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/*
* Copyright (C) 2010 Google Inc. All rights reserved.
* Copyright (C) 2016-2017 Apple 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 AND ITS 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 APPLE OR ITS 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 "IDBKeyPath.h"
#include <wtf/ASCIICType.h>
#include <wtf/dtoa.h>
#include <wtf/text/StringBuilder.h>
namespace WebCore {
class IDBKeyPathLexer {
public:
enum TokenType {
TokenIdentifier,
TokenDot,
TokenEnd,
TokenError
};
explicit IDBKeyPathLexer(const String& s)
: m_string(s)
, m_remainingText(s)
, m_currentTokenType(TokenError)
{
}
TokenType currentTokenType() const { return m_currentTokenType; }
TokenType nextTokenType()
{
m_currentTokenType = lex(m_currentElement);
return m_currentTokenType;
}
const String& currentElement() { return m_currentElement; }
private:
TokenType lex(String&);
TokenType lexIdentifier(String&);
String m_currentElement;
const String m_string;
StringView m_remainingText;
TokenType m_currentTokenType;
};
IDBKeyPathLexer::TokenType IDBKeyPathLexer::lex(String& element)
{
if (m_remainingText.isEmpty())
return TokenEnd;
if (m_remainingText[0] == '.') {
m_remainingText = m_remainingText.substring(1);
return TokenDot;
}
return lexIdentifier(element);
}
namespace {
// The following correspond to grammar in ECMA-262.
const uint32_t unicodeLetter = U_GC_L_MASK | U_GC_NL_MASK;
const uint32_t unicodeCombiningMark = U_GC_MN_MASK | U_GC_MC_MASK;
const uint32_t unicodeDigit = U_GC_ND_MASK;
const uint32_t unicodeConnectorPunctuation = U_GC_PC_MASK;
const UChar ZWNJ = 0x200C;
const UChar ZWJ = 0x200D;
static inline bool isIdentifierStartCharacter(UChar c)
{
return (U_GET_GC_MASK(c) & unicodeLetter) || (c == '$') || (c == '_');
}
static inline bool isIdentifierCharacter(UChar c)
{
return (U_GET_GC_MASK(c) & (unicodeLetter | unicodeCombiningMark | unicodeDigit | unicodeConnectorPunctuation)) || (c == '$') || (c == '_') || (c == ZWNJ) || (c == ZWJ);
}
} // namespace
IDBKeyPathLexer::TokenType IDBKeyPathLexer::lexIdentifier(String& element)
{
StringView start = m_remainingText;
if (!m_remainingText.isEmpty() && isIdentifierStartCharacter(m_remainingText[0]))
m_remainingText = m_remainingText.substring(1);
else
return TokenError;
while (!m_remainingText.isEmpty() && isIdentifierCharacter(m_remainingText[0]))
m_remainingText = m_remainingText.substring(1);
element = start.left(start.length() - m_remainingText.length()).toString();
return TokenIdentifier;
}
static bool IDBIsValidKeyPath(const String& keyPath)
{
IDBKeyPathParseError error;
Vector<String> keyPathElements;
IDBParseKeyPath(keyPath, keyPathElements, error);
return error == IDBKeyPathParseError::None;
}
void IDBParseKeyPath(const String& keyPath, Vector<String>& elements, IDBKeyPathParseError& error)
{
// IDBKeyPath ::= EMPTY_STRING | identifier ('.' identifier)*
// The basic state machine is:
// Start => {Identifier, End}
// Identifier => {Dot, End}
// Dot => {Identifier}
// It bails out as soon as it finds an error, but doesn't discard the bits it managed to parse.
enum ParserState { Identifier, Dot, End };
IDBKeyPathLexer lexer(keyPath);
IDBKeyPathLexer::TokenType tokenType = lexer.nextTokenType();
ParserState state;
if (tokenType == IDBKeyPathLexer::TokenIdentifier)
state = Identifier;
else if (tokenType == IDBKeyPathLexer::TokenEnd)
state = End;
else {
error = IDBKeyPathParseError::Start;
return;
}
while (1) {
switch (state) {
case Identifier : {
IDBKeyPathLexer::TokenType tokenType = lexer.currentTokenType();
ASSERT(tokenType == IDBKeyPathLexer::TokenIdentifier);
String element = lexer.currentElement();
elements.append(element);
tokenType = lexer.nextTokenType();
if (tokenType == IDBKeyPathLexer::TokenDot)
state = Dot;
else if (tokenType == IDBKeyPathLexer::TokenEnd)
state = End;
else {
error = IDBKeyPathParseError::Identifier;
return;
}
break;
}
case Dot: {
IDBKeyPathLexer::TokenType tokenType = lexer.currentTokenType();
ASSERT(tokenType == IDBKeyPathLexer::TokenDot);
tokenType = lexer.nextTokenType();
if (tokenType == IDBKeyPathLexer::TokenIdentifier)
state = Identifier;
else {
error = IDBKeyPathParseError::Dot;
return;
}
break;
}
case End: {
error = IDBKeyPathParseError::None;
return;
}
}
}
}
bool isIDBKeyPathValid(const IDBKeyPath& keyPath)
{
auto visitor = WTF::makeVisitor([](const String& string) {
return IDBIsValidKeyPath(string);
}, [](const Vector<String>& vector) {
if (vector.isEmpty())
return false;
for (auto& key : vector) {
if (!IDBIsValidKeyPath(key))
return false;
}
return true;
});
return std::visit(visitor, keyPath);
}
#if !LOG_DISABLED
String loggingString(const IDBKeyPath& path)
{
auto visitor = WTF::makeVisitor([](const String& string) {
return makeString("< ", string, " >");
}, [](const Vector<String>& strings) {
if (strings.isEmpty())
return "< >"_str;
StringBuilder builder;
builder.append("< ");
for (size_t i = 0; i < strings.size() - 1; ++i) {
builder.append(strings[i]);
builder.append(", ");
}
builder.append(strings.last());
builder.append(" >");
return builder.toString();
});
return std::visit(visitor, path);
}
#endif
} // namespace WebCore