From e15dd966d523731101f70ccf768bba12435a0208 Mon Sep 17 00:00:00 2001 From: Lorry Tar Creator Date: Thu, 15 Oct 2015 09:45:50 +0000 Subject: webkitgtk-2.10.2 --- Source/JavaScriptCore/runtime/JSString.cpp | 430 +++++++++++++++++++++++++++++ 1 file changed, 430 insertions(+) create mode 100644 Source/JavaScriptCore/runtime/JSString.cpp (limited to 'Source/JavaScriptCore/runtime/JSString.cpp') diff --git a/Source/JavaScriptCore/runtime/JSString.cpp b/Source/JavaScriptCore/runtime/JSString.cpp new file mode 100644 index 000000000..eb046ed2d --- /dev/null +++ b/Source/JavaScriptCore/runtime/JSString.cpp @@ -0,0 +1,430 @@ +/* + * Copyright (C) 1999-2002 Harri Porten (porten@kde.org) + * Copyright (C) 2001 Peter Kelly (pmk@post.com) + * Copyright (C) 2004, 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 "JSString.h" + +#include "JSGlobalObject.h" +#include "JSGlobalObjectFunctions.h" +#include "JSObject.h" +#include "JSCInlines.h" +#include "StringObject.h" +#include "StringPrototype.h" +#include "StrongInlines.h" + +namespace JSC { + +const ClassInfo JSString::s_info = { "string", 0, 0, CREATE_METHOD_TABLE(JSString) }; + +void JSRopeString::RopeBuilder::expand() +{ + ASSERT(m_index == JSRopeString::s_maxInternalRopeLength); + JSString* jsString = m_jsString; + RELEASE_ASSERT(jsString); + m_jsString = jsStringBuilder(&m_vm); + m_index = 0; + append(jsString); +} + +void JSString::destroy(JSCell* cell) +{ + JSString* thisObject = static_cast(cell); + thisObject->JSString::~JSString(); +} + +void JSString::dumpToStream(const JSCell* cell, PrintStream& out) +{ + const JSString* thisObject = jsCast(cell); + out.printf("<%p, %s, [%u], ", thisObject, thisObject->className(), thisObject->length()); + if (thisObject->isRope()) + out.printf("[rope]"); + else { + WTF::StringImpl* ourImpl = thisObject->m_value.impl(); + if (ourImpl->is8Bit()) + out.printf("[8 %p]", ourImpl->characters8()); + else + out.printf("[16 %p]", ourImpl->characters16()); + } + out.printf(">"); +} + +void JSString::visitChildren(JSCell* cell, SlotVisitor& visitor) +{ + JSString* thisObject = jsCast(cell); + Base::visitChildren(thisObject, visitor); + + if (thisObject->isRope()) + static_cast(thisObject)->visitFibers(visitor); + else { + StringImpl* impl = thisObject->m_value.impl(); + ASSERT(impl); + visitor.reportExtraMemoryVisited(thisObject, impl->costDuringGC()); + } +} + +void JSRopeString::visitFibers(SlotVisitor& visitor) +{ + if (isSubstring()) { + visitor.append(&substringBase()); + return; + } + for (size_t i = 0; i < s_maxInternalRopeLength && fiber(i); ++i) + visitor.append(&fiber(i)); +} + +static const unsigned maxLengthForOnStackResolve = 2048; + +void JSRopeString::resolveRopeInternal8(LChar* buffer) const +{ + if (isSubstring()) { + StringImpl::copyChars( + buffer, substringBase()->m_value.characters8() + substringOffset(), m_length); + return; + } + + resolveRopeInternal8NoSubstring(buffer); +} + +void JSRopeString::resolveRopeInternal8NoSubstring(LChar* buffer) const +{ + for (size_t i = 0; i < s_maxInternalRopeLength && fiber(i); ++i) { + if (fiber(i)->isRope()) { + resolveRopeSlowCase8(buffer); + return; + } + } + + LChar* position = buffer; + for (size_t i = 0; i < s_maxInternalRopeLength && fiber(i); ++i) { + const StringImpl& fiberString = *fiber(i)->m_value.impl(); + unsigned length = fiberString.length(); + StringImpl::copyChars(position, fiberString.characters8(), length); + position += length; + } + ASSERT((buffer + m_length) == position); +} + +void JSRopeString::resolveRopeInternal16(UChar* buffer) const +{ + if (isSubstring()) { + StringImpl::copyChars( + buffer, substringBase()->m_value.characters16() + substringOffset(), m_length); + return; + } + + resolveRopeInternal16NoSubstring(buffer); +} + +void JSRopeString::resolveRopeInternal16NoSubstring(UChar* buffer) const +{ + for (size_t i = 0; i < s_maxInternalRopeLength && fiber(i); ++i) { + if (fiber(i)->isRope()) { + resolveRopeSlowCase(buffer); + return; + } + } + + UChar* position = buffer; + for (size_t i = 0; i < s_maxInternalRopeLength && fiber(i); ++i) { + const StringImpl& fiberString = *fiber(i)->m_value.impl(); + unsigned length = fiberString.length(); + if (fiberString.is8Bit()) + StringImpl::copyChars(position, fiberString.characters8(), length); + else + StringImpl::copyChars(position, fiberString.characters16(), length); + position += length; + } + ASSERT((buffer + m_length) == position); +} + +void JSRopeString::resolveRopeToAtomicString(ExecState* exec) const +{ + if (m_length > maxLengthForOnStackResolve) { + resolveRope(exec); + m_value = AtomicString(m_value); + setIs8Bit(m_value.impl()->is8Bit()); + return; + } + + if (is8Bit()) { + LChar buffer[maxLengthForOnStackResolve]; + resolveRopeInternal8(buffer); + m_value = AtomicString(buffer, m_length); + setIs8Bit(m_value.impl()->is8Bit()); + } else { + UChar buffer[maxLengthForOnStackResolve]; + resolveRopeInternal16(buffer); + m_value = AtomicString(buffer, m_length); + setIs8Bit(m_value.impl()->is8Bit()); + } + + clearFibers(); + + // If we resolved a string that didn't previously exist, notify the heap that we've grown. + if (m_value.impl()->hasOneRef()) + Heap::heap(this)->reportExtraMemoryAllocated(m_value.impl()->cost()); +} + +void JSRopeString::clearFibers() const +{ + for (size_t i = 0; i < s_maxInternalRopeLength; ++i) + u[i].number = 0; +} + +RefPtr JSRopeString::resolveRopeToExistingAtomicString(ExecState* exec) const +{ + if (m_length > maxLengthForOnStackResolve) { + resolveRope(exec); + if (RefPtr existingAtomicString = AtomicStringImpl::lookUp(m_value.impl())) { + m_value = *existingAtomicString; + setIs8Bit(m_value.impl()->is8Bit()); + clearFibers(); + return existingAtomicString; + } + return nullptr; + } + + if (is8Bit()) { + LChar buffer[maxLengthForOnStackResolve]; + resolveRopeInternal8(buffer); + if (RefPtr existingAtomicString = AtomicStringImpl::lookUp(buffer, m_length)) { + m_value = *existingAtomicString; + setIs8Bit(m_value.impl()->is8Bit()); + clearFibers(); + return existingAtomicString; + } + } else { + UChar buffer[maxLengthForOnStackResolve]; + resolveRopeInternal16(buffer); + if (RefPtr existingAtomicString = AtomicStringImpl::lookUp(buffer, m_length)) { + m_value = *existingAtomicString; + setIs8Bit(m_value.impl()->is8Bit()); + clearFibers(); + return existingAtomicString; + } + } + + return nullptr; +} + +void JSRopeString::resolveRope(ExecState* exec) const +{ + ASSERT(isRope()); + + if (isSubstring()) { + ASSERT(!substringBase()->isRope()); + m_value = substringBase()->m_value.substring(substringOffset(), m_length); + substringBase().clear(); + return; + } + + if (is8Bit()) { + LChar* buffer; + if (RefPtr newImpl = StringImpl::tryCreateUninitialized(m_length, buffer)) { + Heap::heap(this)->reportExtraMemoryAllocated(newImpl->cost()); + m_value = newImpl.release(); + } else { + outOfMemory(exec); + return; + } + resolveRopeInternal8NoSubstring(buffer); + clearFibers(); + ASSERT(!isRope()); + return; + } + + UChar* buffer; + if (RefPtr newImpl = StringImpl::tryCreateUninitialized(m_length, buffer)) { + Heap::heap(this)->reportExtraMemoryAllocated(newImpl->cost()); + m_value = newImpl.release(); + } else { + outOfMemory(exec); + return; + } + + resolveRopeInternal16NoSubstring(buffer); + clearFibers(); + ASSERT(!isRope()); +} + +// Overview: These functions convert a JSString from holding a string in rope form +// down to a simple String 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 +{ + 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 && fiber(i); ++i) + workQueue.append(fiber(i).get()); + + while (!workQueue.isEmpty()) { + JSString* currentFiber = workQueue.last(); + workQueue.removeLast(); + + const LChar* characters; + + if (currentFiber->isRope()) { + JSRopeString* currentFiberAsRope = static_cast(currentFiber); + if (!currentFiberAsRope->isSubstring()) { + for (size_t i = 0; i < s_maxInternalRopeLength && currentFiberAsRope->fiber(i); ++i) + workQueue.append(currentFiberAsRope->fiber(i).get()); + continue; + } + ASSERT(!currentFiberAsRope->substringBase()->isRope()); + characters = + currentFiberAsRope->substringBase()->m_value.characters8() + + currentFiberAsRope->substringOffset(); + } else + characters = currentFiber->m_value.characters8(); + + unsigned length = currentFiber->length(); + position -= length; + StringImpl::copyChars(position, characters, length); + } + + ASSERT(buffer == position); +} + +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 && fiber(i); ++i) + workQueue.append(fiber(i).get()); + + while (!workQueue.isEmpty()) { + JSString* currentFiber = workQueue.last(); + workQueue.removeLast(); + + if (currentFiber->isRope()) { + JSRopeString* currentFiberAsRope = static_cast(currentFiber); + if (currentFiberAsRope->isSubstring()) { + ASSERT(!currentFiberAsRope->substringBase()->isRope()); + StringImpl* string = static_cast( + currentFiberAsRope->substringBase()->m_value.impl()); + unsigned offset = currentFiberAsRope->substringOffset(); + unsigned length = currentFiberAsRope->length(); + position -= length; + if (string->is8Bit()) + StringImpl::copyChars(position, string->characters8() + offset, length); + else + StringImpl::copyChars(position, string->characters16() + offset, length); + continue; + } + for (size_t i = 0; i < s_maxInternalRopeLength && currentFiberAsRope->fiber(i); ++i) + workQueue.append(currentFiberAsRope->fiber(i).get()); + continue; + } + + StringImpl* string = static_cast(currentFiber->m_value.impl()); + unsigned length = string->length(); + position -= length; + if (string->is8Bit()) + StringImpl::copyChars(position, string->characters8(), length); + else + StringImpl::copyChars(position, string->characters16(), length); + } + + ASSERT(buffer == position); +} + +void JSRopeString::outOfMemory(ExecState* exec) const +{ + clearFibers(); + ASSERT(isRope()); + ASSERT(m_value.isNull()); + if (exec) + throwOutOfMemoryError(exec); +} + +JSValue JSString::toPrimitive(ExecState*, PreferredPrimitiveType) const +{ + return const_cast(this); +} + +bool JSString::getPrimitiveNumber(ExecState* exec, double& number, JSValue& result) const +{ + result = this; + number = jsToNumber(view(exec)); + return false; +} + +double JSString::toNumber(ExecState* exec) const +{ + return jsToNumber(view(exec)); +} + +inline StringObject* StringObject::create(VM& vm, JSGlobalObject* globalObject, JSString* string) +{ + StringObject* object = new (NotNull, allocateCell(vm.heap)) StringObject(vm, globalObject->stringObjectStructure()); + object->finishCreation(vm, string); + return object; +} + +JSObject* JSString::toObject(ExecState* exec, JSGlobalObject* globalObject) const +{ + return StringObject::create(exec->vm(), globalObject, const_cast(this)); +} + +JSValue JSString::toThis(JSCell* cell, ExecState* exec, ECMAMode ecmaMode) +{ + if (ecmaMode == StrictMode) + return cell; + return StringObject::create(exec->vm(), exec->lexicalGlobalObject(), jsCast(cell)); +} + +bool JSString::getStringPropertyDescriptor(ExecState* exec, PropertyName propertyName, PropertyDescriptor& descriptor) +{ + if (propertyName == exec->propertyNames().length) { + descriptor.setDescriptor(jsNumber(m_length), DontEnum | DontDelete | ReadOnly); + return true; + } + + Optional index = parseIndex(propertyName); + if (index && index.value() < m_length) { + descriptor.setDescriptor(getIndex(exec, index.value()), DontDelete | ReadOnly); + return true; + } + + return false; +} + +JSString* jsStringWithCacheSlowCase(VM& vm, StringImpl& stringImpl) +{ + if (JSString* string = vm.stringCache.get(&stringImpl)) + return string; + + JSString* string = jsString(&vm, String(stringImpl)); + vm.lastCachedString.set(vm, string); + return string; +} + +} // namespace JSC -- cgit v1.2.1