Very simple container class to hold a pointer to some data on the heap. More...

Public Member Functions
	HeapBlock () noexcept
	Creates a HeapBlock which is initially just a null pointer.
	HeapBlock (const size_t numElements)
	Creates a HeapBlock containing a number of elements.
	~HeapBlock ()
	Destructor.
	operator ElementType * () const noexcept
	Returns a raw pointer to the allocated data.
ElementType *	getData () const noexcept
	Returns a raw pointer to the allocated data.
	operator void * () const noexcept
	Returns a void pointer to the allocated data.
	operator const void * () const noexcept
	Returns a void pointer to the allocated data.
ElementType *	operator-> () const noexcept
	Lets you use indirect calls to the first element in the array.
template<typename IndexType >
ElementType &	operator[] (IndexType index) const noexcept
	Returns a reference to one of the data elements.
template<typename IndexType >
ElementType *	operator+ (IndexType index) const noexcept
	Returns a pointer to a data element at an offset from the start of the array.
bool	operator== (const ElementType *const otherPointer) const noexcept
	Compares the pointer with another pointer.
bool	operator!= (const ElementType *const otherPointer) const noexcept
	Compares the pointer with another pointer.
void	malloc (const size_t newNumElements, const size_t elementSize=sizeof(ElementType))
	Allocates a specified amount of memory.
void	calloc (const size_t newNumElements, const size_t elementSize=sizeof(ElementType))
	Allocates a specified amount of memory and clears it.
void	allocate (const size_t newNumElements, const bool initialiseToZero)
	Allocates a specified amount of memory and optionally clears it.
void	realloc (const size_t newNumElements, const size_t elementSize=sizeof(ElementType))
	Re-allocates a specified amount of memory.
void	free ()
	Frees any currently-allocated data.
void	swapWith (HeapBlock< ElementType > &other) noexcept
	Swaps this object's data with the data of another HeapBlock.
void	clear (size_t numElements) noexcept
	This fills the block with zeros, up to the number of elements specified.

Detailed Description

template<class ElementType>
class HeapBlock< ElementType >

Very simple container class to hold a pointer to some data on the heap.

When you need to allocate some heap storage for something, always try to use this class instead of allocating the memory directly using malloc/free.

A HeapBlock<char> object can be treated in pretty much exactly the same way as an char*, but as long as you allocate it on the stack or as a class member, it's almost impossible for it to leak memory.

It also makes your code much more concise and readable than doing the same thing using direct allocations,

E.g. instead of this:

        int* temp = (int*) malloc (1024 * sizeof (int));
        memcpy (temp, xyz, 1024 * sizeof (int));
        free (temp);
        temp = (int*) calloc (2048 * sizeof (int));
        temp[0] = 1234;
        memcpy (foobar, temp, 2048 * sizeof (int));
        free (temp);

..you could just write this:

        HeapBlock <int> temp (1024);
        memcpy (temp, xyz, 1024 * sizeof (int));
        temp.calloc (2048);
        temp[0] = 1234;
        memcpy (foobar, temp, 2048 * sizeof (int));

The class is extremely lightweight, containing only a pointer to the data, and exposes malloc/realloc/calloc/free methods that do the same jobs as their less object-oriented counterparts. Despite adding safety, you probably won't sacrifice any performance by using this in place of normal pointers.

See also:: Array, OwnedArray, MemoryBlock

Constructor & Destructor Documentation

template<class ElementType>

HeapBlock< ElementType >::HeapBlock ( )

Creates a HeapBlock which is initially just a null pointer.

After creation, you can resize the array using the malloc(), calloc(), or realloc() methods.

template<class ElementType>

HeapBlock< ElementType >::HeapBlock ( const size_t numElements ) [explicit]

Creates a HeapBlock containing a number of elements.

The contents of the block are undefined, as it will have been created by a malloc call.

If you want an array of zero values, you can use the calloc() method instead.

template<class ElementType>

HeapBlock< ElementType >::~HeapBlock ( )

Destructor.

This will free the data, if any has been allocated.

Member Function Documentation

template<class ElementType>

HeapBlock< ElementType >::operator ElementType * ( ) const

Returns a raw pointer to the allocated data.

This may be a null pointer if the data hasn't yet been allocated, or if it has been freed by calling the free() method.

template<class ElementType>

ElementType* HeapBlock< ElementType >::getData ( ) const

Returns a raw pointer to the allocated data.

This may be a null pointer if the data hasn't yet been allocated, or if it has been freed by calling the free() method.

Referenced by ReferenceCountedArray< SynthesiserSound >::addOrReplaceSorted(), ReferenceCountedArray< SynthesiserSound >::addSorted(), OwnedArray< MidiBuffer >::addSorted(), ReferenceCountedArray< SynthesiserSound >::contains(), OwnedArray< MidiBuffer >::contains(), ReferenceCountedArray< SynthesiserSound >::indexOf(), OwnedArray< MidiBuffer >::indexOf(), OwnedArray< MidiBuffer >::removeObject(), ReferenceCountedArray< SynthesiserSound >::sort(), and OwnedArray< MidiBuffer >::sort().

template<class ElementType>

HeapBlock< ElementType >::operator void * ( ) const

Returns a void pointer to the allocated data.

This may be a null pointer if the data hasn't yet been allocated, or if it has been freed by calling the free() method.

template<class ElementType>

HeapBlock< ElementType >::operator const void * ( ) const

Returns a void pointer to the allocated data.

This may be a null pointer if the data hasn't yet been allocated, or if it has been freed by calling the free() method.

template<class ElementType>

ElementType* HeapBlock< ElementType >::operator-> ( ) const

Lets you use indirect calls to the first element in the array.

Obviously this will cause problems if the array hasn't been initialised, because it'll be referencing a null pointer.

template<class ElementType>

template<typename IndexType >

ElementType& HeapBlock< ElementType >::operator[] ( IndexType index ) const

Returns a reference to one of the data elements.

Obviously there's no bounds-checking here, as this object is just a dumb pointer and has no idea of the size it currently has allocated.

template<class ElementType>

template<typename IndexType >

ElementType* HeapBlock< ElementType >::operator+ ( IndexType index ) const

Returns a pointer to a data element at an offset from the start of the array.

This is the same as doing pointer arithmetic on the raw pointer itself.

template<class ElementType>

bool HeapBlock< ElementType >::operator== ( const ElementType *const otherPointer ) const

Compares the pointer with another pointer.

This can be handy for checking whether this is a null pointer.

template<class ElementType>

bool HeapBlock< ElementType >::operator!= ( const ElementType *const otherPointer ) const

Compares the pointer with another pointer.

This can be handy for checking whether this is a null pointer.

template<class ElementType>

void HeapBlock< ElementType >::malloc	(	const size_t	newNumElements,
		const size_t	elementSize = `sizeof (ElementType)`
	)

Allocates a specified amount of memory.

This uses the normal malloc to allocate an amount of memory for this object. Any previously allocated memory will be freed by this method.

The number of bytes allocated will be (newNumElements * elementSize). Normally you wouldn't need to specify the second parameter, but it can be handy if you need to allocate a size in bytes rather than in terms of the number of elements.

The data that is allocated will be freed when this object is deleted, or when you call free() or any of the allocation methods.

Referenced by HeapBlock< ObjectClass * >::allocate(), HeapBlock< ObjectClass * >::malloc(), and HeapBlock< ObjectClass * >::realloc().

template<class ElementType>

void HeapBlock< ElementType >::calloc	(	const size_t	newNumElements,
		const size_t	elementSize = `sizeof (ElementType)`
	)

Allocates a specified amount of memory and clears it.

This does the same job as the malloc() method, but clears the memory that it allocates.

Referenced by HeapBlock< ObjectClass * >::allocate(), and HeapBlock< ObjectClass * >::calloc().

template<class ElementType>

void HeapBlock< ElementType >::allocate	(	const size_t	newNumElements,
		const bool	initialiseToZero
	)

Allocates a specified amount of memory and optionally clears it.

This does the same job as either malloc() or calloc(), depending on the initialiseToZero parameter.

template<class ElementType>

void HeapBlock< ElementType >::realloc	(	const size_t	newNumElements,
		const size_t	elementSize = `sizeof (ElementType)`
	)

Re-allocates a specified amount of memory.

The semantics of this method are the same as malloc() and calloc(), but it uses realloc() to keep as much of the existing data as possible.

Referenced by HeapBlock< ObjectClass * >::realloc().

template<class ElementType>

void HeapBlock< ElementType >::free ( )

Frees any currently-allocated data.

This will free the data and reset this object to be a null pointer.

Referenced by HeapBlock< ObjectClass * >::allocate(), HeapBlock< ObjectClass * >::calloc(), HeapBlock< ObjectClass * >::free(), HeapBlock< ObjectClass * >::malloc(), and HeapBlock< ObjectClass * >::~HeapBlock().

template<class ElementType>

void HeapBlock< ElementType >::swapWith ( HeapBlock< ElementType > & other )

Swaps this object's data with the data of another HeapBlock.

The two objects simply exchange their data pointers.

template<class ElementType>

void HeapBlock< ElementType >::clear ( size_t numElements )

This fills the block with zeros, up to the number of elements specified.

Since the block has no way of knowing its own size, you must make sure that the number of elements you specify doesn't exceed the allocated size.

The documentation for this class was generated from the following file:

juce_HeapBlock.h

HeapBlock< ElementType > Class Template Reference

Public Member Functions

Detailed Description

template<class ElementType> class HeapBlock< ElementType >

Constructor & Destructor Documentation

Member Function Documentation

template<class ElementType>
class HeapBlock< ElementType >