#include "JSString.h"
#include "JSGlobalObject.h"
+#include "JSGlobalObjectFunctions.h"
#include "JSObject.h"
#include "Operations.h"
#include "StringObject.h"
#include "StringPrototype.h"
namespace JSC {
+
+static const unsigned substringFromRopeCutoff = 4;
+
+const ClassInfo JSString::s_info = { "string", 0, 0, 0 };
+
+void JSString::resolveRope(ExecState* exec) const
+{
+ ASSERT(isRope());
+
+ UChar* buffer;
+ if (PassRefPtr<StringImpl> newImpl = StringImpl::tryCreateUninitialized(m_length, buffer))
+ m_value = newImpl;
+ else {
+ outOfMemory(exec);
+ return;
+ }
+
+ RopeImpl::Fiber currentFiber = m_fibers[0];
+
+ if ((m_fiberCount > 2) || (RopeImpl::isRope(currentFiber))
+ || ((m_fiberCount == 2) && (RopeImpl::isRope(m_fibers[1])))) {
+ resolveRopeSlowCase(exec, buffer);
+ return;
+ }
+
+ UChar* position = buffer;
+ StringImpl* string = static_cast<StringImpl*>(currentFiber);
+ unsigned length = string->length();
+ StringImpl::copyChars(position, string->characters(), length);
+
+ if (m_fiberCount > 1) {
+ position += length;
+ currentFiber = m_fibers[1];
+ string = static_cast<StringImpl*>(currentFiber);
+ length = string->length();
+ StringImpl::copyChars(position, string->characters(), length);
+ position += length;
+ }
+
+ ASSERT((buffer + m_length) == position);
+ for (unsigned i = 0; i < m_fiberCount; ++i) {
+ RopeImpl::deref(m_fibers[i]);
+ m_fibers[i] = 0;
+ }
+ m_fiberCount = 0;
+
+ ASSERT(!isRope());
+}
// 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
// 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
+// we would likely have to place all of the constituent StringImpls 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
+// rope-of-ropes.)
+void JSString::resolveRopeSlowCase(ExecState* exec, UChar* buffer) const
{
- ASSERT(isRope());
+ UNUSED_PARAM(exec);
- // 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];
+ workQueue.append(m_fibers[i]);
+ currentFiber = m_fibers[m_fiberCount - 1];
while (true) {
if (RopeImpl::isRope(currentFiber)) {
RopeImpl* rope = static_cast<RopeImpl*>(currentFiber);
workQueue.append(rope->fibers()[i]);
currentFiber = rope->fibers()[fiberCountMinusOne];
} else {
- UStringImpl* string = static_cast<UStringImpl*>(currentFiber);
+ StringImpl* string = static_cast<StringImpl*>(currentFiber);
unsigned length = string->length();
position -= length;
- UStringImpl::copyChars(position, string->characters(), length);
+ StringImpl::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;
+ RopeImpl::deref(m_fibers[i]);
+ m_fibers[i] = 0;
}
m_fiberCount = 0;
-
+
ASSERT(!isRope());
return;
}
}
}
+void JSString::outOfMemory(ExecState* exec) const
+{
+ for (unsigned i = 0; i < m_fiberCount; ++i) {
+ RopeImpl::deref(m_fibers[i]);
+ m_fibers[i] = 0;
+ }
+ m_fiberCount = 0;
+ ASSERT(!isRope());
+ ASSERT(m_value == UString());
+ if (exec)
+ throwOutOfMemoryError(exec);
+}
+
+// This function construsts a substring out of a rope without flattening by reusing the existing fibers.
+// This can reduce memory usage substantially. Since traversing ropes is slow the function will revert
+// back to flattening if the rope turns out to be long.
+JSString* JSString::substringFromRope(ExecState* exec, unsigned substringStart, unsigned substringLength)
+{
+ ASSERT(isRope());
+ ASSERT(substringLength);
+
+ JSGlobalData* globalData = &exec->globalData();
+
+ UString substringFibers[3];
+
+ unsigned fiberCount = 0;
+ unsigned substringFiberCount = 0;
+ unsigned substringEnd = substringStart + substringLength;
+ unsigned fiberEnd = 0;
+
+ RopeIterator end;
+ for (RopeIterator it(m_fibers.data(), m_fiberCount); it != end; ++it) {
+ ++fiberCount;
+ StringImpl* fiberString = *it;
+ unsigned fiberStart = fiberEnd;
+ fiberEnd = fiberStart + fiberString->length();
+ if (fiberEnd <= substringStart)
+ continue;
+ unsigned copyStart = std::max(substringStart, fiberStart);
+ unsigned copyEnd = std::min(substringEnd, fiberEnd);
+ if (copyStart == fiberStart && copyEnd == fiberEnd)
+ substringFibers[substringFiberCount++] = UString(fiberString);
+ else
+ substringFibers[substringFiberCount++] = UString(StringImpl::create(fiberString, copyStart - fiberStart, copyEnd - copyStart));
+ if (fiberEnd >= substringEnd)
+ break;
+ if (fiberCount > substringFromRopeCutoff || substringFiberCount >= 3) {
+ // This turned out to be a really inefficient rope. Just flatten it.
+ resolveRope(exec);
+ return jsSubstring(&exec->globalData(), m_value, substringStart, substringLength);
+ }
+ }
+ ASSERT(substringFiberCount && substringFiberCount <= 3);
+
+ if (substringLength == 1) {
+ ASSERT(substringFiberCount == 1);
+ UChar c = substringFibers[0].characters()[0];
+ if (c <= maxSingleCharacterString)
+ return globalData->smallStrings.singleCharacterString(globalData, c);
+ }
+ if (substringFiberCount == 1)
+ return new (globalData) JSString(globalData, substringFibers[0]);
+ if (substringFiberCount == 2)
+ return new (globalData) JSString(globalData, substringFibers[0], substringFibers[1]);
+ return new (globalData) JSString(globalData, substringFibers[0], substringFibers[1], substringFibers[2]);
+}
+
JSValue JSString::replaceCharacter(ExecState* exec, UChar character, const UString& replacement)
{
if (!isRope()) {
- unsigned matchPosition = m_value.find(character);
- if (matchPosition == UString::NotFound)
+ size_t matchPosition = m_value.find(character);
+ if (matchPosition == notFound)
return JSValue(this);
- return jsString(exec, m_value.substr(0, matchPosition), replacement, m_value.substr(matchPosition + 1));
+ return jsString(exec, m_value.substringSharingImpl(0, matchPosition), replacement, m_value.substringSharingImpl(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) {
+ StringImpl* matchString = 0;
+ size_t matchPosition = notFound;
+ for (RopeIterator it(m_fibers.data(), m_fiberCount); it != end; ++it) {
++fiberCount;
if (matchString)
continue;
- UStringImpl* string = *it;
+ StringImpl* string = *it;
matchPosition = string->find(character);
- if (matchPosition == -1)
+ if (matchPosition == notFound)
continue;
matchString = string;
}
if (!matchString)
return this;
- RopeBuilder builder(replacement.size() ? fiberCount + 2 : fiberCount + 1);
+ RopeBuilder builder(replacement.length() ? 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;
+ for (RopeIterator it(m_fibers.data(), m_fiberCount); it != end; ++it) {
+ StringImpl* string = *it;
if (string != matchString) {
builder.append(UString(string));
continue;
}
- builder.append(UString(string).substr(0, matchPosition));
- if (replacement.size())
+ builder.append(UString(string).substringSharingImpl(0, matchPosition));
+ if (replacement.length())
builder.append(replacement);
- builder.append(UString(string).substr(matchPosition + 1));
+ builder.append(UString(string).substringSharingImpl(matchPosition + 1));
matchString = 0;
}
if (exec->exception())
return jsString(exec, "");
ASSERT(!isRope());
- ASSERT(i < m_value.size());
+ ASSERT(i < m_value.length());
return jsSingleCharacterSubstring(exec, m_value, i);
}
bool JSString::getPrimitiveNumber(ExecState* exec, double& number, JSValue& result)
{
result = this;
- number = value(exec).toDouble();
+ number = jsToNumber(value(exec));
return false;
}
double JSString::toNumber(ExecState* exec) const
{
- return value(exec).toDouble();
+ return jsToNumber(value(exec));
}
UString JSString::toString(ExecState* exec) const
return value(exec);
}
-inline StringObject* StringObject::create(ExecState* exec, JSString* string)
+inline StringObject* StringObject::create(ExecState* exec, JSGlobalObject* globalObject, JSString* string)
{
- return new (exec) StringObject(exec->lexicalGlobalObject()->stringObjectStructure(), string);
+ return new (exec) StringObject(exec->globalData(), globalObject->stringObjectStructure(), string);
}
-JSObject* JSString::toObject(ExecState* exec) const
+JSObject* JSString::toObject(ExecState* exec, JSGlobalObject* globalObject) const
{
- return StringObject::create(exec, const_cast<JSString*>(this));
+ return StringObject::create(exec, globalObject, const_cast<JSString*>(this));
}
JSObject* JSString::toThisObject(ExecState* exec) const
{
- return StringObject::create(exec, const_cast<JSString*>(this));
+ return StringObject::create(exec, exec->lexicalGlobalObject(), const_cast<JSString*>(this));
}
bool JSString::getOwnPropertySlot(ExecState* exec, const Identifier& propertyName, PropertySlot& slot)
bool JSString::getStringPropertyDescriptor(ExecState* exec, const Identifier& propertyName, PropertyDescriptor& descriptor)
{
if (propertyName == exec->propertyNames().length) {
- descriptor.setDescriptor(jsNumber(exec, m_length), DontEnum | DontDelete | ReadOnly);
+ descriptor.setDescriptor(jsNumber(m_length), DontEnum | DontDelete | ReadOnly);
return true;
}
bool isStrictUInt32;
- unsigned i = propertyName.toStrictUInt32(&isStrictUInt32);
+ unsigned i = propertyName.toUInt32(isStrictUInt32);
if (isStrictUInt32 && i < m_length) {
descriptor.setDescriptor(getIndex(exec, i), DontDelete | ReadOnly);
return true;
projects / apple / javascriptcore.git / blobdiff