CTCaer/RetroArch
1
0
Fork 0
mirror of https://github.com/CTCaer/RetroArch.git synced 2024-12-14 06:18:34 +00:00
Code Issues Actions Packages Projects Releases Wiki Activity

Cleanup and optimize rewind a bit. Forced POT buffer size.

Browse Source
This commit is contained in:
Themaister 2011-11-01 21:00:41 +01:00
parent f3e487557e
commit 0c3f6ed66b
4 changed files with 49 additions and 21 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

2
general.h
View File

@ -142,7 +142,7 @@ struct settings
char screenshot_directory[MAXPATHLEN];
bool rewind_enable;
unsigned rewind_buffer_size;
size_t rewind_buffer_size;
unsigned rewind_granularity;
bool pause_nonactive;

64
rewind.c
View File

@ -21,11 +21,14 @@
#include <stdbool.h>
#include <string.h>
#include <assert.h>
#include <limits.h>
#include "general.h"
struct state_manager
{
uint64_t *buffer;
size_t buf_size;
size_t buf_size_mask;
uint32_t *tmp_state;
size_t top_ptr;
size_t bottom_ptr;
@ -33,19 +36,48 @@ struct state_manager
bool first_pop;
};
static inline size_t nearest_pow2_size(size_t v)
{
size_t orig = v;
v--;
v |= v >> 1;
v |= v >> 2;
v |= v >> 4;
if (sizeof(v) * CHAR_BIT >= 16)
v |= v >> 8;
if (sizeof(v) * CHAR_BIT >= 32)
v |= v >> 16;
if (sizeof(v) * CHAR_BIT >= 64)
v |= v >> 32;
v++;
size_t next = v;
size_t prev = v >> 1;
if ((next - orig) < (orig - prev))
return next;
else
return prev;
}
state_manager_t *state_manager_new(size_t state_size, size_t buffer_size, void *init_buffer)
{
if (buffer_size <= state_size * 2 + 1) // Need a sufficient buffer size.
if (buffer_size <= state_size * 4) // Need a sufficient buffer size.
return NULL;
state_manager_t *state = calloc(1, sizeof(*state));
if (!state)
return NULL;
assert(state_size % 4 == 0); // We need 4-byte aligned state_size to avoid having to enforce this with unneeded memcpy's!
// We need 4-byte aligned state_size to avoid having to enforce this with unneeded memcpy's!
assert(state_size % 4 == 0);
state->top_ptr = 1;
state->state_size = (state_size + 3) >> 2; // Multiple of 4.
state->buf_size = (buffer_size + 7) >> 3; // Multiple of 8.
state->state_size = state_size / sizeof(uint32_t); // Works in multiple of 4.
state->buf_size = nearest_pow2_size(buffer_size) / sizeof(uint64_t); // Works in multiple of 8.
state->buf_size_mask = state->buf_size - 1;
SSNES_LOG("Readjusted rewind buffer size to %u MiB\n", (unsigned)(sizeof(uint64_t) * (state->buf_size >> 20)));
if (!(state->buffer = calloc(1, state->buf_size * sizeof(uint64_t))))
goto error;
if (!(state->tmp_state = calloc(1, state->state_size * sizeof(uint32_t))))
@ -81,14 +113,11 @@ bool state_manager_pop(state_manager_t *state, void **data)
return true;
}
if (state->top_ptr == 0)
state->top_ptr = state->buf_size - 1;
else
state->top_ptr--;
state->top_ptr = (state->top_ptr - 1) & state->buf_size_mask;
if (state->top_ptr == state->bottom_ptr) // Our stack is completely empty... :v
{
state->top_ptr = (state->top_ptr + 1) % state->buf_size;
state->top_ptr = (state->top_ptr + 1) & state->buf_size_mask;
return false;
}
@ -99,15 +128,12 @@ bool state_manager_pop(state_manager_t *state, void **data)
uint32_t xor = state->buffer[state->top_ptr] & 0xFFFFFFFFU;
state->tmp_state[addr] ^= xor;
if (state->top_ptr == 0)
state->top_ptr = state->buf_size - 1;
else
state->top_ptr--;
state->top_ptr = (state->top_ptr - 1) & state->buf_size_mask;
}
if (state->top_ptr == state->bottom_ptr) // Our stack is completely empty... :v
{
state->top_ptr = (state->top_ptr + 1) % state->buf_size;
state->top_ptr = (state->top_ptr + 1) & state->buf_size_mask;
return true;
}
@ -116,9 +142,9 @@ bool state_manager_pop(state_manager_t *state, void **data)
static void reassign_bottom(state_manager_t *state)
{
state->bottom_ptr = (state->top_ptr + 1) % state->buf_size;
state->bottom_ptr = (state->top_ptr + 1) & state->buf_size_mask;
while (state->buffer[state->bottom_ptr]) // Skip ahead until we find the first 0 (boundary for state delta).
state->bottom_ptr = (state->bottom_ptr + 1) % state->buf_size;
state->bottom_ptr = (state->bottom_ptr + 1) & state->buf_size_mask;
}
static void generate_delta(state_manager_t *state, const void *data)
@ -128,7 +154,9 @@ static void generate_delta(state_manager_t *state, const void *data)
const uint32_t *new_state = data;
state->buffer[state->top_ptr++] = 0; // For each separate delta, we have a 0 value sentinel in between.
if (state->top_ptr == state->bottom_ptr) // Check if top_ptr and bottom_ptr crossed each other, which means we need to delete old cruft.
// Check if top_ptr and bottom_ptr crossed each other, which means we need to delete old cruft.
if (state->top_ptr == state->bottom_ptr)
crossed = true;
for (uint64_t i = 0; i < state->state_size; i++)
@ -142,7 +170,7 @@ static void generate_delta(state_manager_t *state, const void *data)
if (xor)
{
state->buffer[state->top_ptr] = (i << 32) | xor;
state->top_ptr = (state->top_ptr + 1) % state->buf_size;
state->top_ptr = (state->top_ptr + 1) & state->buf_size_mask;
if (state->top_ptr == state->bottom_ptr)
crossed = true;

2
settings.c
View File

@ -400,7 +400,7 @@ static void parse_config_file(void)
CONFIG_GET_BOOL(rewind_enable, "rewind_enable");
if (config_get_int(conf, "rewind_buffer_size", &tmp_int))
g_settings.rewind_buffer_size = tmp_int * 1000000;
g_settings.rewind_buffer_size = tmp_int * 1000000LLU;
CONFIG_GET_INT(rewind_granularity, "rewind_granularity");

2
ssnes.c
View File

@ -1039,7 +1039,7 @@ static void init_rewind(void)
size_t serial_size = psnes_serialize_size();
g_extern.state_buf = calloc(1, (serial_size + 3) & ~3); // Make sure we allocate at least 4-byte multiple.
psnes_serialize(g_extern.state_buf, serial_size);
SSNES_LOG("Initing rewind buffer with size: %u MB\n", (unsigned)g_settings.rewind_buffer_size / 1000000);
SSNES_LOG("Initing rewind buffer with size: %u MB\n", (unsigned)(g_settings.rewind_buffer_size / 1000000));
g_extern.state_manager = state_manager_new((serial_size + 3) & ~3, g_settings.rewind_buffer_size, g_extern.state_buf);
if (!g_extern.state_manager)
SSNES_WARN("Failed to init rewind buffer. Rewinding will be disabled!\n");