zone.h

/*
Copyright (C) 1996-1997 Id Software, Inc.

This program is free software; you can redistribute it and/or
modify it under the terms of the GNU General Public License
as published by the Free Software Foundation; either version 2
of the License, or (at your option) any later version.

This program is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.

See the GNU General Public License for more details.

You should have received a copy of the GNU General Public License
along with this program; if not, write to the Free Software
Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA  02111-1307, USA.

*/
/*
 memory allocation


H_??? The hunk manages the entire memory block given to quake.  It must be
contiguous.  Memory can be allocated from either the low or high end in a
stack fashion.  The only way memory is released is by resetting one of the
pointers.

Hunk allocations should be given a name, so the Hunk_Print () function
can display usage.

Hunk allocations are guaranteed to be 16 byte aligned.

The video buffers are allocated high to avoid leaving a hole underneath
server allocations when changing to a higher video mode.


Z_??? Zone memory functions used for small, dynamic allocations like text
strings from command input.  There is only about 48K for it, allocated at
the very bottom of the hunk.

Cache_??? Cache memory is for objects that can be dynamically loaded and
can usefully stay persistant between levels.  The size of the cache
fluctuates from level to level.

To allocate a cachable object


Temp_??? Temp memory is used for file loading and surface caching.  The size
of the cache memory is adjusted so that there is a minimum of 512k remaining
for temp memory.


------ Top of Memory -------

high hunk allocations

<--- high hunk reset point held by vid

video buffer

z buffer

surface cache

<--- high hunk used

cachable memory

<--- low hunk used

client and server low hunk allocations

<-- low hunk reset point held by host

startup hunk allocations

Zone block

----- Bottom of Memory -----



*/

void Memory_Init (void *buf, int size);

void Z_Free (void *ptr);
void *Z_Malloc (int size);			// returns 0 filled memory
void *Z_TagMalloc (int size, int tag);

void Z_DumpHeap (void);
void Z_CheckHeap (void);
int Z_FreeMemory (void);

void *Hunk_Alloc (int size);		// returns 0 filled memory
void *Hunk_AllocName (int size, char *name);

void *Hunk_HighAllocName (int size, char *name);

int	Hunk_LowMark (void);
void Hunk_FreeToLowMark (int mark);

int	Hunk_HighMark (void);
void Hunk_FreeToHighMark (int mark);

void *Hunk_TempAlloc (int size);

void Hunk_Check (void);

typedef struct cache_user_s
{
	void	*data;
} cache_user_t;

void Cache_Flush (void);

void *Cache_Check (cache_user_t *c);
// returns the cached data, and moves to the head of the LRU list
// if present, otherwise returns NULL

void Cache_Free (cache_user_t *c);

void *Cache_Alloc (cache_user_t *c, int size, char *name);
// Returns NULL if all purgable data was tossed and there still
// wasn't enough room.

void Cache_Report (void);