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b29cbb6045
beetle-lynx-libretro/mednafen/state.cpp
twinaphex b29cbb6045 Cleanups
2021-09-18 16:54:13 +02:00

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/* Mednafen - Multi-system Emulator
*
* 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
*/
#include <string.h>
#include <boolean.h>
#ifdef _MSC_VER
#include <compat/msvc.h>
#endif
#include "mednafen.h"
#include "mednafen-endian.h"
#include "general.h"
#include "state.h"
#define RLSB MDFNSTATE_RLSB //0x80000000
static int32_t smem_read(StateMem *st, void *buffer, uint32_t len)
{
if ((len + st->loc) > st->len)
return 0;
memcpy(buffer, st->data + st->loc, len);
st->loc += len;
return(len);
}
static int32_t smem_write(StateMem *st, void *buffer, uint32_t len)
{
if ((len + st->loc) > st->malloced)
{
uint32_t newsize = (st->malloced >= 32768) ? st->malloced : (st->initial_malloc ? st->initial_malloc : 32768);
while(newsize < (len + st->loc))
newsize *= 2;
st->data = (uint8_t *)realloc(st->data, newsize);
st->malloced = newsize;
}
memcpy(st->data + st->loc, buffer, len);
st->loc += len;
if (st->loc > st->len)
st->len = st->loc;
return(len);
}
static int32_t smem_seek(StateMem *st, uint32_t offset, int whence)
{
switch(whence)
{
case SEEK_SET: st->loc = offset; break;
case SEEK_END: st->loc = st->len - offset; break;
case SEEK_CUR: st->loc += offset; break;
}
if(st->loc > st->len)
{
st->loc = st->len;
return(-1);
}
return(0);
}
static int smem_write32le(StateMem *st, uint32_t b)
{
uint8_t s[4];
s[0]=b;
s[1]=b>>8;
s[2]=b>>16;
s[3]=b>>24;
return((smem_write(st, s, 4)<4)?0:4);
}
static int smem_read32le(StateMem *st, uint32_t *b)
{
uint8_t s[4];
if(smem_read(st, s, 4) < 4)
return(0);
*b = s[0] | (s[1] << 8) | (s[2] << 16) | (s[3] << 24);
return(4);
}
static bool SubWrite(StateMem *st, SFORMAT *sf, const char *name_prefix = NULL)
{
while(sf->size || sf->name) // Size can sometimes be zero, so also check for the text name. These two should both be zero only at the end of a struct.
{
if(!sf->size || !sf->v)
{
sf++;
continue;
}
if(sf->size == (uint32_t)~0) /* Link to another struct. */
{
if(!SubWrite(st, (SFORMAT *)sf->v, name_prefix))
return(0);
sf++;
continue;
}
int32_t bytesize = sf->size;
char nameo[1 + 256];
int slen = snprintf(nameo + 1, 256, "%s%s", name_prefix ? name_prefix : "", sf->name);
nameo[0] = slen;
smem_write(st, nameo, 1 + nameo[0]);
smem_write32le(st, bytesize);
#ifdef MSB_FIRST
/* Flip the byte order... */
if(sf->flags & MDFNSTATE_BOOL)
{
}
else if(sf->flags & MDFNSTATE_RLSB64)
Endian_A64_Swap(sf->v, bytesize / sizeof(uint64_t));
else if(sf->flags & MDFNSTATE_RLSB32)
Endian_A32_Swap(sf->v, bytesize / sizeof(uint32_t));
else if(sf->flags & MDFNSTATE_RLSB16)
Endian_A16_Swap(sf->v, bytesize / sizeof(uint16_t));
else if(sf->flags & RLSB)
FlipByteOrder((uint8_t*)sf->v, bytesize);
#endif
// Special case for the evil bool type, to convert bool to 1-byte elements.
// Don't do it if we're only saving the raw data.
if(sf->flags & MDFNSTATE_BOOL)
{
for(int32_t bool_monster = 0; bool_monster < bytesize; bool_monster++)
{
uint8_t tmp_bool = ((bool *)sf->v)[bool_monster];
smem_write(st, &tmp_bool, 1);
}
}
else
smem_write(st, (uint8_t *)sf->v, bytesize);
#ifdef MSB_FIRST
/* Now restore the original byte order. */
if(sf->flags & MDFNSTATE_BOOL)
{
}
else if(sf->flags & MDFNSTATE_RLSB64)
Endian_A64_LE_to_NE(sf->v, bytesize / sizeof(uint64_t));
else if(sf->flags & MDFNSTATE_RLSB32)
Endian_A32_LE_to_NE(sf->v, bytesize / sizeof(uint32_t));
else if(sf->flags & MDFNSTATE_RLSB16)
Endian_A16_LE_to_NE(sf->v, bytesize / sizeof(uint16_t));
else if(sf->flags & RLSB)
FlipByteOrder((uint8_t*)sf->v, bytesize);
#endif
sf++;
}
return true;
}
static int WriteStateChunk(StateMem *st, const char *sname, SFORMAT *sf)
{
int32_t data_start_pos;
int32_t end_pos;
uint8_t sname_tmp[32];
size_t sname_len = strlen(sname);
memset(sname_tmp, 0, sizeof(sname_tmp));
memcpy((char *)sname_tmp, sname, (sname_len < 32) ? sname_len : 32);
smem_write(st, sname_tmp, 32);
smem_write32le(st, 0); // We'll come back and write this later.
data_start_pos = st->loc;
if(!SubWrite(st, sf))
return(0);
end_pos = st->loc;
smem_seek(st, data_start_pos - 4, SEEK_SET);
smem_write32le(st, end_pos - data_start_pos);
smem_seek(st, end_pos, SEEK_SET);
return(end_pos - data_start_pos);
}
static SFORMAT *FindSF(const char *name, SFORMAT *sf)
{
/* Size can sometimes be zero, so also check for the text name. These two should both be zero only at the end of a struct. */
while(sf->size || sf->name)
{
if(!sf->size || !sf->v)
{
sf++;
continue;
}
if (sf->size == (uint32)~0) /* Link to another SFORMAT structure. */
{
SFORMAT *temp_sf = FindSF(name, (SFORMAT*)sf->v);
if (temp_sf)
return temp_sf;
}
else
{
assert(sf->name);
if (!strcmp(sf->name, name))
return sf;
}
sf++;
}
return NULL;
}
static int ReadStateChunk(StateMem *st, SFORMAT *sf, int size)
{
int temp = st->loc;
while (st->loc < (temp + size))
{
uint32_t recorded_size; // In bytes
uint8_t toa[1 + 256]; // Don't change to char unless cast toa[0] to unsigned to smem_read() and other places.
if(smem_read(st, toa, 1) != 1)
return(0);
if(smem_read(st, toa + 1, toa[0]) != toa[0])
return 0;
toa[1 + toa[0]] = 0;
smem_read32le(st, &recorded_size);
SFORMAT *tmp = FindSF((char*)toa + 1, sf);
if(tmp)
{
uint32_t expected_size = tmp->size; // In bytes
if(recorded_size != expected_size)
{
if(smem_seek(st, recorded_size, SEEK_CUR) < 0)
return(0);
}
else
{
smem_read(st, (uint8_t *)tmp->v, expected_size);
if(tmp->flags & MDFNSTATE_BOOL)
{
// Converting downwards is necessary for the case of sizeof(bool) > 1
for(int32_t bool_monster = expected_size - 1; bool_monster >= 0; bool_monster--)
{
((bool *)tmp->v)[bool_monster] = ((uint8_t *)tmp->v)[bool_monster];
}
}
#ifdef MSB_FIRST
if(tmp->flags & MDFNSTATE_RLSB64)
Endian_A64_LE_to_NE(tmp->v, expected_size / sizeof(uint64_t));
else if(tmp->flags & MDFNSTATE_RLSB32)
Endian_A32_LE_to_NE(tmp->v, expected_size / sizeof(uint32_t));
else if(tmp->flags & MDFNSTATE_RLSB16)
Endian_A16_LE_to_NE(tmp->v, expected_size / sizeof(uint16_t));
else if(tmp->flags & RLSB)
FlipByteOrder((uint8_t*)tmp->v, expected_size);
#endif
}
}
else
{
if(smem_seek(st, recorded_size, SEEK_CUR) < 0)
return(0);
}
} // while(...)
assert(st->loc == (temp + size));
return 1;
}
/* This function is called by the game driver(NES, GB, GBA) to save a state. */
static int MDFNSS_StateAction_internal(void *st_p, int load, int data_only, SSDescriptor *section)
{
StateMem *st = (StateMem*)st_p;
if(load)
{
char sname[32];
int found = 0;
uint32_t tmp_size;
uint32_t total = 0;
while(smem_read(st, (uint8_t *)sname, 32) == 32)
{
if(smem_read32le(st, &tmp_size) != 4)
return(0);
total += tmp_size + 32 + 4;
// Yay, we found the section
if(!strncmp(sname, section->name, 32))
{
if(!ReadStateChunk(st, section->sf, tmp_size))
return(0);
found = 1;
break;
}
else
{
if(smem_seek(st, tmp_size, SEEK_CUR) < 0)
return(0);
}
}
if(smem_seek(st, -total, SEEK_CUR) < 0)
return(0);
if(!found && !section->optional) // Not found. We are sad!
return(0);
}
else
{
if(!WriteStateChunk(st, section->name, section->sf))
return(0);
}
return(1);
}
int MDFNSS_StateAction(void *st_p, int load, int data_only, SFORMAT *sf, const char *name, bool optional)
{
SSDescriptor love;
StateMem *st = (StateMem*)st_p;
love.sf = sf;
love.name = name;
love.optional = optional;
return(MDFNSS_StateAction_internal(st, load, 0, &love));
}
int MDFNSS_SaveSM(void *st_p, int, int, const void*, const void*, const void*)
{
uint8_t header[32];
StateMem *st = (StateMem*)st_p;
static const char *header_magic = "MDFNSVST";
int neowidth = 0, neoheight = 0;
memset(header, 0, sizeof(header));
memcpy(header, header_magic, 8);
MDFN_en32lsb(header + 16, MEDNAFEN_VERSION_NUMERIC);
MDFN_en32lsb(header + 24, neowidth);
MDFN_en32lsb(header + 28, neoheight);
smem_write(st, header, 32);
if(!StateAction(st, 0, 0))
return(0);
uint32_t sizy = st->loc;
smem_seek(st, 16 + 4, SEEK_SET);
smem_write32le(st, sizy);
return(1);
}
int MDFNSS_LoadSM(void *st_p, int, int)
{
uint8_t header[32];
uint32_t stateversion;
StateMem *st = (StateMem*)st_p;
smem_read(st, header, 32);
if(memcmp(header, "MEDNAFENSVESTATE", 16) && memcmp(header, "MDFNSVST", 8))
return(0);
stateversion = MDFN_de32lsb(header + 16);
return StateAction(st, stateversion, 0);
}
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