1 files changed, 201 insertions, 97 deletions

diff --git a/src/heap.h b/src/heap.h
index 9df4121..1dac69b 100644
--- a/src/heap.h
+++ b/src/heap.h
@@ -13,76 +13,92 @@
 #include "bu/exceptionbase.h"
 #include "bu/util.h"
 #include "bu/queue.h"
+#include "bu/sharedcore.h"
 
 namespace Bu
 {
         subExceptionDecl( HeapException );
 
-        /**
-         * A priority queue that allows for an unlimited number of priorities.  All
-         * objects enqueued must support less-than-comparison.  Then every time an
-         * item is dequeued it is always the least item in the heap.  The heap
-         * operates using a binary tree for storage, which allows most operations
-         * to be very fast.  Enqueueing and dequeueing are both O(log(N)) operatoins
-         * whereas peeking is constant time.
-         *
-         * This heap implementation allows iterating, however please note that any
-         * enqueue or dequeue operation will invalidate the iterator and make it
-         * unusable (if it still works, you shouldn't trust the results).  Also,
-         * the items are not stored in memory in order, they are optomized into a
-         * tree.  This means that the items will be in effectively random order
-         * while iterating through them, and the order cannot be trusted.  Also,
-         * modifying an item in the heap will not cause that item to be re-sorted.
-         * If you want to change the position of an item in the heap you will have
-         * to dequeue every item before it, dequeue that item, change it, and
-         * re-enqueue all of the items removed.
-         */
-        template<typename item, typename cmpfunc=__basicLTCmp<item>, typename itemalloc=std::allocator<item> >
-        class Heap : public Queue<item>
+        template<typename item, typename cmpfunc, typename itemalloc>
+        class Heap;
+
+        template<typename item, typename cmpfunc, typename itemalloc>
+        class HeapCore
         {
-        public:
-                Heap() :
-                        iSize( 7 ),
+        friend class Heap<item, cmpfunc, itemalloc>;
+        friend class SharedCore<
+                Heap<item, cmpfunc, itemalloc>, HeapCore<item, cmpfunc, itemalloc>
+                >;
+        private:
+                HeapCore() :
+                        iSize( 0 ),
                         iFill( 0 ),
-                        aItem( ia.allocate( iSize ) )
+                        aItem( NULL )
                 {
                 }
-                
-                Heap( cmpfunc cmpin ) :
-                        iSize( 7 ),
-                        iFill( 0 ),
-                        aItem( ia.allocate( iSize ) ),
-                        cmp( cmpin )
+
+                virtual ~HeapCore()
                 {
+                        clear();
                 }
 
-                Heap( int iInitialCapacity ) :
-                        iSize( 0 ),
-                        iFill( 0 ),
-                        aItem( NULL )
+                void init()
                 {
-                        for( iSize = 1; iSize < iInitialCapacity; iSize=iSize*2+1 ) { }
+                        if( iSize > 0 )
+                                return;
+
+                        iSize = 7;
+                        iFill = 0;
                         aItem = ia.allocate( iSize );
                 }
-                
-                Heap( cmpfunc cmpin, int iInitialCapacity ) :
-                        iSize( 0 ),
-                        iFill( 0 ),
-                        aItem( NULL ),
-                        cmp( cmpin )
+
+                void init( int iCap )
                 {
-                        for( iSize = 1; iSize < iInitialCapacity; iSize=iSize*2+1 ) { }
+                        if( iSize > 0 )
+                                return;
+
+                        for( iSize = 1; iSize < iCap; iSize=iSize*2+1 ) { }
+                        iFill = 0;
                         aItem = ia.allocate( iSize );
                 }
 
-                virtual ~Heap()
+                void clear()
                 {
+                        if( iSize == 0 )
+                                return;
+
                         for( int j = 0; j < iFill; j++ )
                                 ia.destroy( &aItem[j] );
                         ia.deallocate( aItem, iSize );
                         aItem = NULL;
+                        iSize = 0;
+                        iFill = 0;
                 }
+                
+                void upSize()
+                {
+                        if( iSize == 0 )
+                        {
+                                init();
+                                return;
+                        }
 
+                        item *aNewItems = ia.allocate( iSize*2+1 );
+                        //
+                        // We cannot use a memcopy here because we don't know what kind
+                        // of datastructures are being used, we have to copy them one at
+                        // a time.
+                        //
+                        for( int j = 0; j < iFill; j++ )
+                        {
+                                ia.construct( &aNewItems[j], aItem[j] );
+                                ia.destroy( &aItem[j] );
+                        }
+                        ia.deallocate( aItem, iSize );
+                        aItem = aNewItems;
+                        iSize = iSize*2+1;
+                }
+                
                 virtual void enqueue( const item &it )
                 {
                         item i = it; // TODO: This is a silly workaround, put the i item
@@ -126,20 +142,6 @@ namespace Bu
                         iFill++;
                 }
 
-                virtual item &peek()
-                {
-                        if( iFill == 0 )
-                                throw HeapException("Heap empty.");
-                        return aItem[0];
-                }
-
-                virtual const item &peek() const
-                {
-                        if( iFill == 0 )
-                                throw HeapException("Heap empty.");
-                        return aItem[0];
-                }
-
                 virtual item dequeue()
                 {
                         if( iFill == 0 )
@@ -174,14 +176,117 @@ namespace Bu
                         return iRet;
                 }
 
+        private:
+                int iSize;
+                int iFill;
+                item *aItem;
+                cmpfunc cmp;
+                itemalloc ia;
+        };
+
+        /**
+         * A priority queue that allows for an unlimited number of priorities.  All
+         * objects enqueued must support less-than-comparison.  Then every time an
+         * item is dequeued it is always the least item in the heap.  The heap
+         * operates using a binary tree for storage, which allows most operations
+         * to be very fast.  Enqueueing and dequeueing are both O(log(N)) operatoins
+         * whereas peeking is constant time.
+         *
+         * This heap implementation allows iterating, however please note that any
+         * enqueue or dequeue operation will invalidate the iterator and make it
+         * unusable (if it still works, you shouldn't trust the results).  Also,
+         * the items are not stored in memory in order, they are optomized into a
+         * tree.  This means that the items will be in effectively random order
+         * while iterating through them, and the order cannot be trusted.  Also,
+         * modifying an item in the heap will not cause that item to be re-sorted.
+         * If you want to change the position of an item in the heap you will have
+         * to dequeue every item before it, dequeue that item, change it, and
+         * re-enqueue all of the items removed.
+         */
+        template<typename item, typename cmpfunc=__basicLTCmp<item>, typename itemalloc=std::allocator<item> >
+        class Heap : public Queue<item>, public SharedCore<
+                                 Heap<item, cmpfunc, itemalloc>,
+                                 HeapCore<item, cmpfunc, itemalloc>
+                                 >
+        {
+        private:
+                typedef class Heap<item,cmpfunc,itemalloc> MyType;
+                typedef class HeapCore<item,cmpfunc,itemalloc> Core;
+
+        protected:
+                using SharedCore<MyType, Core>::core;
+                using SharedCore<MyType, Core>::_hardCopy;
+                using SharedCore<MyType, Core>::_resetCore;
+                using SharedCore<MyType, Core>::_allocateCore;
+
+        public:
+                Heap()
+                {
+                }
+                
+                Heap( cmpfunc cmpin )
+                {
+                        core->cmp = cmpin;
+                }
+
+                Heap( int iInitialCapacity )
+                {
+                        core->init( iInitialCapacity );
+                }
+                
+                Heap( cmpfunc cmpin, int iInitialCapacity )
+                {
+                        core->cmp = cmpin;
+                        core->init( iInitialCapacity );
+                }
+
+                Heap( const MyType &rSrc ) :
+                        SharedCore<MyType, Core>( rSrc )
+                {
+                }
+
+                virtual ~Heap()
+                {
+                }
+
+                virtual void enqueue( const item &it )
+                {
+                        _hardCopy();
+
+                        core->enqueue( it );
+                }
+
+                virtual item &peek()
+                {
+                        _hardCopy();
+
+                        if( core->iFill == 0 )
+                                throw HeapException("Heap empty.");
+                        return core->aItem[0];
+                }
+
+                virtual const item &peek() const
+                {
+                        if( core->iFill == 0 )
+                                throw HeapException("Heap empty.");
+                        return core->aItem[0];
+                }
+
+                virtual item dequeue()
+                {
+                        _hardCopy();
+
+                        return core->dequeue();
+                }
+
                 virtual bool isEmpty() const
                 {
-                        return (iFill==0);
+                        return (core->iFill==0);
                 }
 
                 virtual int getSize() const
                 {
-                        return iFill;
+                        return core->iFill;
                 }
 
                 class iterator
@@ -201,7 +306,7 @@ namespace Bu
                         {
                                 if( pHeap == NULL )
                                         throw Bu::ExceptionBase("Iterator not initialized.");
-                                if( iIndex < 0 || iIndex >= pHeap->iFill )
+                                if( iIndex < 0 || iIndex >= pHeap->core->iFill )
                                         throw Bu::ExceptionBase("Iterator out of bounds.");
                         }
 
@@ -230,12 +335,16 @@ namespace Bu
 
                         item &operator*()
                         {
-                                return pHeap->aItem[iIndex];
+                                pHeap->_hardCopy();
+
+                                return pHeap->core->aItem[iIndex];
                         }
 
                         item *operator->()
                         {
-                                return &(pHeap->aItem[iIndex]);
+                                pHeap->_hardCopy();
+
+                                return &(pHeap->core->aItem[iIndex]);
                         }
 
                         iterator &operator++()
@@ -260,7 +369,7 @@ namespace Bu
                         {
                                 checkValid();
                                 iIndex++;
-                                if( iIndex >= pHeap->iFill )
+                                if( iIndex >= pHeap->core->iFill )
                                         iIndex = -1;
 
                                 return *this;
@@ -279,7 +388,7 @@ namespace Bu
                                 checkValid();
                                 iterator ret( *this );
                                 ret.iIndex += iDelta;
-                                if( ret.iIndex >= pHeap->iFill )
+                                if( ret.iIndex >= pHeap->core->iFill )
                                         ret.iIndex = -1;
                                 return ret;
                         }
@@ -294,12 +403,12 @@ namespace Bu
                                 return ret;
                         }
 
-                        operator bool()
+                        operator bool() const
                         {
                                 return iIndex != -1;
                         }
 
-                        bool isValid()
+                        bool isValid() const
                         {
                                 return iIndex != -1;
                         }
@@ -328,7 +437,7 @@ namespace Bu
                         {
                                 if( pHeap == NULL )
                                         throw Bu::ExceptionBase("Iterator not initialized.");
-                                if( iIndex < 0 || iIndex >= pHeap->iFill )
+                                if( iIndex < 0 || iIndex >= pHeap->core->iFill )
                                         throw Bu::ExceptionBase("Iterator out of bounds.");
                         }
 
@@ -363,19 +472,23 @@ namespace Bu
 
                         const item &operator*()
                         {
-                                return pHeap->aItem[iIndex];
+                                pHeap->_hardCopy();
+
+                                return pHeap->core->aItem[iIndex];
                         }
 
                         const item *operator->()
                         {
-                                return &(pHeap->aItem[iIndex]);
+                                pHeap->_hardCopy();
+
+                                return &(pHeap->core->aItem[iIndex]);
                         }
 
                         const_iterator &operator++()
                         {
                                 checkValid();
                                 iIndex++;
-                                if( iIndex >= pHeap->iFill )
+                                if( iIndex >= pHeap->core->iFill )
                                         iIndex = -1;
 
                                 return *this;
@@ -393,7 +506,7 @@ namespace Bu
                         {
                                 checkValid();
                                 iIndex++;
-                                if( iIndex >= pHeap->iFill )
+                                if( iIndex >= pHeap->core->iFill )
                                         iIndex = -1;
 
                                 return *this;
@@ -427,12 +540,12 @@ namespace Bu
                                 return ret;
                         }
 
-                        operator bool()
+                        operator bool() const
                         {
                                 return iIndex != -1;
                         }
 
-                        bool isValid()
+                        bool isValid() const
                         {
                                 return iIndex != -1;
                         }
@@ -452,14 +565,14 @@ namespace Bu
 
                 iterator begin()
                 {
-                        if( iFill == 0 )
+                        if( core->iFill == 0 )
                                 return end();
                         return iterator( this, 0 );
                 }
 
                 const_iterator begin() const
                 {
-                        if( iFill == 0 )
+                        if( core->iFill == 0 )
                                 return end();
                         return const_iterator( this, 0 );
                 }
@@ -475,31 +588,22 @@ namespace Bu
                 }
 
 
-        private:
-                void upSize()
+        protected:
+                virtual Core *_copyCore( Core *src )
                 {
-                        item *aNewItems = ia.allocate( iSize*2+1 );
-                        //
-                        // We cannot use a memcopy here because we don't know what kind
-                        // of datastructures are being used, we have to copy them one at
-                        // a time.
-                        //
-                        for( int j = 0; j < iFill; j++ )
+                        Core *pRet = _allocateCore();
+
+                        pRet->iSize = src->iSize;
+                        pRet->iFill = src->iFill;
+                        pRet->cmp = src->cmp;
+                        pRet->aItem = pRet->ia.allocate( pRet->iSize );
+                        for( int j = 0; j < pRet->iFill; j++ )
                         {
-                                ia.construct( &aNewItems[j], aItem[j] );
-                                ia.destroy( &aItem[j] );
+                                pRet->ia.construct( &pRet->aItem[j], src->aItem[j] );
                         }
-                        ia.deallocate( aItem, iSize );
-                        aItem = aNewItems;
-                        iSize = iSize*2+1;
-                }
 
-        private:
-                int iSize;
-                int iFill;
-                item *aItem;
-                cmpfunc cmp;
-                itemalloc ia;
+                        return pRet;
+                }
         };
 };