Merge pull request #6149 from bhandras/graph_import_rpc

lnd: add `devrpc` sub server and `devrpc.ImportGraph` to import graph dumps

lncfg/color.go

@@ -0,0 +1,34 @@
+package lncfg
+
+import (
+	"encoding/hex"
+	"errors"
+	"image/color"
+	"regexp"
+)
+
+var (
+	// validColorRegexp is a regexp that lets you check if a particular
+	// color string matches the standard hex color format #RRGGBB.
+	validColorRegexp = regexp.MustCompile("^#[A-Fa-f0-9]{6}$")
+)
+
+// ParseHexColor takes a hex string representation of a color in the
+// form "#RRGGBB", parses the hex color values, and returns a color.RGBA
+// struct of the same color.
+func ParseHexColor(colorStr string) (color.RGBA, error) {
+	// Check if the hex color string is a valid color representation.
+	if !validColorRegexp.MatchString(colorStr) {
+		return color.RGBA{}, errors.New("color must be specified " +
+			"using a hexadecimal value in the form #RRGGBB")
+	}
+
+	// Decode the hex color string to bytes.
+	// The resulting byte array is in the form [R, G, B].
+	colorBytes, err := hex.DecodeString(colorStr[1:])
+	if err != nil {
+		return color.RGBA{}, err
+	}
+
+	return color.RGBA{R: colorBytes[0], G: colorBytes[1], B: colorBytes[2]}, nil
+}

lncfg/color_test.go

@@ -0,0 +1,43 @@
+package lncfg
+
+import (
+	"testing"
+)
+
+func TestParseHexColor(t *testing.T) {
+	var colorTestCases = []struct {
+		test  string
+		valid bool // If valid format
+		R     byte
+		G     byte
+		B     byte
+	}{
+		{"#123", false, 0, 0, 0},
+		{"#1234567", false, 0, 0, 0},
+		{"$123456", false, 0, 0, 0},
+		{"#12345+", false, 0, 0, 0},
+		{"#fFGG00", false, 0, 0, 0},
+		{"", false, 0, 0, 0},
+		{"#123456", true, 0x12, 0x34, 0x56},
+		{"#C0FfeE", true, 0xc0, 0xff, 0xee},
+	}
+
+	// Perform the table driven tests.
+	for _, ct := range colorTestCases {
+
+		color, err := ParseHexColor(ct.test)
+		if !ct.valid && err == nil {
+			t.Fatalf("Invalid color string: %s, should return "+
+				"error, but did not", ct.test)
+		}
+
+		if ct.valid && err != nil {
+			t.Fatalf("Color %s valid to parse: %s", ct.test, err)
+		}
+
+		// Ensure that the string to hex decoding is working properly.
+		if color.R != ct.R || color.G != ct.G || color.B != ct.B {
+			t.Fatalf("Color %s incorrectly parsed as %v", ct.test, color)
+		}
+	}
+}