JavaScriptCore-621.1.tar.gz

[apple/javascriptcore.git] / runtime / JSString.cpp

diff --git a/runtime/JSString.cpp b/runtime/JSString.cpp
index 48391de1f9edbdaa7e4e88f52be611429cf7d9ea..1d5e639714f5f47811390be4d7bdeb8030936b8e 100644 (file)
--- a/runtime/JSString.cpp
+++ b/runtime/JSString.cpp
@@ -25,46 +25,175 @@
 
 #include "JSGlobalObject.h"
 #include "JSObject.h"
 
 #include "JSGlobalObject.h"
 #include "JSObject.h"

+#include "Operations.h"

 #include "StringObject.h"
 #include "StringPrototype.h"
 
 namespace JSC {
 
 #include "StringObject.h"
 #include "StringPrototype.h"
 
 namespace JSC {
 

-JSValuePtr JSString::toPrimitive(ExecState*, PreferredPrimitiveType) const
+// 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

 {
 {

-    return const_cast<JSString*>(this);
+    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();
+        }
+    }

 }
 
 }
 

-bool JSString::getPrimitiveNumber(ExecState*, double& number, JSValuePtr& value)
+JSValue JSString::replaceCharacter(ExecState* exec, UChar character, const UString& replacement)

 {
 {

-    value = this;
-    number = m_value.toDouble();
-    return false;
+    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, 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, 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()));

 }
 
 }
 

-bool JSString::toBoolean(ExecState*) const
+JSString* JSString::getIndexSlowCase(ExecState* exec, unsigned i)

 {
 {

-    return !m_value.isEmpty();
+    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);

 }
 
 }
 

-double JSString::toNumber(ExecState*) const
+JSValue JSString::toPrimitive(ExecState*, PreferredPrimitiveType) const

 {
 {

-    return m_value.toDouble();
+    return const_cast<JSString*>(this);
+}
+
+bool JSString::getPrimitiveNumber(ExecState* exec, double& number, JSValue& result)
+{
+    result = this;
+    number = value(exec).toDouble();
+    return false;

 }
 
 }
 

-UString JSString::toString(ExecState*) const
+bool JSString::toBoolean(ExecState*) const

 {
 {

-    return m_value;
+    return m_length;

 }
 
 }
 

-UString JSString::toThisString(ExecState*) const
+double JSString::toNumber(ExecState* exec) const

 {
 {

-    return m_value;
+    return value(exec).toDouble();

 }
 
 }
 

-JSString* JSString::toThisJSString(ExecState*)
+UString JSString::toString(ExecState* exec) const

 {
 {

-    return this;
+    return value(exec);

 }
 
 inline StringObject* StringObject::create(ExecState* exec, JSString* string)
 }
 
 inline StringObject* StringObject::create(ExecState* exec, JSString* string)


@@ -88,9 +217,13 @@ bool JSString::getOwnPropertySlot(ExecState* exec, const Identifier& propertyNam
     // This function should only be called by JSValue::get.
     if (getStringPropertySlot(exec, propertyName, slot))
         return true;
     // 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;
     slot.setBase(this);
     JSObject* object;

-    for (JSValuePtr prototype = exec->lexicalGlobalObject()->stringPrototype(); !prototype.isNull(); prototype = object->prototype()) {
+    for (JSValue prototype = exec->lexicalGlobalObject()->stringPrototype(); !prototype.isNull(); prototype = object->prototype()) {

         object = asObject(prototype);
         if (object->getOwnPropertySlot(exec, propertyName, slot))
             return true;
         object = asObject(prototype);
         if (object->getOwnPropertySlot(exec, propertyName, slot))
             return true;


@@ -99,54 +232,40 @@ bool JSString::getOwnPropertySlot(ExecState* exec, const Identifier& propertyNam
     return true;
 }
 
     return true;
 }
 

-bool JSString::getOwnPropertySlot(ExecState* exec, unsigned propertyName, PropertySlot& slot)
+bool JSString::getStringPropertyDescriptor(ExecState* exec, const Identifier& propertyName, PropertyDescriptor& descriptor)

 {
 {

-    // The semantics here are really getPropertySlot, not getOwnPropertySlot.
-    // This function should only be called by JSValue::get.
-    if (getStringPropertySlot(exec, propertyName, slot))
+    if (propertyName == exec->propertyNames().length) {
+        descriptor.setDescriptor(jsNumber(exec, m_length), DontEnum | DontDelete | ReadOnly);

         return true;
         return true;

-    return JSString::getOwnPropertySlot(exec, Identifier::from(exec, propertyName), slot);
-}
-
-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 new (globalData) JSString(globalData, s);
-}

     
     

-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);
+    bool isStrictUInt32;
+    unsigned i = propertyName.toStrictUInt32(&isStrictUInt32);
+    if (isStrictUInt32 && i < m_length) {
+        descriptor.setDescriptor(getIndex(exec, i), DontDelete | ReadOnly);
+        return true;

     }
     }

-    return new (globalData) JSString(globalData, UString::Rep::create(s.rep(), offset, length));
+    
+    return false;

 }
 
 }
 

-JSString* jsOwnedString(JSGlobalData* globalData, const UString& s)
+bool JSString::getOwnPropertyDescriptor(ExecState* exec, const Identifier& propertyName, PropertyDescriptor& descriptor)

 {
 {

-    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 new (globalData) JSString(globalData, s, JSString::HasOtherOwner);
+    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
 }
 
 } // namespace JSC