#include "config.h"
#include "JSString.h"
#include "JSGlobalObject.h"
#include "JSGlobalObjectFunctions.h"
#include "JSObject.h"
#include "Operations.h"
#include "StringObject.h"
#include "StringPrototype.h"
namespace JSC {
static const unsigned substringFromRopeCutoff = 4;
const ClassInfo JSString::s_info = { "string", 0, 0, 0 };
void JSString::resolveRope(ExecState* exec) const
{
ASSERT(isRope());
UChar* buffer;
if (PassRefPtr<StringImpl> newImpl = StringImpl::tryCreateUninitialized(m_length, buffer))
m_value = newImpl;
else {
outOfMemory(exec);
return;
}
RopeImpl::Fiber currentFiber = m_fibers[0];
if ((m_fiberCount > 2) || (RopeImpl::isRope(currentFiber))
|| ((m_fiberCount == 2) && (RopeImpl::isRope(m_fibers[1])))) {
resolveRopeSlowCase(exec, buffer);
return;
}
UChar* position = buffer;
StringImpl* string = static_cast<StringImpl*>(currentFiber);
unsigned length = string->length();
StringImpl::copyChars(position, string->characters(), length);
if (m_fiberCount > 1) {
position += length;
currentFiber = m_fibers[1];
string = static_cast<StringImpl*>(currentFiber);
length = string->length();
StringImpl::copyChars(position, string->characters(), length);
position += length;
}
ASSERT((buffer + m_length) == position);
for (unsigned i = 0; i < m_fiberCount; ++i) {
RopeImpl::deref(m_fibers[i]);
m_fibers[i] = 0;
}
m_fiberCount = 0;
ASSERT(!isRope());
}
void JSString::resolveRopeSlowCase(ExecState* exec, UChar* buffer) const
{
UNUSED_PARAM(exec);
UChar* position = buffer + m_length;
Vector<RopeImpl::Fiber, 32> workQueue;
RopeImpl::Fiber currentFiber;
for (unsigned i = 0; i < (m_fiberCount - 1); ++i)
workQueue.append(m_fibers[i]);
currentFiber = m_fibers[m_fiberCount - 1];
while (true) {
if (RopeImpl::isRope(currentFiber)) {
RopeImpl* rope = static_cast<RopeImpl*>(currentFiber);
unsigned fiberCountMinusOne = rope->fiberCount() - 1;
for (unsigned i = 0; i < fiberCountMinusOne; ++i)
workQueue.append(rope->fibers()[i]);
currentFiber = rope->fibers()[fiberCountMinusOne];
} else {
StringImpl* string = static_cast<StringImpl*>(currentFiber);
unsigned length = string->length();
position -= length;
StringImpl::copyChars(position, string->characters(), length);
if (workQueue.isEmpty()) {
ASSERT(buffer == position);
for (unsigned i = 0; i < m_fiberCount; ++i) {
RopeImpl::deref(m_fibers[i]);
m_fibers[i] = 0;
}
m_fiberCount = 0;
ASSERT(!isRope());
return;
}
currentFiber = workQueue.last();
workQueue.removeLast();
}
}
}
void JSString::outOfMemory(ExecState* exec) const
{
for (unsigned i = 0; i < m_fiberCount; ++i) {
RopeImpl::deref(m_fibers[i]);
m_fibers[i] = 0;
}
m_fiberCount = 0;
ASSERT(!isRope());
ASSERT(m_value == UString());
if (exec)
throwOutOfMemoryError(exec);
}
JSString* JSString::substringFromRope(ExecState* exec, unsigned substringStart, unsigned substringLength)
{
ASSERT(isRope());
ASSERT(substringLength);
JSGlobalData* globalData = &exec->globalData();
UString substringFibers[3];
unsigned fiberCount = 0;
unsigned substringFiberCount = 0;
unsigned substringEnd = substringStart + substringLength;
unsigned fiberEnd = 0;
RopeIterator end;
for (RopeIterator it(m_fibers.data(), m_fiberCount); it != end; ++it) {
++fiberCount;
StringImpl* fiberString = *it;
unsigned fiberStart = fiberEnd;
fiberEnd = fiberStart + fiberString->length();
if (fiberEnd <= substringStart)
continue;
unsigned copyStart = std::max(substringStart, fiberStart);
unsigned copyEnd = std::min(substringEnd, fiberEnd);
if (copyStart == fiberStart && copyEnd == fiberEnd)
substringFibers[substringFiberCount++] = UString(fiberString);
else
substringFibers[substringFiberCount++] = UString(StringImpl::create(fiberString, copyStart - fiberStart, copyEnd - copyStart));
if (fiberEnd >= substringEnd)
break;
if (fiberCount > substringFromRopeCutoff || substringFiberCount >= 3) {
resolveRope(exec);
return jsSubstring(&exec->globalData(), m_value, substringStart, substringLength);
}
}
ASSERT(substringFiberCount && substringFiberCount <= 3);
if (substringLength == 1) {
ASSERT(substringFiberCount == 1);
UChar c = substringFibers[0].characters()[0];
if (c <= maxSingleCharacterString)
return globalData->smallStrings.singleCharacterString(globalData, c);
}
if (substringFiberCount == 1)
return new (globalData) JSString(globalData, substringFibers[0]);
if (substringFiberCount == 2)
return new (globalData) JSString(globalData, substringFibers[0], substringFibers[1]);
return new (globalData) JSString(globalData, substringFibers[0], substringFibers[1], substringFibers[2]);
}
JSValue JSString::replaceCharacter(ExecState* exec, UChar character, const UString& replacement)
{
if (!isRope()) {
size_t matchPosition = m_value.find(character);
if (matchPosition == notFound)
return JSValue(this);
return jsString(exec, m_value.substringSharingImpl(0, matchPosition), replacement, m_value.substringSharingImpl(matchPosition + 1));
}
RopeIterator end;
size_t fiberCount = 0;
StringImpl* matchString = 0;
size_t matchPosition = notFound;
for (RopeIterator it(m_fibers.data(), m_fiberCount); it != end; ++it) {
++fiberCount;
if (matchString)
continue;
StringImpl* string = *it;
matchPosition = string->find(character);
if (matchPosition == notFound)
continue;
matchString = string;
}
if (!matchString)
return this;
RopeBuilder builder(replacement.length() ? fiberCount + 2 : fiberCount + 1);
if (UNLIKELY(builder.isOutOfMemory()))
return throwOutOfMemoryError(exec);
for (RopeIterator it(m_fibers.data(), m_fiberCount); it != end; ++it) {
StringImpl* string = *it;
if (string != matchString) {
builder.append(UString(string));
continue;
}
builder.append(UString(string).substringSharingImpl(0, matchPosition));
if (replacement.length())
builder.append(replacement);
builder.append(UString(string).substringSharingImpl(matchPosition + 1));
matchString = 0;
}
JSGlobalData* globalData = &exec->globalData();
return JSValue(new (globalData) JSString(globalData, builder.release()));
}
JSString* JSString::getIndexSlowCase(ExecState* exec, unsigned i)
{
ASSERT(isRope());
resolveRope(exec);
if (exec->exception())
return jsString(exec, "");
ASSERT(!isRope());
ASSERT(i < m_value.length());
return jsSingleCharacterSubstring(exec, m_value, i);
}
JSValue JSString::toPrimitive(ExecState*, PreferredPrimitiveType) const
{
return const_cast<JSString*>(this);
}
bool JSString::getPrimitiveNumber(ExecState* exec, double& number, JSValue& result)
{
result = this;
number = jsToNumber(value(exec));
return false;
}
bool JSString::toBoolean(ExecState*) const
{
return m_length;
}
double JSString::toNumber(ExecState* exec) const
{
return jsToNumber(value(exec));
}
UString JSString::toString(ExecState* exec) const
{
return value(exec);
}
inline StringObject* StringObject::create(ExecState* exec, JSGlobalObject* globalObject, JSString* string)
{
return new (exec) StringObject(exec->globalData(), globalObject->stringObjectStructure(), string);
}
JSObject* JSString::toObject(ExecState* exec, JSGlobalObject* globalObject) const
{
return StringObject::create(exec, globalObject, const_cast<JSString*>(this));
}
JSObject* JSString::toThisObject(ExecState* exec) const
{
return StringObject::create(exec, exec->lexicalGlobalObject(), const_cast<JSString*>(this));
}
bool JSString::getOwnPropertySlot(ExecState* exec, const Identifier& propertyName, PropertySlot& slot)
{
if (getStringPropertySlot(exec, propertyName, slot))
return true;
if (propertyName == exec->propertyNames().underscoreProto) {
slot.setValue(exec->lexicalGlobalObject()->stringPrototype());
return true;
}
slot.setBase(this);
JSObject* object;
for (JSValue prototype = exec->lexicalGlobalObject()->stringPrototype(); !prototype.isNull(); prototype = object->prototype()) {
object = asObject(prototype);
if (object->getOwnPropertySlot(exec, propertyName, slot))
return true;
}
slot.setUndefined();
return true;
}
bool JSString::getStringPropertyDescriptor(ExecState* exec, const Identifier& propertyName, PropertyDescriptor& descriptor)
{
if (propertyName == exec->propertyNames().length) {
descriptor.setDescriptor(jsNumber(m_length), DontEnum | DontDelete | ReadOnly);
return true;
}
bool isStrictUInt32;
unsigned i = propertyName.toUInt32(isStrictUInt32);
if (isStrictUInt32 && i < m_length) {
descriptor.setDescriptor(getIndex(exec, i), DontDelete | ReadOnly);
return true;
}
return false;
}
bool JSString::getOwnPropertyDescriptor(ExecState* exec, const Identifier& propertyName, PropertyDescriptor& descriptor)
{
if (getStringPropertyDescriptor(exec, propertyName, descriptor))
return true;
if (propertyName != exec->propertyNames().underscoreProto)
return false;
descriptor.setDescriptor(exec->lexicalGlobalObject()->stringPrototype(), DontEnum);
return true;
}
bool JSString::getOwnPropertySlot(ExecState* exec, unsigned propertyName, PropertySlot& slot)
{
if (getStringPropertySlot(exec, propertyName, slot))
return true;
return JSString::getOwnPropertySlot(exec, Identifier::from(exec, propertyName), slot);
}
}