capnproto

url.h (6066B)

---

 // Copyright (c) 2017 Cloudflare, Inc. and contributors
 // Licensed under the MIT License:
 //
 // Permission is hereby granted, free of charge, to any person obtaining a copy
 // of this software and associated documentation files (the "Software"), to deal
 // in the Software without restriction, including without limitation the rights
 // to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
 // copies of the Software, and to permit persons to whom the Software is
 // furnished to do so, subject to the following conditions:
 //
 // The above copyright notice and this permission notice shall be included in
 // all copies or substantial portions of the Software.
 //
 // THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
 // IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
 // FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
 // AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
 // LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
 // OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
 // THE SOFTWARE.
 
 #pragma once
 
 #include <kj/string.h>
 #include <kj/vector.h>
 #include <inttypes.h>
 
 namespace kj {
 
 struct UrlOptions {
   // A bag of options that you can pass to Url::parse()/tryParse() to customize the parser's
   // behavior.
   //
   // A copy of this options struct will be stored in the parsed Url object, at which point it
   // controls the behavior of the serializer in Url::toString().
 
   bool percentDecode = true;
   // True if URL components should be automatically percent-decoded during parsing, and
   // percent-encoded during serialization.
 
   bool allowEmpty = false;
   // Whether or not to allow empty path and query components when parsing; otherwise, they are
   // silently removed. In other words, setting this false causes consecutive slashes in the path or
   // consecutive ampersands in the query to be collapsed into one, whereas if true then they
   // produce empty components.
 };
 
 struct Url {
   // Represents a URL (or, more accurately, a URI, but whatever).
   //
   // Can be parsed from a string and composed back into a string.
 
   String scheme;
   // E.g. "http", "https".
 
   struct UserInfo {
     String username;
     Maybe<String> password;
   };
 
   Maybe<UserInfo> userInfo;
   // Username / password.
 
   String host;
   // Hostname, including port if specified. We choose not to parse out the port because KJ's
   // network address parsing functions already accept addresses containing port numbers, and
   // because most web standards don't actually want to separate host and port.
 
   Vector<String> path;
   bool hasTrailingSlash = false;
   // Path, split on '/' characters. Note that the individual components of `path` could contain
   // '/' characters if they were percent-encoded in the original URL.
   //
   // No component of the path is allowed to be "", ".", nor ".."; if such components are present,
   // toString() will throw. Note that parse() and parseRelative() automatically resolve such
   // components.
 
   struct QueryParam {
     String name;
     String value;
   };
   Vector<QueryParam> query;
   // Query, e.g. from "?key=value&key2=value2". If a component of the query contains no '=' sign,
   // it will be parsed as a key with a null value, and later serialized with no '=' sign if you call
   // Url::toString().
   //
   // To distinguish between null-valued and empty-valued query parameters, we test whether
   // QueryParam::value is an allocated or unallocated string. For example:
   //
   //     QueryParam { kj::str("name"), nullptr }      // Null-valued; will not have an '=' sign.
   //     QueryParam { kj::str("name"), kj::str("") }  // Empty-valued; WILL have an '=' sign.
 
   Maybe<String> fragment;
   // The stuff after the '#' character (not including the '#' character itself), if present.
 
   using Options = UrlOptions;
   Options options;
 
   // ---------------------------------------------------------------------------
 
   Url() = default;
   Url(Url&&) = default;
   ~Url() noexcept(false);
   Url& operator=(Url&&) = default;
 
   inline Url(String&& scheme, Maybe<UserInfo>&& userInfo, String&& host, Vector<String>&& path,
              bool hasTrailingSlash, Vector<QueryParam>&& query, Maybe<String>&& fragment,
              UrlOptions options)
       : scheme(kj::mv(scheme)), userInfo(kj::mv(userInfo)), host(kj::mv(host)), path(kj::mv(path)),
         hasTrailingSlash(hasTrailingSlash), query(kj::mv(query)), fragment(kj::mv(fragment)),
         options(options) {}
   // This constructor makes brace initialization work in C++11 and C++20 -- but is technically not
   // needed in C++14 nor C++17. Go figure.
 
   Url clone() const;
 
   enum Context {
     REMOTE_HREF,
     // A link to a remote resource. Requires an authority (hostname) section, hence this will
     // reject things like "mailto:" and "data:". This is the default context.
 
     HTTP_PROXY_REQUEST,
     // The URL to place in the first line of an HTTP proxy request. This includes scheme, host,
     // path, and query, but omits userInfo (which should be used to construct the Authorization
     // header) and fragment (which should not be transmitted).
 
     HTTP_REQUEST
     // The path to place in the first line of a regular HTTP request. This includes only the path
     // and query. Scheme, user, host, and fragment are omitted.
 
     // TODO(someday): Add context(s) that supports things like "mailto:", "data:", "blob:". These
     //   don't have an authority section.
   };
 
   kj::String toString(Context context = REMOTE_HREF) const;
   // Convert the URL to a string.
 
   static Url parse(StringPtr text, Context context = REMOTE_HREF, Options options = {});
   static Maybe<Url> tryParse(StringPtr text, Context context = REMOTE_HREF, Options options = {});
   // Parse an absolute URL.
 
   Url parseRelative(StringPtr relative) const;
   Maybe<Url> tryParseRelative(StringPtr relative) const;
   // Parse a relative URL string with this URL as the base.
 };
 
 } // namespace kj