html_srcset_parser.cc | Explore in Territory

/*
 * Copyright (C) 2013 Apple Inc. All rights reserved.
 * Copyright (C) 2013 Google Inc. All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions are
 * met:
 *
 *     * Redistributions of source code must retain the above copyright
 * notice, this list of conditions and the following disclaimer.
 *     * Redistributions in binary form must reproduce the above
 * copyright notice, this list of conditions and the following disclaimer
 * in the documentation and/or other materials provided with the
 * distribution.
 *     * Neither the name of Google Inc. nor the names of its
 * contributors may be used to endorse or promote products derived from
 * this software without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
 * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
 * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
 * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
 * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 */

#ifdef UNSAFE_BUFFERS_BUILD
// TODO(crbug.com/351564777): Remove this and convert code to safer constructs.
#pragma allow_unsafe_buffers
#endif

#include "third_party/blink/renderer/core/html/parser/html_srcset_parser.h"

#include <algorithm>

#include "third_party/blink/public/common/features.h"
#include "third_party/blink/public/platform/web_network_state_notifier.h"
#include "third_party/blink/renderer/core/dom/document.h"
#include "third_party/blink/renderer/core/frame/frame_console.h"
#include "third_party/blink/renderer/core/frame/local_frame.h"
#include "third_party/blink/renderer/core/frame/web_feature.h"
#include "third_party/blink/renderer/core/html/parser/html_parser_idioms.h"
#include "third_party/blink/renderer/core/inspector/console_message.h"
#include "third_party/blink/renderer/platform/heap/garbage_collected.h"
#include "third_party/blink/renderer/platform/instrumentation/use_counter.h"
#include "third_party/blink/renderer/platform/json/json_values.h"
#include "third_party/blink/renderer/platform/loader/fetch/memory_cache.h"
#include "third_party/blink/renderer/platform/loader/fetch/resource_fetcher.h"
#include "third_party/blink/renderer/platform/runtime_enabled_features.h"
#include "third_party/blink/renderer/platform/wtf/text/character_visitor.h"
#include "third_party/blink/renderer/platform/wtf/text/parsing_utilities.h"
#include "third_party/blink/renderer/platform/wtf/text/string_builder.h"
#include "third_party/blink/renderer/platform/wtf/text/string_to_number.h"

namespace blink {

static bool CompareByDensity(const ImageCandidate& first,
                             const ImageCandidate& second) { … }

enum DescriptorTokenizerState { … };

struct DescriptorToken { … };

template <typename CharType>
static void AppendDescriptorAndReset(const CharType* attribute_start,
                                     const CharType*& descriptor_start,
                                     const CharType* position,
                                     Vector<DescriptorToken>& descriptors) { … }

// The following is called appendCharacter to match the spec's terminology.
template <typename CharType>
static void AppendCharacter(const CharType* descriptor_start,
                            const CharType* position) { … }

template <typename CharType>
static bool IsEOF(const CharType* position, const CharType* end) { … }

template <typename CharType>
static void TokenizeDescriptors(const CharType* attribute_start,
                                const CharType*& position,
                                const CharType* attribute_end,
                                Vector<DescriptorToken>& descriptors) { … }

static void SrcsetError(Document* document, String message) { … }

template <typename CharType>
static bool ParseDescriptors(const CharType* attribute,
                             Vector<DescriptorToken>& descriptors,
                             DescriptorParsingResult& result,
                             Document* document) { … }

static bool ParseDescriptors(const String& attribute,
                             Vector<DescriptorToken>& descriptors,
                             DescriptorParsingResult& result,
                             Document* document) { … }

// http://picture.responsiveimages.org/#parse-srcset-attr
template <typename CharType>
static void ParseImageCandidatesFromSrcsetAttribute(
    const String& attribute,
    const CharType* attribute_start,
    unsigned length,
    Vector<ImageCandidate>& image_candidates,
    Document* document) { … }

static void ParseImageCandidatesFromSrcsetAttribute(
    const String& attribute,
    Vector<ImageCandidate>& image_candidates,
    Document* document) { … }

static unsigned SelectionLogic(Vector<ImageCandidate*>& image_candidates,
                               float device_scale_factor) { … }

static unsigned AvoidDownloadIfHigherDensityResourceIsInCache(
    Vector<ImageCandidate*>& image_candidates,
    unsigned winner,
    Document* document) { … }

static ImageCandidate PickBestImageCandidate(
    float device_scale_factor,
    float source_size,
    Vector<ImageCandidate>& image_candidates,
    Document* document = nullptr) { … }

ImageCandidate BestFitSourceForSrcsetAttribute(float device_scale_factor,
                                               float source_size,
                                               const String& srcset_attribute,
                                               Document* document) { … }

ImageCandidate BestFitSourceForImageAttributes(float device_scale_factor,
                                               float source_size,
                                               const String& src_attribute,
                                               const String& srcset_attribute,
                                               Document* document) { … }

String BestFitSourceForImageAttributes(float device_scale_factor,
                                       float source_size,
                                       const String& src_attribute,
                                       ImageCandidate& srcset_image_candidate) { … }

}  // namespace blink
chromium/third_party/blink/renderer/core/html/parser/html_srcset_parser.cc
