rvalloc.c

来自「h.248协议源码」· C语言 代码 · 共 115 行

#if (0)
************************************************************************
Filename:
Description:
************************************************************************
                Copyright (c) 1999 RADVision Inc.
************************************************************************
NOTICE:
This document contains information that is proprietary to RADVision LTD.
No part of this publication may be reproduced in any form whatsoever 
without written prior approval by RADVision LTD..

RADVision LTD. reserves the right to revise this publication and make 
changes without obligation to notify any person of such revisions or 
changes.
************************************************************************
************************************************************************
$Revision:$
$Date:$
$Author: S.Cipolli$ 
************************************************************************
#endif

#include "rvalloc.h"

/*$
{function:
	{name: rvAllocConstruct}	
	{class: RvAlloc}	
	{include: rvalloc.h}
	{description:
		{p: Construct an allocator object.}
	}
	{proto: RvAlloc* rvAllocConstruct(RvAlloc* a, void* pool, size_t maxSize, void* (*alloc)(void*, size_t), void (*dealloc)(void*, size_t, void*));}
	{params:
		{param: {n: a} {d: A pointer to the allocator.}}
		{param: {n: pool} {d: A pointer to a pool.}}
		{param: {n: maxSize} {d: The size of the largest memory block the 
		allocator is capable of allocating.}}
		{param: {n: alloc} {d: A pointer to a function capable of allocating memory
		for the allocator.}}
		{param: {n: dealloc} {d: A pointer to a function capable of deallocating memory
		allocated by the allocator.}}
	}
	{returns: A pointer the allocator or NULL on error.}
	{notes:
		{note: The function specified for the alloc parameter is required to return NULL on 
		error or memory exhaustion.}
	}
}
$*/
RvAlloc* rvAllocConstruct(RvAlloc* a, void* pool, size_t maxSize,
  void* (*alloc)(void*, size_t), 
  void (*dealloc)(void*, size_t, void*)) {
	a->pool = pool;
	a->maxSize = maxSize;
	a->alloc = alloc;
	a->dealloc = dealloc;
	return a;
}

/*$
{function:
	{name: rvAllocAllocate}	
	{class: RvAlloc}	
	{include: rvalloc.h}
	{description:
		{p: Allocate a block of memory of s bytes.}
	}
	{proto: void* rvAllocAllocate(RvAlloc* a, size_t s);}
	{params:
		{param: {n: a} {d: A pointer to the allocator.}}
		{param: {n: s} {d: Number of bytes to allocate.}}
	}
	{returns: 
		A pointer to a suitably sized and aligned 
		block of memory or NULL if memory exhaustion occurs.
	}
}
$*/
void* rvAllocAllocate(RvAlloc* a, size_t s) { 
	if (s > a->maxSize)
		return NULL;
	return a->alloc(a->pool, s); 
}

/*$
{function:
	{name: rvAllocDeallocate}	
	{class: RvAlloc}	
	{include: rvalloc.h}
	{description:
		{p: Deallocate a block of memory pointed to by ptr.  
			The memory must have been previously allocated 
			from the same allocator.
		}
	}
	{proto: void rvAllocDeallocate(RvAlloc* a, size_t s, void* ptr);}
	{params:
		{param: {n: a} {d: A pointer to the allocator.}}
		{param: {n: s} {d: The size of the memory block.}}
		{param: {n: ptr} {d: A pointer to the memory block to deallocate.}}
	}
	{notes:
		{note: 
			Depending on the underlying memory allocator, the size 
			argument (s) my be required or optional.
		}
	}
}
$*/
void rvAllocDeallocate(RvAlloc* a, size_t s, void* ptr) { 
	a->dealloc(a->pool, s, ptr); 
}