[checksum] Micro optimisations; [node] Renamed nodes to receiving and…

… sending; [fsys] ftu now DOES NOT die on 'permission denied's

README.md

@@ -46,7 +46,7 @@ Now you have ftu installed !
 ## ● Usage
 `ftu -h` - to print a usage message
 
-`ftu [FLAGS]`
+`ftu [FLAGs]`
 
 ### ● FLAGs
 - -p [uint] for port

src/checksum/checksum.go

@@ -21,6 +21,7 @@ along with this program.  If not, see <https://www.gnu.org/licenses/>.
 package checksum
 
 import (
+	"bytes"
 	"crypto/sha256"
 	"encoding/hex"
 	"io"
@@ -36,8 +37,8 @@ import (
 // GetPartialCheckSum is default method used to get a file checksum by sender and receiver
 func GetPartialCheckSum(file *os.File) (string, error) {
 	// "capturing" CHUNKSIZE bytes and then skipping STEP bytes before the next chunk until the last one
-	const CHUNKS uint = 100
-	const CHUNKSIZE uint = 100
+	const CHUNKS uint = 50
+	const CHUNKSIZE uint = 50
 	const STEP uint = 250
 
 	fileStats, err := file.Stat()
@@ -48,7 +49,7 @@ func GetPartialCheckSum(file *os.File) (string, error) {
 	fileSize := fileStats.Size()
 
 	if fileSize < int64(CHUNKS*CHUNKSIZE+STEP*(CHUNKS-1)) {
-		// file is too small to chop it in chunks, so just doing full checksum
+		// file is too small to chop it in chunks, so just get the full checksum
 
 		checksum, err := getFullCheckSum(file)
 		if err != nil {
@@ -62,19 +63,20 @@ func GetPartialCheckSum(file *os.File) (string, error) {
 		return "", err
 	}
 
-	var capturedChunks string
+	// var capturedChunks string
+	var capturedChunks bytes.Buffer
 	var read uint64 = 0
 	for i := 0; uint(i) < CHUNKS; i++ {
 		buffer := make([]byte, CHUNKSIZE)
 		r, _ := file.ReadAt(buffer, int64(read))
 
-		capturedChunks += string(buffer)
+		capturedChunks.Write(buffer)
 
 		read += uint64(r)
 		read += uint64(STEP)
 	}
 
-	checksumBytes := sha256.Sum256([]byte(capturedChunks))
+	checksumBytes := sha256.Sum256(capturedChunks.Bytes())
 	checksum := hex.EncodeToString(checksumBytes[:])
 
 	return checksum, nil

src/fsys/dir.go

@@ -22,6 +22,7 @@ package fsys
 
 import (
 	"fmt"
+	"io/fs"
 	"os"
 	"path/filepath"
 )
@@ -63,7 +64,7 @@ func GetDir(path string, recursive bool) (*Directory, error) {
 
 	// loop through each entry in the directory
 	entries, err := os.ReadDir(absPath)
-	if err != nil {
+	if err != nil && err != fs.ErrPermission {
 		return nil, err
 	}
 
@@ -96,7 +97,8 @@ func GetDir(path string, recursive bool) (*Directory, error) {
 
 			innerFile, err := GetFile(innerFilePath)
 			if err != nil {
-				return nil, err
+				// skip this file
+				continue
 			}
 
 			directory.Size += innerFile.Size

src/fsys/file.go

@@ -45,7 +45,7 @@ var ErrorNotFile error = fmt.Errorf("not a file")
 // Get general information about a file with the
 // future ability to open it.
 // NOTE that Handler field is nil BY DEFAULT until you
-// manually call a (file *File) Open() function to open it !
+// manually call (file *File).Open() to open it !
 func GetFile(path string) (*File, error) {
 	absPath, err := filepath.Abs(path)
 	if err != nil {

src/main.go

@@ -30,9 +30,9 @@ import (
 )
 
 var (
-	VERSION string = "v2.2.2"
+	VERSION string = "v2.2.3"
 
-	versionInformation string = fmt.Sprintf("ftu %s\n\nCopyright (C) 2021,2022  Kasyanov Nikolay Alexeevich (Unbewohnte (https://unbewohnte.xyz/))\nThis program comes with ABSOLUTELY NO WARRANTY.\nThis is free software, and you are welcome to redistribute it under certain conditions; type \"ftu -l\" for details.\n", VERSION)
+	versionInformation string = fmt.Sprintf("ftu %s\nfile transferring utility\n\nCopyright (C) 2021,2022  Kasyanov Nikolay Alexeevich (Unbewohnte (me@unbewohnte.xyz))\nThis program comes with ABSOLUTELY NO WARRANTY.\nThis is free software, and you are welcome to redistribute it under certain conditions; type \"ftu -l\" for details.\n", VERSION)
 
 	//go:embed COPYING
 	licenseInformation string
@@ -52,7 +52,7 @@ var (
 
 func init() {
 	flag.Usage = func() {
-		fmt.Printf("ftu -[FLAG]...\n\n")
+		fmt.Printf("ftu -[FLAGs]\n\n")
 
 		fmt.Printf("[FLAGs]\n\n")
 		fmt.Printf("| -p [Uinteger_here] for port\n")
@@ -122,19 +122,19 @@ func main() {
 		VerboseOutput: *VERBOSE,
 		IsSending:     isSending,
 		WorkingPort:   *PORT,
-		ServerSide: &node.ServerSideNodeOptions{
+		SenderSide: &node.SenderNodeOptions{
 			ServingPath: *SEND,
 			Recursive:   *RECUSRIVE,
 		},
-		ClientSide: &node.ClientSideNodeOptions{
+		ReceiverSide: &node.ReceiverNodeOptions{
 			ConnectionAddr:      *ADDRESS,
 			DownloadsFolderPath: *DOWNLOADS_DIR,
 		},
 	}
 
 	node, err := node.NewNode(&nodeOptions)
 	if err != nil {
-		fmt.Printf("Error constructing a new node: %s\n", err)
+		fmt.Printf("[ERROR] Error constructing a new node: %s\n", err)
 		os.Exit(-1)
 	}
 

src/node/node.go

@@ -91,7 +91,7 @@ func NewNode(options *NodeOptions) (*Node, error) {
 	var isDir bool
 	if options.IsSending {
 		// sending node preparation
-		sendingPathStats, err := os.Stat(options.ServerSide.ServingPath)
+		sendingPathStats, err := os.Stat(options.SenderSide.ServingPath)
 		if err != nil {
 			return nil, err
 		}
@@ -106,12 +106,12 @@ func NewNode(options *NodeOptions) (*Node, error) {
 	} else {
 		// receiving node preparation
 		var err error
-		options.ClientSide.DownloadsFolderPath, err = filepath.Abs(options.ClientSide.DownloadsFolderPath)
+		options.ReceiverSide.DownloadsFolderPath, err = filepath.Abs(options.ReceiverSide.DownloadsFolderPath)
 		if err != nil {
 			return nil, err
 		}
 
-		err = os.MkdirAll(options.ClientSide.DownloadsFolderPath, os.ModePerm)
+		err = os.MkdirAll(options.ReceiverSide.DownloadsFolderPath, os.ModePerm)
 		if err != nil {
 			return nil, err
 		}
@@ -125,22 +125,22 @@ func NewNode(options *NodeOptions) (*Node, error) {
 		isSending:     options.IsSending,
 		netInfo: &netInfo{
 			Port:          options.WorkingPort,
-			ConnAddr:      options.ClientSide.ConnectionAddr,
+			ConnAddr:      options.ReceiverSide.ConnectionAddr,
 			EncryptionKey: nil,
 			Conn:          nil,
 		},
 		stopped: false,
 		transferInfo: &transferInfo{
 			Sending: &sending{
-				ServingPath:       options.ServerSide.ServingPath,
-				Recursive:         options.ServerSide.Recursive,
+				ServingPath:       options.SenderSide.ServingPath,
+				Recursive:         options.SenderSide.Recursive,
 				IsDirectory:       isDir,
 				TotalTransferSize: 0,
 				SentBytes:         0,
 			},
 			Receiving: &receiving{
 				AcceptedFiles:     nil,
-				DownloadsPath:     options.ClientSide.DownloadsFolderPath,
+				DownloadsPath:     options.ReceiverSide.DownloadsFolderPath,
 				ReceivedBytes:     0,
 				TotalDownloadSize: 0,
 			},
@@ -512,7 +512,7 @@ func (node *Node) send() {
 			default:
 				node.stopped = true
 
-				fmt.Printf("\nAn error occured while sending a piece of \"%s\": %s", node.transferInfo.Sending.FilesToSend[currentFileIndex].Name, err)
+				fmt.Printf("\n[ERROR] An error occured while sending a piece of \"%s\": %s", node.transferInfo.Sending.FilesToSend[currentFileIndex].Name, err)
 				panic(err)
 			}
 		}
@@ -525,7 +525,7 @@ func (node *Node) receive() {
 	// connect to the sending node
 	err := node.connect()
 	if err != nil {
-		fmt.Printf("\nCould not connect to %s:%d", node.netInfo.ConnAddr, node.netInfo.Port)
+		fmt.Printf("\n[ERROR] Could not connect to %s:%d", node.netInfo.ConnAddr, node.netInfo.Port)
 		os.Exit(-1)
 	}
 
@@ -823,7 +823,10 @@ func (node *Node) receive() {
 					}
 
 					if realChecksum != acceptedFile.Checksum {
-						fmt.Printf("\n| \"%s\" is corrupted", acceptedFile.Name)
+						if node.verboseOutput {
+							fmt.Printf("\n[ERROR] \"%s\" is corrupted", acceptedFile.Name)
+						}
+
 						acceptedFile.Close()
 						break
 					} else {

src/node/options.go

@@ -20,12 +20,12 @@ along with this program.  If not, see <https://www.gnu.org/licenses/>.
 
 package node
 
-type ServerSideNodeOptions struct {
+type SenderNodeOptions struct {
 	ServingPath string
 	Recursive   bool
 }
 
-type ClientSideNodeOptions struct {
+type ReceiverNodeOptions struct {
 	ConnectionAddr      string
 	DownloadsFolderPath string
 }
@@ -35,6 +35,6 @@ type NodeOptions struct {
 	IsSending     bool
 	WorkingPort   uint
 	VerboseOutput bool
-	ServerSide    *ServerSideNodeOptions
-	ClientSide    *ClientSideNodeOptions
+	SenderSide    *SenderNodeOptions
+	ReceiverSide  *ReceiverNodeOptions
 }

src/protocol/send.go

@@ -174,7 +174,7 @@ func SendPiece(file *fsys.File, connection net.Conn, encrKey []byte) (uint64, er
 
 	if encrKey != nil {
 		// account for padding
-		canSendBytes -= 32
+		canSendBytes -= 48
 	}
 
 	if (file.Size - file.SentBytes) < canSendBytes {