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// Copyright (c) 2019 Alexander Medvednikov. All rights reserved.
// Use of this source code is governed by an MIT license
// that can be found in the LICENSE file.
// Package url parses URLs and implements query escaping.
// See RFC 3986. This package generally follows RFC 3986, except where
// it deviates for compatibility reasons.
// Based off: https://github.com/golang/go/blob/master/src/net/url/url.go
// Last commit: https://github.com/golang/go/commit/61bb56ad63992a3199acc55b2537c8355ef887b6
// Copyright 2009 The Go Authors. All rights reserved.
// Use of this source code is governed by a BSD-style
// license that can be found in the LICENSE file.
module urllib
import strings
enum EncodingMode {
encode_path
encode_path_segment
encode_host
encode_zone
encode_user_password
encode_query_component
encode_fragment
}
const (
err_msg_escape = 'invalid URL escape'
err_msg_parse = 'error parsing url'
)
fn error_msg(message, val string) string {
mut msg := 'net.urllib: $message'
if val != '' { msg = '$msg ($val)' }
return msg
}
// Return true if the specified character should be escaped when
// appearing in a URL string, according to RFC 3986.
//
// Please be informed that for now should_escape does not check all
// reserved characters correctly. See golang.org/issue/5684.
fn should_escape(c byte, mode EncodingMode) bool {
// §2.3 Unreserved characters (alphanum)
if (`a` <= c && c <= `z`) || (`A` <= c && c <= `Z`) || (`0` <= c && c <= `9`) {
return false
}
if mode == .encode_host || mode == .encode_zone {
// §3.2.2 host allows
// sub-delims = `!` / `$` / `&` / ``` / `(` / `)` / `*` / `+` / `,` / `;` / `=`
// as part of reg-name.
// We add : because we include :port as part of host.
// We add [ ] because we include [ipv6]:port as part of host.
// We add < > because they`re the only characters left that
// we could possibly allow, and parse will reject them if we
// escape them (because hosts can`t use %-encoding for
// ASCII bytes).
switch c {
case `!`, `$`, `&`, `\\`, `(`, `)`, `*`, `+`, `,`, `;`, `=`, `:`, `[`, `]`, `<`, `>`, `"`:
return false
}
}
switch c {
case `-`, `_`, `.`, `~`: // §2.3 Unreserved characters (mark)
return false
case `$`, `&`, `+`, `,`, `/`, `:`, `;`, `=`, `?`, `@`: // §2.2 Reserved characters (reserved)
// Different sections of the URL allow a few of
// the reserved characters to appear unescaped.
switch mode {
case EncodingMode.encode_path: // §3.3
// The RFC allows : @ & = + $ but saves / ; , for assigning
// meaning to individual path segments. This package
// only manipulates the path as a whole, so we allow those
// last three as well. That leaves only ? to escape.
return c == `?`
case EncodingMode.encode_path_segment: // §3.3
// The RFC allows : @ & = + $ but saves / ; , for assigning
// meaning to individual path segments.
return c == `/` || c == `;` || c == `,` || c == `?`
case EncodingMode.encode_user_password: // §3.2.1
// The RFC allows `;`, `:`, `&`, `=`, `+`, `$`, and `,` in
// userinfo, so we must escape only `@`, `/`, and `?`.
// The parsing of userinfo treats `:` as special so we must escape
// that too.
return c == `@` || c == `/` || c == `?` || c == `:`
case EncodingMode.encode_query_component: // §3.4
// The RFC reserves (so we must escape) everything.
return true
case EncodingMode.encode_fragment: // §4.1
// The RFC text is silent but the grammar allows
// everything, so escape nothing.
return false
}
}
if mode == .encode_fragment {
// RFC 3986 §2.2 allows not escaping sub-delims. A subset of sub-delims are
// included in reserved from RFC 2396 §2.2. The remaining sub-delims do not
// need to be escaped. To minimize potential breakage, we apply two restrictions:
// (1) we always escape sub-delims outside of the fragment, and (2) we always
// escape single quote to avoid breaking callers that had previously assumed that
// single quotes would be escaped. See issue #19917.
switch c {
case `!`, `(`, `)`, `*`:
return false
}
}
// Everything else must be escaped.
return true
}
// query_unescape does the inverse transformation of query_escape,
// converting each 3-byte encoded substring of the form '%AB' into the
// hex-decoded byte 0xAB.
// It returns an error if any % is not followed by two hexadecimal
// digits.
pub fn query_unescape(s string) ?string {
return unescape(s, .encode_query_component)
}
// path_unescape does the inverse transformation of path_escape,
// converting each 3-byte encoded substring of the form '%AB' into the
// hex-decoded byte 0xAB. It returns an error if any % is not followed
// by two hexadecimal digits.
//
// path_unescape is identical to query_unescape except that it does not
// unescape '+' to ' ' (space).
pub fn path_unescape(s string) ?string {
return unescape(s, .encode_path_segment)
}
// unescape unescapes a string; the mode specifies
// which section of the URL string is being unescaped.
fn unescape(s_ string, mode EncodingMode) ?string {
mut s := s_
// Count %, check that they're well-formed.
mut n := 0
mut has_plus := false
for i := 0; i < s.len; {
x := s[i]
switch x {
case `%`:
if s == '' {
break
}
n++
if i+2 >= s.len || !ishex(s[i+1]) || !ishex(s[i+2]) {
s = s.right(i)
if s.len > 3 {
s = s.left(3)
}
return error(error_msg(err_msg_escape, s))
}
// Per https://tools.ietf.org/html/rfc3986#page-21
// in the host component %-encoding can only be used
// for non-ASCII bytes.
// But https://tools.ietf.org/html/rfc6874#section-2
// introduces %25 being allowed to escape a percent sign
// in IPv6 scoped-address literals. Yay.
if mode == .encode_host && unhex(s[i+1]) < 8 && s.substr(i, i+3) != '%25' {
return error(error_msg(err_msg_escape, s.substr(i, i+3)))
}
if mode == .encode_zone {
// RFC 6874 says basically 'anything goes' for zone identifiers
// and that even non-ASCII can be redundantly escaped,
// but it seems prudent to restrict %-escaped bytes here to those
// that are valid host name bytes in their unescaped form.
// That is, you can use escaping in the zone identifier but not
// to introduce bytes you couldn't just write directly.
// But Windows puts spaces here! Yay.
v := byte(unhex(s[i+1])<<byte(4) | unhex(s[i+2]))
if s.substr(i, i+3) != '%25' && v != ` ` && should_escape(v, .encode_host) {
error(error_msg(err_msg_escape, s.substr(i, i+3)))
}
}
i += 3
case `+`:
has_plus = mode == .encode_query_component
i++
default:
if (mode == .encode_host || mode == .encode_zone) && s[i] < 0x80 && should_escape(s[i], mode) {
error(error_msg('invalid character in host name', s.substr(i, i+1)))
}
i++
}
}
if n == 0 && !has_plus {
return s
}
mut t := strings.new_builder(s.len - 2*n)
for i := 0; i < s.len; i++ {
x := s[i]
switch x {
case `%`:
t.write( byte(unhex(s[i+1])<<byte(4) | unhex(s[i+2])).str() )
i += 2
case `+`:
if mode == .encode_query_component {
t.write(' ')
} else {
t.write('+')
}
default:
t.write(s[i].str())
}
}
return t.str()
}
// query_escape escapes the string so it can be safely placed
// inside a URL query.
pub fn query_escape(s string) string {
return escape(s, .encode_query_component)
}
// path_escape escapes the string so it can be safely placed inside a URL path segment,
// replacing special characters (including /) with %XX sequences as needed.
pub fn path_escape(s string) string {
return escape(s, .encode_path_segment)
}
fn escape(s string, mode EncodingMode) string {
mut space_count := 0
mut hex_count := 0
mut c := byte(0)
for i := 0; i < s.len; i++ {
c = s[i]
if should_escape(c, mode) {
if c == ` ` && mode == .encode_query_component {
space_count++
} else {
hex_count++
}
}
}
if space_count == 0 && hex_count == 0 {
return s
}
mut buf := [byte(0); 64]
mut t := []byte
required := s.len + 2*hex_count
if required <= buf.len {
t = buf.left(required)
} else {
t = [byte(0); required]
}
if hex_count == 0 {
copy(t, s.bytes())
for i := 0; i < s.len; i++ {
if s[i] == ` ` {
t[i] = `+`
}
}
return string(t)
}
ctab := '0123456789ABCDEF'
mut j := 0
for i := 0; i < s.len; i++ {
c1 := s[i]
if c1 == ` ` && mode == .encode_query_component {
t[j] = `+`
j++
} else if should_escape(c1, mode) {
t[j] = `%`
t[j+1] = ctab[c1>>4]
t[j+2] = ctab[c1&15]
j += 3
} else {
t[j] = s[i]
j++
}
}
return string(t)
}
// A URL represents a parsed URL (technically, a URI reference).
//
// The general form represented is:
//
// [scheme:][//[userinfo@]host][/]path[?query][#fragment]
//
// URLs that do not start with a slash after the scheme are interpreted as:
//
// scheme:opaque[?query][#fragment]
//
// Note that the path field is stored in decoded form: /%47%6f%2f becomes /Go/.
// A consequence is that it is impossible to tell which slashes in the path were
// slashes in the raw URL and which were %2f. This distinction is rarely important,
// but when it is, the code should use raw_path, an optional field which only gets
// set if the default encoding is different from path.
//
// URL's String method uses the escaped_path method to obtain the path. See the
// escaped_path method for more details.
struct URL {
pub: mut:
scheme string
opaque string // encoded opaque data
user *Userinfo // username and password information
host string // host or host:port
path string // path (relative paths may omit leading slash)
raw_path string // encoded path hint (see escaped_path method)
force_query bool // append a query ('?') even if raw_query is empty
raw_query string // encoded query values, without '?'
fragment string // fragment for references, without '#'
}
// user returns a Userinfo containing the provided username
// and no password set.
pub fn user(username string) *Userinfo {
return &Userinfo{
username: username,
password: '',
password_set: false
}
}
// user_password returns a Userinfo containing the provided username
// and password.
//
// This functionality should only be used with legacy web sites.
// RFC 2396 warns that interpreting Userinfo this way
// ``is NOT RECOMMENDED, because the passing of authentication
// information in clear text (such as URI) has proven to be a
// security risk in almost every case where it has been used.''
fn user_password(username, password string) *Userinfo {
return &Userinfo{username, password, true}
}
// The Userinfo type is an immutable encapsulation of username and
// password details for a URL. An existing Userinfo value is guaranteed
// to have a username set (potentially empty, as allowed by RFC 2396),
// and optionally a password.
struct Userinfo {
pub:
username string
password string
password_set bool
}
fn (u &Userinfo) empty() bool {
return u.username == '' && u.password == ''
}
// string returns the encoded userinfo information in the standard form
// of 'username[:password]'.
fn (u &Userinfo) string() string {
if u.empty() {
return ''
}
mut s := escape(u.username, .encode_user_password)
if u.password_set {
s += ':' + escape(u.password, .encode_user_password)
}
return s
}
// Maybe rawurl is of the form scheme:path.
// (scheme must be [a-zA-Z][a-zA-Z0-9+-.]*)
// If so, return [scheme, path]; else return ['', rawurl]
fn split_by_scheme(rawurl string) ?[]string {
for i := 0; i < rawurl.len; i++ {
c := rawurl[i]
if (`a` <= c && c <= `z`) || (`A` <= c && c <= `Z`) {
// do nothing
}
else if (`0` <= c && c <= `9`) || (c == `+` || c == `-` || c == `.`) {
if i == 0 {
return ['', rawurl]
}
}
else if c == `:` {
if i == 0 {
return error(error_msg('missing protocol scheme', ''))
}
return [rawurl.left(i), rawurl.right(i+1)]
}
else {
// we have encountered an invalid character,
// so there is no valid scheme
return ['', rawurl]
}
}
return ['', rawurl]
}
fn get_scheme(rawurl string) ?string {
split := split_by_scheme(rawurl) or {
return err
}
return split[0]
}
// Maybe s is of the form t c u.
// If so, return t, c u (or t, u if cutc == true).
// If not, return s, ''.
fn split(s string, c string, cutc bool) []string {
i := s.index(c)
if i < 0 {
return [s, '']
}
if cutc {
return [s.left(i), s.right(i+c.len)]
}
return [s.left(i), s.right(i)]
}
// parse parses rawurl into a URL structure.
//
// The rawurl may be relative (a path, without a host) or absolute
// (starting with a scheme). Trying to parse a hostname and path
// without a scheme is invalid but may not necessarily return an
// error, due to parsing ambiguities.
pub fn parse(rawurl string) ?URL {
// Cut off #frag
p := split(rawurl, '#', true)
u := p[0]
frag := p[1]
mut url := _parse(u, false) or {
return error(error_msg(err_msg_parse, u))
}
if frag == '' {
return url
}
f := unescape(frag, .encode_fragment) or {
return error(error_msg(err_msg_parse, u))
}
url.fragment = f
return url
}
// parse_request_uri parses rawurl into a URL structure. It assumes that
// rawurl was received in an HTTP request, so the rawurl is interpreted
// only as an absolute URI or an absolute path.
// The string rawurl is assumed not to have a #fragment suffix.
// (Web browsers strip #fragment before sending the URL to a web server.)
fn parse_request_uri(rawurl string) ?URL {
return _parse(rawurl, true)
}
// _parse parses a URL from a string in one of two contexts. If
// via_request is true, the URL is assumed to have arrived via an HTTP request,
// in which case only absolute URLs or path-absolute relative URLs are allowed.
// If via_request is false, all forms of relative URLs are allowed.
fn _parse(rawurl string, via_request bool) ?URL {
if string_contains_ctl_byte(rawurl) {
return error(error_msg('invalid control character in URL', rawurl))
}
if rawurl == '' && via_request {
return error(error_msg('empty URL', ''))
}
mut url := URL{}
if rawurl == '*' {
url.path = '*'
return url
}
// Split off possible leading 'http:', 'mailto:', etc.
// Cannot contain escaped characters.
p := split_by_scheme(rawurl) or {
return error(err)
}
url.scheme = p[0]
mut rest := p[1]
url.scheme = url.scheme.to_lower()
// if rest.ends_with('?') && strings.count(rest, '?') == 1 {
if rest.ends_with('?') && !rest.trim_right('?').contains('?') {
url.force_query = true
rest = rest.left(rest.len-1)
} else {
parts := split(rest, '?', true)
rest = parts[0]
url.raw_query = parts[1]
}
if !rest.starts_with('/') {
if url.scheme != '' {
// We consider rootless paths per RFC 3986 as opaque.
url.opaque = rest
return url
}
if via_request {
return error(error_msg('invalid URI for request', ''))
}
// Avoid confusion with malformed schemes, like cache_object:foo/bar.
// See golang.org/issue/16822.
//
// RFC 3986, §3.3:
// In addition, a URI reference (Section 4.1) may be a relative-path reference,
// in which case the first path segment cannot contain a colon (':') character.
colon := rest.index(':')
slash := rest.index('/')
if colon >= 0 && (slash < 0 || colon < slash) {
// First path segment has colon. Not allowed in relative URL.
return error(error_msg('first path segment in URL cannot contain colon', ''))
}
}
if (url.scheme != '' || !via_request && !rest.starts_with('///')) && rest.starts_with('//') {
parts := split(rest.right(2), '/', false)
authority := parts[0]
rest = parts[1]
a := parse_authority(authority) or {
return error(err)
}
url.user = a.user
url.host = a.host
}
// Set path and, optionally, raw_path.
// raw_path is a hint of the encoding of path. We don't want to set it if
// the default escaping of path is equivalent, to help make sure that people
// don't rely on it in general.
_ := url.set_path(rest) or {
return error(err)
}
return url
}
struct ParseAuthorityRes {
user &Userinfo
host string
}
fn parse_authority(authority string) ?ParseAuthorityRes {
i := authority.last_index('@')
mut host := ''
mut user := user('')
if i < 0 {
h := parse_host(authority) or {
return error(err)
}
host = h
} else {
h := parse_host(authority.right(i+1)) or {
return error(err)
}
host = h
}
if i < 0 {
return ParseAuthorityRes{host: host}
}
mut userinfo := authority.left(i)
if !valid_userinfo(userinfo) {
return error(error_msg('invalid userinfo', ''))
}
if !userinfo.contains(':') {
u := unescape(userinfo, .encode_user_password) or {
return error(err)
}
userinfo = u
user = user(userinfo)
} else {
parts := split(userinfo, ':', true)
mut username := parts[0]
mut password := parts[1]
u := unescape(username, .encode_user_password) or {
return error(err)
}
username = u
p := unescape(password, .encode_user_password) or {
return error(err)
}
password = p
user = user_password(username, password)
}
return ParseAuthorityRes{
user: user
host: host
}
}
// parse_host parses host as an authority without user
// information. That is, as host[:port].
fn parse_host(host string) ?string {
if host.starts_with('[') {
// parse an IP-Literal in RFC 3986 and RFC 6874.
// E.g., '[fe80::1]', '[fe80::1%25en0]', '[fe80::1]:80'.
mut i := host.last_index(']')
if i < 0 {
return error(error_msg('missing \']\' in host', ''))
}
mut colon_port := host.right(i+1)
if !valid_optional_port(colon_port) {
return error(error_msg('invalid port $colon_port after host ', ''))
}
// RFC 6874 defines that %25 (%-encoded percent) introduces
// the zone identifier, and the zone identifier can use basically
// any %-encoding it likes. That's different from the host, which
// can only %-encode non-ASCII bytes.
// We do impose some restrictions on the zone, to avoid stupidity
// like newlines.
zone := host.left(i).index('%25')
if zone >= 0 {
host1 := unescape(host.left(zone), .encode_host) or {
return err
}
host2 := unescape(host.substr(zone, i), .encode_zone) or {
return err
}
host3 := unescape(host.right(i), .encode_host) or {
return err
}
return host1 + host2 + host3
} else {
i = host.last_index(':')
if i != -1 {
colon_port = host.right(i)
if !valid_optional_port(colon_port) {
return error(error_msg('invalid port $colon_port after host ', ''))
}
}
}
}
h := unescape(host, .encode_host) or {
return err
}
return h
//host = h
//return host
}
// set_path sets the path and raw_path fields of the URL based on the provided
// escaped path p. It maintains the invariant that raw_path is only specified
// when it differs from the default encoding of the path.
// For example:
// - set_path('/foo/bar') will set path='/foo/bar' and raw_path=''
// - set_path('/foo%2fbar') will set path='/foo/bar' and raw_path='/foo%2fbar'
// set_path will return an error only if the provided path contains an invalid
// escaping.
fn (u mut URL) set_path(p string) ?bool {
path := unescape(p, .encode_path) or {
return error(err)
}
u.path = path
escp := escape(path, .encode_path)
if p == escp {
// Default encoding is fine.
u.raw_path = ''
} else {
u.raw_path = p
}
return true
}
// escaped_path returns the escaped form of u.path.
// In general there are multiple possible escaped forms of any path.
// escaped_path returns u.raw_path when it is a valid escaping of u.path.
// Otherwise escaped_path ignores u.raw_path and computes an escaped
// form on its own.
// The String and request_uri methods use escaped_path to construct
// their results.
// In general, code should call escaped_path instead of
// reading u.raw_path directly.
fn (u &URL) escaped_path() string {
if u.raw_path != '' && valid_encoded_path(u.raw_path) {
p := unescape(u.raw_path, .encode_path)
return u.raw_path
}
if u.path == '*' {
return '*' // don't escape (Issue 11202)
}
return escape(u.path, .encode_path)
}
// valid_encoded_path reports whether s is a valid encoded path.
// It must not contain any bytes that require escaping during path encoding.
fn valid_encoded_path(s string) bool {
for i := 0; i < s.len; i++ {
// RFC 3986, Appendix A.
// pchar = unreserved / pct-encoded / sub-delims / ':' / '@'.
// should_escape is not quite compliant with the RFC,
// so we check the sub-delims ourselves and let
// should_escape handle the others.
x := s[i]
switch x {
case `!`, `$`, `&`, `\\`, `(`, `)`, `*`, `+`, `,`, `;`, `=`, `:`, `@`:
// ok
case `[`, `]`:
// ok - not specified in RFC 3986 but left alone by modern browsers
case `%`:
// ok - percent encoded, will decode
default:
if should_escape(s[i], .encode_path) {
return false
}
}
}
return true
}
// valid_optional_port reports whether port is either an empty string
// or matches /^:\d*$/
fn valid_optional_port(port string) bool {
if port == '' {
return true
}
if port[0] != `:` {
return false
}
for b in port.right(1) {
if b < `0` || b > `9` {
return false
}
}
return true
}
// str reassembles the URL into a valid URL string.
// The general form of the result is one of:
//
// scheme:opaque?query#fragment
// scheme://userinfo@host/path?query#fragment
//
// If u.opaque is non-empty, String uses the first form;
// otherwise it uses the second form.
// Any non-ASCII characters in host are escaped.
// To obtain the path, String uses u.escaped_path().
//
// In the second form, the following rules apply:
// - if u.scheme is empty, scheme: is omitted.
// - if u.user is nil, userinfo@ is omitted.
// - if u.host is empty, host/ is omitted.
// - if u.scheme and u.host are empty and u.user is nil,
// the entire scheme://userinfo@host/ is omitted.
// - if u.host is non-empty and u.path begins with a /,
// the form host/path does not add its own /.
// - if u.raw_query is empty, ?query is omitted.
// - if u.fragment is empty, #fragment is omitted.
pub fn (u &URL) str() string {
mut buf := strings.new_builder(200)
if u.scheme != '' {
buf.write(u.scheme)
buf.write(':')
}
if u.opaque != '' {
buf.write(u.opaque)
} else {
if u.scheme != '' || u.host != '' || !u.user.empty() {
if u.host != '' || u.path != '' || !u.user.empty() {
buf.write('//')
}
if !u.user.empty() {
buf.write(u.user.string())
buf.write('@')
}
if u.host != '' {
buf.write(escape(u.host, .encode_host))
}
}
path := u.escaped_path()
if path != '' && path[0] != `/` && u.host != '' {
buf.write('/')
}
if buf.len == 0 {
// RFC 3986 §4.2
// A path segment that contains a colon character (e.g., 'this:that')
// cannot be used as the first segment of a relative-path reference, as
// it would be mistaken for a scheme name. Such a segment must be
// preceded by a dot-segment (e.g., './this:that') to make a relative-
// path reference.
i := path.index(':')
if i > -1 && path.left(i).index('/') == -1 {
buf.write('./')
}
}
buf.write(path)
}
if u.force_query || u.raw_query != '' {
buf.write('?')
buf.write(u.raw_query)
}
if u.fragment != '' {
buf.write('#')
buf.write(escape(u.fragment, .encode_fragment))
}
return buf.str()
}
// Values maps a string key to a list of values.
// It is typically used for query parameters and form values.
// Unlike in the http.Header map, the keys in a Values map
// are case-sensitive.
// parseQuery parses the URL-encoded query string and returns
// a map listing the values specified for each key.
// parseQuery always returns a non-nil map containing all the
// valid query parameters found; err describes the first decoding error
// encountered, if any.
//
// Query is expected to be a list of key=value settings separated by
// ampersands or semicolons. A setting without an equals sign is
// interpreted as a key set to an empty value.
pub fn parse_query(query string) ?Values {
mut m := new_values()
_ := _parse_query(mut m, query) or {
return error(err)
}
return m
}
// parse_query_silent is the same as parse_query
// but any errors will be silent
fn parse_query_silent(query string) Values {
mut m := new_values()
_ := _parse_query(mut m, query)
return m
}
fn _parse_query(m mut Values, query string) ?bool {
mut had_error := false
mut q := query
for q != '' {
mut key := q
mut i := key.index_any('&;')
if i >= 0 {
q = key.right(i+1)
key = key.left(i)
} else {
q = ''
}
if key == '' {
continue
}
mut value := ''
i = key.index('=')
if i >= 0 {
value = key.right(i+1)
key = key.left(i)
}
k := query_unescape(key) or {
had_error = true
continue
}
key = k
v := query_unescape(value) or {
had_error = true
continue
}
value = v
m.add(key, value)
}
if had_error {
return error(error_msg('error parsing query string', ''))
}
return true
}
// encode encodes the values into ``URL encoded'' form
// ('bar=baz&foo=quux') sorted by key.
pub fn (v Values) encode() string {
if v.size == 0 {
return ''
}
mut buf := strings.new_builder(200)
mut keys := []string
for k, _ in v.data {
keys << k
}
keys.sort()
for k in keys {
vs := v.data[k]
key_kscaped := query_escape(k)
for _, val in vs.data {
if buf.len > 0 {
buf.write('&')
}
buf.write(key_kscaped)
buf.write('=')
buf.write(query_escape(val))
}
}
return buf.str()
}
// resolve_path applies special path segments from refs and applies
// them to base, per RFC 3986.
fn resolve_path(base, ref string) string {
mut full := ''
if ref == '' {
full = base
} else if ref[0] != `/` {
i := base.last_index('/')
full = base.left(i+1) + ref
} else {
full = ref
}
if full == '' {
return ''
}
mut dst := []string
src := full.split('/')
for _, elem in src {
switch elem {
case '.':
// drop
case '..':
if dst.len > 0 {
dst = dst.left(dst.len-1)
}
default:
dst << elem
}
}
last := src[src.len-1]
if last == '.' || last == '..' {
// Add final slash to the joined path.
dst << ''
}
return '/' + dst.join('/').trim_left('/')
}
// is_abs reports whether the URL is absolute.
// Absolute means that it has a non-empty scheme.
pub fn (u &URL) is_abs() bool {
return u.scheme != ''
}
// parse parses a URL in the context of the receiver. The provided URL
// may be relative or absolute. parse returns nil, err on parse
// failure, otherwise its return value is the same as resolve_reference.
pub fn (u &URL) parse(ref string) ?URL {
refurl := parse(ref) or {
return error(err)
}
return u.resolve_reference(refurl)
}
// resolve_reference resolves a URI reference to an absolute URI from
// an absolute base URI u, per RFC 3986 Section 5.2. The URI reference
// may be relative or absolute. resolve_reference always returns a new
// URL instance, even if the returned URL is identical to either the
// base or reference. If ref is an absolute URL, then resolve_reference
// ignores base and returns a copy of ref.
pub fn (u &URL) resolve_reference(ref &URL) ?URL {
mut url := *ref
if ref.scheme == '' {
url.scheme = u.scheme
}
if ref.scheme != '' || ref.host != '' || !ref.user.empty() {
// The 'absoluteURI' or 'net_path' cases.
// We can ignore the error from set_path since we know we provided a
// validly-escaped path.
url.set_path(resolve_path(ref.escaped_path(), ''))
return url
}
if ref.opaque != '' {
url.user = user('')
url.host = ''
url.path = ''
return url
}
if ref.path == '' && ref.raw_query == '' {
url.raw_query = u.raw_query
if ref.fragment == '' {
url.fragment = u.fragment
}
}
// The 'abs_path' or 'rel_path' cases.
url.host = u.host
url.user = u.user
url.set_path(resolve_path(u.escaped_path(), ref.escaped_path()))
return url
}
// query parses raw_query and returns the corresponding values.
// It silently discards malformed value pairs.
// To check errors use parseQuery.
pub fn (u &URL) query() Values {
v := parse_query_silent(u.raw_query)
return v
}
// request_uri returns the encoded path?query or opaque?query
// string that would be used in an HTTP request for u.
pub fn (u &URL) request_uri() string {
mut result := u.opaque
if result == '' {
result = u.escaped_path()
if result == '' {
result = '/'
}
} else {
if result.starts_with('//') {
result = u.scheme + ':' + result
}
}
if u.force_query || u.raw_query != '' {
result += '?' + u.raw_query
}
return result
}
// hostname returns u.host, stripping any valid port number if present.
//
// If the result is enclosed in square brackets, as literal IPv6 addresses are,
// the square brackets are removed from the result.
pub fn (u &URL) hostname() string {
host_port := split_host_port(u.host)
return host_port[0]
}
// port returns the port part of u.host, without the leading colon.
// If u.host doesn't contain a port, port returns an empty string.
pub fn (u &URL) port() string {
host_port := split_host_port(u.host)
return host_port[1]
}
// split_host_port separates host and port. If the port is not valid, it returns
// the entire input as host, and it doesn't check the validity of the host.
// Per RFC 3986, it requires ports to be numeric.
fn split_host_port(hostport string) []string {
mut host := hostport
mut port := ''
colon := host.last_index(':')
if colon != -1 && valid_optional_port(host.right(colon)) {
port = host.right(colon+1)
host = host.left(colon)
}
if host.starts_with('[') && host.ends_with(']') {
host = host.substr(1, host.len-1)
}
return [host, port]
}
// valid_userinfo reports whether s is a valid userinfo string per RFC 3986
// Section 3.2.1:
// userinfo = *( unreserved / pct-encoded / sub-delims / ':' )
// unreserved = ALPHA / DIGIT / '-' / '.' / '_' / '~'
// sub-delims = '!' / '$' / '&' / ''' / '(' / ')'
// / '*' / '+' / ',' / ';' / '='
//
// It doesn't validate pct-encoded. The caller does that via fn unescape.
pub fn valid_userinfo(s string) bool {
for r in s {
if `A` <= r && r <= `Z` {
continue
}
if `a` <= r && r <= `z` {
continue
}
if `0` <= r && r <= `9` {
continue
}
switch r {
case `-`, `.`, `_`, `:`, `~`, `!`, `$`, `&`, `\\`,
`(`, `)`, `*`, `+`, `,`, `;`, `=`, `%`, `@`:
continue
default:
return false
}
}
return true
}
// string_contains_ctl_byte reports whether s contains any ASCII control character.
fn string_contains_ctl_byte(s string) bool {
for i := 0; i < s.len; i++ {
b := s[i]
if b < ` ` || b == 0x7f {
return true
}
}
return false
}
pub fn ishex(c byte) bool {
if `0` <= c && c <= `9` {
return true
} else if `a` <= c && c <= `f` {
return true
} else if `A` <= c && c <= `F` {
return true
}
return false
}
fn unhex(c byte) byte {
if `0` <= c && c <= `9` {
return c - `0`
} else if `a` <= c && c <= `f` {
return c - `a` + 10
} else if `A` <= c && c <= `F` {
return c - `A` + 10
}
return 0
}