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utils

// Copyright 2014 Manu Martinez-Almeida.  All rights reserved.
// Use of this source code is governed by a MIT style
// license that can be found in the LICENSE file.

package gin

import (
"encoding/xml"
"net/http"
"os"
"path"
"reflect"
"runtime"
"strings"
)

// BindKey indicates a default bind key.
const BindKey = "_gin-gonic/gin/bindkey"

// Bind is a helper function for given interface object and returns a Gin middleware.
func Bind(val interface{}) HandlerFunc {
value := reflect.ValueOf(val)
if value.Kind() == reflect.Ptr {
panic(`Bind struct can not be a pointer. Example:
Use: gin.Bind(Struct{}) instead of gin.Bind(&Struct{})
`)
}
typ := value.Type()

return func(c *Context) {
obj := reflect.New(typ).Interface()
if c.Bind(obj) == nil {
c.Set(BindKey, obj)
}
}
}

// WrapF is a helper function for wrapping http.HandlerFunc and returns a Gin middleware.
func WrapF(f http.HandlerFunc) HandlerFunc {
return func(c *Context) {
f(c.Writer, c.Request)
}
}

// WrapH is a helper function for wrapping http.Handler and returns a Gin middleware.
func WrapH(h http.Handler) HandlerFunc {
return func(c *Context) {
h.ServeHTTP(c.Writer, c.Request)
}
}

// H is a shortcut for map[string]interface{}
type H map[string]interface{}

// MarshalXML allows type H to be used with xml.Marshal.
func (h H) MarshalXML(e *xml.Encoder, start xml.StartElement) error {
start.Name = xml.Name{
Space: "",
Local: "map",
}
if err := e.EncodeToken(start); err != nil {
return err
}
for key, value := range h {
elem := xml.StartElement{
Name: xml.Name{Space: "", Local: key},
Attr: []xml.Attr{},
}
if err := e.EncodeElement(value, elem); err != nil {
return err
}
}

return e.EncodeToken(xml.EndElement{Name: start.Name})
}

func assert1(guard bool, text string) {
if !guard {
panic(text)
}
}

func filterFlags(content string) string {
for i, char := range content {
if char == ' ' || char == ';' {
return content[:i]
}
}
return content
}

func chooseData(custom, wildcard interface{}) interface{} {
if custom != nil {
return custom
}
if wildcard != nil {
return wildcard
}
panic("negotiation config is invalid")
}

func parseAccept(acceptHeader string) []string {
parts := strings.Split(acceptHeader, ",")
out := make([]string, 0, len(parts))
for _, part := range parts {
if i := strings.IndexByte(part, ';'); i > 0 {
part = part[:i]
}
if part = strings.TrimSpace(part); part != "" {
out = append(out, part)
}
}
return out
}

func lastChar(str string) uint8 {
if str == "" {
panic("The length of the string can't be 0")
}
return str[len(str)-1]
}

func nameOfFunction(f interface{}) string {
return runtime.FuncForPC(reflect.ValueOf(f).Pointer()).Name()
}

func joinPaths(absolutePath, relativePath string) string {
if relativePath == "" {
return absolutePath
}

finalPath := path.Join(absolutePath, relativePath)
if lastChar(relativePath) == '/' && lastChar(finalPath) != '/' {
return finalPath + "/"
}
return finalPath
}

func resolveAddress(addr []string) string {
switch len(addr) {
case 0:
if port := os.Getenv("PORT"); port != "" {
debugPrint("Environment variable PORT=\"%s\"", port)
return ":" + port
}
debugPrint("Environment variable PORT is undefined. Using port :8080 by default")
return ":8080"
case 1:
return addr[0]
default:
panic("too many parameters")
}
}