Adding upstream version 2.52.6.

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

middleware/logger/template_chain.go

@@ -0,0 +1,70 @@
+package logger
+
+import (
+	"bytes"
+	"errors"
+
+	"github.com/gofiber/fiber/v2/utils"
+)
+
+// buildLogFuncChain analyzes the template and creates slices with the functions for execution and
+// slices with the fixed parts of the template and the parameters
+//
+// fixParts contains the fixed parts of the template or parameters if a function is stored in the funcChain at this position
+// funcChain contains for the parts which exist the functions for the dynamic parts
+// funcChain and fixParts always have the same length and contain nil for the parts where no data is required in the chain,
+// if a function exists for the part, a parameter for it can also exist in the fixParts slice
+func buildLogFuncChain(cfg *Config, tagFunctions map[string]LogFunc) ([][]byte, []LogFunc, error) {
+	// process flow is copied from the fasttemplate flow https://github.com/valyala/fasttemplate/blob/2a2d1afadadf9715bfa19683cdaeac8347e5d9f9/template.go#L23-L62
+	templateB := utils.UnsafeBytes(cfg.Format)
+	startTagB := utils.UnsafeBytes(startTag)
+	endTagB := utils.UnsafeBytes(endTag)
+	paramSeparatorB := utils.UnsafeBytes(paramSeparator)
+
+	var fixParts [][]byte
+	var funcChain []LogFunc
+
+	for {
+		currentPos := bytes.Index(templateB, startTagB)
+		if currentPos < 0 {
+			// no starting tag found in the existing template part
+			break
+		}
+		// add fixed part
+		funcChain = append(funcChain, nil)
+		fixParts = append(fixParts, templateB[:currentPos])
+
+		templateB = templateB[currentPos+len(startTagB):]
+		currentPos = bytes.Index(templateB, endTagB)
+		if currentPos < 0 {
+			// cannot find end tag - just write it to the output.
+			funcChain = append(funcChain, nil)
+			fixParts = append(fixParts, startTagB)
+			break
+		}
+		// ## function block ##
+		// first check for tags with parameters
+		if index := bytes.Index(templateB[:currentPos], paramSeparatorB); index != -1 {
+			logFunc, ok := tagFunctions[utils.UnsafeString(templateB[:index+1])]
+			if !ok {
+				return nil, nil, errors.New("No parameter found in \"" + utils.UnsafeString(templateB[:currentPos]) + "\"")
+			}
+			funcChain = append(funcChain, logFunc)
+			// add param to the fixParts
+			fixParts = append(fixParts, templateB[index+1:currentPos])
+		} else if logFunc, ok := tagFunctions[utils.UnsafeString(templateB[:currentPos])]; ok {
+			// add functions without parameter
+			funcChain = append(funcChain, logFunc)
+			fixParts = append(fixParts, nil)
+		}
+		// ## function block end ##
+
+		// reduce the template string
+		templateB = templateB[currentPos+len(endTagB):]
+	}
+	// set the rest
+	funcChain = append(funcChain, nil)
+	fixParts = append(fixParts, templateB)
+
+	return fixParts, funcChain, nil
+}