FCL/sf/mw/qtwebkit: comparison JavaScriptCore/runtime/JSString.h

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+:4f2f89ce4247
+/*
+*  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 "JSNumberCell.h"
+#include "PropertyDescriptor.h"
+#include "PropertySlot.h"
+#include "RopeImpl.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.rep());
+}
+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;
+}
+UStringImpl* operator*()
+{
+WorkItem& item = m_workQueue.last();
+RopeImpl::Fiber fiber = item.fibers[item.i];
+ASSERT(!RopeImpl::isRope(fiber));
+return static_cast<UStringImpl*>(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->stringStructure.get())
+, m_length(value.size())
+, m_value(value)
+, m_fiberCount(0)
+{
+ASSERT(!m_value.isNull());
+Heap::heap(this)->reportExtraMemoryCost(value.cost());
+}
+enum HasOtherOwnerType { HasOtherOwner };
+JSString(JSGlobalData* globalData, const UString& value, HasOtherOwnerType)
+: JSCell(globalData->stringStructure.get())
+, m_length(value.size())
+, m_value(value)
+, m_fiberCount(0)
+{
+ASSERT(!m_value.isNull());
+}
+JSString(JSGlobalData* globalData, PassRefPtr<UStringImpl> value, HasOtherOwnerType)
+: JSCell(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->stringStructure.get())
+, m_length(rope->length())
+, m_fiberCount(1)
+{
+m_other.m_fibers[0] = rope.releaseRef();
+}
+// 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->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->stringStructure.get())
+, m_length(s1->length() + u2.size())
+, 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->stringStructure.get())
+, m_length(u1.size() + 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().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->stringStructure.get())
+, m_length(u1.size() + u2.size())
+, 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->stringStructure.get())
+, m_length(u1.size() + u2.size() + u3.size())
+, 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->stringStructure.get())
+, m_length(value.size())
+, 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.cost());
+}
+~JSString()
+{
+ASSERT(vptr() == JSGlobalData::jsStringVPtr);
+for (unsigned i = 0; i < m_fiberCount; ++i)
+RopeImpl::deref(m_other.m_fibers[i]);
+if (!m_fiberCount && m_other.m_finalizerCallback)
+m_other.m_finalizerCallback(this, m_other.m_finalizerContext);
+}
+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 PassRefPtr<Structure> createStructure(JSValue proto) { return Structure::create(proto, TypeInfo(StringType, OverridesGetOwnPropertySlot | NeedsThisConversion), AnonymousSlotCount); }
+private:
+enum VPtrStealingHackType { VPtrStealingHack };
+JSString(VPtrStealingHackType)
+: JSCell(0)
+, m_fiberCount(0)
+{
+}
+void resolveRope(ExecState*) const;
+void appendStringInConstruct(unsigned& index, const UString& string)
+{
+UStringImpl* impl = string.rep();
+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(asCell(v)->isString());
+JSString* s = static_cast<JSString*>(asCell(v));
+ASSERT(s->size() == 1);
+appendStringInConstruct(index, s);
+m_length += s->length();
+} else {
+UString u(v.toString(exec));
+UStringImpl* impl = u.rep();
+impl->ref();
+m_other.m_fibers[index++] = impl;
+m_length += u.size();
+}
+}
+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*) 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 size() { 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);
+};
+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(asCell(value)->isString());
+return static_cast<JSString*>(asCell(value));
+}
+inline JSString* jsEmptyString(JSGlobalData* globalData)
+{
+return globalData->smallStrings.emptyString(globalData);
+}
+inline JSString* jsSingleCharacterString(JSGlobalData* globalData, UChar c)
+{
+if (c <= 0xFF)
+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.size()));
+UChar c = s.data()[offset];
+if (c <= 0xFF)
+return globalData->smallStrings.singleCharacterString(globalData, c);
+return fixupVPtr(globalData, new (globalData) JSString(globalData, UString(UStringImpl::create(s.rep(), 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.size() > 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.size());
+return jsSingleCharacterSubstring(exec, m_value, i);
+}
+inline JSString* jsString(JSGlobalData* globalData, const UString& s)
+{
+int size = s.size();
+if (!size)
+return globalData->smallStrings.emptyString(globalData);
+if (size == 1) {
+UChar c = s.data()[0];
+if (c <= 0xFF)
+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.size() && (s.size() > 1 || s.data()[0] > 0xFF));
+JSGlobalData* globalData = &exec->globalData();
+return fixupVPtr(globalData, new (globalData) JSString(globalData, s, callback, context));
+}
+inline JSString* jsSubstring(JSGlobalData* globalData, const UString& s, unsigned offset, unsigned length)
+{
+ASSERT(offset <= static_cast<unsigned>(s.size()));
+ASSERT(length <= static_cast<unsigned>(s.size()));
+ASSERT(offset + length <= static_cast<unsigned>(s.size()));
+if (!length)
+return globalData->smallStrings.emptyString(globalData);
+if (length == 1) {
+UChar c = s.data()[offset];
+if (c <= 0xFF)
+return globalData->smallStrings.singleCharacterString(globalData, c);
+}
+return fixupVPtr(globalData, new (globalData) JSString(globalData, UString(UStringImpl::create(s.rep(), offset, length)), JSString::HasOtherOwner));
+}
+inline JSString* jsOwnedString(JSGlobalData* globalData, const UString& s)
+{
+int size = s.size();
+if (!size)
+return globalData->smallStrings.emptyString(globalData);
+if (size == 1) {
+UChar c = s.data()[0];
+if (c <= 0xFF)
+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(exec, m_length));
+return true;
+}
+bool isStrictUInt32;
+unsigned i = propertyName.toStrictUInt32(&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
+{
+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()->toPrimitive(exec, NoPreference).toString(exec);
+}
+} // namespace JSC
+#endif // JSString_h