/*
* Copyright (C) 1999-2001 Harri Porten (porten@kde.org)
* Copyright (C) 2001 Peter Kelly (pmk@post.com)
* 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.
*
*/
#ifndef JSString_h
#define JSString_h
#include "CallFrame.h"
#include "CommonIdentifiers.h"
#include "Identifier.h"
#include "PropertyDescriptor.h"
#include "PropertySlot.h"
#include "RopeImpl.h"
#include "Structure.h"
namespace JSC {
class JSString;
JSString* jsEmptyString(JSGlobalData*);
JSString* jsEmptyString(ExecState*);
JSString* jsString(JSGlobalData*, const UString&); // returns empty string if passed null string
JSString* jsString(ExecState*, const UString&); // returns empty string if passed null string
JSString* jsSingleCharacterString(JSGlobalData*, UChar);
JSString* jsSingleCharacterString(ExecState*, UChar);
JSString* jsSingleCharacterSubstring(ExecState*, const UString&, unsigned offset);
JSString* jsSubstring(JSGlobalData*, const UString&, unsigned offset, unsigned length);
JSString* jsSubstring(ExecState*, const UString&, unsigned offset, unsigned length);
// Non-trivial strings are two or more characters long.
// These functions are faster than just calling jsString.
JSString* jsNontrivialString(JSGlobalData*, const UString&);
JSString* jsNontrivialString(ExecState*, const UString&);
JSString* jsNontrivialString(JSGlobalData*, const char*);
JSString* jsNontrivialString(ExecState*, const char*);
// Should be used for strings that are owned by an object that will
// likely outlive the JSValue this makes, such as the parse tree or a
// DOM object that contains a UString
JSString* jsOwnedString(JSGlobalData*, const UString&);
JSString* jsOwnedString(ExecState*, const UString&);
typedef void (*JSStringFinalizerCallback)(JSString*, void* context);
JSString* jsStringWithFinalizer(ExecState*, const UString&, JSStringFinalizerCallback callback, void* context);
class JS_EXPORTCLASS JSString : public JSCell {
public:
friend class JIT;
friend class JSGlobalData;
friend class SpecializedThunkJIT;
friend struct ThunkHelpers;
class RopeBuilder {
public:
RopeBuilder(unsigned fiberCount)
: m_index(0)
, m_rope(RopeImpl::tryCreateUninitialized(fiberCount))
{
}
bool isOutOfMemory() { return !m_rope; }
void append(RopeImpl::Fiber& fiber)
{
ASSERT(m_rope);
m_rope->initializeFiber(m_index, fiber);
}
void append(const UString& string)
{
ASSERT(m_rope);
m_rope->initializeFiber(m_index, string.impl());
}
void append(JSString* jsString)
{
if (jsString->isRope()) {
for (unsigned i = 0; i < jsString->m_fiberCount; ++i)
append(jsString->m_other.m_fibers[i]);
} else
append(jsString->string());
}
PassRefPtr<RopeImpl> release()
{
ASSERT(m_index == m_rope->fiberCount());
return m_rope.release();
}
unsigned length() { return m_rope->length(); }
private:
unsigned m_index;
RefPtr<RopeImpl> m_rope;
};
class RopeIterator {
public:
RopeIterator() { }
RopeIterator(RopeImpl::Fiber* fibers, size_t fiberCount)
{
ASSERT(fiberCount);
m_workQueue.append(WorkItem(fibers, fiberCount));
skipRopes();
}
RopeIterator& operator++()
{
WorkItem& item = m_workQueue.last();
ASSERT(!RopeImpl::isRope(item.fibers[item.i]));
if (++item.i == item.fiberCount)
m_workQueue.removeLast();
skipRopes();
return *this;
}
StringImpl* operator*()
{
WorkItem& item = m_workQueue.last();
RopeImpl::Fiber fiber = item.fibers[item.i];
ASSERT(!RopeImpl::isRope(fiber));
return static_cast<StringImpl*>(fiber);
}
bool operator!=(const RopeIterator& other) const
{
return m_workQueue != other.m_workQueue;
}
private:
struct WorkItem {
WorkItem(RopeImpl::Fiber* fibers, size_t fiberCount)
: fibers(fibers)
, fiberCount(fiberCount)
, i(0)
{
}
bool operator!=(const WorkItem& other) const
{
return fibers != other.fibers || fiberCount != other.fiberCount || i != other.i;
}
RopeImpl::Fiber* fibers;
size_t fiberCount;
size_t i;
};
void skipRopes()
{
if (m_workQueue.isEmpty())
return;
while (1) {
WorkItem& item = m_workQueue.last();
RopeImpl::Fiber fiber = item.fibers[item.i];
if (!RopeImpl::isRope(fiber))
break;
RopeImpl* rope = static_cast<RopeImpl*>(fiber);
if (++item.i == item.fiberCount)
m_workQueue.removeLast();
m_workQueue.append(WorkItem(rope->fibers(), rope->fiberCount()));
}
}
Vector<WorkItem, 16> m_workQueue;
};
ALWAYS_INLINE JSString(JSGlobalData* globalData, const UString& value)
: JSCell(*globalData, globalData->stringStructure.get())
, m_length(value.length())
, m_value(value)
, m_fiberCount(0)
{
ASSERT(!m_value.isNull());
Heap::heap(this)->reportExtraMemoryCost(value.impl()->cost());
}
enum HasOtherOwnerType { HasOtherOwner };
JSString(JSGlobalData* globalData, const UString& value, HasOtherOwnerType)
: JSCell(*globalData, globalData->stringStructure.get())
, m_length(value.length())
, m_value(value)
, m_fiberCount(0)
{
ASSERT(!m_value.isNull());
}
JSString(JSGlobalData* globalData, PassRefPtr<StringImpl> value, HasOtherOwnerType)
: JSCell(*globalData, globalData->stringStructure.get())
, m_length(value->length())
, m_value(value)
, m_fiberCount(0)
{
ASSERT(!m_value.isNull());
}
JSString(JSGlobalData* globalData, PassRefPtr<RopeImpl> rope)
: JSCell(*globalData, globalData->stringStructure.get())
, m_length(rope->length())
, m_fiberCount(1)
{
m_other.m_fibers[0] = rope.leakRef();
}
// This constructor constructs a new string by concatenating s1 & s2.
// This should only be called with fiberCount <= 3.
JSString(JSGlobalData* globalData, unsigned fiberCount, JSString* s1, JSString* s2)
: JSCell(*globalData, globalData->stringStructure.get())
, m_length(s1->length() + s2->length())
, m_fiberCount(fiberCount)
{
ASSERT(fiberCount <= s_maxInternalRopeLength);
unsigned index = 0;
appendStringInConstruct(index, s1);
appendStringInConstruct(index, s2);
ASSERT(fiberCount == index);
}
// This constructor constructs a new string by concatenating s1 & s2.
// This should only be called with fiberCount <= 3.
JSString(JSGlobalData* globalData, unsigned fiberCount, JSString* s1, const UString& u2)
: JSCell(*globalData, globalData->stringStructure.get())
, m_length(s1->length() + u2.length())
, m_fiberCount(fiberCount)
{
ASSERT(fiberCount <= s_maxInternalRopeLength);
unsigned index = 0;
appendStringInConstruct(index, s1);
appendStringInConstruct(index, u2);
ASSERT(fiberCount == index);
}
// This constructor constructs a new string by concatenating s1 & s2.
// This should only be called with fiberCount <= 3.
JSString(JSGlobalData* globalData, unsigned fiberCount, const UString& u1, JSString* s2)
: JSCell(*globalData, globalData->stringStructure.get())
, m_length(u1.length() + s2->length())
, m_fiberCount(fiberCount)
{
ASSERT(fiberCount <= s_maxInternalRopeLength);
unsigned index = 0;
appendStringInConstruct(index, u1);
appendStringInConstruct(index, s2);
ASSERT(fiberCount == index);
}
// This constructor constructs a new string by concatenating v1, v2 & v3.
// This should only be called with fiberCount <= 3 ... which since every
// value must require a fiberCount of at least one implies that the length
// for each value must be exactly 1!
JSString(ExecState* exec, JSValue v1, JSValue v2, JSValue v3)
: JSCell(exec->globalData(), exec->globalData().stringStructure.get())
, m_length(0)
, m_fiberCount(s_maxInternalRopeLength)
{
unsigned index = 0;
appendValueInConstructAndIncrementLength(exec, index, v1);
appendValueInConstructAndIncrementLength(exec, index, v2);
appendValueInConstructAndIncrementLength(exec, index, v3);
ASSERT(index == s_maxInternalRopeLength);
}
// This constructor constructs a new string by concatenating u1 & u2.
JSString(JSGlobalData* globalData, const UString& u1, const UString& u2)
: JSCell(*globalData, globalData->stringStructure.get())
, m_length(u1.length() + u2.length())
, m_fiberCount(2)
{
unsigned index = 0;
appendStringInConstruct(index, u1);
appendStringInConstruct(index, u2);
ASSERT(index <= s_maxInternalRopeLength);
}
// This constructor constructs a new string by concatenating u1, u2 & u3.
JSString(JSGlobalData* globalData, const UString& u1, const UString& u2, const UString& u3)
: JSCell(*globalData, globalData->stringStructure.get())
, m_length(u1.length() + u2.length() + u3.length())
, m_fiberCount(s_maxInternalRopeLength)
{
unsigned index = 0;
appendStringInConstruct(index, u1);
appendStringInConstruct(index, u2);
appendStringInConstruct(index, u3);
ASSERT(index <= s_maxInternalRopeLength);
}
JSString(JSGlobalData* globalData, const UString& value, JSStringFinalizerCallback finalizer, void* context)
: JSCell(*globalData, globalData->stringStructure.get())
, m_length(value.length())
, m_value(value)
, m_fiberCount(0)
{
ASSERT(!m_value.isNull());
// nasty hack because we can't union non-POD types
m_other.m_finalizerCallback = finalizer;
m_other.m_finalizerContext = context;
Heap::heap(this)->reportExtraMemoryCost(value.impl()->cost());
}
~JSString()
{
ASSERT(vptr() == JSGlobalData::jsStringVPtr);
if (!m_fiberCount) {
if (m_other.m_finalizerCallback)
m_other.m_finalizerCallback(this, m_other.m_finalizerContext);
} else {
unsigned i = 0;
do
RopeImpl::deref(m_other.m_fibers[i]);
while (++i < m_fiberCount);
}
}
const UString& value(ExecState* exec) const
{
if (isRope())
resolveRope(exec);
return m_value;
}
const UString& tryGetValue() const
{
if (isRope())
resolveRope(0);
return m_value;
}
unsigned length() { return m_length; }
bool getStringPropertySlot(ExecState*, const Identifier& propertyName, PropertySlot&);
bool getStringPropertySlot(ExecState*, unsigned propertyName, PropertySlot&);
bool getStringPropertyDescriptor(ExecState*, const Identifier& propertyName, PropertyDescriptor&);
bool canGetIndex(unsigned i) { return i < m_length; }
JSString* getIndex(ExecState*, unsigned);
JSString* getIndexSlowCase(ExecState*, unsigned);
JSValue replaceCharacter(ExecState*, UChar, const UString& replacement);
static Structure* createStructure(JSGlobalData& globalData, JSValue proto) { return Structure::create(globalData, proto, TypeInfo(StringType, OverridesGetOwnPropertySlot | NeedsThisConversion), AnonymousSlotCount, 0); }
private:
JSString(VPtrStealingHackType)
: JSCell(VPtrStealingHack)
, m_fiberCount(0)
{
}
void resolveRope(ExecState*) const;
JSString* substringFromRope(ExecState*, unsigned offset, unsigned length);
void appendStringInConstruct(unsigned& index, const UString& string)
{
StringImpl* impl = string.impl();
impl->ref();
m_other.m_fibers[index++] = impl;
}
void appendStringInConstruct(unsigned& index, JSString* jsString)
{
if (jsString->isRope()) {
for (unsigned i = 0; i < jsString->m_fiberCount; ++i) {
RopeImpl::Fiber fiber = jsString->m_other.m_fibers[i];
fiber->ref();
m_other.m_fibers[index++] = fiber;
}
} else
appendStringInConstruct(index, jsString->string());
}
void appendValueInConstructAndIncrementLength(ExecState* exec, unsigned& index, JSValue v)
{
if (v.isString()) {
ASSERT(v.asCell()->isString());
JSString* s = static_cast<JSString*>(v.asCell());
ASSERT(s->fiberCount() == 1);
appendStringInConstruct(index, s);
m_length += s->length();
} else {
UString u(v.toString(exec));
StringImpl* impl = u.impl();
impl->ref();
m_other.m_fibers[index++] = impl;
m_length += u.length();
}
}
virtual JSValue toPrimitive(ExecState*, PreferredPrimitiveType) const;
virtual bool getPrimitiveNumber(ExecState*, double& number, JSValue& value);
virtual bool toBoolean(ExecState*) const;
virtual double toNumber(ExecState*) const;
virtual JSObject* toObject(ExecState*, JSGlobalObject*) const;
virtual UString toString(ExecState*) const;
virtual JSObject* toThisObject(ExecState*) const;
// Actually getPropertySlot, not getOwnPropertySlot (see JSCell).
virtual bool getOwnPropertySlot(ExecState*, const Identifier& propertyName, PropertySlot&);
virtual bool getOwnPropertySlot(ExecState*, unsigned propertyName, PropertySlot&);
virtual bool getOwnPropertyDescriptor(ExecState*, const Identifier&, PropertyDescriptor&);
static const unsigned s_maxInternalRopeLength = 3;
// A string is represented either by a UString or a RopeImpl.
unsigned m_length;
mutable UString m_value;
mutable unsigned m_fiberCount;
// This structure exists to support a temporary workaround for a GC issue.
struct JSStringFinalizerStruct {
JSStringFinalizerStruct() : m_finalizerCallback(0) {}
union {
mutable FixedArray<RopeImpl::Fiber, s_maxInternalRopeLength> m_fibers;
struct {
JSStringFinalizerCallback m_finalizerCallback;
void* m_finalizerContext;
};
};
} m_other;
bool isRope() const { return m_fiberCount; }
UString& string() { ASSERT(!isRope()); return m_value; }
unsigned fiberCount() { return m_fiberCount ? m_fiberCount : 1; }
friend JSValue jsString(ExecState* exec, JSString* s1, JSString* s2);
friend JSValue jsString(ExecState* exec, const UString& u1, JSString* s2);
friend JSValue jsString(ExecState* exec, JSString* s1, const UString& u2);
friend JSValue jsString(ExecState* exec, Register* strings, unsigned count);
friend JSValue jsString(ExecState* exec, JSValue thisValue);
friend JSString* jsStringWithFinalizer(ExecState*, const UString&, JSStringFinalizerCallback callback, void* context);
friend JSString* jsSubstring(ExecState* exec, JSString* s, unsigned offset, unsigned length);
};
JSString* asString(JSValue);
// When an object is created from a different DLL, MSVC changes vptr to a "local" one right after invoking a constructor,
// see <http://groups.google.com/group/microsoft.public.vc.language/msg/55cdcefeaf770212>.
// This breaks isJSString(), and we don't need that hack anyway, so we change vptr back to primary one.
// The below function must be called by any inline function that invokes a JSString constructor.
#if COMPILER(MSVC) && !defined(BUILDING_JavaScriptCore)
inline JSString* fixupVPtr(JSGlobalData* globalData, JSString* string) { string->setVPtr(globalData->jsStringVPtr); return string; }
#else
inline JSString* fixupVPtr(JSGlobalData*, JSString* string) { return string; }
#endif
inline JSString* asString(JSValue value)
{
ASSERT(value.asCell()->isString());
return static_cast<JSString*>(value.asCell());
}
inline JSString* jsEmptyString(JSGlobalData* globalData)
{
return globalData->smallStrings.emptyString(globalData);
}
inline JSString* jsSingleCharacterString(JSGlobalData* globalData, UChar c)
{
if (c <= maxSingleCharacterString)
return globalData->smallStrings.singleCharacterString(globalData, c);
return fixupVPtr(globalData, new (globalData) JSString(globalData, UString(&c, 1)));
}
inline JSString* jsSingleCharacterSubstring(ExecState* exec, const UString& s, unsigned offset)
{
JSGlobalData* globalData = &exec->globalData();
ASSERT(offset < static_cast<unsigned>(s.length()));
UChar c = s.characters()[offset];
if (c <= maxSingleCharacterString)
return globalData->smallStrings.singleCharacterString(globalData, c);
return fixupVPtr(globalData, new (globalData) JSString(globalData, UString(StringImpl::create(s.impl(), offset, 1))));
}
inline JSString* jsNontrivialString(JSGlobalData* globalData, const char* s)
{
ASSERT(s);
ASSERT(s[0]);
ASSERT(s[1]);
return fixupVPtr(globalData, new (globalData) JSString(globalData, s));
}
inline JSString* jsNontrivialString(JSGlobalData* globalData, const UString& s)
{
ASSERT(s.length() > 1);
return fixupVPtr(globalData, new (globalData) JSString(globalData, s));
}
inline JSString* JSString::getIndex(ExecState* exec, unsigned i)
{
ASSERT(canGetIndex(i));
if (isRope())
return getIndexSlowCase(exec, i);
ASSERT(i < m_value.length());
return jsSingleCharacterSubstring(exec, m_value, i);
}
inline JSString* jsString(JSGlobalData* globalData, const UString& s)
{
int size = s.length();
if (!size)
return globalData->smallStrings.emptyString(globalData);
if (size == 1) {
UChar c = s.characters()[0];
if (c <= maxSingleCharacterString)
return globalData->smallStrings.singleCharacterString(globalData, c);
}
return fixupVPtr(globalData, new (globalData) JSString(globalData, s));
}
inline JSString* jsStringWithFinalizer(ExecState* exec, const UString& s, JSStringFinalizerCallback callback, void* context)
{
ASSERT(s.length() && (s.length() > 1 || s.characters()[0] > maxSingleCharacterString));
JSGlobalData* globalData = &exec->globalData();
return fixupVPtr(globalData, new (globalData) JSString(globalData, s, callback, context));
}
inline JSString* jsSubstring(ExecState* exec, JSString* s, unsigned offset, unsigned length)
{
ASSERT(offset <= static_cast<unsigned>(s->length()));
ASSERT(length <= static_cast<unsigned>(s->length()));
ASSERT(offset + length <= static_cast<unsigned>(s->length()));
JSGlobalData* globalData = &exec->globalData();
if (!length)
return globalData->smallStrings.emptyString(globalData);
if (s->isRope())
return s->substringFromRope(exec, offset, length);
return jsSubstring(globalData, s->m_value, offset, length);
}
inline JSString* jsSubstring(JSGlobalData* globalData, const UString& s, unsigned offset, unsigned length)
{
ASSERT(offset <= static_cast<unsigned>(s.length()));
ASSERT(length <= static_cast<unsigned>(s.length()));
ASSERT(offset + length <= static_cast<unsigned>(s.length()));
if (!length)
return globalData->smallStrings.emptyString(globalData);
if (length == 1) {
UChar c = s.characters()[offset];
if (c <= maxSingleCharacterString)
return globalData->smallStrings.singleCharacterString(globalData, c);
}
return fixupVPtr(globalData, new (globalData) JSString(globalData, UString(StringImpl::create(s.impl(), offset, length)), JSString::HasOtherOwner));
}
inline JSString* jsOwnedString(JSGlobalData* globalData, const UString& s)
{
int size = s.length();
if (!size)
return globalData->smallStrings.emptyString(globalData);
if (size == 1) {
UChar c = s.characters()[0];
if (c <= maxSingleCharacterString)
return globalData->smallStrings.singleCharacterString(globalData, c);
}
return fixupVPtr(globalData, new (globalData) JSString(globalData, s, JSString::HasOtherOwner));
}
inline JSString* jsEmptyString(ExecState* exec) { return jsEmptyString(&exec->globalData()); }
inline JSString* jsString(ExecState* exec, const UString& s) { return jsString(&exec->globalData(), s); }
inline JSString* jsSingleCharacterString(ExecState* exec, UChar c) { return jsSingleCharacterString(&exec->globalData(), c); }
inline JSString* jsSubstring(ExecState* exec, const UString& s, unsigned offset, unsigned length) { return jsSubstring(&exec->globalData(), s, offset, length); }
inline JSString* jsNontrivialString(ExecState* exec, const UString& s) { return jsNontrivialString(&exec->globalData(), s); }
inline JSString* jsNontrivialString(ExecState* exec, const char* s) { return jsNontrivialString(&exec->globalData(), s); }
inline JSString* jsOwnedString(ExecState* exec, const UString& s) { return jsOwnedString(&exec->globalData(), s); }
ALWAYS_INLINE bool JSString::getStringPropertySlot(ExecState* exec, const Identifier& propertyName, PropertySlot& slot)
{
if (propertyName == exec->propertyNames().length) {
slot.setValue(jsNumber(m_length));
return true;
}
bool isStrictUInt32;
unsigned i = propertyName.toUInt32(isStrictUInt32);
if (isStrictUInt32 && i < m_length) {
slot.setValue(getIndex(exec, i));
return true;
}
return false;
}
ALWAYS_INLINE bool JSString::getStringPropertySlot(ExecState* exec, unsigned propertyName, PropertySlot& slot)
{
if (propertyName < m_length) {
slot.setValue(getIndex(exec, propertyName));
return true;
}
return false;
}
inline bool isJSString(JSGlobalData* globalData, JSValue v) { return v.isCell() && v.asCell()->vptr() == globalData->jsStringVPtr; }
// --- JSValue inlines ----------------------------
inline UString JSValue::toString(ExecState* exec) const
{
if (isString())
return static_cast<JSString*>(asCell())->value(exec);
if (isInt32())
return exec->globalData().numericStrings.add(asInt32());
if (isDouble())
return exec->globalData().numericStrings.add(asDouble());
if (isTrue())
return "true";
if (isFalse())
return "false";
if (isNull())
return "null";
if (isUndefined())
return "undefined";
ASSERT(isCell());
return asCell()->toString(exec);
}
inline UString JSValue::toPrimitiveString(ExecState* exec) const
{
ASSERT(!isString());
if (isInt32())
return exec->globalData().numericStrings.add(asInt32());
if (isDouble())
return exec->globalData().numericStrings.add(asDouble());
if (isTrue())
return "true";
if (isFalse())
return "false";
if (isNull())
return "null";
if (isUndefined())
return "undefined";
ASSERT(isCell());
return asCell()->toPrimitive(exec, NoPreference).toString(exec);
}
} // namespace JSC
#endif // JSString_h