UString UString::spliceSubstringsWithSeparators(const Range *substringRanges, int rangeCount, const UString *separators, int separatorCount) const
{
  int totalLength = 0;

  for (int i = 0; i < rangeCount; i++) {
    totalLength += substringRanges[i].length;
  }
  for (int i = 0; i < separatorCount; i++) {
    totalLength += separators[i].size();
  }

  UChar *buffer = static_cast<UChar *>(malloc(totalLength * sizeof(UChar)));

  int maxCount = MAX(rangeCount, separatorCount);
  int bufferPos = 0;
  for (int i = 0; i < maxCount; i++) {
    if (i < rangeCount) {
      memcpy(buffer + bufferPos, data() + substringRanges[i].position, substringRanges[i].length * sizeof(UChar));
      bufferPos += substringRanges[i].length;
    }
    if (i < separatorCount) {
      memcpy(buffer + bufferPos, separators[i].data(), separators[i].size() * sizeof(UChar));
      bufferPos += separators[i].size();
    }
  }

  UString::Rep *rep = UString::Rep::create(buffer, totalLength);
  UString result = UString(rep);
  rep->deref();

  return result;
}

void PropertyMap::clear()
{
    if (!_table) {
#if USE_SINGLE_ENTRY
        UString::Rep *key = _singleEntry.key;
        if (key) {
            key->deref();
            _singleEntry.key = 0;
        }
#endif
        return;
    }

    int size = _table->size;
    Entry *entries = _table->entries;
    for (int i = 0; i < size; i++) {
        UString::Rep *key = entries[i].key;
        if (isValid(key)) {
            key->deref();
            entries[i].key = 0;
            entries[i].value = 0;
        }
    }
    _table->keyCount = 0;
    _table->sentinelCount = 0;
}

void PropertyMap::checkConsistency()
{
    if (!_table)
        return;

    int count = 0;
    int sentinelCount = 0;
    for (int j = 0; j != _table->size; ++j) {
        UString::Rep *rep = _table->entries[j].key;
        if (!rep)
            continue;
        if (rep == deletedSentinel()) {
            ++sentinelCount;
            continue;
        }
        unsigned h = rep->hash();
        int i = h & _table->sizeMask;
        int k = 0;
        while (UString::Rep *key = _table->entries[i].key) {
            if (rep == key)
                break;
            if (k == 0)
                k = 1 | (h % _table->sizeMask);
            i = (i + k) & _table->sizeMask;
        }
        assert(i == j);
        ++count;
    }
    assert(count == _table->keyCount);
    assert(sentinelCount == _table->sentinelCount);
    assert(_table->size >= 16);
    assert(_table->sizeMask);
    assert(_table->size == _table->sizeMask + 1);
}

size_t JSStringGetMaximumUTF8CStringSize(JSStringRef string)
{
    UString::Rep* rep = toJS(string);
    
    // Any UTF8 character > 3 bytes encodes as a UTF16 surrogate pair.
    return rep->size() * 3 + 1; // + 1 for terminating '\0'
}

EXPORT
void JSStringRelease(JSStringRef string)
{
    JSLock lock;
    UString::Rep* rep = toJS(string);
    rep->deref();
}

 static void translate(UString::Rep*& location, const UCharBuffer& buf, unsigned hash)
 {
     UChar* d;
     UString::Rep* r = UString::Rep::createUninitialized(buf.length, d).releaseRef();
     for (unsigned i = 0; i != buf.length; i++)
         d[i] = buf.s[i];
     r->setHash(hash);
     location = r; 
 }

bool Structure::despecifyFunction(const Identifier& propertyName)
{
    ASSERT(!propertyName.isNull());

    materializePropertyMapIfNecessary();
    if (!m_propertyTable)
        return false;

    UString::Rep* rep = propertyName._ustring.rep();

    unsigned i = rep->existingHash();

#if DUMP_PROPERTYMAP_STATS
    ++numProbes;
#endif

    unsigned entryIndex = m_propertyTable->entryIndices[i & m_propertyTable->sizeMask];
    if (entryIndex == emptyEntryIndex)
        return false;

    if (rep == m_propertyTable->entries()[entryIndex - 1].key) {
        ASSERT(m_propertyTable->entries()[entryIndex - 1].specificValue);
        m_propertyTable->entries()[entryIndex - 1].specificValue = 0;
        return true;
    }

#if DUMP_PROPERTYMAP_STATS
    ++numCollisions;
#endif

    unsigned k = 1 | doubleHash(rep->existingHash());

    while (1) {
        i += k;

#if DUMP_PROPERTYMAP_STATS
        ++numRehashes;
#endif

        entryIndex = m_propertyTable->entryIndices[i & m_propertyTable->sizeMask];
        if (entryIndex == emptyEntryIndex)
            return false;

        if (rep == m_propertyTable->entries()[entryIndex - 1].key) {
            ASSERT(m_propertyTable->entries()[entryIndex - 1].specificValue);
            m_propertyTable->entries()[entryIndex - 1].specificValue = 0;
            return true;
        }
    }
}

AtomicStringImpl* AtomicString::find(const KJS::Identifier& identifier)
{
    if (identifier.isNull())
        return 0;

    UString::Rep* string = identifier.ustring().rep();
    unsigned length = string->size();
    if (!length)
        return static_cast<AtomicStringImpl*>(StringImpl::empty());

    HashAndCharacters buffer = { string->computedHash(), string->data(), length }; 
    HashSet<StringImpl*>::iterator iterator = stringTable->find<HashAndCharacters, HashAndCharactersTranslator>(buffer);
    if (iterator == stringTable->end())
        return 0;
    return static_cast<AtomicStringImpl*>(*iterator);
}

PassRefPtr<StringImpl> AtomicString::add(const KJS::UString& ustring)
{
    if (ustring.isNull())
        return 0;

    UString::Rep* string = ustring.rep();
    unsigned length = string->size();
    if (!length)
        return StringImpl::empty();

    HashAndCharacters buffer = { string->hash(), string->data(), length }; 
    pair<HashSet<StringImpl*>::iterator, bool> addResult = stringTable->add<HashAndCharacters, HashAndCharactersTranslator>(buffer);
    if (!addResult.second)
        return *addResult.first;
    return adoptRef(*addResult.first);
}

void HashTable::createTable(JSGlobalData* globalData) const
{
    ASSERT(!table);
    HashEntry* entries = new HashEntry[hashSizeMask + 1];
    for (int i = 0; i <= hashSizeMask; ++i)
        entries[i].key = 0;
    for (int i = 0; values[i].key; ++i) {
        UString::Rep* identifier = Identifier::add(globalData, values[i].key).releaseRef();
        int hashIndex = identifier->computedHash() & hashSizeMask;
        ASSERT(!entries[hashIndex].key);
        entries[hashIndex].key = identifier;
        entries[hashIndex].integerValue = values[i].value;
        entries[hashIndex].attributes = values[i].attributes;
        entries[hashIndex].length = values[i].length;
    }
    table = entries;
}

UString UString::substr(int pos, int len) const
{
  if (pos < 0)
    pos = 0;
  else if (pos >= (int) size())
    pos = size();
  if (len < 0)
    len = size();
  if (pos + len >= (int) size())
    len = size() - pos;

  UString::Rep *newRep = Rep::create(rep, pos, len);
  UString result(newRep);
  newRep->deref();

  return result;
}

JSValue *PropertyMap::get(const Identifier &name, unsigned &attributes) const
{
    assert(!name.isNull());
    
    UString::Rep *rep = name._ustring.rep();
    
    if (!_table) {
#if USE_SINGLE_ENTRY
        UString::Rep *key = _singleEntry.key;
        if (rep == key) {
            attributes = _singleEntry.attributes;
            return _singleEntry.value;
        }
#endif
        return 0;
    }
    
    unsigned h = rep->hash();
    int sizeMask = _table->sizeMask;
    Entry *entries = _table->entries;
    int i = h & sizeMask;
    int k = 0;
#if DUMP_STATISTICS
    ++numProbes;
    numCollisions += entries[i].key && entries[i].key != rep;
#endif
    while (UString::Rep *key = entries[i].key) {
        if (rep == key) {
            attributes = entries[i].attributes;
            return entries[i].value;
        }
        if (k == 0)
            k = 1 | (h % sizeMask);
        i = (i + k) & sizeMask;
#if DUMP_STATISTICS
        ++numRehashes;
#endif
    }
    return 0;
}

UString UString::substr(int pos, int len) const
{
  int s = size();

  if (pos < 0)
    pos = 0;
  else if (pos >= s)
    pos = s;
  if (len < 0)
    len = s;
  if (pos + len >= s)
    len = s - pos;

  if (pos == 0 && len == s)
    return *this;

  UString::Rep *newRep = Rep::create(rep, pos, len);
  UString result(newRep);
  newRep->deref();

  return result;
}

void HashTable::createTable(JSGlobalData* globalData) const
{
#if ENABLE(PERFECT_HASH_SIZE)
    ASSERT(!table);
    HashEntry* entries = new HashEntry[hashSizeMask + 1];
    for (int i = 0; i <= hashSizeMask; ++i)
        entries[i].setKey(0);
    for (int i = 0; values[i].key; ++i) {
        UString::Rep* identifier = Identifier::add(globalData, values[i].key).releaseRef();
        int hashIndex = identifier->computedHash() & hashSizeMask;
        ASSERT(!entries[hashIndex].key());
        entries[hashIndex].initialize(identifier, values[i].attributes, values[i].value1, values[i].value2);
    }
    table = entries;
#else
    ASSERT(!table);
    int linkIndex = compactHashSizeMask + 1;
    HashEntry* entries = new HashEntry[compactSize];
    for (int i = 0; i < compactSize; ++i)
        entries[i].setKey(0);
    for (int i = 0; values[i].key; ++i) {
        UString::Rep* identifier = Identifier::add(globalData, values[i].key).releaseRef();
        int hashIndex = identifier->computedHash() & compactHashSizeMask;
        HashEntry* entry = &entries[hashIndex];

        if (entry->key()) {
            while (entry->next()) {
                entry = entry->next();
            }
            ASSERT(linkIndex < compactSize);
            entry->setNext(&entries[linkIndex++]);
            entry = entry->next();
        }

        entry->initialize(identifier, values[i].attributes, values[i].value1, values[i].value2);
    }
    table = entries;
#endif
}

PropertyMap::~PropertyMap()
{
    if (!_table) {
#if USE_SINGLE_ENTRY
        UString::Rep *key = _singleEntry.key;
        if (key)
            key->deref();
#endif
        return;
    }
    
    int minimumKeysToProcess = _table->keyCount + _table->sentinelCount;
    Entry *entries = _table->entries;
    for (int i = 0; i < minimumKeysToProcess; i++) {
        UString::Rep *key = entries[i].key;
        if (key) {
            if (key != deletedSentinel())
                key->deref();
        } else
            ++minimumKeysToProcess;
    }
    fastFree(_table);
}

// 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 UString::Reps 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
{
    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_stringLength, buffer))
        m_value = newImpl;
    else {
        for (unsigned i = 0; i < m_ropeLength; ++i) {
            m_fibers[i].deref();
            m_fibers[i] = static_cast<void*>(0);
        }
        m_ropeLength = 0;
        ASSERT(!isRope());
        ASSERT(m_value == UString());
        throwOutOfMemoryError(exec);
        return;
    }
    UChar* position = buffer + m_stringLength;

    // Start with the current Rope.
    Vector<Rope::Fiber, 32> workQueue;
    Rope::Fiber currentFiber;
    for (unsigned i = 0; i < (m_ropeLength - 1); ++i)
        workQueue.append(m_fibers[i]);
    currentFiber = m_fibers[m_ropeLength - 1];
    while (true) {
        if (currentFiber.isRope()) {
            Rope* rope = currentFiber.rope();
            // 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 ropeLengthMinusOne = rope->ropeLength() - 1;
            for (unsigned i = 0; i < ropeLengthMinusOne; ++i)
                workQueue.append(rope->fibers(i));
            currentFiber = rope->fibers(ropeLengthMinusOne);
        } else {
            UString::Rep* string = currentFiber.string();
            unsigned length = string->size();
            position -= length;
            UStringImpl::copyChars(position, string->data(), 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_ropeLength; ++i) {
                    m_fibers[i].deref();
                    m_fibers[i] = static_cast<void*>(0);
                }
                m_ropeLength = 0;

                ASSERT(!isRope());
                return;
            }

            // No! - set the next item up to process.
            currentFiber = workQueue.last();
            workQueue.removeLast();
        }
    }
}

CFStringRef JSStringCopyCFString(CFAllocatorRef alloc, JSStringRef string)
{
    UString::Rep* rep = toJS(string);
    return CFStringCreateWithCharacters(alloc, reinterpret_cast<const UniChar*>(rep->data()), rep->size());
}

JSStringRef JSStringRetain(JSStringRef string)
{
    JSLock lock;
    UString::Rep* rep = toJS(string);
    return toRef(rep->ref());
}

EXPORT
size_t JSStringGetLength(JSStringRef string)
{
    UString::Rep* rep = toJS(string);
    return rep->size();
}

EXPORT
const JSChar* JSStringGetCharactersPtr(JSStringRef string)
{
    UString::Rep* rep = toJS(string);
    return reinterpret_cast<const JSChar*>(rep->data());
}