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Savestate wraparound.
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Keep save state index from growing forever when using the auto
increment feature, and add a feature to have reserved indexes
which will not be overwritten by the wraparound.

By selecting reserved index 10, and max_keep as 5, slots 10..15
will be used in rotation, and one gap will always be maintained
due to garbage collection. This gap is used for detecting
last state. Example: slots 10,11,13,14,15 have a file -> gap is 12,
and most recent state is in slot 11.
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@zoltanvb
zoltanvb committed Aug 31, 2024
1 parent 73b456e commit e9b29df
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Showing 12 changed files with 291 additions and 102 deletions.
291 changes: 197 additions & 94 deletions command.c
View file
Original file line number Diff line number Diff line change
Expand Up @@ -1419,91 +1419,40 @@ void command_event_load_auto_state(void)
savestate_name_auto, "failed");
}

void command_event_set_savestate_auto_index(settings_t *settings)
/* TODO: refactor also replay slot handling here */
static void scan_states(settings_t *settings,
unsigned *last_index, char *file_to_delete)
{
size_t i;
char state_base[128];
char state_dir[PATH_MAX_LENGTH];

struct string_list *dir_list = NULL;
unsigned max_idx = 0;
runloop_state_t *runloop_st = runloop_state_get_ptr();
bool savestate_auto_index = settings->bools.savestate_auto_index;
bool show_hidden_files = settings->bools.show_hidden_files;

if (!savestate_auto_index)
return;

/* Find the file in the same directory as runloop_st->savestate_name
* with the largest numeral suffix.
*
* E.g. /foo/path/content.state, will try to find
* /foo/path/content.state%d, where %d is the largest number available.
*/
fill_pathname_basedir(state_dir, runloop_st->name.savestate,
sizeof(state_dir));

dir_list = dir_list_new_special(state_dir, DIR_LIST_PLAIN, NULL,
show_hidden_files);

if (!dir_list)
return;

fill_pathname_base(state_base, runloop_st->name.savestate,
sizeof(state_base));

for (i = 0; i < dir_list->size; i++)
{
unsigned idx;
char elem_base[128] = {0};
const char *end = NULL;
const char *dir_elem = dir_list->elems[i].data;

fill_pathname_base(elem_base, dir_elem, sizeof(elem_base));

if (strstr(elem_base, state_base) != elem_base)
continue;

end = dir_elem + strlen(dir_elem);
while ((end > dir_elem) && ISDIGIT((int)end[-1]))
end--;

idx = (unsigned)strtoul(end, NULL, 0);
if (idx > max_idx)
max_idx = idx;
}

dir_list_free(dir_list);

configuration_set_int(settings, settings->ints.state_slot, max_idx);

RARCH_LOG("[State]: %s: #%d\n",
msg_hash_to_str(MSG_FOUND_LAST_STATE_SLOT),
max_idx);
}

void command_event_set_savestate_garbage_collect(
unsigned max_to_keep,
bool show_hidden_files
)
{
size_t i, cnt = 0;
runloop_state_t *runloop_st = runloop_state_get_ptr();
bool show_hidden_files = settings->bools.show_hidden_files;
bool savestate_wraparound = settings->bools.savestate_wraparound;
unsigned savestate_max_keep = settings->uints.savestate_max_keep;
unsigned reserved_indexes = settings->uints.savestate_reserved_indexes;
int curr_state_slot = settings->ints.state_slot;

unsigned max_idx = 0;
unsigned loa_idx = 0;
unsigned min_idx = UINT_MAX;
unsigned gap_idx = UINT_MAX;
unsigned del_idx = UINT_MAX;
retro_bits_512_t slot_mapping_low = {0};
retro_bits_512_t slot_mapping_high = {0};

struct string_list *dir_list = NULL;
const char *savefile_root = NULL;
size_t savefile_root_length = 0;

size_t i, cnt = 0;
char state_dir[PATH_MAX_LENGTH];
/* TODO: Base name of 128 may be too short */
char state_base[128];
runloop_state_t *runloop_st = runloop_state_get_ptr();

struct string_list *dir_list = NULL;
unsigned min_idx = UINT_MAX;
const char *oldest_save = NULL;

/* Similar to command_event_set_savestate_auto_index(),
* this will find the lowest numbered save-state */
fill_pathname_basedir(state_dir, runloop_st->name.savestate,
sizeof(state_dir));

dir_list = dir_list_new_special(state_dir, DIR_LIST_PLAIN, NULL,
show_hidden_files);

if (!dir_list)
return;

Expand All @@ -1513,7 +1462,7 @@ void command_event_set_savestate_garbage_collect(
for (i = 0; i < dir_list->size; i++)
{
unsigned idx;
char elem_base[128];
char elem_base[128] = {0};
const char *ext = NULL;
const char *end = NULL;
const char *dir_elem = dir_list->elems[i].data;
Expand All @@ -1535,39 +1484,196 @@ void command_event_set_savestate_garbage_collect(
if (!string_starts_with(elem_base, state_base))
continue;

/* This looks like a valid save */
cnt++;
/* This looks like a valid savestate */
/* Save filename root and length (once) */
if (savefile_root_length == 0)
{
savefile_root = dir_elem;
savefile_root_length = strlen(dir_elem);
}

/* > Get index */
/* Decode the savestate index */
end = dir_elem + strlen(dir_elem);
while ((end > dir_elem) && ISDIGIT((int)end[-1]))
{
end--;

if (savefile_root == dir_elem)
savefile_root_length--;
}
idx = string_to_unsigned(end);

/* > Check if this is the lowest index so far */
/* Simple administration: max, min, total. */
if (idx > max_idx)
max_idx = idx;
if (idx < min_idx)
min_idx = idx;
cnt++;

/* Maintain a 2x512 bit map of occupied save states */
if (idx<512)
BIT512_SET(slot_mapping_low,idx);
else if (idx<1024)
BIT512_SET(slot_mapping_high,idx-512);
}

/* No wraparound: delete lowest, load highest (already set), gap is irrelevant */
if (!savestate_wraparound)
{
del_idx = min_idx;
loa_idx = max_idx;
}
else
{
/* Next loop on the bitmap, since the file system may have presented the files in any order above */
for(i=reserved_indexes ; i <= reserved_indexes + savestate_max_keep ; i++)
{
min_idx = idx;
oldest_save = dir_elem;
/* Unoccupied save slots */
if ((i < 512 && !BIT512_GET(slot_mapping_low, i)) ||
(i > 511 && !BIT512_GET(slot_mapping_high, i-512)) )
{
/* Gap index: lowest free slot in the wraparound range */
if (gap_idx == UINT_MAX)
gap_idx = i;
}
/* Occupied save slots */
else
{
/* Del index: first occupied slot in the wraparound range,
after gap index */
if (gap_idx < UINT_MAX &&
del_idx == UINT_MAX)
del_idx = i;
}
}
/* Special cases of wraparound */
/* No previous savestate - set to end, so that first save
goes to first allowed index */
if (cnt == 0)
{
loa_idx = reserved_indexes + savestate_max_keep;
gap_idx = reserved_indexes + savestate_max_keep;
del_idx = reserved_indexes + savestate_max_keep;
}
/* No gap found - deduct from current index or default
and set (missing) gap index to be deleted */
else if (gap_idx == UINT_MAX)
{
if ( (unsigned)curr_state_slot >= reserved_indexes &&
(unsigned)curr_state_slot < reserved_indexes + savestate_max_keep)
{
gap_idx = curr_state_slot + 1;
loa_idx = curr_state_slot;
}
else if ( (unsigned)curr_state_slot == reserved_indexes + savestate_max_keep)
{
gap_idx = reserved_indexes;
loa_idx = reserved_indexes + savestate_max_keep;
}
else
{
gap_idx = reserved_indexes;
loa_idx = reserved_indexes + savestate_max_keep;
}
del_idx = gap_idx;
}
/* Gap found */
else
{
/* No candidate to delete */
if (del_idx == UINT_MAX)
{
/* Either gap is at the end of the range: wraparound.
or there is no better idea than the lowest index */
del_idx = reserved_indexes;
}
/* Adjust load index */
if (gap_idx == reserved_indexes)
loa_idx = reserved_indexes + savestate_max_keep;
else
loa_idx = gap_idx - 1;
}
}
RARCH_DBG("[State]: savestate scanning finished, used slots:%d, min-max:%d-%d, "
"load index %d, gap index %d, delete index %d\n",
cnt, min_idx, max_idx, loa_idx, gap_idx, del_idx);

if (last_index != NULL)
{
*last_index = loa_idx;
}
if (file_to_delete != NULL && cnt >= savestate_max_keep)
{
strlcpy(file_to_delete, savefile_root, savefile_root_length+1);
snprintf(file_to_delete+savefile_root_length, 5, "%d", del_idx);
}

dir_list_free(dir_list);
}

/* Logic moved here so that all save state wraparound code is in one file. */
int command_event_get_next_savestate_auto_index(settings_t *settings)
{
unsigned reserved_indexes = settings->uints.savestate_reserved_indexes;
unsigned savestate_max_keep = settings->uints.savestate_max_keep;
bool savestate_wraparound = settings->bools.savestate_wraparound;
int new_state_slot = settings->ints.state_slot + 1;

if (savestate_wraparound)
{
/* If previous save was not in the wraparound range, or it overflows,
return to the start of the range. */
if( (unsigned)new_state_slot > reserved_indexes + savestate_max_keep)
new_state_slot = reserved_indexes;
/* If previous save was in the overwrite prevented range (possible manual save),
find out where to resume */
else if ((unsigned)new_state_slot < reserved_indexes + 1)
{
unsigned max_idx = 0;
scan_states(settings, &max_idx, NULL);
new_state_slot = (int) max_idx;
}
}
/* Note: basic increment (without wraparound) can go on indefinitely */
return new_state_slot;
}

void command_event_set_savestate_auto_index(settings_t *settings)
{
unsigned max_idx = 0;
bool savestate_auto_index = settings->bools.savestate_auto_index;

if (!savestate_auto_index)
return;

scan_states(settings, &max_idx, NULL);
configuration_set_int(settings, settings->ints.state_slot, max_idx);

RARCH_LOG("[State]: %s: #%d\n",
msg_hash_to_str(MSG_FOUND_LAST_STATE_SLOT),
max_idx);
}

static void command_event_set_savestate_garbage_collect(settings_t *settings)
{
char state_to_delete[PATH_MAX_LENGTH] = {0};
size_t i;

scan_states(settings, NULL, state_to_delete);
/* Only delete one save state per save action
* > Conservative behaviour, designed to minimise
* the risk of deleting multiple incorrect files
* in case of accident */
if (!string_is_empty(oldest_save) && (cnt > max_to_keep))
if (!string_is_empty(state_to_delete))
{
filestream_delete(oldest_save);
filestream_delete(state_to_delete);
RARCH_DBG("[State]: garbage collect, deleting \"%s\" \n",state_to_delete);
/* Construct the save state thumbnail name
* and delete that one as well. */
i = strlcpy(state_dir,oldest_save,PATH_MAX_LENGTH);
strlcpy(state_dir + i,".png",STRLEN_CONST(".png")+1);
filestream_delete(state_dir);
i = strlen(state_to_delete);
strlcpy(state_to_delete + i,".png",STRLEN_CONST(".png")+1);
filestream_delete(state_to_delete);
RARCH_DBG("[State]: garbage collect, deleting \"%s\" \n",state_to_delete);
}

dir_list_free(dir_list);
}

void command_event_set_replay_auto_index(settings_t *settings)
Expand Down Expand Up @@ -1998,10 +2104,7 @@ bool command_event_main_state(unsigned cmd)

/* Clean up excess savestates if necessary */
if (savestate_auto_index && (savestate_max_keep > 0))
command_event_set_savestate_garbage_collect(
settings->uints.savestate_max_keep,
settings->bools.show_hidden_files
);
command_event_set_savestate_garbage_collect(settings);

if (frame_time_counter_reset_after_save_state)
video_st->frame_time_count = 0;
Expand Down
6 changes: 2 additions & 4 deletions command.h
View file
Original file line number Diff line number Diff line change
Expand Up @@ -381,10 +381,8 @@ void command_event_load_auto_state(void);
void command_event_set_savestate_auto_index(
settings_t *settings);

void command_event_set_savestate_garbage_collect(
unsigned max_to_keep,
bool show_hidden_files
);
int command_event_get_next_savestate_auto_index(
settings_t *settings);

void command_event_set_replay_auto_index(
settings_t *settings);
Expand Down
11 changes: 11 additions & 0 deletions config.def.h
View file
Original file line number Diff line number Diff line change
Expand Up @@ -1353,6 +1353,10 @@
* to the highest existing value. */
#define DEFAULT_SAVESTATE_AUTO_INDEX false

/* When auto incrementing state index, wrap around after
* saving savestate_max_keep amount of states. */
#define DEFAULT_SAVESTATE_WRAPAROUND false

/* Specifies the maximum number of savestates to keep
* when savestate auto index is enabled
* > When limit is exceeded, savestate with the lowest
Expand All @@ -1362,6 +1366,13 @@
* savestates will be deleted in this case) */
#define DEFAULT_SAVESTATE_MAX_KEEP 0

/* Specifies the maximum number of savestates to exclude
* when savestate auto increment and wraparound is on.
* This enables user to have this many "manual"
* save states that the auto increment will not
* overwrite. */
#define DEFAULT_SAVESTATE_RESERVED_INDEXES 0

/* When recording replays, replay index is automatically
* incremented before recording starts.
* When the content is loaded, replay index will be set
Expand Down
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