q3gcache.cpp

奇趣公司比较新的qt/emd版本

*/

bool Q3GCache::remove_string(const QString &key)
{
    Item d = take_string(key);
    if (d)
	deleteItem(d);
    return d != 0;
}

bool Q3GCache::remove_other(const char *key)
{
    Item d = take_other(key);
    if (d)
	deleteItem(d);
    return d != 0;
}


/*!
  Takes the item with key \a key out of the cache. The item is not
  deleted. If no item has this \a key 0 is returned.
*/

Q3PtrCollection::Item Q3GCache::take_string(const QString &key)
{
    Q3CacheItem *ci = dict->take_string(key);	// take from dict
    Item d;
    if (ci) {
	d = ci->data;
	tCost -= ci->cost;
	lruList->take(ci);			// take from list
	delete (QString*)ci->key;
	delete ci;
    } else {
	d = 0;
    }
    return d;
}

/*!
  Takes the item with key \a key out of the cache. The item is not
  deleted. If no item has this \a key 0 is returned.
*/

Q3PtrCollection::Item Q3GCache::take_other(const char *key)
{
    Q3CacheItem *ci;
    if (keytype == AsciiKey)
	ci = dict->take_ascii(key);
    else
	ci = dict->take_int((long)key);
    Item d;
    if (ci) {
	d = ci->data;
	tCost -= ci->cost;
	lruList->take(ci);			// take from list
	if (copyk)
	    delete [] (char *)ci->key;
	delete ci;
    } else {
	d = 0;
    }
    return d;
}


/*!
  Clears the cache.
*/

void Q3GCache::clear()
{
    Q3CacheItem *ci;
    while ((ci = lruList->first())) {
	switch (keytype) {
	    case StringKey:
		dict->remove_string(ci);
		delete (QString*)ci->key;
		break;
	    case AsciiKey:
		dict->remove_ascii(ci);
		if (copyk)
		    delete [] (char*)ci->key;
		break;
	    case IntKey:
		dict->remove_int(ci);
		break;
	    case PtrKey:			// unused
		break;
	}
	deleteItem(ci->data);			// delete data
	lruList->removeFirst();			// remove from list
    }
    tCost = 0;
}


/*!
  Finds an item for \a key in the cache and adds a reference if \a ref is true.
*/

Q3PtrCollection::Item Q3GCache::find_string(const QString &key, bool ref) const
{
    Q3CacheItem *ci = dict->find_string(key);
#if defined(QT_DEBUG)
    lruList->finds++;
#endif
    if (ci) {
#if defined(QT_DEBUG)
	lruList->hits++;
	lruList->hitCosts += ci->cost;
#endif
	if (ref)
	    lruList->reference(ci);
	return ci->data;
    }
    return 0;
}


/*!
  Finds an item for \a key in the cache and adds a reference if \a ref is true.
*/

Q3PtrCollection::Item Q3GCache::find_other(const char *key, bool ref) const
{
    Q3CacheItem *ci = keytype == AsciiKey ? dict->find_ascii(key)
					 : dict->find_int((long)key);
#if defined(QT_DEBUG)
    lruList->finds++;
#endif
    if (ci) {
#if defined(QT_DEBUG)
	lruList->hits++;
	lruList->hitCosts += ci->cost;
#endif
	if (ref)
	    lruList->reference(ci);
	return ci->data;
    }
    return 0;
}


/*!
  Allocates cache space for one or more items.
*/

bool Q3GCache::makeRoomFor(int cost, int priority)
{
    if (cost > mCost)				// cannot make room for more
	return false;				//   than maximum cost
    if (priority == -1)
	priority = 32767;
    register Q3CacheItem *ci = lruList->last();
    int cntCost = 0;
    int dumps	= 0;				// number of items to dump
    while (cntCost < cost && ci && ci->skipPriority <= priority) {
	cntCost += ci->cost;
	ci	 = lruList->prev();
	dumps++;
    }
    if (cntCost < cost)			// can enough cost be dumped?
	return false;				// no
#if defined(QT_DEBUG)
    Q_ASSERT(dumps > 0);
#endif
    while (dumps--) {
	ci = lruList->last();
#if defined(QT_DEBUG)
	lruList->dumps++;
	lruList->dumpCosts += ci->cost;
#endif
	switch (keytype) {
	    case StringKey:
		dict->remove_string(ci);
		delete (QString*)ci->key;
		break;
	    case AsciiKey:
		dict->remove_ascii(ci);
		if (copyk)
		    delete [] (char *)ci->key;
		break;
	    case IntKey:
		dict->remove_int(ci);
		break;
	    case PtrKey:			// unused
		break;
	}
	deleteItem(ci->data);			// delete data
	lruList->removeLast();			// remove from list
    }
    tCost -= cntCost;
    return true;
}


/*!
  Outputs debug statistics.
*/

void Q3GCache::statistics() const
{
#if defined(QT_DEBUG)
    QString line;
    line.fill(QLatin1Char('*'), 80);
    qDebug("%s", line.ascii());
    qDebug("CACHE STATISTICS:");
    qDebug("cache contains %d item%s, with a total cost of %d",
	   count(), count() != 1 ? "s" : "", tCost);
    qDebug("maximum cost is %d, cache is %d%% full.",
	   mCost, (200*tCost + mCost) / (mCost*2));
    qDebug("find() has been called %d time%s",
	   lruList->finds, lruList->finds != 1 ? "s" : "");
    qDebug("%d of these were hits, items found had a total cost of %d.",
	   lruList->hits,lruList->hitCosts);
    qDebug("%d item%s %s been inserted with a total cost of %d.",
	   lruList->inserts,lruList->inserts != 1 ? "s" : "",
	   lruList->inserts != 1 ? "have" : "has", lruList->insertCosts);
    qDebug("%d item%s %s too large or had too low priority to be inserted.",
	   lruList->insertMisses, lruList->insertMisses != 1 ? "s" : "",
	   lruList->insertMisses != 1 ? "were" : "was");
    qDebug("%d item%s %s been thrown away with a total cost of %d.",
	   lruList->dumps, lruList->dumps != 1 ? "s" : "",
	   lruList->dumps != 1 ? "have" : "has", lruList->dumpCosts);
    qDebug("Statistics from internal dictionary class:");
    dict->statistics();
    qDebug("%s", line.ascii());
#endif
}


/*****************************************************************************
  Q3GCacheIterator member functions
 *****************************************************************************/

/*!
  \class Q3GCacheIterator qgcache.h
  \reentrant
  \brief The Q3GCacheIterator class is an internal class for implementing Q3CacheIterator and
  QIntCacheIterator.

  \internal

  Q3GCacheIterator is a strictly internal class that does the heavy work for
  Q3CacheIterator and QIntCacheIterator.
*/

/*!
  Constructs an iterator that operates on the cache \a c.
*/

Q3GCacheIterator::Q3GCacheIterator(const Q3GCache &c)
{
    it = new Q3CListIt(c.lruList);
#if defined(QT_DEBUG)
    Q_ASSERT(it != 0);
#endif
}

/*!
  Constructs an iterator that operates on the same cache as \a ci.
*/

Q3GCacheIterator::Q3GCacheIterator(const Q3GCacheIterator &ci)
{
    it = new Q3CListIt(ci.it);
#if defined(QT_DEBUG)
    Q_ASSERT(it != 0);
#endif
}

/*!
  Destroys the iterator.
*/

Q3GCacheIterator::~Q3GCacheIterator()
{
    delete it;
}

/*!
  Assigns the iterator \a ci to this cache iterator.
*/

Q3GCacheIterator &Q3GCacheIterator::operator=(const Q3GCacheIterator &ci)
{
    *it = *ci.it;
    return *this;
}

/*!
  Returns the number of items in the cache.
*/

uint Q3GCacheIterator::count() const
{
    return it->count();
}

/*!
  Returns true if the iterator points to the first item.
*/

bool  Q3GCacheIterator::atFirst() const
{
    return it->atFirst();
}

/*!
  Returns true if the iterator points to the last item.
*/

bool Q3GCacheIterator::atLast() const
{
    return it->atLast();
}

/*!
  Sets the list iterator to point to the first item in the cache.
*/

Q3PtrCollection::Item Q3GCacheIterator::toFirst()
{
    Q3CacheItem *item = it->toFirst();
    return item ? item->data : 0;
}

/*!
  Sets the list iterator to point to the last item in the cache.
*/

Q3PtrCollection::Item Q3GCacheIterator::toLast()
{
    Q3CacheItem *item = it->toLast();
    return item ? item->data : 0;
}

/*!
  Returns the current item.
*/

Q3PtrCollection::Item Q3GCacheIterator::get() const
{
    Q3CacheItem *item = it->current();
    return item ? item->data : 0;
}

/*!
  Returns the key of the current item.
*/

QString Q3GCacheIterator::getKeyString() const
{
    Q3CacheItem *item = it->current();
    return item ? *((QString*)item->key) : QString();
}

/*!
  Returns the key of the current item, as a \0-terminated C string.
*/

const char *Q3GCacheIterator::getKeyAscii() const
{
    Q3CacheItem *item = it->current();
    return item ? (const char *)item->key : 0;
}

/*!
  Returns the key of the current item, as a long.
*/

long Q3GCacheIterator::getKeyInt() const
{
    Q3CacheItem *item = it->current();
    return item ? (long)item->key : 0;
}

/*!
  Moves to the next item (postfix).
*/

Q3PtrCollection::Item Q3GCacheIterator::operator()()
{
    Q3CacheItem *item = it->operator()();
    return item ? item->data : 0;
}

/*!
  Moves to the next item (prefix).
*/

Q3PtrCollection::Item Q3GCacheIterator::operator++()
{
    Q3CacheItem *item = it->operator++();
    return item ? item->data : 0;
}

/*!
  Moves \a jump positions forward.
*/

Q3PtrCollection::Item Q3GCacheIterator::operator+=(uint jump)
{
    Q3CacheItem *item = it->operator+=(jump);
    return item ? item->data : 0;
}

/*!
  Moves to the previous item (prefix).
*/

Q3PtrCollection::Item Q3GCacheIterator::operator--()
{
    Q3CacheItem *item = it->operator--();
    return item ? item->data : 0;
}

/*!
  Moves \a jump positions backward.
*/

Q3PtrCollection::Item Q3GCacheIterator::operator-=(uint jump)
{
    Q3CacheItem *item = it->operator-=(jump);
    return item ? item->data : 0;
}