| /* |
| * Copyright (C) 2008, 2010, 2013, 2014 Apple Inc. All Rights Reserved. |
| * Copyright (C) 2009 Torch Mobile, Inc. http://www.torchmobile.com/ |
| * Copyright (C) 2010 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: |
| * 1. Redistributions of source code must retain the above copyright |
| * notice, this list of conditions and the following disclaimer. |
| * 2. 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. |
| * |
| * THIS SOFTWARE IS PROVIDED BY APPLE INC. ``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 APPLE INC. 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. |
| */ |
| |
| #include "config.h" |
| #include "CSSPreloadScanner.h" |
| |
| #include "HTMLParserIdioms.h" |
| #include <wtf/SetForScope.h> |
| |
| namespace WebCore { |
| |
| CSSPreloadScanner::CSSPreloadScanner() |
| : m_state(Initial) |
| , m_requests(nullptr) |
| { |
| } |
| |
| CSSPreloadScanner::~CSSPreloadScanner() = default; |
| |
| void CSSPreloadScanner::reset() |
| { |
| m_state = Initial; |
| m_rule.clear(); |
| m_ruleValue.clear(); |
| } |
| |
| void CSSPreloadScanner::scan(const HTMLToken::DataVector& data, PreloadRequestStream& requests) |
| { |
| ASSERT(!m_requests); |
| SetForScope change(m_requests, &requests); |
| |
| for (UChar c : data) { |
| if (m_state == DoneParsingImportRules) |
| break; |
| |
| tokenize(c); |
| } |
| } |
| |
| inline void CSSPreloadScanner::tokenize(UChar c) |
| { |
| // We are just interested in @import rules, no need for real tokenization here |
| // Searching for other types of resources is probably low payoff. |
| switch (m_state) { |
| case Initial: |
| if (isHTMLSpace(c)) |
| break; |
| if (c == '@') |
| m_state = RuleStart; |
| else if (c == '/') |
| m_state = MaybeComment; |
| else |
| m_state = DoneParsingImportRules; |
| break; |
| case MaybeComment: |
| if (c == '*') |
| m_state = Comment; |
| else |
| m_state = Initial; |
| break; |
| case Comment: |
| if (c == '*') |
| m_state = MaybeCommentEnd; |
| break; |
| case MaybeCommentEnd: |
| if (c == '*') |
| break; |
| if (c == '/') |
| m_state = Initial; |
| else |
| m_state = Comment; |
| break; |
| case RuleStart: |
| if (isASCIIAlpha(c)) { |
| m_rule.clear(); |
| m_ruleValue.clear(); |
| m_ruleConditions.clear(); |
| m_rule.append(c); |
| m_state = Rule; |
| } else |
| m_state = Initial; |
| break; |
| case Rule: |
| if (isHTMLSpace(c)) |
| m_state = AfterRule; |
| else if (c == ';') |
| m_state = Initial; |
| else |
| m_rule.append(c); |
| break; |
| case AfterRule: |
| if (isHTMLSpace(c)) |
| break; |
| if (c == ';') |
| m_state = Initial; |
| else if (c == '{') |
| m_state = DoneParsingImportRules; |
| else { |
| m_state = RuleValue; |
| m_ruleValue.append(c); |
| } |
| break; |
| case RuleValue: |
| if (isHTMLSpace(c)) |
| m_state = AfterRuleValue; |
| else if (c == ';') |
| emitRule(); |
| else |
| m_ruleValue.append(c); |
| break; |
| case AfterRuleValue: |
| if (isHTMLSpace(c)) |
| break; |
| if (c == ';') |
| emitRule(); |
| else if (c == '{') |
| m_state = DoneParsingImportRules; |
| else { |
| m_state = RuleConditions; |
| m_ruleConditions.append(c); |
| } |
| break; |
| case RuleConditions: |
| if (c == ';') |
| emitRule(); |
| else if (c == '{') |
| m_state = DoneParsingImportRules; |
| else |
| m_ruleConditions.append(c); |
| break; |
| case DoneParsingImportRules: |
| ASSERT_NOT_REACHED(); |
| break; |
| } |
| } |
| |
| static String parseCSSStringOrURL(const UChar* characters, size_t length) |
| { |
| size_t offset = 0; |
| size_t reducedLength = length; |
| |
| while (reducedLength && isHTMLSpace(characters[offset])) { |
| ++offset; |
| --reducedLength; |
| } |
| while (reducedLength && isHTMLSpace(characters[offset + reducedLength - 1])) |
| --reducedLength; |
| |
| if (reducedLength >= 5 |
| && (characters[offset] == 'u' || characters[offset] == 'U') |
| && (characters[offset + 1] == 'r' || characters[offset + 1] == 'R') |
| && (characters[offset + 2] == 'l' || characters[offset + 2] == 'L') |
| && characters[offset + 3] == '(' |
| && characters[offset + reducedLength - 1] == ')') { |
| offset += 4; |
| reducedLength -= 5; |
| } |
| |
| while (reducedLength && isHTMLSpace(characters[offset])) { |
| ++offset; |
| --reducedLength; |
| } |
| while (reducedLength && isHTMLSpace(characters[offset + reducedLength - 1])) |
| --reducedLength; |
| |
| if (reducedLength < 2 || characters[offset] != characters[offset + reducedLength - 1] || !(characters[offset] == '\'' || characters[offset] == '"')) |
| return String(); |
| offset++; |
| reducedLength -= 2; |
| |
| while (reducedLength && isHTMLSpace(characters[offset])) { |
| ++offset; |
| --reducedLength; |
| } |
| while (reducedLength && isHTMLSpace(characters[offset + reducedLength - 1])) |
| --reducedLength; |
| |
| return String(characters + offset, reducedLength); |
| } |
| |
| static bool hasValidImportConditions(StringView conditions) |
| { |
| if (conditions.isEmpty()) |
| return true; |
| |
| conditions = conditions.stripLeadingAndTrailingMatchedCharacters(isHTMLSpace<UChar>); |
| |
| // FIXME: Support multiple conditions. |
| // FIXME: Support media queries. |
| // FIXME: Support supports(). |
| |
| auto end = conditions.find(')'); |
| if (end != notFound) |
| return end == conditions.length() - 1 && conditions.startsWith("layer("_s); |
| |
| return conditions == "layer"_s; |
| } |
| |
| void CSSPreloadScanner::emitRule() |
| { |
| StringView rule(m_rule.data(), m_rule.size()); |
| if (equalLettersIgnoringASCIICase(rule, "import"_s)) { |
| String url = parseCSSStringOrURL(m_ruleValue.data(), m_ruleValue.size()); |
| StringView conditions(m_ruleConditions.data(), m_ruleConditions.size()); |
| if (!url.isEmpty() && hasValidImportConditions(conditions)) { |
| URL baseElementURL; // FIXME: This should be passed in from the HTMLPreloadScanner via scan(): without it we will get relative URLs wrong. |
| // FIXME: Should this be including the charset in the preload request? |
| m_requests->append(makeUnique<PreloadRequest>("css"_s, url, baseElementURL, CachedResource::Type::CSSStyleSheet, String(), PreloadRequest::ModuleScript::No, ReferrerPolicy::EmptyString)); |
| } |
| m_state = Initial; |
| } else if (equalLettersIgnoringASCIICase(rule, "charset"_s)) |
| m_state = Initial; |
| else |
| m_state = DoneParsingImportRules; |
| m_rule.clear(); |
| m_ruleValue.clear(); |
| m_ruleConditions.clear(); |
| } |
| |
| } |
