third_party/WebKit/Source/platform/network/LinkHeader.cpp

// Copyright 2015 The Chromium Authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.

#include "platform/network/LinkHeader.h"

#include "base/strings/string_util.h"
#include "components/link_header_util/link_header_util.h"
#include "wtf/text/ParsingUtilities.h"

namespace blink {

// Verify that the parameter is a link-extension which according to spec doesn't
// have to have a value.
static bool isExtensionParameter(LinkHeader::LinkParameterName name) {
  return name >= LinkHeader::LinkParameterUnknown;
}

static LinkHeader::LinkParameterName parameterNameFromString(
    base::StringPiece name) {
  if (base::EqualsCaseInsensitiveASCII(name, "rel"))
    return LinkHeader::LinkParameterRel;
  if (base::EqualsCaseInsensitiveASCII(name, "anchor"))
    return LinkHeader::LinkParameterAnchor;
  if (base::EqualsCaseInsensitiveASCII(name, "crossorigin"))
    return LinkHeader::LinkParameterCrossOrigin;
  if (base::EqualsCaseInsensitiveASCII(name, "title"))
    return LinkHeader::LinkParameterTitle;
  if (base::EqualsCaseInsensitiveASCII(name, "media"))
    return LinkHeader::LinkParameterMedia;
  if (base::EqualsCaseInsensitiveASCII(name, "type"))
    return LinkHeader::LinkParameterType;
  if (base::EqualsCaseInsensitiveASCII(name, "rev"))
    return LinkHeader::LinkParameterRev;
  if (base::EqualsCaseInsensitiveASCII(name, "hreflang"))
    return LinkHeader::LinkParameterHreflang;
  if (base::EqualsCaseInsensitiveASCII(name, "as"))
    return LinkHeader::LinkParameterAs;
  return LinkHeader::LinkParameterUnknown;
}

void LinkHeader::setValue(LinkParameterName name, const String& value) {
  if (name == LinkParameterRel && !m_rel)
    m_rel = value.lower();
  else if (name == LinkParameterAnchor)
    m_isValid = false;
  else if (name == LinkParameterCrossOrigin)
    m_crossOrigin = value;
  else if (name == LinkParameterAs)
    m_as = value.lower();
  else if (name == LinkParameterType)
    m_mimeType = value.lower();
  else if (name == LinkParameterMedia)
    m_media = value.lower();
}

template <typename Iterator>
LinkHeader::LinkHeader(Iterator begin, Iterator end) : m_isValid(true) {
  std::string url;
  std::unordered_map<std::string, base::Optional<std::string>> params;
  m_isValid = link_header_util::ParseLinkHeaderValue(begin, end, &url, &params);
  if (!m_isValid)
    return;

  m_url = String(&url[0], url.length());
  for (const auto& param : params) {
    LinkParameterName name = parameterNameFromString(param.first);
    if (!isExtensionParameter(name) && !param.second)
      m_isValid = false;
    std::string value = param.second.value_or("");
    setValue(name, String(&value[0], value.length()));
  }
}

LinkHeaderSet::LinkHeaderSet(const String& header) {
  if (header.isNull())
    return;

  DCHECK(header.is8Bit()) << "Headers should always be 8 bit";
  std::string headerString(reinterpret_cast<const char*>(header.characters8()),
                           header.length());
  for (const auto& value : link_header_util::SplitLinkHeader(headerString))
    m_headerSet.append(LinkHeader(value.first, value.second));
}

}  // namespace blink