Adding upstream version 0.8.9.

Signed-off-by: Daniel Baumann <daniel@debian.org>

pkg/services/generic/custom_query.go

@@ -0,0 +1,74 @@
+package generic
+
+import (
+	"net/url"
+	"strings"
+)
+
+// Constants for character values and offsets.
+const (
+	ExtraPrefixChar      = '$'       // Prefix for extra data in query parameters
+	HeaderPrefixChar     = '@'       // Prefix for header values in query parameters
+	CaseOffset           = 'a' - 'A' // Offset between lowercase and uppercase letters
+	UppercaseA           = 'A'       // ASCII value for uppercase A
+	UppercaseZ           = 'Z'       // ASCII value for uppercase Z
+	DashChar             = '-'       // Dash character for header formatting
+	HeaderCapacityFactor = 2         // Estimated capacity multiplier for header string builder
+)
+
+func normalizedHeaderKey(key string) string {
+	stringBuilder := strings.Builder{}
+	stringBuilder.Grow(len(key) * HeaderCapacityFactor)
+
+	for i, c := range key {
+		if UppercaseA <= c && c <= UppercaseZ {
+			// Char is uppercase
+			if i > 0 && key[i-1] != DashChar {
+				// Add missing dash
+				stringBuilder.WriteRune(DashChar)
+			}
+		} else if i == 0 || key[i-1] == DashChar {
+			// First char, or previous was dash
+			c -= CaseOffset
+		}
+
+		stringBuilder.WriteRune(c)
+	}
+
+	return stringBuilder.String()
+}
+
+func appendCustomQueryValues(
+	query url.Values,
+	headers map[string]string,
+	extraData map[string]string,
+) {
+	for key, value := range headers {
+		query.Set(string(HeaderPrefixChar)+key, value)
+	}
+
+	for key, value := range extraData {
+		query.Set(string(ExtraPrefixChar)+key, value)
+	}
+}
+
+func stripCustomQueryValues(query url.Values) (map[string]string, map[string]string) {
+	headers := make(map[string]string)
+	extraData := make(map[string]string)
+
+	for key, values := range query {
+		switch key[0] {
+		case HeaderPrefixChar:
+			headerKey := normalizedHeaderKey(key[1:])
+			headers[headerKey] = values[0]
+		case ExtraPrefixChar:
+			extraData[key[1:]] = values[0]
+		default:
+			continue
+		}
+
+		delete(query, key)
+	}
+
+	return headers, extraData
+}