/
normalize.go
223 lines (206 loc) · 5.06 KB
/
normalize.go
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/*
* Package normalize normalizes URLs
*/
package normalize
import (
"fmt"
"net/url"
"regexp"
"sort"
"strings"
)
var ipv6Regexp, _ = regexp.Compile("([0-9A-F]+:)+[0-9A-F]+")
var ipv4Regexp, _ = regexp.Compile("([0-9]+[.])+[0-9]+")
func Normalize(url *url.URL) {
addSlash(url)
removeDefaultPort(url)
lowerCaseScheme(url)
lowerCaseDomain(url)
removeDoubleSlashes(url)
removeDirectoryDots(url)
}
func removeDirectoryDots(url *url.URL) {
url.Path = strings.Replace(url.Path, "/./", "/", -1)
if strings.Contains(url.Path, "..") {
seg := strings.Split(url.Path, "/")
stk := NewStack(1000)
for _, s := range seg {
if len(s) == 0 {
continue
}
if strings.EqualFold(s, string("..")) {
stk.Pop()
} else {
stk.Push(s)
}
}
if stk.Top > 0 {
r := stk.Data[0:stk.Top]
url.Path = fmt.Sprintf("/%s/", strings.Join(r, "/"))
}
}
}
func removeDoubleSlashes(url *url.URL) {
url.Path = strings.Replace(url.Path, "//", "/", -1)
}
func lowerCaseDomain(url *url.URL) {
url.Host = strings.ToLower(url.Host)
}
func lowerCaseScheme(url *url.URL) {
url.Scheme = strings.ToLower(url.Scheme)
}
func removeDefaultPort(url *url.URL) {
/*
* Have to ensure that not removing the last part of an ipv6
* address if it happens to be :80 as unlikely as that may be.
*/
host := url.Host
if host[len(host)-3:] == ":80" {
if found := ipv6Regexp.FindStringIndex(url.Host); found != nil {
if strings.Count(host, ":") < 8 {
return
}
}
url.Host = host[:len(host)-3]
}
}
func addSlash(url *url.URL) {
if len(url.Path) == 0 {
url.Path = "/"
}
}
/*
* Removes directory indexes when they point to the same place as
* the directory. For example if index.html points to / and
* index.html is given for the index parameter it will be removed
* from the URL
*/
func RemoveDirectoryIndex(url *url.URL, index string) {
pathLen := len(url.Path)
indexLen := len(index)
if pathLen >= indexLen {
if url.Path[pathLen-indexLen:] == index {
url.Path = url.Path[:pathLen-indexLen]
}
}
}
/*
* Ordes query variables in alphabetic order. Order of variables
* in a query string should not matter, but some implementations
* may require an order, so this is in a separate emthod.
*/
func NormalizeQueryVariableOrder(url *url.URL) {
keys := []string{}
values := url.Query()
for k, _ := range values {
keys = append(keys, k)
}
sort.Strings(keys)
variables := []string{}
for _, key := range keys {
for _, value := range values[key] {
if len(value) > 0 {
variables = append(variables, key+"="+value)
} else {
variables = append(variables, key)
}
}
}
url.RawQuery = strings.Join(variables, "&")
}
/*
* Remove query variables that have default values. Provide a set of defaults
* (defaults[key] = value) wher key is the variable name and value is the string
* represenation of the default value.
*/
func RemoveDefaultQueryValues(url *url.URL, defaults map[string]string) {
keys := []string{}
values := url.Query()
for k, _ := range values {
keys = append(keys, k)
}
variables := []string{}
for _, key := range keys {
defaultValue, ok := defaults[key]
for _, value := range values[key] {
if len(value) > 0 {
if !ok || value != defaultValue {
variables = append(variables, key+"="+value)
}
} else {
variables = append(variables, key)
}
}
}
url.RawQuery = strings.Join(variables, "&")
}
/*
* Removes www. from a URL. Use if www. points to same resource as
* non-www address.
*/
func NormalizeWWW(url *url.URL, showWWW bool) {
var foundWWW bool
if found := ipv6Regexp.FindStringIndex(url.Host); found != nil {
return
}
if found := ipv4Regexp.FindStringIndex(url.Host); found != nil {
return
}
if len(url.Host) <= 4 {
foundWWW = false
} else {
foundWWW = url.Host[:4] == "www."
}
if showWWW && !foundWWW {
url.Host = "www." + url.Host
} else if !showWWW && foundWWW {
url.Host = url.Host[4:]
}
}
/*
* Remove arbitary query variables. Include a slice of array variables
* to check against. If query variables are found not in the given slice,
* they are removed.
*/
func NormalizeQuery(url *url.URL, params []string) {
keys := []string{}
values := url.Query()
for k, _ := range values {
keys = append(keys, k)
}
variables := []string{}
for _, key := range keys {
for _, expectedParam := range params {
if expectedParam == key {
for _, value := range values[key] {
if len(value) > 0 {
variables = append(variables, key+"="+value)
} else {
variables = append(variables, key)
}
}
}
}
}
url.RawQuery = strings.Join(variables, "&")
}
/*
* Normalize scheme or protocol. For example if valid scheme is url
* and not urls, url is changed to url if 'url' is given as scheme.
*/
func NormalizeScheme(url *url.URL, scheme string) {
url.Scheme = scheme
}
/*
* Remove #fragment from a URL.
*/
func RemoveFragment(url *url.URL) {
url.Fragment = ""
}
/*
* Replaces domain or IP with given domain. Use to replace IP addresses with
* domain or domains that point to the same resource as prime domain.
*/
func NormalizeDomain(url *url.URL, domain string) {
url.Host = domain
}