link_header_util.cc | Explore in Territory

// Copyright 2016 The Chromium Authors
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.

#include "components/link_header_util/link_header_util.h"

#include <algorithm>

#include "base/strings/string_util.h"
#include "net/http/http_util.h"

namespace link_header_util {

namespace {

// A variation of base::StringTokenizer and net::HttpUtil::ValuesIterator.
// Takes the parsing of StringTokenizer and adds support for quoted strings that
// are quoted by matching <> (and does not support escaping in those strings).
// Also has the behavior of ValuesIterator where it strips whitespace from all
// values and only outputs non-empty values.
// Only supports ',' as separator and supports "" and <> as quote chars.
class ValueTokenizer { … };

// Parses the URL part of a Link header. When successful |url_begin| points
// to the beginning of the url, |url_end| points to the end of the url and
// |params_begin| points to the first character after the '>' character at the
// end of the url.
bool ExtractURL(std::string::const_iterator begin,
                std::string::const_iterator end,
                std::string::const_iterator* url_begin,
                std::string::const_iterator* url_end,
                std::string::const_iterator* params_begin) { … }

}  // namespace

std::vector<StringIteratorPair> SplitLinkHeader(const std::string& header) { … }

// Parses one link in a link header into its url and parameters.
// A link is of the form "<some-url>; param1=value1; param2=value2".
// Returns false if parsing the link failed, returns true on success. This
// method is more lenient than the RFC. It doesn't fail on things like invalid
// characters in the URL, and also doesn't verify that certain parameters should
// or shouldn't be quoted strings.
// If a parameter occurs more than once in the link, only the first value is
// returned in params as this is the required behavior for all attributes chrome
// currently cares about in link headers.
bool ParseLinkHeaderValue(
    std::string::const_iterator begin,
    std::string::const_iterator end,
    std::string* url,
    std::unordered_map<std::string, std::optional<std::string>>* params) { … }

}  // namespace link_header_util
chromium/components/link_header_util/link_header_util.cc
