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iostream: Create properties on-demand instead of upfront.

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It's possible that IOStreams might get created and thrown away a lot, perhaps
at any point in an app's lifetime, so it makes sense to avoid doing the work
of maintaining a properties group for each, if the app hasn't requested it,
since this requires a bunch of allocations and locks.

It's not necessarily worth doing this for other SDL objects, like SDL_Window,
since there are likely to only be a few of them, and likely created at startup
and living for the entire lifespan of the app.

Fixes #14436.
This commit is contained in:
Ryan C. Gordon
2026-07-12 12:01:09 -04:00
committed by Sam Lantinga
parent daf519ae05
commit c9ebec4687
1 changed files with 73 additions and 36 deletions
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109
src/io/SDL_iostream.c
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@@ -41,14 +41,21 @@
#include "SDL_iostream_c.h"
/* This file provides a general interface for SDL to read and write
data sources. It can easily be extended to files, memory, etc.
*/
// IOStreams have various Properties. The first time SDL_GetIOProperties() is
// called, it creates the SDL_PropertiesID and then uses this function
// interface to fill in the appropriate props for the stream on-demand.
typedef void (*SetIOPropertiesFn)(SDL_PropertiesID props, void *userdata);
struct SDL_IOStream
{
SDL_IOStreamInterface iface;
void *userdata;
SetIOPropertiesFn setioprops;
SDL_IOStatus status;
SDL_PropertiesID props;
};
@@ -425,6 +432,12 @@ static bool SDLCALL windows_file_close(void *userdata)
return result;
}
static void windows_setioprops(SDL_PropertiesID props, void *userdata)
{
const IOStreamWindowsData *iodata = (const IOStreamWindowsData *) userdata;
SDL_SetPointerProperty(props, SDL_PROP_IOSTREAM_WINDOWS_HANDLE_POINTER, iodata->h);
}
SDL_IOStream *SDL_IOFromHandle(HANDLE handle, const char *mode, bool autoclose)
{
IOStreamWindowsData *iodata = (IOStreamWindowsData *) SDL_calloc(1, sizeof (*iodata));
@@ -470,10 +483,7 @@ SDL_IOStream *SDL_IOFromHandle(HANDLE handle, const char *mode, bool autoclose)
if (!iostr) {
iface.close(iodata);
} else {
const SDL_PropertiesID props = SDL_GetIOProperties(iostr);
if (props) {
SDL_SetPointerProperty(props, SDL_PROP_IOSTREAM_WINDOWS_HANDLE_POINTER, iodata->h);
}
iostr->setioprops = windows_setioprops;
}
return iostr;
@@ -636,6 +646,12 @@ static bool SDLCALL fd_close(void *userdata)
return status;
}
static void fd_setioprops(SDL_PropertiesID props, void *userdata)
{
const IOStreamFDData *iodata = (const IOStreamFDData *) userdata;
SDL_SetNumberProperty(props, SDL_PROP_IOSTREAM_FILE_DESCRIPTOR_NUMBER, iodata->fd);
}
SDL_IOStream *SDL_IOFromFD(int fd, bool autoclose)
{
IOStreamFDData *iodata = (IOStreamFDData *) SDL_calloc(1, sizeof (*iodata));
@@ -662,10 +678,7 @@ SDL_IOStream *SDL_IOFromFD(int fd, bool autoclose)
if (!iostr) {
iface.close(iodata);
} else {
const SDL_PropertiesID props = SDL_GetIOProperties(iostr);
if (props) {
SDL_SetNumberProperty(props, SDL_PROP_IOSTREAM_FILE_DESCRIPTOR_NUMBER, fd);
}
iostr->setioprops = fd_setioprops;
}
return iostr;
@@ -834,6 +847,14 @@ static bool SDLCALL stdio_close(void *userdata)
return status;
}
static void stdio_setioprops(SDL_PropertiesID props, void *userdata)
{
const IOStreamStdioData *iodata = (const IOStreamStdioData *) userdata;
FILE *fp = iodata->fp;
SDL_SetPointerProperty(props, SDL_PROP_IOSTREAM_STDIO_FILE_POINTER, fp);
SDL_SetNumberProperty(props, SDL_PROP_IOSTREAM_FILE_DESCRIPTOR_NUMBER, fileno(fp));
}
SDL_IOStream *SDL_IOFromFP(FILE *fp, bool autoclose)
{
IOStreamStdioData *iodata = (IOStreamStdioData *) SDL_calloc(1, sizeof (*iodata));
@@ -860,11 +881,7 @@ SDL_IOStream *SDL_IOFromFP(FILE *fp, bool autoclose)
if (!iostr) {
iface.close(iodata);
} else {
const SDL_PropertiesID props = SDL_GetIOProperties(iostr);
if (props) {
SDL_SetPointerProperty(props, SDL_PROP_IOSTREAM_STDIO_FILE_POINTER, fp);
SDL_SetNumberProperty(props, SDL_PROP_IOSTREAM_FILE_DESCRIPTOR_NUMBER, fileno(fp));
}
iostr->setioprops = stdio_setioprops;
}
return iostr;
@@ -878,6 +895,7 @@ typedef struct IOStreamMemData
Uint8 *base;
Uint8 *here;
Uint8 *stop;
size_t size;
SDL_PropertiesID props;
} IOStreamMemData;
@@ -960,6 +978,15 @@ static bool SDLCALL mem_close(void *userdata)
return true;
}
static void mem_setioprops(SDL_PropertiesID props, void *userdata)
{
IOStreamMemData *iodata = (IOStreamMemData *) userdata;
SDL_SetPointerProperty(props, SDL_PROP_IOSTREAM_MEMORY_POINTER, iodata->base);
SDL_SetNumberProperty(props, SDL_PROP_IOSTREAM_MEMORY_SIZE_NUMBER, iodata->size);
SDL_assert(iodata->props == 0);
iodata->props = props;
}
// Functions to create SDL_IOStream structures from various data sources
// private platforms might define SKIP_STDIO_DIR_TEST in their build configs, too.
@@ -977,6 +1004,13 @@ static bool IsStdioFileADirectory(FILE *f)
#define IsStdioFileADirectory(f) false
#endif
#ifdef SDL_PLATFORM_ANDROID
static void android_setioprops(SDL_PropertiesID props, void *userdata)
{
SDL_SetPointerProperty(props, SDL_PROP_IOSTREAM_ANDROID_AASSET_POINTER, userdata);
}
#endif
SDL_IOStream *SDL_IOFromFile(const char *file, const char *mode)
{
SDL_IOStream *iostr = NULL;
@@ -1056,10 +1090,7 @@ SDL_IOStream *SDL_IOFromFile(const char *file, const char *mode)
if (!iostr) {
iface.close(iodata);
} else {
const SDL_PropertiesID props = SDL_GetIOProperties(iostr);
if (props) {
SDL_SetPointerProperty(props, SDL_PROP_IOSTREAM_ANDROID_AASSET_POINTER, iodata);
}
iostr->setioprops = android_setioprops;
}
#elif defined(SDL_PLATFORM_IOS)
@@ -1153,18 +1184,15 @@ SDL_IOStream *SDL_IOFromMem(void *mem, size_t size)
iodata->base = (Uint8 *)mem;
iodata->here = iodata->base;
iodata->stop = iodata->base + size;
iodata->size = size;
SDL_IOStream *iostr = SDL_OpenIO(&iface, iodata);
if (!iostr) {
SDL_free(iodata);
} else {
const SDL_PropertiesID props = SDL_GetIOProperties(iostr);
if (props) {
iodata->props = props;
SDL_SetPointerProperty(props, SDL_PROP_IOSTREAM_MEMORY_POINTER, mem);
SDL_SetNumberProperty(props, SDL_PROP_IOSTREAM_MEMORY_SIZE_NUMBER, size);
}
iostr->setioprops = mem_setioprops;
}
return iostr;
}
@@ -1196,19 +1224,15 @@ SDL_IOStream *SDL_IOFromConstMem(const void *mem, size_t size)
if (!iostr) {
SDL_free(iodata);
} else {
const SDL_PropertiesID props = SDL_GetIOProperties(iostr);
if (props) {
iodata->props = props;
SDL_SetPointerProperty(props, SDL_PROP_IOSTREAM_MEMORY_POINTER, (void *)mem);
SDL_SetNumberProperty(props, SDL_PROP_IOSTREAM_MEMORY_SIZE_NUMBER, size);
}
iostr->setioprops = mem_setioprops;
}
return iostr;
}
typedef struct IOStreamDynamicMemData
{
SDL_IOStream *stream;
SDL_PropertiesID props;
IOStreamMemData data;
Uint8 *end;
} IOStreamDynamicMemData;
@@ -1237,7 +1261,7 @@ static size_t SDLCALL dynamic_mem_read(void *userdata, void *ptr, size_t size, S
static bool dynamic_mem_realloc(IOStreamDynamicMemData *iodata, size_t size)
{
size_t chunksize = (size_t)SDL_GetNumberProperty(SDL_GetIOProperties(iodata->stream), SDL_PROP_IOSTREAM_DYNAMIC_CHUNKSIZE_NUMBER, 0);
size_t chunksize = (size_t)SDL_GetNumberProperty(iodata->props, SDL_PROP_IOSTREAM_DYNAMIC_CHUNKSIZE_NUMBER, 1024);
if (!chunksize) {
chunksize = 1024;
}
@@ -1256,7 +1280,7 @@ static bool dynamic_mem_realloc(IOStreamDynamicMemData *iodata, size_t size)
iodata->data.here = base + here_offset;
iodata->data.stop = base + stop_offset;
iodata->end = base + length;
return SDL_SetPointerProperty(SDL_GetIOProperties(iodata->stream), SDL_PROP_IOSTREAM_DYNAMIC_MEMORY_POINTER, base);
return iodata->props ? SDL_SetPointerProperty(iodata->props, SDL_PROP_IOSTREAM_DYNAMIC_MEMORY_POINTER, base) : true;
}
static size_t SDLCALL dynamic_mem_write(void *userdata, const void *ptr, size_t size, SDL_IOStatus *status)
@@ -1279,12 +1303,20 @@ static size_t SDLCALL dynamic_mem_write(void *userdata, const void *ptr, size_t
static bool SDLCALL dynamic_mem_close(void *userdata)
{
const IOStreamDynamicMemData *iodata = (IOStreamDynamicMemData *) userdata;
void *mem = SDL_GetPointerProperty(SDL_GetIOProperties(iodata->stream), SDL_PROP_IOSTREAM_DYNAMIC_MEMORY_POINTER, NULL);
void *mem = iodata->props ? SDL_GetPointerProperty(iodata->props, SDL_PROP_IOSTREAM_DYNAMIC_MEMORY_POINTER, NULL) : iodata->data.base;
SDL_free(mem);
SDL_free(userdata);
return true;
}
static void dynamic_mem_setioprops(SDL_PropertiesID props, void *userdata)
{
IOStreamDynamicMemData *iodata = (IOStreamDynamicMemData *) userdata;
SDL_SetPointerProperty(props, SDL_PROP_IOSTREAM_DYNAMIC_MEMORY_POINTER, iodata->data.base);
SDL_assert(iodata->props == 0);
iodata->props = props;
}
SDL_IOStream *SDL_IOFromDynamicMem(void)
{
IOStreamDynamicMemData *iodata = (IOStreamDynamicMemData *) SDL_calloc(1, sizeof (*iodata));
@@ -1301,11 +1333,12 @@ SDL_IOStream *SDL_IOFromDynamicMem(void)
iface.close = dynamic_mem_close;
SDL_IOStream *iostr = SDL_OpenIO(&iface, iodata);
if (iostr) {
iodata->stream = iostr;
} else {
if (!iostr) {
SDL_free(iodata);
} else {
iostr->setioprops = dynamic_mem_setioprops;
}
return iostr;
}
@@ -1496,6 +1529,10 @@ SDL_PropertiesID SDL_GetIOProperties(SDL_IOStream *context)
if (context->props == 0) {
context->props = SDL_CreateProperties();
if (context->props && context->setioprops) {
context->setioprops(context->props, context->userdata);
context->setioprops = NULL; // NULL so we don't try to set props again, just in case.
}
}
return context->props;
}