ref: split source

src/backend.go

@@ -0,0 +1,151 @@
+package main
+
+import (
+	"encoding/binary"
+	"fmt"
+	"image"
+	"image/png"
+	"log"
+	"net"
+	"os"
+	"strings"
+	"time"
+)
+
+func Scan(brotherIP string, brotherPort int, resolution int, color string, adf bool) ([]byte, int, int) {
+	log.Println("Valid IP address, opening socket...")
+
+	socket, err := net.Dial("tcp", fmt.Sprintf("%s:%d", brotherIP, brotherPort))
+
+	HandleError(err)
+
+	defer socket.Close()
+
+	width, heigth := SendRequest(socket, resolution, color, adf)
+
+	bytes := GetScanBytes(socket)
+
+	return RemoveHeaders(bytes), width, heigth
+}
+
+func SendRequest(socket net.Conn, resolution int, _mode string, adf bool) (int, int) {
+
+	mode, compression := GetCompressionMode(_mode)
+
+	log.Println("Reading scanner status...")
+
+	status := ReadPacket(socket)[:7]
+
+	if status != "+OK 200" {
+		HandleError(fmt.Errorf("invalid reply from scanner: %s", status))
+	}
+
+	log.Println("Leasing options...")
+
+	request := []byte(fmt.Sprintf("\x1bI\nR=%d,%d\nM=%s\n\x80", resolution, resolution, mode))
+	SendPacket(socket, request)
+
+	offer := ReadPacket(socket)
+
+	if !adf {
+		log.Println("Disabling automatic document feeder (ADF)")
+
+		request = []byte("\x1bD\nADF\n\x80")
+		SendPacket(socket, request)
+
+		ReadPacket(socket)
+	}
+
+	log.Println("Sending scan request...")
+
+	offerOptions := strings.Split(offer, ",")
+
+	width, height := 0, 0
+	fmt.Sscanf(offerOptions[4], "%d", &width)
+	fmt.Sscanf(offerOptions[6], "%d", &height)
+
+	requestFormat := "\x1bX\nR=%v,%v\nM=%s\nC=%s\nJ=MID\nB=50\nN=50\nA=0,0,%v,%v\n\x80"
+
+	request = []byte(fmt.Sprintf(requestFormat, offerOptions[1], offerOptions[1], mode, compression, width, height))
+	SendPacket(socket, request)
+
+	log.Println("Scanning started...")
+
+	return width, height
+}
+
+func GetScanBytes(socket net.Conn) []byte {
+	log.Println("Getting packets...")
+
+	packet := make([]byte, 2048)
+	scanBytes := make([]byte, 0)
+
+readPackets:
+	for {
+		socket.SetDeadline(time.Now().Add(time.Second * 5))
+		bytes, err := socket.Read(packet)
+
+		switch err := err.(type) {
+		case net.Error:
+			if err.Timeout() {
+				break readPackets
+			}
+
+		case nil:
+			scanBytes = append(scanBytes, packet[:bytes]...)
+
+		default:
+			HandleError(err)
+		}
+	}
+
+	return scanBytes
+}
+
+func SaveImage(data []byte, width int, height int, name string, color string) {
+
+	log.Println("Saving image...")
+
+	_, compression := GetCompressionMode(color)
+
+	if compression != "JPEG" {
+
+		img := image.NewGray(image.Rectangle{
+			image.Point{0, 0},
+			image.Point{width, height},
+		})
+
+		for y := 0; y < height-40; y++ {
+
+			for x := 0; x < width; x++ {
+				img.SetGray(x, y, colorToGray(data[y*width+x]))
+			}
+		}
+
+		file, err := os.Create(name)
+		HandleError(err)
+
+		png.Encode(file, img)
+
+	} else {
+
+		err := os.WriteFile(name, data, 0644)
+		HandleError(err)
+	}
+}
+
+func RemoveHeaders(scan []byte) []byte {
+	log.Println("Removing headers from bytes...")
+
+	const headerLen int = 12
+
+	payloadLen := binary.LittleEndian.Uint16(scan[headerLen-2 : headerLen])
+	chunkSize := int(payloadLen) + headerLen
+	scanOutput := make([]byte, 0)
+
+	for i := 0; i < len(scan)-chunkSize; i += chunkSize {
+		scanOutput = append(scanOutput, scan[i+headerLen:i+chunkSize]...)
+	}
+
+	return scanOutput
+}

src/main.go

@@ -1,17 +1,9 @@
 package main
 
 import (
-	"encoding/binary"
 	"flag"
 	"fmt"
-	"image"
-	"image/color"
-	"image/png"
-	"log"
 	"net"
-	"os"
-	"strings"
-	"time"
 )
 
 func main() {
@@ -29,173 +21,7 @@ func main() {
 		HandleError(fmt.Errorf("invalid IP address: %s", *brotherIP))
 	}
 
-	log.Println("Valid IP address, opening socket...")
-
-	socket, err := net.Dial("tcp", fmt.Sprintf("%s:%d", *brotherIP, brotherPort))
-
-	HandleError(err)
-
-	defer socket.Close()
-
-	width, heigth := SendRequest(socket, *resolution, *color, *adf)
-
-	bytes := GetScanBytes(socket)
-
-	rawImage := RemoveHeaders(bytes)
+	rawImage, width, heigth := Scan(*brotherIP, brotherPort, *resolution, *color, *adf)
 
 	SaveImage(rawImage, width, heigth, *name, *color)
-
-}
-
-func SendRequest(socket net.Conn, resolution int, _mode string, adf bool) (int, int) {
-
-	mode, compression := GetCompressionMode(_mode)
-
-	log.Println("Reading scanner status...")
-
-	status := ReadPacket(socket)[:7]
-
-	if status != "+OK 200" {
-		HandleError(fmt.Errorf("invalid reply from scanner: %s", status))
-	}
-
-	log.Println("Leasing options...")
-
-	request := []byte(fmt.Sprintf("\x1bI\nR=%d,%d\nM=%s\n\x80", resolution, resolution, mode))
-	SendPacket(socket, request)
-
-	offer := ReadPacket(socket)
-
-	if !adf {
-		log.Println("Disabling automatic document feeder (ADF)")
-
-		request = []byte("\x1bD\nADF\n\x80")
-		SendPacket(socket, request)
-
-		ReadPacket(socket)
-	}
-
-	log.Println("Sending scan request...")
-
-	offerOptions := strings.Split(offer, ",")
-
-	width, height := 0, 0
-	fmt.Sscanf(offerOptions[4], "%d", &width)
-	fmt.Sscanf(offerOptions[6], "%d", &height)
-
-	requestFormat := "\x1bX\nR=%v,%v\nM=%s\nC=%s\nJ=MID\nB=50\nN=50\nA=0,0,%v,%v\n\x80"
-
-	request = []byte(fmt.Sprintf(requestFormat, offerOptions[1], offerOptions[1], mode, compression, width, height))
-	SendPacket(socket, request)
-
-	log.Println("Scanning started...")
-
-	return width, height
-}
-
-func GetScanBytes(socket net.Conn) []byte {
-	log.Println("Getting packets...")
-
-	packet := make([]byte, 2048)
-	scanBytes := make([]byte, 0)
-
-readPackets:
-	for {
-		socket.SetDeadline(time.Now().Add(time.Second * 5))
-		bytes, err := socket.Read(packet)
-
-		switch err := err.(type) {
-		case net.Error:
-			if err.Timeout() {
-				break readPackets
-			}
-
-		case nil:
-			scanBytes = append(scanBytes, packet[:bytes]...)
-
-		default:
-			HandleError(err)
-		}
-	}
-
-	return scanBytes
-}
-
-func SaveImage(data []byte, width int, height int, name string, color string) {
-
-	log.Println("Saving image...")
-
-	_, compression := GetCompressionMode(color)
-
-	if compression != "JPEG" {
-
-		img := image.NewGray(image.Rectangle{
-			image.Point{0, 0},
-			image.Point{width, height},
-		})
-
-		for y := 0; y < height-40; y++ {
-
-			for x := 0; x < width; x++ {
-				img.SetGray(x, y, colorToGray(data[y*width+x]))
-			}
-		}
-
-		file, _ := os.Create(name)
-		png.Encode(file, img)
-
-	} else {
-		os.WriteFile(name, data, 0644)
-	}
-}
-
-func colorToGray(byte byte) color.Gray {
-	return color.Gray{Y: byte}
-}
-
-func HandleError(err error) {
-
-	if err != nil {
-		log.Fatal(err)
-		os.Exit(1)
-	}
-}
-
-func GetCompressionMode(_mode string) (string, string) {
-
-	if _mode == "GRAY64" {
-		return _mode, "NONE"
-	} else {
-		return "CGRAY", "JPEG"
-	}
-}
-
-func RemoveHeaders(scan []byte) []byte {
-	log.Println("Removing headers from bytes...")
-
-	const headerLen int = 12
-
-	payloadLen := binary.LittleEndian.Uint16(scan[headerLen-2 : headerLen])
-	chunkSize := int(payloadLen) + headerLen
-	scanOutput := make([]byte, 0)
-
-	for i := 0; i < len(scan)-chunkSize; i += chunkSize {
-		scanOutput = append(scanOutput, scan[i+headerLen:i+chunkSize]...)
-	}
-
-	return scanOutput
-}
-
-func SendPacket(socket net.Conn, packet []byte) {
-	_, err := socket.Write(packet)
-	HandleError(err)
-}
-
-func ReadPacket(socket net.Conn) string {
-	reply := make([]byte, 64)
-
-	_, err := socket.Read(reply)
-	HandleError(err)
-
-	return string(reply)
 }

src/utils.go

@@ -0,0 +1,43 @@
+package main
+
+import (
+	"image/color"
+	"log"
+	"net"
+	"os"
+)
+
+func SendPacket(socket net.Conn, packet []byte) {
+	_, err := socket.Write(packet)
+	HandleError(err)
+}
+
+func ReadPacket(socket net.Conn) string {
+	reply := make([]byte, 64)
+
+	_, err := socket.Read(reply)
+	HandleError(err)
+
+	return string(reply)
+}
+
+func HandleError(err error) {
+
+	if err != nil {
+		log.Fatal(err)
+		os.Exit(1)
+	}
+}
+
+func GetCompressionMode(_mode string) (string, string) {
+
+	if _mode == "GRAY64" {
+		return _mode, "NONE"
+	} else {
+		return "CGRAY", "JPEG"
+	}
+}
+
+func colorToGray(byte byte) color.Gray {
+	return color.Gray{Y: byte}
+}