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generator/parser/rpp/appendedlist.h  view on Meta::CPAN

   but WITHOUT ANY WARRANTY; without even the implied warranty of
   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
   Library General Public License for more details.

   You should have received a copy of the GNU Library General Public License
   along with this library; see the file COPYING.LIB.  If not, write to
   the Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor,
   Boston, MA 02110-1301, USA.
*/

#ifndef APPENDEDLIST_H
#define APPENDEDLIST_H

#include <QtCore/QMutex>
#include <QtCore/QVector>
#include <QtCore/QStack>
#include <QtCore/QPair>
// #include <kglobal.h>
// #include <kdebug.h>
#include "../kdevvarlengtharray.h"
#include <iostream>
#include <time.h>

namespace KDevelop {
class AbstractItemRepository;
/**
 * This file contains macros and classes that can be used to conveniently implement classes that store the data of an arbitrary count
 * of additional lists within the same memory block directly behind the class data, in a way that one the whole data can be stored by one copy-operation
 * to another place, like needed in ItemRepository. These macros simplify having two versions of a class: One that has its lists attached in memory,
 * and one version that has them contained as a directly accessible KDevVarLengthArray. Both versions have their lists accessible through access-functions,
 * have a completeSize() function that computes the size of the one-block version, and a copyListsFrom(..) function which can copy the lists from one
 * version to the other.
 *
 * @warning Always follow these rules:
 * You must call initalizeAppendedLists(bool) on construction, also in any copy-constructor, but before calling copyFrom(..).
 * The parameter to that function should be whether the lists in the items should be dynamic, and thus most times "true".
 * You must call freeAppendedLists() on destruction, our you will be leaking memory(only when dynamic)
 *
 * For each embedded list, you must use macros to define a global hash that will be used to allocate the temporary lists, example fir identifier.cpp:
 * DEFINE_LIST_MEMBER_HASH(IdentifierPrivate, templateIdentifiers, uint);
 *
 * See identifier.cpp for an example how to use these classes. @todo Document this a bit more
 * */


enum {
  DynamicAppendedListMask = 1 << 31
};
enum {
  DynamicAppendedListRevertMask = 0xffffffff - DynamicAppendedListMask
};
/**
 * Manages a repository of items for temporary usage. The items will be allocated with an index on alloc(),
 * and freed on free(index). When freed, the same index will be re-used for a later allocation, thus no real allocations
 * will be happening in most cases.
 * The returned indices will always be ored with DynamicAppendedListMask.
 *
 */
template<class T, bool threadSafe = true>
class TemporaryDataManager {
  public:
    TemporaryDataManager(QString id = QString()) : m_itemsUsed(0), m_itemsSize(0), m_items(0), m_id(id) {
      uint first = alloc();  //Allocate the zero item, just to reserve that index
      Q_ASSERT(first == (uint)DynamicAppendedListMask);
    }
    ~TemporaryDataManager() {
      free(DynamicAppendedListMask); //Free the zero index, so we don't get wrong warnings
      uint cnt = usedItemCount();
      if(cnt) //Don't use kDebug, because that may not work during destruction
        std::cout << m_id.toLocal8Bit().data() << " There were items left on destruction: " << usedItemCount() << "\n";

      for(uint a = 0; a < m_itemsUsed; ++a)
        delete m_items[a];
    }

    inline T& getItem(uint index) {
      //For performance reasons this function does not lock the mutex, it's called too often and must be
      //extremely fast. There is special measures in alloc() to make this safe.
      Q_ASSERT(index & DynamicAppendedListMask);

      return *m_items[index & KDevelop::DynamicAppendedListRevertMask];
    }

    ///Allocates an item index, which from now on you can get using getItem, until you call free(..) on the index.
    ///The returned item is not initialized and may contain random older content, so you should clear it after getting it for the first time
    uint alloc() {

      if(threadSafe)
        m_mutex.lock();

      uint ret;
      if(!m_freeIndicesWithData.isEmpty()) {
        ret = m_freeIndicesWithData.pop();
      }else if(!m_freeIndices.isEmpty()) {
        ret = m_freeIndices.pop();
        Q_ASSERT(!m_items[ret]);
        m_items[ret] = new T;
      }else{

        if(m_itemsUsed >= m_itemsSize) {
          //We need to re-allocate
          uint newItemsSize = m_itemsSize + 20 + (m_itemsSize/3);
          T** newItems = new T*[newItemsSize];
          memcpy(newItems, m_items, sizeof(T*) * m_itemsSize);

          T** oldItems = m_items;
          m_items = newItems;
          m_itemsSize = newItemsSize;
          //The only function that does not lock the mutex is getItem(..), because that function must be very efficient.
          //Since it's only a few instructions from the moment m_items is read to the moment it's used,
          //deleting the old data after a few seconds should be safe.
          m_deleteLater.append(qMakePair(time(0), oldItems));

          //We do this in this place so it isn't called too often. The result is that we will always have some additional data around.
          //However the index itself should anyway not consume too much data.
          if(!m_deleteLater.isEmpty()) {
            while(!m_deleteLater.isEmpty()) {
              //We delete after 5 seconds
              if(time(0) - m_deleteLater.first().first > 5) {
                delete[] m_deleteLater.first().second;
                m_deleteLater.removeFirst();

generator/parser/rpp/appendedlist.h  view on Meta::CPAN

          for(; otherCurr < otherEnd; ++otherCurr) \
            item.append(*otherCurr); \
        }else{ \
          Q_ASSERT(name ## Data == 0); /* It is dangerous to overwrite the contents of non-dynamic lists(Most probably a mistake) */ \
          name ## Data = rhs.name ## Size(); \
          type* curr = const_cast<type*>(name());  type* end = curr + name ## Size(); \
          const type* otherCurr = rhs.name(); \
          for(; curr < end; ++curr, ++otherCurr) \
            new (curr) type(*otherCurr); /* Call the copy constructors */ \
        }\
      } \
      void name ## NeedDynamicList() { Q_ASSERT(appendedListsDynamic()); if((name ## Data & KDevelop::DynamicAppendedListRevertMask) == 0) { name ## Data = temporaryHash ## container ## name().alloc(); Q_ASSERT(temporaryHash ## container ## name().ge...
      void name ## Initialize(bool dynamic) { name ## Data = (dynamic ? KDevelop::DynamicAppendedListMask : 0); }  \
      void name ## Free() { if(appendedListsDynamic()) { if(name ## Data & KDevelop::DynamicAppendedListRevertMask) temporaryHash ## container ## name().free(name ## Data); } else { type* curr = const_cast<type*>(name());  type* end = curr + name ## ...


///@todo Make these things a bit faster(less recursion)

#define APPENDED_LIST_FIRST(container, type, name)        APPENDED_LIST_COMMON(container, type, name) \
                                               const type* name() const { if((name ## Data & KDevelop::DynamicAppendedListRevertMask) == 0) return 0; if(!appendedListsDynamic()) return (type*)(((char*)this) + classSize() + offsetBehindBase()); else r...
                                               unsigned int name ## OffsetBehind() const { return name ## Size() * sizeof(type) + offsetBehindBase(); } \
                                               template<class T> bool name ## ListChainEquals( const T& rhs ) const { return name ## Equals(rhs); } \
                                               template<class T> void name ## CopyAllFrom( const T& rhs ) { name ## CopyFrom(rhs); } \
                                               void name ## InitializeChain(bool dynamic) { name ## Initialize(dynamic); }  \
                                               void name ## FreeChain() { name ## Free(); }

#define APPENDED_LIST(container, type, name, predecessor) APPENDED_LIST_COMMON(container, type, name) \
                                               const type* name() const {if((name ## Data & KDevelop::DynamicAppendedListRevertMask) == 0) return 0; if(!appendedListsDynamic()) return (type*)(((char*)this) + classSize() + predecessor ## OffsetBehind(...
                                               unsigned int name ## OffsetBehind() const { return name ## Size() * sizeof(type) + predecessor ## OffsetBehind(); } \
                                               template<class T> bool name ## ListChainEquals( const T& rhs ) const { return name ## Equals(rhs) && predecessor ## ListChainEquals(rhs); } \
                                               template<class T> void name ## CopyAllFrom( const T& rhs ) { predecessor ## CopyAllFrom(rhs); name ## CopyFrom(rhs); } \
                                               void name ## InitializeChain(bool dynamic) { name ## Initialize(dynamic); predecessor ## InitializeChain(dynamic);  }  \
                                               void name ## FreeChain() { name ## Free(); predecessor ## FreeChain(); }

#define END_APPENDED_LISTS(container, predecessor) /* Returns the size of the object containing the appended lists, including them */ \
                                      unsigned int completeSize() const { return classSize() + predecessor ## OffsetBehind(); } \
                                     /* Compares all local appended lists(not from base classes) and returns true if they are equal */                \
                                      template<class T> bool listsEqual(const T& rhs) const { return predecessor ## ListChainEquals(rhs); } \
                                     /* Copies all the local appended lists(not from base classes) from the given item.*/   \
                                      template<class T> void copyListsFrom(const T& rhs) { return predecessor ## CopyAllFrom(rhs); } \
                                      void initializeAppendedLists(bool dynamic = appendedListDynamicDefault()) { predecessor ## Data = (dynamic ? KDevelop::DynamicAppendedListMask : 0); predecessor ## InitializeChain(dynamic); } \
                                      void freeAppendedLists() { predecessor ## FreeChain(); } \
                                      bool appendedListsDynamic() const { return predecessor ## Data & KDevelop::DynamicAppendedListMask; } \
                                      unsigned int offsetBehindLastList() const { return predecessor ## OffsetBehind(); } \
                                      size_t dynamicSize() const { return offsetBehindLastList() + classSize(); }
/**
 * This is a class that allows you easily putting instances of your class into an ItemRepository as seen in itemrepository.h.
 * All your class needs to do is:
 * - Be implemented using the APPENDED_LIST macros.
  * - Have a real copy-constructor that additionally takes a "bool dynamic = true" parameter, which should be given to initializeAppendedLists
 * - Except for these appended lists, only contain directly copyable data like indices(no pointers, no virtual functions)
 * - Implement operator==(..) which should compare everything, including the lists. @warning The default operator will not work!
 * - Implement a hash() function. The hash should equal for two instances when operator==(..) returns true.
 * - Should be completely functional without a constructor called, only the data copied
 * - Implement a "bool persistent() const" function, that should check the reference-count or other information to decide whether the item should stay in the repository
 * If those conditions are fulfilled, the data can easily be put into a repository using this request class.
 * */

template<class Type, uint averageAppendedBytes = 8>
class AppendedListItemRequest {
  public:
  AppendedListItemRequest(const Type& item) : m_item(item) {
  }

  enum {
    AverageSize = sizeof(Type) + averageAppendedBytes
  };

  unsigned int hash() const {
    return m_item.hash();
  }

  size_t itemSize() const {
      return m_item.dynamicSize();
  }

  void createItem(Type* item) const {
    new (item) Type(m_item, false);
  }
  
  static void destroy(Type* item, KDevelop::AbstractItemRepository&) {
    item->~Type();
  }
  
  static bool persistent(const Type* item) {
    return item->persistent();
  }

  bool equals(const Type* item) const {
    return m_item == *item;
  }

  const Type& m_item;
};
}

///This function is outside of the namespace, so it can always be found. It's used as default-parameter to initializeAppendedLists(..),
///and you can for example implement a function called like this in your local class hierarchy to override this default.
inline bool appendedListDynamicDefault() {
  return true;
}

#endif