X-Git-Url: https://git.saurik.com/apple/javascriptcore.git/blobdiff_plain/4e4e5a6f2694187498445a6ac6f1634ce8141119..6fe7ccc865dc7d7541b93c5bcaf6368d2c98a174:/runtime/JSString.cpp?ds=sidebyside diff --git a/runtime/JSString.cpp b/runtime/JSString.cpp index 1d5e639..904cc4d 100644 --- a/runtime/JSString.cpp +++ b/runtime/JSString.cpp @@ -24,140 +24,189 @@ #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; -// Overview: this methods converts a JSString from holding a string in rope form -// down to a simple UString representation. It does so by building up the string -// backwards, since we want to avoid recursion, we expect that the tree structure -// representing the rope is likely imbalanced with more nodes down the left side -// (since appending to the string is likely more common) - and as such resolving -// in this fashion should minimize work queue size. (If we built the queue forwards -// we would likely have to place all of the constituent UStringImpls into the -// Vector before performing any concatenation, but by working backwards we likely -// only fill the queue with the number of substrings at any given level in a -// rope-of-ropes.) -void JSString::resolveRope(ExecState* exec) const +const ClassInfo JSString::s_info = { "string", 0, 0, 0, CREATE_METHOD_TABLE(JSString) }; + +void JSRopeString::RopeBuilder::expand() +{ + ASSERT(m_index == JSRopeString::s_maxInternalRopeLength); + JSString* jsString = m_jsString; + m_jsString = jsStringBuilder(&m_globalData); + m_index = 0; + append(jsString); +} + +void JSString::destroy(JSCell* cell) +{ + JSString* thisObject = jsCast(cell); + thisObject->JSString::~JSString(); +} + +void JSString::visitChildren(JSCell* cell, SlotVisitor& visitor) +{ + JSString* thisObject = jsCast(cell); + Base::visitChildren(thisObject, visitor); + + if (thisObject->isRope()) + static_cast(thisObject)->visitFibers(visitor); +} + +void JSRopeString::visitFibers(SlotVisitor& visitor) +{ + for (size_t i = 0; i < s_maxInternalRopeLength && m_fibers[i]; ++i) + visitor.append(&m_fibers[i]); +} + +void JSRopeString::resolveRope(ExecState* exec) const { ASSERT(isRope()); - // Allocate the buffer to hold the final string, position initially points to the end. - UChar* buffer; - if (PassRefPtr newImpl = UStringImpl::tryCreateUninitialized(m_length, buffer)) - m_value = newImpl; - else { - for (unsigned i = 0; i < m_fiberCount; ++i) { - RopeImpl::deref(m_other.m_fibers[i]); - m_other.m_fibers[i] = 0; + if (is8Bit()) { + LChar* buffer; + if (RefPtr newImpl = StringImpl::tryCreateUninitialized(m_length, buffer)) { + Heap::heap(this)->reportExtraMemoryCost(newImpl->cost()); + m_value = newImpl.release(); + } else { + outOfMemory(exec); + return; + } + + for (size_t i = 0; i < s_maxInternalRopeLength && m_fibers[i]; ++i) { + if (m_fibers[i]->isRope()) + return resolveRopeSlowCase8(buffer); + } + + LChar* position = buffer; + for (size_t i = 0; i < s_maxInternalRopeLength && m_fibers[i]; ++i) { + StringImpl* string = m_fibers[i]->m_value.impl(); + unsigned length = string->length(); + StringImpl::copyChars(position, string->characters8(), length); + position += length; + m_fibers[i].clear(); } - m_fiberCount = 0; + ASSERT((buffer + m_length) == position); ASSERT(!isRope()); - ASSERT(m_value == UString()); - if (exec) - throwOutOfMemoryError(exec); + return; } - UChar* position = buffer + m_length; - - // Start with the current RopeImpl. - Vector workQueue; - RopeImpl::Fiber currentFiber; - for (unsigned i = 0; i < (m_fiberCount - 1); ++i) - workQueue.append(m_other.m_fibers[i]); - currentFiber = m_other.m_fibers[m_fiberCount - 1]; - while (true) { - if (RopeImpl::isRope(currentFiber)) { - RopeImpl* rope = static_cast(currentFiber); - // Copy the contents of the current rope into the workQueue, with the last item in 'currentFiber' - // (we will be working backwards over the rope). - unsigned fiberCountMinusOne = rope->fiberCount() - 1; - for (unsigned i = 0; i < fiberCountMinusOne; ++i) - workQueue.append(rope->fibers()[i]); - currentFiber = rope->fibers()[fiberCountMinusOne]; - } else { - UStringImpl* string = static_cast(currentFiber); - unsigned length = string->length(); - position -= length; - UStringImpl::copyChars(position, string->characters(), length); - - // Was this the last item in the work queue? - if (workQueue.isEmpty()) { - // Create a string from the UChar buffer, clear the rope RefPtr. - ASSERT(buffer == position); - for (unsigned i = 0; i < m_fiberCount; ++i) { - RopeImpl::deref(m_other.m_fibers[i]); - m_other.m_fibers[i] = 0; - } - m_fiberCount = 0; - - ASSERT(!isRope()); - return; - } - - // No! - set the next item up to process. - currentFiber = workQueue.last(); - workQueue.removeLast(); - } + + UChar* buffer; + if (RefPtr newImpl = StringImpl::tryCreateUninitialized(m_length, buffer)) { + Heap::heap(this)->reportExtraMemoryCost(newImpl->cost()); + m_value = newImpl.release(); + } else { + outOfMemory(exec); + return; } + + for (size_t i = 0; i < s_maxInternalRopeLength && m_fibers[i]; ++i) { + if (m_fibers[i]->isRope()) + return resolveRopeSlowCase(buffer); + } + + UChar* position = buffer; + for (size_t i = 0; i < s_maxInternalRopeLength && m_fibers[i]; ++i) { + StringImpl* string = m_fibers[i]->m_value.impl(); + unsigned length = string->length(); + StringImpl::copyChars(position, string->characters(), length); + position += length; + m_fibers[i].clear(); + } + ASSERT((buffer + m_length) == position); + ASSERT(!isRope()); } -JSValue JSString::replaceCharacter(ExecState* exec, UChar character, const UString& replacement) +// Overview: These functions convert a JSString from holding a string in rope form +// down to a simple UString representation. It does so by building up the string +// backwards, since we want to avoid recursion, we expect that the tree structure +// representing the rope is likely imbalanced with more nodes down the left side +// (since appending to the string is likely more common) - and as such resolving +// in this fashion should minimize work queue size. (If we built the queue forwards +// we would likely have to place all of the constituent StringImpls into the +// Vector before performing any concatenation, but by working backwards we likely +// only fill the queue with the number of substrings at any given level in a +// rope-of-ropes.) +void JSRopeString::resolveRopeSlowCase8(LChar* buffer) const { - if (!isRope()) { - unsigned matchPosition = m_value.find(character); - if (matchPosition == UString::NotFound) - return JSValue(this); - return jsString(exec, m_value.substr(0, matchPosition), replacement, m_value.substr(matchPosition + 1)); + LChar* position = buffer + m_length; // We will be working backwards over the rope. + Vector workQueue; // Putting strings into a Vector is only OK because there are no GC points in this method. + + for (size_t i = 0; i < s_maxInternalRopeLength && m_fibers[i]; ++i) { + workQueue.append(m_fibers[i].get()); + // Clearing here works only because there are no GC points in this method. + m_fibers[i].clear(); } - RopeIterator end; - - // Count total fibers and find matching string. - size_t fiberCount = 0; - UStringImpl* matchString = 0; - int matchPosition = -1; - for (RopeIterator it(m_other.m_fibers, m_fiberCount); it != end; ++it) { - ++fiberCount; - if (matchString) - continue; + while (!workQueue.isEmpty()) { + JSString* currentFiber = workQueue.last(); + workQueue.removeLast(); - UStringImpl* string = *it; - matchPosition = string->find(character); - if (matchPosition == -1) + if (currentFiber->isRope()) { + JSRopeString* currentFiberAsRope = static_cast(currentFiber); + for (size_t i = 0; i < s_maxInternalRopeLength && currentFiberAsRope->m_fibers[i]; ++i) + workQueue.append(currentFiberAsRope->m_fibers[i].get()); continue; - matchString = string; + } + + StringImpl* string = static_cast(currentFiber->m_value.impl()); + unsigned length = string->length(); + position -= length; + StringImpl::copyChars(position, string->characters8(), length); } - if (!matchString) - return this; + ASSERT(buffer == position); + ASSERT(!isRope()); +} + +void JSRopeString::resolveRopeSlowCase(UChar* buffer) const +{ + UChar* position = buffer + m_length; // We will be working backwards over the rope. + Vector workQueue; // These strings are kept alive by the parent rope, so using a Vector is OK. + + for (size_t i = 0; i < s_maxInternalRopeLength && m_fibers[i]; ++i) + workQueue.append(m_fibers[i].get()); - RopeBuilder builder(replacement.size() ? fiberCount + 2 : fiberCount + 1); - if (UNLIKELY(builder.isOutOfMemory())) - return throwOutOfMemoryError(exec); + while (!workQueue.isEmpty()) { + JSString* currentFiber = workQueue.last(); + workQueue.removeLast(); - for (RopeIterator it(m_other.m_fibers, m_fiberCount); it != end; ++it) { - UStringImpl* string = *it; - if (string != matchString) { - builder.append(UString(string)); + if (currentFiber->isRope()) { + JSRopeString* currentFiberAsRope = static_cast(currentFiber); + for (size_t i = 0; i < s_maxInternalRopeLength && currentFiberAsRope->m_fibers[i]; ++i) + workQueue.append(currentFiberAsRope->m_fibers[i].get()); continue; } - builder.append(UString(string).substr(0, matchPosition)); - if (replacement.size()) - builder.append(replacement); - builder.append(UString(string).substr(matchPosition + 1)); - matchString = 0; + StringImpl* string = static_cast(currentFiber->m_value.impl()); + unsigned length = string->length(); + position -= length; + StringImpl::copyChars(position, string->characters(), length); } - JSGlobalData* globalData = &exec->globalData(); - return JSValue(new (globalData) JSString(globalData, builder.release())); + ASSERT(buffer == position); + ASSERT(!isRope()); } -JSString* JSString::getIndexSlowCase(ExecState* exec, unsigned i) +void JSRopeString::outOfMemory(ExecState* exec) const +{ + for (size_t i = 0; i < s_maxInternalRopeLength && m_fibers[i]; ++i) + m_fibers[i].clear(); + ASSERT(isRope()); + ASSERT(m_value == UString()); + if (exec) + throwOutOfMemoryError(exec); +} + +JSString* JSRopeString::getIndexSlowCase(ExecState* exec, unsigned i) { ASSERT(isRope()); resolveRope(exec); @@ -165,7 +214,7 @@ JSString* JSString::getIndexSlowCase(ExecState* exec, unsigned i) if (exec->exception()) return jsString(exec, ""); ASSERT(!isRope()); - ASSERT(i < m_value.size()); + ASSERT(i < m_value.length()); return jsSingleCharacterSubstring(exec, m_value, i); } @@ -174,10 +223,10 @@ JSValue JSString::toPrimitive(ExecState*, PreferredPrimitiveType) const return const_cast(this); } -bool JSString::getPrimitiveNumber(ExecState* exec, double& number, JSValue& result) +bool JSString::getPrimitiveNumber(ExecState* exec, double& number, JSValue& result) const { result = this; - number = value(exec).toDouble(); + number = jsToNumber(value(exec)); return false; } @@ -188,44 +237,38 @@ bool JSString::toBoolean(ExecState*) const double JSString::toNumber(ExecState* exec) const { - return value(exec).toDouble(); -} - -UString JSString::toString(ExecState* exec) const -{ - return value(exec); + return jsToNumber(value(exec)); } -inline StringObject* StringObject::create(ExecState* exec, JSString* string) +inline StringObject* StringObject::create(ExecState* exec, JSGlobalObject* globalObject, JSString* string) { - return new (exec) StringObject(exec->lexicalGlobalObject()->stringObjectStructure(), string); + StringObject* object = new (NotNull, allocateCell(*exec->heap())) StringObject(exec->globalData(), globalObject->stringObjectStructure()); + object->finishCreation(exec->globalData(), string); + return object; } -JSObject* JSString::toObject(ExecState* exec) const +JSObject* JSString::toObject(ExecState* exec, JSGlobalObject* globalObject) const { - return StringObject::create(exec, const_cast(this)); + return StringObject::create(exec, globalObject, const_cast(this)); } -JSObject* JSString::toThisObject(ExecState* exec) const +JSObject* JSString::toThisObject(JSCell* cell, ExecState* exec) { - return StringObject::create(exec, const_cast(this)); + return StringObject::create(exec, exec->lexicalGlobalObject(), jsCast(cell)); } -bool JSString::getOwnPropertySlot(ExecState* exec, const Identifier& propertyName, PropertySlot& slot) +bool JSString::getOwnPropertySlot(JSCell* cell, ExecState* exec, const Identifier& propertyName, PropertySlot& slot) { + JSString* thisObject = jsCast(cell); // The semantics here are really getPropertySlot, not getOwnPropertySlot. // This function should only be called by JSValue::get. - if (getStringPropertySlot(exec, propertyName, slot)) - return true; - if (propertyName == exec->propertyNames().underscoreProto) { - slot.setValue(exec->lexicalGlobalObject()->stringPrototype()); + if (thisObject->getStringPropertySlot(exec, propertyName, slot)) return true; - } - slot.setBase(this); + slot.setBase(thisObject); JSObject* object; for (JSValue prototype = exec->lexicalGlobalObject()->stringPrototype(); !prototype.isNull(); prototype = object->prototype()) { object = asObject(prototype); - if (object->getOwnPropertySlot(exec, propertyName, slot)) + if (object->methodTable()->getOwnPropertySlot(object, exec, propertyName, slot)) return true; } slot.setUndefined(); @@ -235,12 +278,12 @@ bool JSString::getOwnPropertySlot(ExecState* exec, const Identifier& propertyNam bool JSString::getStringPropertyDescriptor(ExecState* exec, const Identifier& propertyName, PropertyDescriptor& descriptor) { if (propertyName == exec->propertyNames().length) { - descriptor.setDescriptor(jsNumber(exec, m_length), DontEnum | DontDelete | ReadOnly); + descriptor.setDescriptor(jsNumber(m_length), DontEnum | DontDelete | ReadOnly); return true; } bool isStrictUInt32; - unsigned i = propertyName.toStrictUInt32(&isStrictUInt32); + unsigned i = propertyName.toUInt32(isStrictUInt32); if (isStrictUInt32 && i < m_length) { descriptor.setDescriptor(getIndex(exec, i), DontDelete | ReadOnly); return true; @@ -249,23 +292,14 @@ bool JSString::getStringPropertyDescriptor(ExecState* exec, const Identifier& pr 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) +bool JSString::getOwnPropertySlotByIndex(JSCell* cell, ExecState* exec, unsigned propertyName, PropertySlot& slot) { + JSString* thisObject = jsCast(cell); // The semantics here are really getPropertySlot, not getOwnPropertySlot. // This function should only be called by JSValue::get. - if (getStringPropertySlot(exec, propertyName, slot)) + if (thisObject->getStringPropertySlot(exec, propertyName, slot)) return true; - return JSString::getOwnPropertySlot(exec, Identifier::from(exec, propertyName), slot); + return JSString::getOwnPropertySlot(thisObject, exec, Identifier::from(exec, propertyName), slot); } } // namespace JSC