diff options
Diffstat (limited to 'JavaScriptCore/runtime/JSString.h')
| -rw-r--r-- | JavaScriptCore/runtime/JSString.h | 270 |
1 files changed, 116 insertions, 154 deletions
diff --git a/JavaScriptCore/runtime/JSString.h b/JavaScriptCore/runtime/JSString.h index cff8e3a..85d3c8e 100644 --- a/JavaScriptCore/runtime/JSString.h +++ b/JavaScriptCore/runtime/JSString.h @@ -29,6 +29,7 @@ #include "JSNumberCell.h" #include "PropertyDescriptor.h" #include "PropertySlot.h" +#include "RopeImpl.h" namespace JSC { @@ -41,7 +42,6 @@ namespace JSC { JSString* jsSingleCharacterString(JSGlobalData*, UChar); JSString* jsSingleCharacterString(ExecState*, UChar); - JSString* jsSingleCharacterSubstring(JSGlobalData*, const UString&, unsigned offset); 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); @@ -66,183 +66,132 @@ namespace JSC { public: friend class JIT; friend class JSGlobalData; + friend class SpecializedThunkJIT; + friend struct ThunkHelpers; - // A Rope is a string composed of a set of substrings. - class Rope : public RefCounted<Rope> { + class RopeBuilder { public: - // A Rope is composed from a set of smaller strings called Fibers. - // Each Fiber in a rope is either UString::Rep or another Rope. - class Fiber { - public: - Fiber() : m_value(0) {} - Fiber(UString::Rep* string) : m_value(reinterpret_cast<intptr_t>(string)) {} - Fiber(Rope* rope) : m_value(reinterpret_cast<intptr_t>(rope) | 1) {} - - Fiber(void* nonFiber) : m_value(reinterpret_cast<intptr_t>(nonFiber)) {} - - void deref() - { - if (isRope()) - rope()->deref(); - else - string()->deref(); - } - - Fiber& ref() - { - if (isString()) - string()->ref(); - else - rope()->ref(); - return *this; - } - - unsigned refAndGetLength() - { - if (isString()) { - UString::Rep* rep = string(); - return rep->ref()->size(); - } else { - Rope* r = rope(); - r->ref(); - return r->stringLength(); - } - } - - bool isRope() { return m_value & 1; } - Rope* rope() { return reinterpret_cast<Rope*>(m_value & ~1); } - bool isString() { return !isRope(); } - UString::Rep* string() { return reinterpret_cast<UString::Rep*>(m_value); } - - void* nonFiber() { return reinterpret_cast<void*>(m_value); } - private: - intptr_t m_value; - }; - - // Creates a Rope comprising of 'ropeLength' Fibers. - // The Rope is constructed in an uninitialized state - initialize must be called for each Fiber in the Rope. - static PassRefPtr<Rope> createOrNull(unsigned ropeLength) + RopeBuilder(unsigned fiberCount) + : m_index(0) + , m_rope(RopeImpl::tryCreateUninitialized(fiberCount)) { - void* allocation; - if (tryFastMalloc(sizeof(Rope) + (ropeLength - 1) * sizeof(Fiber)).getValue(allocation)) - return adoptRef(new (allocation) Rope(ropeLength)); - return 0; } - ~Rope(); - void destructNonRecursive(); + bool isOutOfMemory() { return !m_rope; } - void append(unsigned &index, Fiber& fiber) + void append(RopeImpl::Fiber& fiber) { - m_fibers[index++] = fiber; - m_stringLength += fiber.refAndGetLength(); + ASSERT(m_rope); + m_rope->initializeFiber(m_index, fiber); } - void append(unsigned &index, const UString& string) + void append(const UString& string) { - UString::Rep* rep = string.rep(); - m_fibers[index++] = Fiber(rep); - m_stringLength += rep->ref()->size(); + ASSERT(m_rope); + m_rope->initializeFiber(m_index, string.rep()); } - void append(unsigned& index, JSString* jsString) + void append(JSString* jsString) { if (jsString->isRope()) { - for (unsigned i = 0; i < jsString->m_ropeLength; ++i) - append(index, jsString->m_fibers[i]); + for (unsigned i = 0; i < jsString->m_fiberCount; ++i) + append(jsString->m_other.m_fibers[i]); } else - append(index, jsString->string()); + append(jsString->string()); } - unsigned ropeLength() { return m_ropeLength; } - unsigned stringLength() { return m_stringLength; } - Fiber& fibers(unsigned index) { return m_fibers[index]; } + PassRefPtr<RopeImpl> release() + { + ASSERT(m_index == m_rope->fiberCount()); + return m_rope.release(); + } + + unsigned length() { return m_rope->length(); } private: - Rope(unsigned ropeLength) : m_ropeLength(ropeLength), m_stringLength(0) {} - void* operator new(size_t, void* inPlace) { return inPlace; } - - unsigned m_ropeLength; - unsigned m_stringLength; - Fiber m_fibers[1]; + unsigned m_index; + RefPtr<RopeImpl> m_rope; }; ALWAYS_INLINE JSString(JSGlobalData* globalData, const UString& value) : JSCell(globalData->stringStructure.get()) - , m_stringLength(value.size()) + , m_length(value.size()) , m_value(value) - , m_ropeLength(0) + , 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_stringLength(value.size()) + , m_length(value.size()) , m_value(value) - , m_ropeLength(0) + , m_fiberCount(0) { + ASSERT(!m_value.isNull()); } JSString(JSGlobalData* globalData, PassRefPtr<UString::Rep> value, HasOtherOwnerType) : JSCell(globalData->stringStructure.get()) - , m_stringLength(value->size()) + , m_length(value->length()) , m_value(value) - , m_ropeLength(0) + , m_fiberCount(0) { + ASSERT(!m_value.isNull()); } - JSString(JSGlobalData* globalData, PassRefPtr<JSString::Rope> rope) + JSString(JSGlobalData* globalData, PassRefPtr<RopeImpl> rope) : JSCell(globalData->stringStructure.get()) - , m_stringLength(rope->stringLength()) - , m_ropeLength(1) + , m_length(rope->length()) + , m_fiberCount(1) { - m_fibers[0] = rope.releaseRef(); + m_other.m_fibers[0] = rope.releaseRef(); } // This constructor constructs a new string by concatenating s1 & s2. - // This should only be called with ropeLength <= 3. - JSString(JSGlobalData* globalData, unsigned ropeLength, JSString* s1, JSString* s2) + // This should only be called with fiberCount <= 3. + JSString(JSGlobalData* globalData, unsigned fiberCount, JSString* s1, JSString* s2) : JSCell(globalData->stringStructure.get()) - , m_stringLength(s1->length() + s2->length()) - , m_ropeLength(ropeLength) + , m_length(s1->length() + s2->length()) + , m_fiberCount(fiberCount) { - ASSERT(ropeLength <= s_maxInternalRopeLength); + ASSERT(fiberCount <= s_maxInternalRopeLength); unsigned index = 0; appendStringInConstruct(index, s1); appendStringInConstruct(index, s2); - ASSERT(ropeLength == index); + ASSERT(fiberCount == index); } // This constructor constructs a new string by concatenating s1 & s2. - // This should only be called with ropeLength <= 3. - JSString(JSGlobalData* globalData, unsigned ropeLength, JSString* s1, const UString& u2) + // This should only be called with fiberCount <= 3. + JSString(JSGlobalData* globalData, unsigned fiberCount, JSString* s1, const UString& u2) : JSCell(globalData->stringStructure.get()) - , m_stringLength(s1->length() + u2.size()) - , m_ropeLength(ropeLength) + , m_length(s1->length() + u2.size()) + , m_fiberCount(fiberCount) { - ASSERT(ropeLength <= s_maxInternalRopeLength); + ASSERT(fiberCount <= s_maxInternalRopeLength); unsigned index = 0; appendStringInConstruct(index, s1); appendStringInConstruct(index, u2); - ASSERT(ropeLength == index); + ASSERT(fiberCount == index); } // This constructor constructs a new string by concatenating s1 & s2. - // This should only be called with ropeLength <= 3. - JSString(JSGlobalData* globalData, unsigned ropeLength, const UString& u1, JSString* s2) + // This should only be called with fiberCount <= 3. + JSString(JSGlobalData* globalData, unsigned fiberCount, const UString& u1, JSString* s2) : JSCell(globalData->stringStructure.get()) - , m_stringLength(u1.size() + s2->length()) - , m_ropeLength(ropeLength) + , m_length(u1.size() + s2->length()) + , m_fiberCount(fiberCount) { - ASSERT(ropeLength <= s_maxInternalRopeLength); + ASSERT(fiberCount <= s_maxInternalRopeLength); unsigned index = 0; appendStringInConstruct(index, u1); appendStringInConstruct(index, s2); - ASSERT(ropeLength == index); + ASSERT(fiberCount == index); } // This constructor constructs a new string by concatenating v1, v2 & v3. - // This should only be called with ropeLength <= 3 ... which since every - // value must require a ropeLength of at least one implies that the length + // 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_stringLength(0) - , m_ropeLength(s_maxInternalRopeLength) + , m_length(0) + , m_fiberCount(s_maxInternalRopeLength) { unsigned index = 0; appendValueInConstructAndIncrementLength(exec, index, v1); @@ -253,26 +202,25 @@ namespace JSC { JSString(JSGlobalData* globalData, const UString& value, JSStringFinalizerCallback finalizer, void* context) : JSCell(globalData->stringStructure.get()) - , m_stringLength(value.size()) + , m_length(value.size()) , m_value(value) - , m_ropeLength(0) + , m_fiberCount(0) { + ASSERT(!m_value.isNull()); // nasty hack because we can't union non-POD types - m_fibers[0] = reinterpret_cast<void*>(reinterpret_cast<ptrdiff_t>(finalizer)); - m_fibers[1] = context; + 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_ropeLength; ++i) - m_fibers[i].deref(); + for (unsigned i = 0; i < m_fiberCount; ++i) + RopeImpl::deref(m_other.m_fibers[i]); - if (!m_ropeLength && m_fibers[0].nonFiber()) { - JSStringFinalizerCallback finalizer = reinterpret_cast<JSStringFinalizerCallback>(m_fibers[0].nonFiber()); - finalizer(this, m_fibers[1].nonFiber()); - } + if (!m_fiberCount && m_other.m_finalizerCallback) + m_other.m_finalizerCallback(this, m_other.m_finalizerContext); } const UString& value(ExecState* exec) const @@ -288,14 +236,15 @@ namespace JSC { ASSERT(isRope() == m_value.isNull()); return m_value; } - unsigned length() { return m_stringLength; } + 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_stringLength; } + bool canGetIndex(unsigned i) { return i < m_length; } JSString* getIndex(ExecState*, unsigned); + JSString* getIndexSlowCase(ExecState*, unsigned); static PassRefPtr<Structure> createStructure(JSValue proto) { return Structure::create(proto, TypeInfo(StringType, OverridesGetOwnPropertySlot | NeedsThisConversion), AnonymousSlotCount); } @@ -303,7 +252,7 @@ namespace JSC { enum VPtrStealingHackType { VPtrStealingHack }; JSString(VPtrStealingHackType) : JSCell(0) - , m_ropeLength(0) + , m_fiberCount(0) { } @@ -311,14 +260,19 @@ namespace JSC { void appendStringInConstruct(unsigned& index, const UString& string) { - m_fibers[index++] = Rope::Fiber(string.rep()->ref()); + 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_ropeLength; ++i) - m_fibers[index++] = jsString->m_fibers[i].ref(); + 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()); } @@ -328,13 +282,15 @@ namespace JSC { if (v.isString()) { ASSERT(asCell(v)->isString()); JSString* s = static_cast<JSString*>(asCell(v)); - ASSERT(s->ropeLength() == 1); + ASSERT(s->fiberCount() == 1); appendStringInConstruct(index, s); - m_stringLength += s->length(); + m_length += s->length(); } else { UString u(v.toString(exec)); - m_fibers[index++] = Rope::Fiber(u.rep()->ref()); - m_stringLength += u.size(); + UStringImpl* impl = u.rep(); + impl->ref(); + m_other.m_fibers[index++] = impl; + m_length += u.size(); } } @@ -346,8 +302,6 @@ namespace JSC { virtual UString toString(ExecState*) const; virtual JSObject* toThisObject(ExecState*) const; - virtual UString toThisString(ExecState*) const; - virtual JSString* toThisJSString(ExecState*); // Actually getPropertySlot, not getOwnPropertySlot (see JSCell). virtual bool getOwnPropertySlot(ExecState*, const Identifier& propertyName, PropertySlot&); @@ -356,15 +310,25 @@ namespace JSC { static const unsigned s_maxInternalRopeLength = 3; - // A string is represented either by a UString or a Rope. - unsigned m_stringLength; + // A string is represented either by a UString or a RopeImpl. + unsigned m_length; mutable UString m_value; - mutable unsigned m_ropeLength; - mutable Rope::Fiber m_fibers[s_maxInternalRopeLength]; + mutable unsigned m_fiberCount; + // This structure exists to support a temporary workaround for a GC issue. + struct JSStringFinalizerStruct { + JSStringFinalizerStruct() : m_finalizerCallback(0) {} + union { + mutable RopeImpl::Fiber m_fibers[s_maxInternalRopeLength]; + struct { + JSStringFinalizerCallback m_finalizerCallback; + void* m_finalizerContext; + }; + }; + } m_other; - bool isRope() const { return m_ropeLength; } + bool isRope() const { return m_fiberCount; } UString& string() { ASSERT(!isRope()); return m_value; } - unsigned ropeLength() { return m_ropeLength ? m_ropeLength : 1; } + unsigned fiberCount() { 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); @@ -404,8 +368,9 @@ namespace JSC { return fixupVPtr(globalData, new (globalData) JSString(globalData, UString(&c, 1))); } - inline JSString* jsSingleCharacterSubstring(JSGlobalData* globalData, const UString& s, unsigned offset) + 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) @@ -430,7 +395,10 @@ namespace JSC { inline JSString* JSString::getIndex(ExecState* exec, unsigned i) { ASSERT(canGetIndex(i)); - return jsSingleCharacterSubstring(&exec->globalData(), value(exec), i); + if (isRope()) + return getIndexSlowCase(exec, i); + ASSERT(i < m_value.size()); + return jsSingleCharacterSubstring(exec, value(exec), i); } inline JSString* jsString(JSGlobalData* globalData, const UString& s) @@ -484,7 +452,6 @@ namespace JSC { 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* jsSingleCharacterSubstring(ExecState* exec, const UString& s, unsigned offset) { return jsSingleCharacterSubstring(&exec->globalData(), s, offset); } 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); } @@ -493,14 +460,14 @@ namespace JSC { ALWAYS_INLINE bool JSString::getStringPropertySlot(ExecState* exec, const Identifier& propertyName, PropertySlot& slot) { if (propertyName == exec->propertyNames().length) { - slot.setValue(jsNumber(exec, m_stringLength)); + slot.setValue(jsNumber(exec, m_length)); return true; } bool isStrictUInt32; unsigned i = propertyName.toStrictUInt32(&isStrictUInt32); - if (isStrictUInt32 && i < m_stringLength) { - slot.setValue(jsSingleCharacterSubstring(exec, value(exec), i)); + if (isStrictUInt32 && i < m_length) { + slot.setValue(getIndex(exec, i)); return true; } @@ -509,8 +476,8 @@ namespace JSC { ALWAYS_INLINE bool JSString::getStringPropertySlot(ExecState* exec, unsigned propertyName, PropertySlot& slot) { - if (propertyName < m_stringLength) { - slot.setValue(jsSingleCharacterSubstring(exec, value(exec), propertyName)); + if (propertyName < m_length) { + slot.setValue(getIndex(exec, propertyName)); return true; } @@ -521,11 +488,6 @@ namespace JSC { // --- JSValue inlines ---------------------------- - inline JSString* JSValue::toThisJSString(ExecState* exec) - { - return isCell() ? asCell()->toThisJSString(exec) : jsString(exec, toString(exec)); - } - inline UString JSValue::toString(ExecState* exec) const { if (isString()) |