--- /dev/null Thu Jan 01 00:00:00 1970 +0000
+++ b/JavaScriptCore/runtime/JSString.cpp Fri Sep 17 09:02:29 2010 +0300
@@ -0,0 +1,271 @@
+/*
+ * 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 "JSObject.h"
+#include "Operations.h"
+#include "StringObject.h"
+#include "StringPrototype.h"
+
+namespace JSC {
+
+// 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
+{
+ ASSERT(isRope());
+
+ // Allocate the buffer to hold the final string, position initially points to the end.
+ UChar* buffer;
+ if (PassRefPtr<UStringImpl> 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;
+ }
+ m_fiberCount = 0;
+ ASSERT(!isRope());
+ ASSERT(m_value == UString());
+ if (exec)
+ throwOutOfMemoryError(exec);
+ return;
+ }
+ UChar* position = buffer + m_length;
+
+ // Start with the current RopeImpl.
+ Vector<RopeImpl::Fiber, 32> 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<RopeImpl*>(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<UStringImpl*>(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();
+ }
+ }
+}
+
+JSValue JSString::replaceCharacter(ExecState* exec, UChar character, const UString& replacement)
+{
+ 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));
+ }
+
+ 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.data(), m_fiberCount); it != end; ++it) {
+ ++fiberCount;
+ if (matchString)
+ continue;
+
+ UStringImpl* string = *it;
+ matchPosition = string->find(character);
+ if (matchPosition == -1)
+ continue;
+ matchString = string;
+ }
+
+ if (!matchString)
+ return this;
+
+ RopeBuilder builder(replacement.size() ? fiberCount + 2 : fiberCount + 1);
+ if (UNLIKELY(builder.isOutOfMemory()))
+ return throwOutOfMemoryError(exec);
+
+ for (RopeIterator it(m_other.m_fibers.data(), m_fiberCount); it != end; ++it) {
+ UStringImpl* string = *it;
+ if (string != matchString) {
+ builder.append(UString(string));
+ continue;
+ }
+
+ builder.append(UString(string).substr(0, matchPosition));
+ if (replacement.size())
+ builder.append(replacement);
+ builder.append(UString(string).substr(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);
+ // Return a safe no-value result, this should never be used, since the excetion will be thrown.
+ if (exec->exception())
+ return jsString(exec, "");
+ ASSERT(!isRope());
+ ASSERT(i < m_value.size());
+ 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 = value(exec).toDouble();
+ return false;
+}
+
+bool JSString::toBoolean(ExecState*) const
+{
+ return m_length;
+}
+
+double JSString::toNumber(ExecState* exec) const
+{
+ return value(exec).toDouble();
+}
+
+UString JSString::toString(ExecState* exec) const
+{
+ return value(exec);
+}
+
+inline StringObject* StringObject::create(ExecState* exec, JSString* string)
+{
+ return new (exec) StringObject(exec->lexicalGlobalObject()->stringObjectStructure(), string);
+}
+
+JSObject* JSString::toObject(ExecState* exec) const
+{
+ return StringObject::create(exec, const_cast<JSString*>(this));
+}
+
+JSObject* JSString::toThisObject(ExecState* exec) const
+{
+ return StringObject::create(exec, const_cast<JSString*>(this));
+}
+
+bool JSString::getOwnPropertySlot(ExecState* exec, const Identifier& propertyName, PropertySlot& slot)
+{
+ // 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());
+ 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(exec, m_length), DontEnum | DontDelete | ReadOnly);
+ return true;
+ }
+
+ bool isStrictUInt32;
+ unsigned i = propertyName.toStrictUInt32(&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)
+{
+ // The semantics here are really getPropertySlot, not getOwnPropertySlot.
+ // This function should only be called by JSValue::get.
+ if (getStringPropertySlot(exec, propertyName, slot))
+ return true;
+ return JSString::getOwnPropertySlot(exec, Identifier::from(exec, propertyName), slot);
+}
+
+} // namespace JSC