First cut

usbid/parse.go

@@ -0,0 +1,162 @@
+package usbid
+
+import (
+	"bufio"
+	"fmt"
+	"io"
+	"strconv"
+	"strings"
+
+	"github.com/kylelemons/gousb/usb"
+)
+
+type Vendor struct {
+	Name    string
+	Devices map[usb.ID]*Device
+}
+
+func (v Vendor) String() string {
+	return v.Name
+}
+
+// TODO(kevlar) s/device/
+type Device struct {
+	Name       string
+	Interfaces map[usb.ID]string
+}
+
+func (d Device) String() string {
+	return d.Name
+}
+
+/*
+type Class struct {
+	Name string
+	SubClass map[usb.ID]*SubClass
+}
+
+type SubClass struct {
+	Name string
+	Protocol map[usb.ID]string
+}
+*/
+
+func ParseIDs(r io.Reader) (map[usb.ID]*Vendor, error) {
+	vendors := make(map[usb.ID]*Vendor, 2800)
+
+	split := func(s string) (kind string, level int, id usb.ID, name string, err error) {
+		pieces := strings.SplitN(s, "  ", 2)
+		if len(pieces) != 2 {
+			err = fmt.Errorf("malformatted line %q", s)
+			return
+		}
+
+		// Save the name
+		name = pieces[1]
+
+		// Parse out the level
+		for len(pieces[0]) > 0 && pieces[0][0] == '\t' {
+			level, pieces[0] = level+1, pieces[0][1:]
+		}
+
+		// Parse the first piece to see if it has a kind
+		first := strings.SplitN(pieces[0], " ", 2)
+		if len(first) == 2 {
+			kind, pieces[0] = first[0], first[1]
+		}
+
+		// Parse the ID
+		i, err := strconv.ParseUint(pieces[0], 16, 16)
+		if err != nil {
+			err = fmt.Errorf("malformatted id %q: %s", pieces[0], err)
+			return
+		}
+		id = usb.ID(i)
+		
+		return
+	}
+
+	// Hold the interim values
+	var vendor *Vendor
+	var device *Device
+
+	parseVendor := func(level int, id usb.ID, name string) error {
+		switch level {
+		case 0:
+			vendor = &Vendor{
+				Name: name,
+			}
+			vendors[id] = vendor
+
+		case 1:
+			if vendor == nil {
+				return fmt.Errorf("product line without vendor line")
+			}
+
+			device = &Device{
+				Name: name,
+			}
+			if vendor.Devices == nil {
+				vendor.Devices = make(map[usb.ID]*Device)
+			}
+			vendor.Devices[id] = device
+
+		case 2:
+			if device == nil {
+				return fmt.Errorf("interface line without device line")
+			}
+
+			if device.Interfaces == nil {
+				device.Interfaces = make(map[usb.ID]string)
+			}
+			device.Interfaces[id] = name
+
+		default:
+			return fmt.Errorf("too many levels of nesting for vendor block")
+		}
+
+		return nil
+	}
+
+	// TODO(kevlar): Parse class information, etc
+	//var class *Class
+	//var subclass *SubClass
+
+	var kind string
+
+	lines := bufio.NewReaderSize(r, 512)
+parseLines:
+	for lineno := 0; ; lineno++ {
+		b, isPrefix, err := lines.ReadLine()
+		switch {
+		case err == io.EOF:
+			break parseLines
+		case err != nil:
+			return nil, err
+		case isPrefix:
+			return nil, fmt.Errorf("line %d: line too long", lineno)
+		}
+		line := string(b)
+
+		if len(line) == 0 || line[0] == '#' {
+			continue
+		}
+
+		k, level, id, name, err := split(line)
+		if err != nil {
+			return nil, fmt.Errorf("line %d: %s", lineno, err)
+		}
+		if k != "" {
+			kind = k
+		}
+
+		switch kind {
+		case "": err = parseVendor(level, id, name)
+		}
+		if err != nil {
+			return nil, fmt.Errorf("line %d: %s", lineno, err)
+		}
+	}
+
+	return vendors, nil
+}