Source/JavaScriptCore/runtime/Identifier.cpp - platform/external/webkit - Git at Google

 /*
  *  Copyright (C) 2003, 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 "Identifier.h"

 #include "CallFrame.h"
 #include "JSObject.h"
 #include "NumericStrings.h"
 #include "ScopeChain.h"
 #include <new> // for placement new
 #include <string.h> // for strlen
 #include <wtf/Assertions.h>
 #include <wtf/FastMalloc.h>
 #include <wtf/HashSet.h>
 #include <wtf/WTFThreadData.h>
 #include <wtf/text/StringHash.h>

 using WTF::ThreadSpecific;

 namespace JSC {

 IdentifierTable::~IdentifierTable()
 {
     HashSet<StringImpl*>::iterator end = m_table.end();
     for (HashSet<StringImpl*>::iterator iter = m_table.begin(); iter != end; ++iter)
         (*iter)->setIsIdentifier(false);
 }
 std::pair<HashSet<StringImpl*>::iterator, bool> IdentifierTable::add(StringImpl* value)
 {
     std::pair<HashSet<StringImpl*>::iterator, bool> result = m_table.add(value);
     (*result.first)->setIsIdentifier(true);
     return result;
 }
 template<typename U, typename V>
 std::pair<HashSet<StringImpl*>::iterator, bool> IdentifierTable::add(U value)
 {
     std::pair<HashSet<StringImpl*>::iterator, bool> result = m_table.add<U, V>(value);
     (*result.first)->setIsIdentifier(true);
     return result;
 }

 IdentifierTable* createIdentifierTable()
 {
     return new IdentifierTable;
 }

 void deleteIdentifierTable(IdentifierTable* table)
 {
     delete table;
 }

 bool Identifier::equal(const StringImpl* r, const char* s)
 {
     int length = r->length();
     const UChar* d = r->characters();
     for (int i = 0; i != length; ++i)
         if (d[i] != (unsigned char)s[i])
             return false;
     return s[length] == 0;
 }

 bool Identifier::equal(const StringImpl* r, const UChar* s, unsigned length)
 {
     if (r->length() != length)
         return false;
     const UChar* d = r->characters();
     for (unsigned i = 0; i != length; ++i)
         if (d[i] != s[i])
             return false;
     return true;
 }

 struct IdentifierCStringTranslator {
     static unsigned hash(const char* c)
     {
         return StringHasher::computeHash<char>(c);
     }

     static bool equal(StringImpl* r, const char* s)
     {
         return Identifier::equal(r, s);
     }

     static void translate(StringImpl*& location, const char* c, unsigned hash)
     {
         size_t length = strlen(c);
         UChar* d;
         StringImpl* r = StringImpl::createUninitialized(length, d).leakRef();
         for (size_t i = 0; i != length; i++)
             d[i] = static_cast<unsigned char>(c[i]); // use unsigned char to zero-extend instead of sign-extend
         r->setHash(hash);
         location = r;
     }
 };

 PassRefPtr<StringImpl> Identifier::add(JSGlobalData* globalData, const char* c)
 {
     if (!c)
         return 0;
     if (!c[0])
         return StringImpl::empty();
     if (!c[1])
         return add(globalData, globalData->smallStrings.singleCharacterStringRep(static_cast<unsigned char>(c[0])));

     IdentifierTable& identifierTable = *globalData->identifierTable;
     LiteralIdentifierTable& literalIdentifierTable = identifierTable.literalTable();

     const LiteralIdentifierTable::iterator& iter = literalIdentifierTable.find(c);
     if (iter != literalIdentifierTable.end())
         return iter->second;

     pair<HashSet<StringImpl*>::iterator, bool> addResult = identifierTable.add<const char*, IdentifierCStringTranslator>(c);

     // If the string is newly-translated, then we need to adopt it.
     // The boolean in the pair tells us if that is so.
     RefPtr<StringImpl> addedString = addResult.second ? adoptRef(*addResult.first) : *addResult.first;

     literalIdentifierTable.add(c, addedString.get());

     return addedString.release();
 }

 PassRefPtr<StringImpl> Identifier::add(ExecState* exec, const char* c)
 {
     return add(&exec->globalData(), c);
 }

 struct UCharBuffer {
     const UChar* s;
     unsigned int length;
 };

 struct IdentifierUCharBufferTranslator {
     static unsigned hash(const UCharBuffer& buf)
     {
         return StringHasher::computeHash<UChar>(buf.s, buf.length);
     }

     static bool equal(StringImpl* str, const UCharBuffer& buf)
     {
         return Identifier::equal(str, buf.s, buf.length);
     }

     static void translate(StringImpl*& location, const UCharBuffer& buf, unsigned hash)
     {
         UChar* d;
         StringImpl* r = StringImpl::createUninitialized(buf.length, d).leakRef();
         for (unsigned i = 0; i != buf.length; i++)
             d[i] = buf.s[i];
         r->setHash(hash);
         location = r;
     }
 };

 uint32_t Identifier::toUInt32(const UString& string, bool& ok)
 {
     ok = false;

     unsigned length = string.length();
     const UChar* characters = string.characters();

     // An empty string is not a number.
     if (!length)
         return 0;

     // Get the first character, turning it into a digit.
     uint32_t value = characters[0] - '0';
     if (value > 9)
         return 0;

     // Check for leading zeros. If the first characher is 0, then the
     // length of the string must be one - e.g. "042" is not equal to "42".
     if (!value && length > 1)
         return 0;

     while (--length) {
         // Multiply value by 10, checking for overflow out of 32 bits.
         if (value > 0xFFFFFFFFU / 10)
             return 0;
         value *= 10;

         // Get the next character, turning it into a digit.
         uint32_t newValue = *(++characters) - '0';
         if (newValue > 9)
             return 0;

         // Add in the old value, checking for overflow out of 32 bits.
         newValue += value;
         if (newValue < value)
             return 0;
         value = newValue;
     }

     ok = true;
     return value;
 }

 PassRefPtr<StringImpl> Identifier::add(JSGlobalData* globalData, const UChar* s, int length)
 {
     if (length == 1) {
         UChar c = s[0];
         if (c <= maxSingleCharacterString)
             return add(globalData, globalData->smallStrings.singleCharacterStringRep(c));
     }
     if (!length)
         return StringImpl::empty();
     UCharBuffer buf = {s, length};
     pair<HashSet<StringImpl*>::iterator, bool> addResult = globalData->identifierTable->add<UCharBuffer, IdentifierUCharBufferTranslator>(buf);

     // If the string is newly-translated, then we need to adopt it.
     // The boolean in the pair tells us if that is so.
     return addResult.second ? adoptRef(*addResult.first) : *addResult.first;
 }

 PassRefPtr<StringImpl> Identifier::add(ExecState* exec, const UChar* s, int length)
 {
     return add(&exec->globalData(), s, length);
 }

 PassRefPtr<StringImpl> Identifier::addSlowCase(JSGlobalData* globalData, StringImpl* r)
 {
     ASSERT(!r->isIdentifier());
     // The empty & null strings are static singletons, and static strings are handled
     // in ::add() in the header, so we should never get here with a zero length string.
     ASSERT(r->length());

     if (r->length() == 1) {
         UChar c = r->characters()[0];
         if (c <= maxSingleCharacterString)
             r = globalData->smallStrings.singleCharacterStringRep(c);
             if (r->isIdentifier())
                 return r;
     }

     return *globalData->identifierTable->add(r).first;
 }

 PassRefPtr<StringImpl> Identifier::addSlowCase(ExecState* exec, StringImpl* r)
 {
     return addSlowCase(&exec->globalData(), r);
 }

 Identifier Identifier::from(ExecState* exec, unsigned value)
 {
     return Identifier(exec, exec->globalData().numericStrings.add(value));
 }

 Identifier Identifier::from(ExecState* exec, int value)
 {
     return Identifier(exec, exec->globalData().numericStrings.add(value));
 }

 Identifier Identifier::from(ExecState* exec, double value)
 {
     return Identifier(exec, exec->globalData().numericStrings.add(value));
 }

 Identifier Identifier::from(JSGlobalData* globalData, unsigned value)
 {
     return Identifier(globalData, globalData->numericStrings.add(value));
 }

 Identifier Identifier::from(JSGlobalData* globalData, int value)
 {
     return Identifier(globalData, globalData->numericStrings.add(value));
 }

 Identifier Identifier::from(JSGlobalData* globalData, double value)
 {
     return Identifier(globalData, globalData->numericStrings.add(value));
 }

 #ifndef NDEBUG

 void Identifier::checkCurrentIdentifierTable(JSGlobalData* globalData)
 {
     // Check the identifier table accessible through the threadspecific matches the
     // globalData's identifier table.
     ASSERT_UNUSED(globalData, globalData->identifierTable == wtfThreadData().currentIdentifierTable());
 }

 void Identifier::checkCurrentIdentifierTable(ExecState* exec)
 {
     checkCurrentIdentifierTable(&exec->globalData());
 }

 #else

 // These only exists so that our exports are the same for debug and release builds.
 // This would be an ASSERT_NOT_REACHED(), but we're in NDEBUG only code here!
 void Identifier::checkCurrentIdentifierTable(JSGlobalData*) { CRASH(); }
 void Identifier::checkCurrentIdentifierTable(ExecState*) { CRASH(); }

 #endif

 } // namespace JSC
	/*
	* Copyright (C) 2003, 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 "Identifier.h"

	#include "CallFrame.h"
	#include "JSObject.h"
	#include "NumericStrings.h"
	#include "ScopeChain.h"
	#include <new> // for placement new
	#include <string.h> // for strlen
	#include <wtf/Assertions.h>
	#include <wtf/FastMalloc.h>
	#include <wtf/HashSet.h>
	#include <wtf/WTFThreadData.h>
	#include <wtf/text/StringHash.h>

	using WTF::ThreadSpecific;

	namespace JSC {

	IdentifierTable::~IdentifierTable()
	{
	HashSet<StringImpl*>::iterator end = m_table.end();
	for (HashSet<StringImpl*>::iterator iter = m_table.begin(); iter != end; ++iter)
	(*iter)->setIsIdentifier(false);
	}
	std::pair<HashSet<StringImpl>::iterator, bool> IdentifierTable::add(StringImpl value)
	{
	std::pair<HashSet<StringImpl*>::iterator, bool> result = m_table.add(value);
	(*result.first)->setIsIdentifier(true);
	return result;
	}
	template<typename U, typename V>
	std::pair<HashSet<StringImpl*>::iterator, bool> IdentifierTable::add(U value)
	{
	std::pair<HashSet<StringImpl*>::iterator, bool> result = m_table.add<U, V>(value);
	(*result.first)->setIsIdentifier(true);
	return result;
	}

	IdentifierTable* createIdentifierTable()
	{
	return new IdentifierTable;
	}

	void deleteIdentifierTable(IdentifierTable* table)
	{
	delete table;
	}

	bool Identifier::equal(const StringImpl* r, const char* s)
	{
	int length = r->length();
	const UChar* d = r->characters();
	for (int i = 0; i != length; ++i)
	if (d[i] != (unsigned char)s[i])
	return false;
	return s[length] == 0;
	}

	bool Identifier::equal(const StringImpl* r, const UChar* s, unsigned length)
	{
	if (r->length() != length)
	return false;
	const UChar* d = r->characters();
	for (unsigned i = 0; i != length; ++i)
	if (d[i] != s[i])
	return false;
	return true;
	}

	struct IdentifierCStringTranslator {
	static unsigned hash(const char* c)
	{
	return StringHasher::computeHash<char>(c);
	}

	static bool equal(StringImpl* r, const char* s)
	{
	return Identifier::equal(r, s);
	}

	static void translate(StringImpl& location, const char c, unsigned hash)
	{
	size_t length = strlen(c);
	UChar* d;
	StringImpl* r = StringImpl::createUninitialized(length, d).leakRef();
	for (size_t i = 0; i != length; i++)
	d[i] = static_cast<unsigned char>(c[i]); // use unsigned char to zero-extend instead of sign-extend
	r->setHash(hash);
	location = r;
	}
	};

	PassRefPtr<StringImpl> Identifier::add(JSGlobalData* globalData, const char* c)
	{
	if (!c)
	return 0;
	if (!c[0])
	return StringImpl::empty();
	if (!c[1])
	return add(globalData, globalData->smallStrings.singleCharacterStringRep(static_cast<unsigned char>(c[0])));

	IdentifierTable& identifierTable = *globalData->identifierTable;
	LiteralIdentifierTable& literalIdentifierTable = identifierTable.literalTable();

	const LiteralIdentifierTable::iterator& iter = literalIdentifierTable.find(c);
	if (iter != literalIdentifierTable.end())
	return iter->second;

	pair<HashSet<StringImpl>::iterator, bool> addResult = identifierTable.add<const char, IdentifierCStringTranslator>(c);

	// If the string is newly-translated, then we need to adopt it.
	// The boolean in the pair tells us if that is so.
	RefPtr<StringImpl> addedString = addResult.second ? adoptRef(addResult.first) : addResult.first;

	literalIdentifierTable.add(c, addedString.get());

	return addedString.release();
	}

	PassRefPtr<StringImpl> Identifier::add(ExecState* exec, const char* c)
	{
	return add(&exec->globalData(), c);
	}

	struct UCharBuffer {
	const UChar* s;
	unsigned int length;
	};

	struct IdentifierUCharBufferTranslator {
	static unsigned hash(const UCharBuffer& buf)
	{
	return StringHasher::computeHash<UChar>(buf.s, buf.length);
	}

	static bool equal(StringImpl* str, const UCharBuffer& buf)
	{
	return Identifier::equal(str, buf.s, buf.length);
	}

	static void translate(StringImpl*& location, const UCharBuffer& buf, unsigned hash)
	{
	UChar* d;
	StringImpl* r = StringImpl::createUninitialized(buf.length, d).leakRef();
	for (unsigned i = 0; i != buf.length; i++)
	d[i] = buf.s[i];
	r->setHash(hash);
	location = r;
	}
	};

	uint32_t Identifier::toUInt32(const UString& string, bool& ok)
	{
	ok = false;

	unsigned length = string.length();
	const UChar* characters = string.characters();

	// An empty string is not a number.
	if (!length)
	return 0;

	// Get the first character, turning it into a digit.
	uint32_t value = characters[0] - '0';
	if (value > 9)
	return 0;

	// Check for leading zeros. If the first characher is 0, then the
	// length of the string must be one - e.g. "042" is not equal to "42".
	if (!value && length > 1)
	return 0;

	while (--length) {
	// Multiply value by 10, checking for overflow out of 32 bits.
	if (value > 0xFFFFFFFFU / 10)
	return 0;
	value *= 10;

	// Get the next character, turning it into a digit.
	uint32_t newValue = *(++characters) - '0';
	if (newValue > 9)
	return 0;

	// Add in the old value, checking for overflow out of 32 bits.
	newValue += value;
	if (newValue < value)
	return 0;
	value = newValue;
	}

	ok = true;
	return value;
	}

	PassRefPtr<StringImpl> Identifier::add(JSGlobalData* globalData, const UChar* s, int length)
	{
	if (length == 1) {
	UChar c = s[0];
	if (c <= maxSingleCharacterString)
	return add(globalData, globalData->smallStrings.singleCharacterStringRep(c));
	}
	if (!length)
	return StringImpl::empty();
	UCharBuffer buf = {s, length};
	pair<HashSet<StringImpl*>::iterator, bool> addResult = globalData->identifierTable->add<UCharBuffer, IdentifierUCharBufferTranslator>(buf);

	// If the string is newly-translated, then we need to adopt it.
	// The boolean in the pair tells us if that is so.
	return addResult.second ? adoptRef(addResult.first) : addResult.first;
	}

	PassRefPtr<StringImpl> Identifier::add(ExecState* exec, const UChar* s, int length)
	{
	return add(&exec->globalData(), s, length);
	}

	PassRefPtr<StringImpl> Identifier::addSlowCase(JSGlobalData* globalData, StringImpl* r)
	{
	ASSERT(!r->isIdentifier());
	// The empty & null strings are static singletons, and static strings are handled
	// in ::add() in the header, so we should never get here with a zero length string.
	ASSERT(r->length());

	if (r->length() == 1) {
	UChar c = r->characters()[0];
	if (c <= maxSingleCharacterString)
	r = globalData->smallStrings.singleCharacterStringRep(c);
	if (r->isIdentifier())
	return r;
	}

	return *globalData->identifierTable->add(r).first;
	}

	PassRefPtr<StringImpl> Identifier::addSlowCase(ExecState* exec, StringImpl* r)
	{
	return addSlowCase(&exec->globalData(), r);
	}

	Identifier Identifier::from(ExecState* exec, unsigned value)
	{
	return Identifier(exec, exec->globalData().numericStrings.add(value));
	}

	Identifier Identifier::from(ExecState* exec, int value)
	{
	return Identifier(exec, exec->globalData().numericStrings.add(value));
	}

	Identifier Identifier::from(ExecState* exec, double value)
	{
	return Identifier(exec, exec->globalData().numericStrings.add(value));
	}

	Identifier Identifier::from(JSGlobalData* globalData, unsigned value)
	{
	return Identifier(globalData, globalData->numericStrings.add(value));
	}

	Identifier Identifier::from(JSGlobalData* globalData, int value)
	{
	return Identifier(globalData, globalData->numericStrings.add(value));
	}

	Identifier Identifier::from(JSGlobalData* globalData, double value)
	{
	return Identifier(globalData, globalData->numericStrings.add(value));
	}

	#ifndef NDEBUG

	void Identifier::checkCurrentIdentifierTable(JSGlobalData* globalData)
	{
	// Check the identifier table accessible through the threadspecific matches the
	// globalData's identifier table.
	ASSERT_UNUSED(globalData, globalData->identifierTable == wtfThreadData().currentIdentifierTable());
	}

	void Identifier::checkCurrentIdentifierTable(ExecState* exec)
	{
	checkCurrentIdentifierTable(&exec->globalData());
	}

	#else

	// These only exists so that our exports are the same for debug and release builds.
	// This would be an ASSERT_NOT_REACHED(), but we're in NDEBUG only code here!
	void Identifier::checkCurrentIdentifierTable(JSGlobalData*) { CRASH(); }
	void Identifier::checkCurrentIdentifierTable(ExecState*) { CRASH(); }

	#endif

	} // namespace JSC