/************************************************************
Copyright 1987 by Digital Equipment Corporation, Maynard, Massachusetts,
and the Massachusetts Institute of Technology, Cambridge, Massachusetts.

                        All Rights Reserved

DIGITAL DISCLAIMS ALL WARRANTIES WITH REGARD TO THIS SOFTWARE, INCLUDING
ALL IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS, IN NO EVENT SHALL
DIGITAL BE LIABLE FOR ANY SPECIAL, INDIRECT OR CONSEQUENTIAL DAMAGES OR
ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS,
WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION,
ARISING OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS
SOFTWARE.

********************************************************/
/*
 * Copyright 1993 by Digital Equipment Corporation, Maynard, Massachusetts.
 * 
 * Permission to use, copy, modify, distribute, and sell this software and its 
 * documentation for any purpose is hereby granted without fee, provided that 
 * the above copyright notice appear in all copies and that both that 
 * copyright notice and this permission notice appear in supporting 
 * documentation, and that the name of Digital not be used in advertising or 
 * publicity pertaining to distribution of the software without specific, 
 * written prior permission.  Digital makes no representations about the 
 * suitability of this software for any purpose.  It is provided "as is" 
 * without express or implied warranty.
 * 
 * DIGITAL DISCLAIMS ALL WARRANTIES WITH REGARD TO THIS SOFTWARE, INCLUDING 
 * ALL IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS, IN NO EVENT SHALL 
 * DIGITAL BE LIABLE FOR ANY SPECIAL, INDIRECT OR CONSEQUENTIAL DAMAGES OR ANY 
 * DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN 
 * AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF 
 * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
 */

/*	Routines to manage various kinds of resources:
 *
 *	CreateNewResourceType, CreateNewResourceClass, InitClientResources,
 *	FakeClientID, AddResource, FreeResource, FreeClientResources,
 *	FreeAllResources, LookupIDByType, LookupIDByClass
 */

/* 
 *      a resource is a 32 bit quantity.  the upper 12 bits are client id.  
 *      client provides a 19 bit resource id. this is "hashed" by me by
 *      taking the 10 lower bits and xor'ing with the mid 10 bits.
 *
 *      It is sometimes necessary for the server to create an ID that looks
 *      like it belongs to a client.  This ID, however,  must not be one
 *      the client actually can create, or we have the potential for conflict.
 *      The 20th bit of the ID is resevered for the server's use for this
 *      purpose.  By setting CLIENT_ID(id) to the client, the SERVER_BIT to
 *      1, and an otherwise unused ID in the low 19 bits, we can create a
 *      resource "owned" by the client.
 *      
 *      The following IDs are currently reserved for siccing on the client:
 *      1 - allocated color to be freed when the client dies
 */

#include "audio.h"
#include "misc.h"
#include "os.h"
#include "resource.h"
#include "diastruct.h" 
#include "opaque.h"
#include "acstruct.h"
#include "acfuncs.h"				/* to get FreeAC */

extern void FlushClientCaches();
static void RebuildTable();

#define INITBUCKETS 64
#define INITHASHSIZE 6
#define MAXHASHSIZE 11

typedef struct _Resource {
    struct _Resource	*next;
    AID			id;
    RESTYPE		type;
    pointer		value;
} ResourceRec, *ResourcePtr;
#define NullResource ((ResourcePtr)NULL)

typedef struct _ClientResource {
    ResourcePtr *resources;
    int		elements;
    int		buckets;
    int		hashsize;	/* log(2)(buckets) */
    AID		fakeID;
    AID		expectID;
} ClientResourceRec;

static RESTYPE lastResourceType;
static RESTYPE lastResourceClass;
static RESTYPE TypeMask;

typedef int (*DeleteType)();

static DeleteType *DeleteFuncs = (DeleteType *)NULL;

RESTYPE
CreateNewResourceType(deleteFunc)
    DeleteType deleteFunc;
{
    RESTYPE next = lastResourceType + 1;
    DeleteType *funcs;

    if (next & lastResourceClass)
	return 0;
    funcs = (DeleteType *)xrealloc(DeleteFuncs,
				   (next + 1) * sizeof(DeleteType));
    if (!funcs)
	return 0;
    lastResourceType = next;
    DeleteFuncs = funcs;
    DeleteFuncs[next] = deleteFunc;
    return next;
}

RESTYPE
CreateNewResourceClass()
{
    RESTYPE next = lastResourceClass >> 1;

    if (next & lastResourceType)
	return 0;
    lastResourceClass = next;
    TypeMask = next - 1;
    return next;
}

ClientResourceRec clientTable[MAXCLIENTS];

/*****************
 * InitClientResources
 *    When a new client is created, call this to allocate space
 *    in resource table
 *****************/

ABool
InitClientResources(client)
    ClientPtr client;
{
    register int i, j;
 
    if (client == serverClient)
    {

	lastResourceType = RT_LASTPREDEF;
	lastResourceClass = RC_LASTPREDEF;
	TypeMask = RC_LASTPREDEF - 1;
	if (DeleteFuncs)
	    xfree(DeleteFuncs);
	DeleteFuncs = (DeleteType *)xalloc((lastResourceType + 1) *
					   sizeof(DeleteType));
	if (!DeleteFuncs)
	    return FALSE;
	DeleteFuncs[RT_AC & TypeMask] = (IntProc) FreeAC;
    }
    clientTable[i = client->index].resources =
	(ResourcePtr *)xalloc(INITBUCKETS*sizeof(ResourcePtr));
    if (!clientTable[i].resources)
	return FALSE;
    clientTable[i].buckets = INITBUCKETS;
    clientTable[i].elements = 0;
    clientTable[i].hashsize = INITHASHSIZE;
    clientTable[i].fakeID = 100;
    clientTable[i].expectID = client->clientAsMask;
    for (j=0; j<INITBUCKETS; j++) 
    {
        clientTable[i].resources[j] = NullResource;
    }
    return TRUE;
}

static int
Hash(client, id)
    int client;
    register AID id;
{
    id &= RESOURCE_ID_MASK;
    switch (clientTable[client].hashsize)
    {
	case 6:
	    return ((int)(0x03F & (id ^ (id>>6) ^ (id>>12))));
	case 7:
	    return ((int)(0x07F & (id ^ (id>>7) ^ (id>>13))));
	case 8:
	    return ((int)(0x0FF & (id ^ (id>>8) ^ (id>>16))));
	case 9:
	    return ((int)(0x1FF & (id ^ (id>>9))));
	case 10:
	    return ((int)(0x3FF & (id ^ (id>>10))));
	case 11:
	    return ((int)(0x7FF & (id ^ (id>>11))));
    }
    return -1;
}

AID
FakeClientID(client)
    int client;
{
	return (
	    (client<<CLIENTOFFSET) + (SERVER_BIT) +
	    ((clientTable[client].fakeID++) & RESOURCE_ID_MASK));
}

ABool
AddResource(id, type, value)
    AID id;
    RESTYPE type;
    pointer value;
{
    int client;
    register ClientResourceRec *rrec;
    register ResourcePtr res, *head;
    	
    client = CLIENT_ID(id);
    rrec = &clientTable[client];
    if (!rrec->buckets)
    {
	ErrorF("AddResource(%x, %x, %x), client=%d \n",
		id, type, value, client);
        FatalError("client not in use\n");
    }
    if ((rrec->elements >= 4*rrec->buckets) &&
	(rrec->hashsize < MAXHASHSIZE))
	RebuildTable(client);
    head = &rrec->resources[Hash(client, id)];
    res = (ResourcePtr)xalloc(sizeof(ResourceRec));
    if (!res)
    {
	(*DeleteFuncs[type & TypeMask])(value, id);
	return FALSE;
    }
    res->next = *head;
    res->id = id;
    res->type = type;
    res->value = value;
    *head = res;
    rrec->elements++;
    if (!(id & SERVER_BIT) && (id >= rrec->expectID))
	rrec->expectID = id + 1;
    return TRUE;
}

static void
RebuildTable(client)
    int client;
{
    register int j;
    register ResourcePtr res, next;
    ResourcePtr **tails, *resources;
    register ResourcePtr **tptr, *rptr;

    /*
     * For now, preserve insertion order, since some dda layers depend
     * on resources being free in the opposite order they are added.
     */

    j = 2 * clientTable[client].buckets;
    tails = (ResourcePtr **)ALLOCATE_LOCAL(j * sizeof(ResourcePtr *));
    if (!tails)
	return;
    resources = (ResourcePtr *)xalloc(j * sizeof(ResourcePtr));
    if (!resources)
    {
	DEALLOCATE_LOCAL(tails);
	return;
    }
    for (rptr = resources, tptr = tails; --j >= 0; rptr++, tptr++)
    {
	*rptr = NullResource;
	*tptr = rptr;
    }
    clientTable[client].hashsize++;
    for (j = clientTable[client].buckets,
	 rptr = clientTable[client].resources;
	 --j >= 0;
	 rptr++)
    {
	for (res = *rptr; res; res = next)
	{
	    next = res->next;
	    res->next = NullResource;
	    tptr = &tails[Hash(client, res->id)];
	    **tptr = res;
	    *tptr = &res->next;
	}
    }
    DEALLOCATE_LOCAL(tails);
    clientTable[client].buckets *= 2;
    xfree(clientTable[client].resources);
    clientTable[client].resources = resources;
}

void
FreeResource(id, skipDeleteFuncType)
    AID id;
    RESTYPE skipDeleteFuncType;
{
    int		cid;
    register    ResourcePtr res;
    register	ResourcePtr *prev, *head;
    register	int *eltptr;
    int		elements;
    ABool	gotOne = FALSE;

    if (((cid = CLIENT_ID(id)) < MAXCLIENTS) && clientTable[cid].buckets)
    {
	head = &clientTable[cid].resources[Hash(cid, id)];
	eltptr = &clientTable[cid].elements;

	prev = head;
	while ( (res = *prev) != NULL)
	{
	    if (res->id == id)
	    {
		RESTYPE rtype = res->type;
		*prev = res->next;
		elements = --*eltptr;
		if (rtype & RC_CACHED)
		    FlushClientCaches(res->id);
		if (rtype != skipDeleteFuncType)
		    (*DeleteFuncs[rtype & TypeMask])(res->value, res->id);
		xfree(res);
		if (*eltptr != elements)
		    prev = head; /* prev may no longer be valid */
		gotOne = TRUE;
	    }
	    else
		prev = &res->next;
        }
    }
    if (!gotOne)
	FatalError("Freeing resource id=%X which isn't there", id);
}
void
FreeResourceByType(id, type, skipFree)
    AID id;
    RESTYPE type;
    ABool    skipFree;
{
    int		cid;
    register    ResourcePtr res;
    register	ResourcePtr *prev, *head;

    if (((cid = CLIENT_ID(id)) < MAXCLIENTS) && clientTable[cid].buckets)
    {
	head = &clientTable[cid].resources[Hash(cid, id)];

	prev = head;
	while ( (res = *prev) != NULL)
	{
	    if (res->id == id && res->type == type)
	    {
		*prev = res->next;
		if (type & RC_CACHED)
		    FlushClientCaches(res->id);
		if (!skipFree)
		    (*DeleteFuncs[type & TypeMask])(res->value, res->id);
		xfree(res);
		break;
	    }
	    else
		prev = &res->next;
        }
    }
}

/*
 * Change the value associated with a resource id.  Caller
 * is responsible for "doing the right thing" with the old
 * data
 */

ABool
ChangeResourceValue (id, rtype, value)
    AID	id;
    RESTYPE rtype;
    pointer value;
{
    int    cid;
    register    ResourcePtr res;

    if (((cid = CLIENT_ID(id)) < MAXCLIENTS) && clientTable[cid].buckets)
    {
	res = clientTable[cid].resources[Hash(cid, id)];

	for (; res; res = res->next)
	    if ((res->id == id) && (res->type == rtype))
	    {
		if (rtype & RC_CACHED)
		    FlushClientCaches(res->id);
		res->value = value;
		return TRUE;
	    }
    }
    return FALSE;
}

void
FreeClientResources(client)
    ClientPtr client;
{
    register ResourcePtr *resources;
    register ResourcePtr this;
    int j;

    /* This routine shouldn't be called with a null client, but just in
	case ... */

    if (!client)
	return;

    resources = clientTable[client->index].resources;
    for (j=0; j < clientTable[client->index].buckets; j++) 
    {
        /* It may seem silly to update the head of this resource list as
	we delete the members, since the entire list will be deleted any way, 
	but there are some resource deletion functions "FreeClientPixels" for 
	one which do a LookupID on another resource id (a Colormap id in this
	case), so the resource list must be kept valid up to the point that
	it is deleted, so every time we delete a resource, we must update the
	head, just like in FreeResource. I hope that this doesn't slow down
	mass deletion appreciably. PRH */

	ResourcePtr *head;

	head = &resources[j];

        for (this = *head; this; this = *head)
	{
	    RESTYPE rtype = this->type;
	    *head = this->next;
	    if (rtype & RC_CACHED)
		FlushClientCaches(this->id);
	    (*DeleteFuncs[rtype & TypeMask])(this->value, this->id);
	    xfree(this);	    
	}
    }
    xfree(clientTable[client->index].resources);
    clientTable[client->index].buckets = 0;
}

FreeAllResources()
{
    int	i;

    for (i=0; i<currentMaxClients; i++) 
    {
        if (clientTable[i].buckets) 
	    FreeClientResources(clients[i]);
    }
}

ABool
LegalNewID(id, client)
    AID id;
    register ClientPtr client;
{
    return ((client->clientAsMask == CLIENT_BITS(id)) && !(id & SERVER_BIT) &&
	    ((clientTable[client->index].expectID <= id) ||
	     !LookupIDByClass(id, RC_ANY)));
}

/*
 *  LookupIDByType returns the object with the given id and type, else NULL.
 */ 
pointer
LookupIDByType(id, rtype)
    AID id;
    RESTYPE rtype;
{
    int    cid;
    register    ResourcePtr res;

    if (((cid = CLIENT_ID(id)) < MAXCLIENTS) && clientTable[cid].buckets)
    {
	res = clientTable[cid].resources[Hash(cid, id)];

	for (; res; res = res->next)
	    if ((res->id == id) && (res->type == rtype))
		return res->value;
    }
    return (pointer)NULL;
}

/*
 *  LookupIDByClass returns the object with the given id and any one of the
 *  given classes, else NULL.
 */ 
pointer
LookupIDByClass(id, classes)
    AID id;
    RESTYPE classes;
{
    int    cid;
    register    ResourcePtr res;

    if (((cid = CLIENT_ID(id)) < MAXCLIENTS) && clientTable[cid].buckets)
    {
	res = clientTable[cid].resources[Hash(cid, id)];

	for (; res; res = res->next)
	    if ((res->id == id) && (res->type & classes))
		return res->value;
    }
    return (pointer)NULL;
}
