Merge pull request #27 from kylelemons/rawread_benchmark

Rawread improvements

rawread/main.go

@@ -20,20 +20,58 @@ import (
 	"flag"
 	"fmt"
 	"log"
+	"os"
+	"strconv"
+	"strings"
 
 	"github.com/kylelemons/gousb/usb"
 	"github.com/kylelemons/gousb/usbid"
 )
 
 var (
-	device   = flag.String("device", "vend:prod", "Device to which to connect")
-	config   = flag.Int("config", 1, "Endpoint to which to connect")
-	iface    = flag.Int("interface", 0, "Endpoint to which to connect")
-	setup    = flag.Int("setup", 0, "Endpoint to which to connect")
-	endpoint = flag.Int("endpoint", 1, "Endpoint to which to connect")
+	vidPID   = flag.String("vidpid", "", "VID:PID of the device to which to connect. Exclusive with busaddr flag.")
+	busAddr  = flag.String("busaddr", "", "Bus:address of the device to which to connect. Exclusive with vidpid flag.")
+	config   = flag.Uint("config", 1, "Endpoint to which to connect")
+	iface    = flag.Uint("interface", 0, "Endpoint to which to connect")
+	setup    = flag.Uint("setup", 0, "Endpoint to which to connect")
+	endpoint = flag.Uint("endpoint", 1, "Endpoint to which to connect")
 	debug    = flag.Int("debug", 3, "Debug level for libusb")
+	size     = flag.Uint("read_size", 1024, "Number of bytes of data to read in a single transaction.")
+	num      = flag.Uint("read_num", 0, "Number of read transactions to perform. 0 means infinite.")
 )
 
+func parseVIDPID(vidPid string) (usb.ID, usb.ID, error) {
+	s := strings.Split(vidPid, ":")
+	if len(s) != 2 {
+		return 0, 0, fmt.Errorf("want VID:PID, two 32-bit hex numbers separated by colon, e.g. 1d6b:0002")
+	}
+	vid, err := strconv.ParseUint(s[0], 16, 32)
+	if err != nil {
+		return 0, 0, fmt.Errorf("VID must be a hexadecimal 32-bit number, e.g. 1d6b")
+	}
+	pid, err := strconv.ParseUint(s[1], 16, 32)
+	if err != nil {
+		return 0, 0, fmt.Errorf("PID must be a hexadecimal 32-bit number, e.g. 1d6b")
+	}
+	return usb.ID(vid), usb.ID(pid), nil
+}
+
+func parseBusAddr(busAddr string) (uint8, uint8, error) {
+	s := strings.Split(busAddr, ":")
+	if len(s) != 2 {
+		return 0, 0, fmt.Errorf("want bus:addr, two 8-bit decimal unsigned integers separated by colon, e.g. 1:1")
+	}
+	bus, err := strconv.ParseUint(s[0], 10, 8)
+	if err != nil {
+		return 0, 0, fmt.Errorf("bus number must be an 8-bit decimal unsigned integer")
+	}
+	addr, err := strconv.ParseUint(s[1], 10, 8)
+	if err != nil {
+		return 0, 0, fmt.Errorf("device address must be an 8-bit decimal unsigned integer")
+	}
+	return uint8(bus), uint8(addr), nil
+}
+
 func main() {
 	flag.Parse()
 
@@ -43,40 +81,41 @@ func main() {
 
 	ctx.Debug(*debug)
 
-	log.Printf("Scanning for device %q...", *device)
+	var devName string
+	var vid, pid usb.ID
+	var bus, addr uint8
+	switch {
+	case *vidPID == "" && *busAddr == "":
+		log.Fatal("You need to specify the device through a --vidpid flag or through a --busaddr flag.")
+	case *vidPID != "" && *busAddr != "":
+		log.Fatal("You can't use --vidpid flag together with --busaddr. Pick one.")
+	case *vidPID != "":
+		var err error
+		vid, pid, err = parseVIDPID(*vidPID)
+		if err != nil {
+			log.Fatalf("Invalid value for --vidpid (%q): %v", *vidPID, err)
+		}
+		devName = fmt.Sprintf("VID:PID %s:%s", vid, pid)
+	default:
+		var err error
+		bus, addr, err = parseBusAddr(*busAddr)
+		if err != nil {
+			log.Fatalf("Invalid value for --busaddr (%q): %v", *busAddr, err)
+		}
+		devName = fmt.Sprintf("bus:addr %d:%d", bus, addr)
+	}
 
+	log.Printf("Scanning for device %q...", devName)
 	// ListDevices is used to find the devices to open.
 	devs, err := ctx.ListDevices(func(desc *usb.Descriptor) bool {
-		if fmt.Sprintf("%s:%s", desc.Vendor, desc.Product) != *device {
-			return false
+		switch {
+		case vid == desc.Vendor && pid == desc.Product:
+			return true
+		case bus == desc.Bus && addr == desc.Address:
+			return true
 		}
-
-		// The usbid package can be used to print out human readable information.
-		fmt.Printf("  Protocol: %s\n", usbid.Classify(desc))
-
-		// The configurations can be examined from the Descriptor, though they can only
-		// be set once the device is opened.  All configuration references must be closed,
-		// to free up the memory in libusb.
-		for _, cfg := range desc.Configs {
-			// This loop just uses more of the built-in and usbid pretty printing to list
-			// the USB devices.
-			fmt.Printf("  %s:\n", cfg)
-			for _, alt := range cfg.Interfaces {
-				fmt.Printf("    --------------\n")
-				for _, iface := range alt.Setups {
-					fmt.Printf("    %s\n", iface)
-					fmt.Printf("      %s\n", usbid.Classify(iface))
-					for _, end := range iface.Endpoints {
-						fmt.Printf("      %s\n", end)
-					}
-				}
-			}
-			fmt.Printf("    --------------\n")
-		}
-
-		return true
+		return false
 	})
-
 	// All Devices returned from ListDevices must be closed.
 	defer func() {
 		for _, d := range devs {
@@ -84,22 +123,58 @@ func main() {
 		}
 	}()
 
-	// ListDevices can occaionally fail, so be sure to check its return value.
+	// ListDevices can occasionally fail, so be sure to check its return value.
 	if err != nil {
-		log.Fatalf("list: %s", err)
+		log.Printf("Warning: ListDevices: %s.", err)
 	}
-
-	if len(devs) == 0 {
-		log.Fatalf("no devices found")
+	switch {
+	case len(devs) == 0:
+		log.Fatal("No matching devices found.")
+	case len(devs) > 1:
+		log.Printf("Warning: multiple devices found. Using bus %d, addr %d.", devs[0].Bus, devs[0].Address)
+		for _, d := range devs[1:] {
+			d.Close()
+		}
+		devs = devs[:1]
 	}
-
 	dev := devs[0]
 
-	log.Printf("Connecting to endpoint...")
-	log.Printf("- %#v", dev.Descriptor)
+	// The usbid package can be used to print out human readable information.
+	log.Printf("  Protocol: %s\n", usbid.Classify(dev.Descriptor))
+
+	// The configurations can be examined from the Descriptor, though they can only
+	// be set once the device is opened.  All configuration references must be closed,
+	// to free up the memory in libusb.
+	for _, cfg := range dev.Configs {
+		// This loop just uses more of the built-in and usbid pretty printing to list
+		// the USB devices.
+		log.Printf("  %s:\n", cfg)
+		for _, alt := range cfg.Interfaces {
+			log.Printf("    --------------\n")
+			for _, iface := range alt.Setups {
+				log.Printf("    %s\n", iface)
+				log.Printf("      %s\n", usbid.Classify(iface))
+				for _, end := range iface.Endpoints {
+					log.Printf("      %s\n", end)
+				}
+			}
+		}
+		log.Printf("    --------------\n")
+	}
+
+	log.Printf("Connecting to endpoint %d...", *endpoint)
 	ep, err := dev.OpenEndpoint(uint8(*config), uint8(*iface), uint8(*setup), uint8(*endpoint)|uint8(usb.ENDPOINT_DIR_IN))
 	if err != nil {
 		log.Fatalf("open: %s", err)
 	}
-	_ = ep
+	log.Print("Reading...")
+
+	buf := make([]byte, *size)
+	for i := uint(0); *num == 0 || i < *num; i++ {
+		num, err := ep.Read(buf)
+		if err != nil {
+			log.Fatalf("Reading from device failed: %v", err)
+		}
+		os.Stdout.Write(buf[:num])
+	}
 }

usb/constants.go

@@ -87,7 +87,7 @@ func (dt DescriptorType) String() string {
 type EndpointDirection uint8
 
 const (
-	ENDPOINT_NUM_MASK                   = 0x03
+	ENDPOINT_NUM_MASK                   = 0x0f
 	ENDPOINT_DIR_IN   EndpointDirection = C.LIBUSB_ENDPOINT_IN
 	ENDPOINT_DIR_OUT  EndpointDirection = C.LIBUSB_ENDPOINT_OUT
 	ENDPOINT_DIR_MASK EndpointDirection = 0x80

usb/iso.c

@@ -74,8 +74,8 @@ int extract_data(struct libusb_transfer *xfer, void *raw, int max, unsigned char
 
 		// Copy the data
 		int len = pkt.actual_length;
-		if (len > max) {
-			len = max;
+		if (copied + len > max) {
+			len = max - copied;
 		}
 		memcpy(out, in, len);
 		copied += len;
@@ -84,10 +84,14 @@ int extract_data(struct libusb_transfer *xfer, void *raw, int max, unsigned char
 		in += pkt.length;
 		out += len;
 
+        if (copied == max) {
+                break;
+        }
+
 		// Extract first error
 		if (pkt.status == 0 || *status != 0) {
 			continue;
-		}	
+		}
 		*status = pkt.status;
 	}
 	return copied;

usb/iso.go

@@ -37,18 +37,21 @@ func iso_callback(cptr unsafe.Pointer) {
 	close(ch)
 }
 
-func (end *endpoint) allocTransfer() *Transfer {
-	const (
-		iso_packets = 8 // 128 // 242
-	)
-
-	xfer := C.libusb_alloc_transfer(C.int(iso_packets))
+func (end *endpoint) allocTransfer(maxLen int) *Transfer {
+	isoPacketSize := end.EndpointInfo.MaxIsoPacket
+	// the larget the input buffer, the more packets we use in a single
+	// transfer.
+	numIsoPackets := maxLen / int(isoPacketSize)
+	if numIsoPackets*int(isoPacketSize) < maxLen {
+		numIsoPackets++
+	}
+	xfer := C.libusb_alloc_transfer(C.int(numIsoPackets))
 	if xfer == nil {
 		log.Printf("usb: transfer allocation failed?!")
 		return nil
 	}
 
-	buf := make([]byte, iso_packets*end.EndpointInfo.MaxIsoPacket)
+	buf := make([]byte, numIsoPackets*int(end.EndpointInfo.MaxIsoPacket))
 	done := make(chan struct{}, 1)
 
 	xfer.dev_handle = end.Device.handle
@@ -57,7 +60,7 @@ func (end *endpoint) allocTransfer() *Transfer {
 
 	xfer.buffer = (*C.uchar)((unsafe.Pointer)(&buf[0]))
 	xfer.length = C.int(len(buf))
-	xfer.num_iso_packets = iso_packets
+	xfer.num_iso_packets = C.int(numIsoPackets)
 
 	C.libusb_set_iso_packet_lengths(xfer, C.uint(end.EndpointInfo.MaxIsoPacket))
 	/*
@@ -130,7 +133,7 @@ func (t *Transfer) Close() error {
 }
 
 func isochronous_xfer(e *endpoint, buf []byte, timeout time.Duration) (int, error) {
-	t := e.allocTransfer()
+	t := e.allocTransfer(len(buf))
 	defer t.Close()
 
 	if err := t.Submit(timeout); err != nil {