]> git.saurik.com Git - apple/javascriptcore.git/blobdiff - runtime/JSString.cpp
JavaScriptCore-7600.1.4.9.tar.gz
[apple/javascriptcore.git] / runtime / JSString.cpp
index 6f0b09d13b5e29da2673dbd149b123beb270a7bc..10a16d9733d73d5d42e17bd6f26b2fa27d18de21 100644 (file)
 #include "JSGlobalObject.h"
 #include "JSGlobalObjectFunctions.h"
 #include "JSObject.h"
-#include "Operations.h"
+#include "JSCInlines.h"
 #include "StringObject.h"
 #include "StringPrototype.h"
+#include "StrongInlines.h"
 
 namespace JSC {
     
-static const unsigned substringFromRopeCutoff = 4;
-
 const ClassInfo JSString::s_info = { "string", 0, 0, 0, CREATE_METHOD_TABLE(JSString) };
 
 void JSRopeString::RopeBuilder::expand()
@@ -52,26 +51,34 @@ void JSString::destroy(JSCell* cell)
     thisObject->JSString::~JSString();
 }
 
-void JSString::visitChildren(JSCell* cell, SlotVisitor& visitor)
+void JSString::dumpToStream(const JSCell* cell, PrintStream& out)
 {
-    JSString* thisObject = jsCast<JSString*>(cell);
-    Base::visitChildren(thisObject, visitor);
-    
-    MARK_LOG_MESSAGE1("[%u]: ", thisObject->length());
-
-#if ENABLE(OBJECT_MARK_LOGGING)
-    if (!thisObject->isRope()) {
+    const JSString* thisObject = jsCast<const JSString*>(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())
-            MARK_LOG_MESSAGE1("[8 %p]", ourImpl->characters8());
+            out.printf("[8 %p]", ourImpl->characters8());
         else
-            MARK_LOG_MESSAGE1("[16 %p]", ourImpl->characters16());
-    } else
-        MARK_LOG_MESSAGE0("[rope]: ");
-#endif
+            out.printf("[16 %p]", ourImpl->characters16());
+    }
+    out.printf(">");
+}
 
+void JSString::visitChildren(JSCell* cell, SlotVisitor& visitor)
+{
+    JSString* thisObject = jsCast<JSString*>(cell);
+    Base::visitChildren(thisObject, visitor);
+    
     if (thisObject->isRope())
         static_cast<JSRopeString*>(thisObject)->visitFibers(visitor);
+    else {
+        StringImpl* impl = thisObject->m_value.impl();
+        ASSERT(impl);
+        visitor.reportExtraMemoryUsage(thisObject, impl->costDuringGC());
+    }
 }
 
 void JSRopeString::visitFibers(SlotVisitor& visitor)
@@ -80,6 +87,113 @@ void JSRopeString::visitFibers(SlotVisitor& visitor)
         visitor.append(&m_fibers[i]);
 }
 
+static const unsigned maxLengthForOnStackResolve = 2048;
+
+void JSRopeString::resolveRopeInternal8(LChar* buffer) const
+{
+    for (size_t i = 0; i < s_maxInternalRopeLength && m_fibers[i]; ++i) {
+        if (m_fibers[i]->isRope()) {
+            resolveRopeSlowCase8(buffer);
+            return;
+        }
+    }
+
+    LChar* position = buffer;
+    for (size_t i = 0; i < s_maxInternalRopeLength && m_fibers[i]; ++i) {
+        const StringImpl& fiberString = *m_fibers[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
+{
+    for (size_t i = 0; i < s_maxInternalRopeLength && m_fibers[i]; ++i) {
+        if (m_fibers[i]->isRope()) {
+            resolveRopeSlowCase(buffer);
+            return;
+        }
+    }
+
+    UChar* position = buffer;
+    for (size_t i = 0; i < s_maxInternalRopeLength && m_fibers[i]; ++i) {
+        const StringImpl& fiberString = *m_fibers[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);
+        return;
+    }
+
+    if (is8Bit()) {
+        LChar buffer[maxLengthForOnStackResolve];
+        resolveRopeInternal8(buffer);
+        m_value = AtomicString(buffer, m_length);
+    } else {
+        UChar buffer[maxLengthForOnStackResolve];
+        resolveRopeInternal16(buffer);
+        m_value = AtomicString(buffer, m_length);
+    }
+
+    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)->reportExtraMemoryCost(m_value.impl()->cost());
+}
+
+void JSRopeString::clearFibers() const
+{
+    for (size_t i = 0; i < s_maxInternalRopeLength && m_fibers[i]; ++i)
+        m_fibers[i].clear();
+}
+
+AtomicStringImpl* JSRopeString::resolveRopeToExistingAtomicString(ExecState* exec) const
+{
+    if (m_length > maxLengthForOnStackResolve) {
+        resolveRope(exec);
+        if (AtomicStringImpl* existingAtomicString = AtomicString::find(m_value.impl())) {
+            m_value = *existingAtomicString;
+            clearFibers();
+            return existingAtomicString;
+        }
+        return nullptr;
+    }
+
+    if (is8Bit()) {
+        LChar buffer[maxLengthForOnStackResolve];
+        resolveRopeInternal8(buffer);
+        if (AtomicStringImpl* existingAtomicString = AtomicString::find(buffer, m_length)) {
+            m_value = *existingAtomicString;
+            clearFibers();
+            return existingAtomicString;
+        }
+    } else {
+        UChar buffer[maxLengthForOnStackResolve];
+        resolveRopeInternal16(buffer);
+        if (AtomicStringImpl* existingAtomicString = AtomicString::find(buffer, m_length)) {
+            m_value = *existingAtomicString;
+            clearFibers();
+            return existingAtomicString;
+        }
+    }
+
+    return nullptr;
+}
+
 void JSRopeString::resolveRope(ExecState* exec) const
 {
     ASSERT(isRope());
@@ -93,23 +207,9 @@ void JSRopeString::resolveRope(ExecState* exec) const
             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();
-        }
-        ASSERT((buffer + m_length) == position);
+        resolveRopeInternal8(buffer);
+        clearFibers();
         ASSERT(!isRope());
-
         return;
     }
 
@@ -122,23 +222,8 @@ void JSRopeString::resolveRope(ExecState* exec) const
         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();
-        if (string->is8Bit())
-            StringImpl::copyChars(position, string->characters8(), length);
-        else
-            StringImpl::copyChars(position, string->characters16(), length);
-        position += length;
-        m_fibers[i].clear();
-    }
-    ASSERT((buffer + m_length) == position);
+    resolveRopeInternal16(buffer);
+    clearFibers();
     ASSERT(!isRope());
 }
 
@@ -157,11 +242,8 @@ void JSRopeString::resolveRopeSlowCase8(LChar* buffer) const
     LChar* position = buffer + m_length; // We will be working backwards over the rope.
     Vector<JSString*, 32, UnsafeVectorOverflow> 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) {
+    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();
-    }
 
     while (!workQueue.isEmpty()) {
         JSString* currentFiber = workQueue.last();
@@ -181,7 +263,6 @@ void JSRopeString::resolveRopeSlowCase8(LChar* buffer) const
     }
 
     ASSERT(buffer == position);
-    ASSERT(!isRope());
 }
 
 void JSRopeString::resolveRopeSlowCase(UChar* buffer) const
@@ -213,13 +294,11 @@ void JSRopeString::resolveRopeSlowCase(UChar* buffer) const
     }
 
     ASSERT(buffer == position);
-    ASSERT(!isRope());
 }
 
 void JSRopeString::outOfMemory(ExecState* exec) const
 {
-    for (size_t i = 0; i < s_maxInternalRopeLength && m_fibers[i]; ++i)
-        m_fibers[i].clear();
+    clearFibers();
     ASSERT(isRope());
     ASSERT(m_value.isNull());
     if (exec)
@@ -260,39 +339,23 @@ double JSString::toNumber(ExecState* exec) const
     return jsToNumber(value(exec));
 }
 
-inline StringObject* StringObject::create(ExecState* exec, JSGlobalObject* globalObject, JSString* string)
+inline StringObject* StringObject::create(VM& vm, JSGlobalObject* globalObject, JSString* string)
 {
-    StringObject* object = new (NotNull, allocateCell<StringObject>(*exec->heap())) StringObject(exec->vm(), globalObject->stringObjectStructure());
-    object->finishCreation(exec->vm(), string);
+    StringObject* object = new (NotNull, allocateCell<StringObject>(vm.heap)) StringObject(vm, globalObject->stringObjectStructure());
+    object->finishCreation(vm, string);
     return object;
 }
 
 JSObject* JSString::toObject(ExecState* exec, JSGlobalObject* globalObject) const
 {
-    return StringObject::create(exec, globalObject, const_cast<JSString*>(this));
+    return StringObject::create(exec->vm(), globalObject, const_cast<JSString*>(this));
 }
 
-JSObject* JSString::toThisObject(JSCell* cell, ExecState* exec)
+JSValue JSString::toThis(JSCell* cell, ExecState* exec, ECMAMode ecmaMode)
 {
-    return StringObject::create(exec, exec->lexicalGlobalObject(), jsCast<JSString*>(cell));
-}
-
-bool JSString::getOwnPropertySlot(JSCell* cell, ExecState* exec, PropertyName propertyName, PropertySlot& slot)
-{
-    JSString* thisObject = jsCast<JSString*>(cell);
-    // The semantics here are really getPropertySlot, not getOwnPropertySlot.
-    // This function should only be called by JSValue::get.
-    if (thisObject->getStringPropertySlot(exec, propertyName, slot))
-        return true;
-    slot.setBase(thisObject);
-    JSObject* object;
-    for (JSValue prototype = exec->lexicalGlobalObject()->stringPrototype(); !prototype.isNull(); prototype = object->prototype()) {
-        object = asObject(prototype);
-        if (object->methodTable()->getOwnPropertySlot(object, exec, propertyName, slot))
-            return true;
-    }
-    slot.setUndefined();
-    return true;
+    if (ecmaMode == StrictMode)
+        return cell;
+    return StringObject::create(exec->vm(), exec->lexicalGlobalObject(), jsCast<JSString*>(cell));
 }
 
 bool JSString::getStringPropertyDescriptor(ExecState* exec, PropertyName propertyName, PropertyDescriptor& descriptor)
@@ -312,14 +375,13 @@ bool JSString::getStringPropertyDescriptor(ExecState* exec, PropertyName propert
     return false;
 }
 
-bool JSString::getOwnPropertySlotByIndex(JSCell* cell, ExecState* exec, unsigned propertyName, PropertySlot& slot)
+JSString* jsStringWithCacheSlowCase(VM& vm, StringImpl& stringImpl)
 {
-    JSString* thisObject = jsCast<JSString*>(cell);
-    // The semantics here are really getPropertySlot, not getOwnPropertySlot.
-    // This function should only be called by JSValue::get.
-    if (thisObject->getStringPropertySlot(exec, propertyName, slot))
-        return true;
-    return JSString::getOwnPropertySlot(thisObject, exec, Identifier::from(exec, propertyName), slot);
+    auto addResult = vm.stringCache.add(&stringImpl, nullptr);
+    if (addResult.isNewEntry)
+        addResult.iterator->value = jsString(&vm, String(stringImpl));
+    vm.lastCachedString.set(vm, addResult.iterator->value.get());
+    return addResult.iterator->value.get();
 }
 
 } // namespace JSC