Source/WebCore/platform/SharedStringHash.cpp - WebKit - Git at Google

 /*
  * Copyright (C) 1999 Lars Knoll (knoll@kde.org)
  *           (C) 1999 Antti Koivisto (koivisto@kde.org)
  *           (C) 2001 Dirk Mueller (mueller@kde.org)
  *           (C) 2006 Alexey Proskuryakov (ap@webkit.org)
  * Copyright (C) 2004, 2005, 2006, 2007, 2008 Apple Inc. All rights reserved.
  *
  * This library is free software; you can redistribute it and/or
  * modify it under the terms of the GNU Library General Public
  * License as published by the Free Software Foundation; either
  * version 2 of the License, or (at your option) any later version.
  *
  * This library is distributed in the hope that it will be useful,
  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  * Library General Public License for more details.
  *
  * You should have received a copy of the GNU Library General Public License
  * along with this library; see the file COPYING.LIB.  If not, write to
  * the Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor,
  * Boston, MA 02110-1301, USA.
  */

 #include "config.h"
 #include "SharedStringHash.h"

 #include <wtf/URL.h>
 #include <wtf/text/AtomicString.h>
 #include <wtf/text/StringHash.h>
 #include <wtf/text/StringView.h>

 namespace WebCore {

 template <typename CharacterType>
 static inline size_t findSlashDotDotSlash(const CharacterType* characters, size_t length, size_t position)
 {
     if (length < 4)
         return notFound;
     size_t loopLimit = length - 3;
     for (size_t i = position; i < loopLimit; ++i) {
         if (characters[i] == '/' && characters[i + 1] == '.' && characters[i + 2] == '.' && characters[i + 3] == '/')
             return i;
     }
     return notFound;
 }

 template <typename CharacterType>
 static inline size_t findSlashSlash(const CharacterType* characters, size_t length, size_t position)
 {
     if (length < 2)
         return notFound;
     size_t loopLimit = length - 1;
     for (size_t i = position; i < loopLimit; ++i) {
         if (characters[i] == '/' && characters[i + 1] == '/')
             return i;
     }
     return notFound;
 }

 template <typename CharacterType>
 static inline size_t findSlashDotSlash(const CharacterType* characters, size_t length, size_t position)
 {
     if (length < 3)
         return notFound;
     size_t loopLimit = length - 2;
     for (size_t i = position; i < loopLimit; ++i) {
         if (characters[i] == '/' && characters[i + 1] == '.' && characters[i + 2] == '/')
             return i;
     }
     return notFound;
 }

 template <typename CharacterType>
 static inline bool containsColonSlashSlash(const CharacterType* characters, unsigned length)
 {
     if (length < 3)
         return false;
     unsigned loopLimit = length - 2;
     for (unsigned i = 0; i < loopLimit; ++i) {
         if (characters[i] == ':' && characters[i + 1] == '/' && characters[i + 2] == '/')
             return true;
     }
     return false;
 }

 template <typename CharacterType>
 static inline void squeezeOutNullCharacters(Vector<CharacterType, 512>& string)
 {
     size_t size = string.size();
     size_t i = 0;
     for (i = 0; i < size; ++i) {
         if (!string[i])
             break;
     }
     if (i == size)
         return;
     size_t j = i;
     for (++i; i < size; ++i) {
         if (CharacterType character = string[i])
             string[j++] = character;
     }
     ASSERT(j < size);
     string.shrink(j);
 }

 template <typename CharacterType>
 static void cleanSlashDotDotSlashes(Vector<CharacterType, 512>& path, size_t firstSlash)
 {
     size_t slash = firstSlash;
     do {
         size_t previousSlash = slash ? reverseFind(path.data(), path.size(), '/', slash - 1) : notFound;
         // Don't remove the host, i.e. http://foo.org/../foo.html
         if (previousSlash == notFound || (previousSlash > 3 && path[previousSlash - 2] == ':' && path[previousSlash - 1] == '/')) {
             path[slash] = 0;
             path[slash + 1] = 0;
             path[slash + 2] = 0;
         } else {
             for (size_t i = previousSlash; i < slash + 3; ++i)
                 path[i] = 0;
         }
         slash += 3;
     } while ((slash = findSlashDotDotSlash(path.data(), path.size(), slash)) != notFound);
     squeezeOutNullCharacters(path);
 }

 template <typename CharacterType>
 static void mergeDoubleSlashes(Vector<CharacterType, 512>& path, size_t firstSlash)
 {
     size_t refPos = find(path.data(), path.size(), '#');
     if (!refPos || refPos == notFound)
         refPos = path.size();

     size_t slash = firstSlash;
     while (slash < refPos) {
         if (!slash || path[slash - 1] != ':')
             path[slash++] = 0;
         else
             slash += 2;
         if ((slash = findSlashSlash(path.data(), path.size(), slash)) == notFound)
             break;
     }
     squeezeOutNullCharacters(path);
 }

 template <typename CharacterType>
 static void cleanSlashDotSlashes(Vector<CharacterType, 512>& path, size_t firstSlash)
 {
     size_t slash = firstSlash;
     do {
         path[slash] = 0;
         path[slash + 1] = 0;
         slash += 2;
     } while ((slash = findSlashDotSlash(path.data(), path.size(), slash)) != notFound);
     squeezeOutNullCharacters(path);
 }

 template <typename CharacterType>
 static inline void cleanPath(Vector<CharacterType, 512>& path)
 {
     // FIXME: Should not do this in the query or anchor part of the URL.
     size_t firstSlash = findSlashDotDotSlash(path.data(), path.size(), 0);
     if (firstSlash != notFound)
         cleanSlashDotDotSlashes(path, firstSlash);

     // FIXME: Should not do this in the query part.
     firstSlash = findSlashSlash(path.data(), path.size(), 0);
     if (firstSlash != notFound)
         mergeDoubleSlashes(path, firstSlash);

     // FIXME: Should not do this in the query or anchor part.
     firstSlash = findSlashDotSlash(path.data(), path.size(), 0);
     if (firstSlash != notFound)
         cleanSlashDotSlashes(path, firstSlash);
 }

 template <typename CharacterType>
 static inline bool matchLetter(CharacterType c, char lowercaseLetter)
 {
     return (c | 0x20) == lowercaseLetter;
 }

 template <typename CharacterType>
 static inline bool needsTrailingSlash(const CharacterType* characters, unsigned length)
 {
     if (length < 6)
         return false;
     if (!matchLetter(characters[0], 'h') || !matchLetter(characters[1], 't') || !matchLetter(characters[2], 't') || !matchLetter(characters[3], 'p'))
         return false;
     if (!(characters[4] == ':' || (matchLetter(characters[4], 's') && characters[5] == ':')))
         return false;

     unsigned pos = characters[4] == ':' ? 5 : 6;

     // Skip initial two slashes if present.
     if (pos + 1 < length && characters[pos] == '/' && characters[pos + 1] == '/')
         pos += 2;

     // Find next slash.
     while (pos < length && characters[pos] != '/')
         ++pos;

     return pos == length;
 }

 template <typename CharacterType>
 static ALWAYS_INLINE SharedStringHash computeSharedStringHashInline(const CharacterType* url, unsigned length)
 {
     return AlreadyHashed::avoidDeletedValue(StringHasher::computeHash(url, length));
 }

 SharedStringHash computeSharedStringHash(const String& url)
 {
     unsigned length = url.length();
     if (!length || url.is8Bit())
         return computeSharedStringHashInline(url.characters8(), length);
     return computeSharedStringHashInline(url.characters16(), length);
 }

 SharedStringHash computeSharedStringHash(const UChar* url, unsigned length)
 {
     return computeSharedStringHashInline(url, length);
 }

 template <typename CharacterType>
 static ALWAYS_INLINE void computeSharedStringHashInline(const URL& base, const CharacterType* characters, unsigned length, Vector<CharacterType, 512>& buffer)
 {
     if (!length)
         return;

     // This is a poor man's completeURL. Faster with less memory allocation.
     // FIXME: It's missing a lot of what completeURL does and a lot of what URL does.
     // For example, it does not handle international domain names properly.

     // FIXME: It is wrong that we do not do further processing on strings that have "://" in them:
     //    1) The "://" could be in the query or anchor.
     //    2) The URL's path could have a "/./" or a "/../" or a "//" sequence in it.

     // FIXME: needsTrailingSlash does not properly return true for a URL that has no path, but does
     // have a query or anchor.

     bool hasColonSlashSlash = containsColonSlashSlash(characters, length);

     if (hasColonSlashSlash && !needsTrailingSlash(characters, length)) {
         buffer.append(characters, length);
         return;
     }


     if (hasColonSlashSlash) {
         // FIXME: This is incorrect for URLs that have a query or anchor; the "/" needs to go at the
         // end of the path, *before* the query or anchor.
         buffer.append(characters, length);
         buffer.append('/');
         return;
     }

     if (!length)
         append(buffer, base.string());
     else {
         switch (characters[0]) {
         case '/':
             append(buffer, StringView(base.string()).substring(0, base.pathStart()));
             break;
         case '#':
             append(buffer, StringView(base.string()).substring(0, base.pathEnd()));
             break;
         default:
             append(buffer, StringView(base.string()).substring(0, base.pathAfterLastSlash()));
             break;
         }
     }
     buffer.append(characters, length);
     cleanPath(buffer);
     if (needsTrailingSlash(buffer.data(), buffer.size())) {
         // FIXME: This is incorrect for URLs that have a query or anchor; the "/" needs to go at the
         // end of the path, *before* the query or anchor.
         buffer.append('/');
     }

     return;
 }

 SharedStringHash computeVisitedLinkHash(const URL& base, const AtomicString& attributeURL)
 {
     if (attributeURL.isEmpty())
         return 0;

     if (!base.string().isEmpty() && base.string().is8Bit() && attributeURL.is8Bit()) {
         Vector<LChar, 512> url;
         computeSharedStringHashInline(base, attributeURL.characters8(), attributeURL.length(), url);
         if (url.isEmpty())
             return 0;

         return computeSharedStringHashInline(url.data(), url.size());
     }

     Vector<UChar, 512> url;
     auto upconvertedCharacters = StringView(attributeURL.string()).upconvertedCharacters();
     const UChar* characters = upconvertedCharacters;
     computeSharedStringHashInline(base, characters, attributeURL.length(), url);
     if (url.isEmpty())
         return 0;

     return computeSharedStringHashInline(url.data(), url.size());
 }

 } // namespace WebCore
	/*
	* Copyright (C) 1999 Lars Knoll (knoll@kde.org)
	* (C) 1999 Antti Koivisto (koivisto@kde.org)
	* (C) 2001 Dirk Mueller (mueller@kde.org)
	* (C) 2006 Alexey Proskuryakov (ap@webkit.org)
	* Copyright (C) 2004, 2005, 2006, 2007, 2008 Apple Inc. All rights reserved.
	*
	* This library is free software; you can redistribute it and/or
	* modify it under the terms of the GNU Library General Public
	* License as published by the Free Software Foundation; either
	* version 2 of the License, or (at your option) any later version.
	*
	* This library is distributed in the hope that it will be useful,
	* but WITHOUT ANY WARRANTY; without even the implied warranty of
	* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
	* Library General Public License for more details.
	*
	* You should have received a copy of the GNU Library General Public License
	* along with this library; see the file COPYING.LIB. If not, write to
	* the Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor,
	* Boston, MA 02110-1301, USA.
	*/

	#include "config.h"
	#include "SharedStringHash.h"

	#include <wtf/URL.h>
	#include <wtf/text/AtomicString.h>
	#include <wtf/text/StringHash.h>
	#include <wtf/text/StringView.h>

	namespace WebCore {

	template <typename CharacterType>
	static inline size_t findSlashDotDotSlash(const CharacterType* characters, size_t length, size_t position)
	{
	if (length < 4)
	return notFound;
	size_t loopLimit = length - 3;
	for (size_t i = position; i < loopLimit; ++i) {
	if (characters[i] == '/' && characters[i + 1] == '.' && characters[i + 2] == '.' && characters[i + 3] == '/')
	return i;
	}
	return notFound;
	}

	template <typename CharacterType>
	static inline size_t findSlashSlash(const CharacterType* characters, size_t length, size_t position)
	{
	if (length < 2)
	return notFound;
	size_t loopLimit = length - 1;
	for (size_t i = position; i < loopLimit; ++i) {
	if (characters[i] == '/' && characters[i + 1] == '/')
	return i;
	}
	return notFound;
	}

	template <typename CharacterType>
	static inline size_t findSlashDotSlash(const CharacterType* characters, size_t length, size_t position)
	{
	if (length < 3)
	return notFound;
	size_t loopLimit = length - 2;
	for (size_t i = position; i < loopLimit; ++i) {
	if (characters[i] == '/' && characters[i + 1] == '.' && characters[i + 2] == '/')
	return i;
	}
	return notFound;
	}

	template <typename CharacterType>
	static inline bool containsColonSlashSlash(const CharacterType* characters, unsigned length)
	{
	if (length < 3)
	return false;
	unsigned loopLimit = length - 2;
	for (unsigned i = 0; i < loopLimit; ++i) {
	if (characters[i] == ':' && characters[i + 1] == '/' && characters[i + 2] == '/')
	return true;
	}
	return false;
	}

	template <typename CharacterType>
	static inline void squeezeOutNullCharacters(Vector<CharacterType, 512>& string)
	{
	size_t size = string.size();
	size_t i = 0;
	for (i = 0; i < size; ++i) {
	if (!string[i])
	break;
	}
	if (i == size)
	return;
	size_t j = i;
	for (++i; i < size; ++i) {
	if (CharacterType character = string[i])
	string[j++] = character;
	}
	ASSERT(j < size);
	string.shrink(j);
	}

	template <typename CharacterType>
	static void cleanSlashDotDotSlashes(Vector<CharacterType, 512>& path, size_t firstSlash)
	{
	size_t slash = firstSlash;
	do {
	size_t previousSlash = slash ? reverseFind(path.data(), path.size(), '/', slash - 1) : notFound;
	// Don't remove the host, i.e. http://foo.org/../foo.html
	if (previousSlash == notFound \|\| (previousSlash > 3 && path[previousSlash - 2] == ':' && path[previousSlash - 1] == '/')) {
	path[slash] = 0;
	path[slash + 1] = 0;
	path[slash + 2] = 0;
	} else {
	for (size_t i = previousSlash; i < slash + 3; ++i)
	path[i] = 0;
	}
	slash += 3;
	} while ((slash = findSlashDotDotSlash(path.data(), path.size(), slash)) != notFound);
	squeezeOutNullCharacters(path);
	}

	template <typename CharacterType>
	static void mergeDoubleSlashes(Vector<CharacterType, 512>& path, size_t firstSlash)
	{
	size_t refPos = find(path.data(), path.size(), '#');
	if (!refPos \|\| refPos == notFound)
	refPos = path.size();

	size_t slash = firstSlash;
	while (slash < refPos) {
	if (!slash \|\| path[slash - 1] != ':')
	path[slash++] = 0;
	else
	slash += 2;
	if ((slash = findSlashSlash(path.data(), path.size(), slash)) == notFound)
	break;
	}
	squeezeOutNullCharacters(path);
	}

	template <typename CharacterType>
	static void cleanSlashDotSlashes(Vector<CharacterType, 512>& path, size_t firstSlash)
	{
	size_t slash = firstSlash;
	do {
	path[slash] = 0;
	path[slash + 1] = 0;
	slash += 2;
	} while ((slash = findSlashDotSlash(path.data(), path.size(), slash)) != notFound);
	squeezeOutNullCharacters(path);
	}

	template <typename CharacterType>
	static inline void cleanPath(Vector<CharacterType, 512>& path)
	{
	// FIXME: Should not do this in the query or anchor part of the URL.
	size_t firstSlash = findSlashDotDotSlash(path.data(), path.size(), 0);
	if (firstSlash != notFound)
	cleanSlashDotDotSlashes(path, firstSlash);

	// FIXME: Should not do this in the query part.
	firstSlash = findSlashSlash(path.data(), path.size(), 0);
	if (firstSlash != notFound)
	mergeDoubleSlashes(path, firstSlash);

	// FIXME: Should not do this in the query or anchor part.
	firstSlash = findSlashDotSlash(path.data(), path.size(), 0);
	if (firstSlash != notFound)
	cleanSlashDotSlashes(path, firstSlash);
	}

	template <typename CharacterType>
	static inline bool matchLetter(CharacterType c, char lowercaseLetter)
	{
	return (c \| 0x20) == lowercaseLetter;
	}

	template <typename CharacterType>
	static inline bool needsTrailingSlash(const CharacterType* characters, unsigned length)
	{
	if (length < 6)
	return false;
	if (!matchLetter(characters[0], 'h') \|\| !matchLetter(characters[1], 't') \|\| !matchLetter(characters[2], 't') \|\| !matchLetter(characters[3], 'p'))
	return false;
	if (!(characters[4] == ':' \|\| (matchLetter(characters[4], 's') && characters[5] == ':')))
	return false;

	unsigned pos = characters[4] == ':' ? 5 : 6;

	// Skip initial two slashes if present.
	if (pos + 1 < length && characters[pos] == '/' && characters[pos + 1] == '/')
	pos += 2;

	// Find next slash.
	while (pos < length && characters[pos] != '/')
	++pos;

	return pos == length;
	}

	template <typename CharacterType>
	static ALWAYS_INLINE SharedStringHash computeSharedStringHashInline(const CharacterType* url, unsigned length)
	{
	return AlreadyHashed::avoidDeletedValue(StringHasher::computeHash(url, length));
	}

	SharedStringHash computeSharedStringHash(const String& url)
	{
	unsigned length = url.length();
	if (!length \|\| url.is8Bit())
	return computeSharedStringHashInline(url.characters8(), length);
	return computeSharedStringHashInline(url.characters16(), length);
	}

	SharedStringHash computeSharedStringHash(const UChar* url, unsigned length)
	{
	return computeSharedStringHashInline(url, length);
	}

	template <typename CharacterType>
	static ALWAYS_INLINE void computeSharedStringHashInline(const URL& base, const CharacterType* characters, unsigned length, Vector<CharacterType, 512>& buffer)
	{
	if (!length)
	return;

	// This is a poor man's completeURL. Faster with less memory allocation.
	// FIXME: It's missing a lot of what completeURL does and a lot of what URL does.
	// For example, it does not handle international domain names properly.

	// FIXME: It is wrong that we do not do further processing on strings that have "://" in them:
	// 1) The "://" could be in the query or anchor.
	// 2) The URL's path could have a "/./" or a "/../" or a "//" sequence in it.

	// FIXME: needsTrailingSlash does not properly return true for a URL that has no path, but does
	// have a query or anchor.

	bool hasColonSlashSlash = containsColonSlashSlash(characters, length);

	if (hasColonSlashSlash && !needsTrailingSlash(characters, length)) {
	buffer.append(characters, length);
	return;
	}


	if (hasColonSlashSlash) {
	// FIXME: This is incorrect for URLs that have a query or anchor; the "/" needs to go at the
	// end of the path, before the query or anchor.
	buffer.append(characters, length);
	buffer.append('/');
	return;
	}

	if (!length)
	append(buffer, base.string());
	else {
	switch (characters[0]) {
	case '/':
	append(buffer, StringView(base.string()).substring(0, base.pathStart()));
	break;
	case '#':
	append(buffer, StringView(base.string()).substring(0, base.pathEnd()));
	break;
	default:
	append(buffer, StringView(base.string()).substring(0, base.pathAfterLastSlash()));
	break;
	}
	}
	buffer.append(characters, length);
	cleanPath(buffer);
	if (needsTrailingSlash(buffer.data(), buffer.size())) {
	// FIXME: This is incorrect for URLs that have a query or anchor; the "/" needs to go at the
	// end of the path, before the query or anchor.
	buffer.append('/');
	}

	return;
	}

	SharedStringHash computeVisitedLinkHash(const URL& base, const AtomicString& attributeURL)
	{
	if (attributeURL.isEmpty())
	return 0;

	if (!base.string().isEmpty() && base.string().is8Bit() && attributeURL.is8Bit()) {
	Vector<LChar, 512> url;
	computeSharedStringHashInline(base, attributeURL.characters8(), attributeURL.length(), url);
	if (url.isEmpty())
	return 0;

	return computeSharedStringHashInline(url.data(), url.size());
	}

	Vector<UChar, 512> url;
	auto upconvertedCharacters = StringView(attributeURL.string()).upconvertedCharacters();
	const UChar* characters = upconvertedCharacters;
	computeSharedStringHashInline(base, characters, attributeURL.length(), url);
	if (url.isEmpty())
	return 0;

	return computeSharedStringHashInline(url.data(), url.size());
	}

	} // namespace WebCore