add URL utils

base/url.go

@@ -0,0 +1,88 @@
+package base
+
+import (
+	"strings"
+	"net/url"
+)
+
+func stringsReverseIndexByte(s string, c byte) int {
+	for i := len(s) - 1; i >= 0; i-- {
+		if s[i] == c {
+			return i
+		}
+	}
+	return -1
+}
+
+// URLGetBasePath returns the base path of a RTSP URL.
+// We assume that the URL doesn't contain a control path.
+func URLGetBasePath(u *url.URL) string {
+	if u.RawPath != "" {
+		return u.RawPath[1:] // remove leading slash
+	}
+	return u.Path[1:] // remove leading slash
+}
+
+// URLGetBaseControlPath returns the base path and the control path of a RTSP URL.
+// We assume that the URL contains a control path.
+func URLGetBaseControlPath(u *url.URL) (string, string, bool) {
+	pathAndQuery := ""
+	if u.RawPath != "" {
+		pathAndQuery += u.RawPath
+	} else {
+		pathAndQuery += u.Path
+	}
+	if u.RawQuery != "" {
+		pathAndQuery += "?" + u.RawQuery
+	}
+
+	pathAndQuery = pathAndQuery[1:] // remove leading slash
+
+	pos := stringsReverseIndexByte(pathAndQuery, '/')
+	if pos < 0 {
+		return "", "", false
+	}
+
+	basePath := pathAndQuery[:pos]
+
+	// remove query from basePath
+	i := strings.IndexByte(basePath, '?')
+	if i >= 0 {
+		basePath = basePath[:i]
+	}
+
+	if len(basePath) == 0 {
+		return "", "", false
+	}
+
+	controlPath := pathAndQuery[pos+1:]
+	if len(controlPath) == 0 {
+		return "", "", false
+	}
+
+	return basePath, controlPath, true
+}
+
+// URLAddControlPath adds a control path to a RTSP url.
+func URLAddControlPath(u *url.URL, controlPath string) {
+	// always insert the control path at the end of the url
+	if u.RawQuery != "" {
+		if !strings.HasSuffix(u.RawQuery, "/") {
+			u.RawQuery += "/"
+		}
+		u.RawQuery += controlPath
+
+	} else {
+		if u.RawPath != "" {
+			if !strings.HasSuffix(u.RawPath, "/") {
+				u.RawPath += "/"
+			}
+			u.RawPath += controlPath
+		}
+
+		if !strings.HasSuffix(u.Path, "/") {
+			u.Path += "/"
+		}
+		u.Path += controlPath
+	}
+}