-// ProtocolInfo data type
+// AgentProtocol data type
 type AgentProtocol struct {
 	Protocol string `json:"protocol"` // protocol name, e.g. srmv2
 	Backend  string `json:"backend"`  // backend storage end-point, e.g. srm://cms-srm.cern.ch:8443/srm/managerv2?SFN=

utils/fetch.go

@@ -311,7 +311,7 @@ func List2Set(arr []string) []string {
 	return out
 }
 
-// Provides a list of host IPs
+// HostIP provides a list of host IPs
 func HostIP() []string {
 	var out []string
 	addrs, err := net.InterfaceAddrs()