From 55bd9f5311de14341c165fee899593707d31ebda Mon Sep 17 00:00:00 2001
From: "Ryan C. Gordon" <[EMAIL REDACTED]>
Date: Fri, 27 Sep 2024 14:45:29 -0400
Subject: [PATCH] iostream: flush() should attempt to sync file data to
physical media.
---
src/file/SDL_iostream.c | 33 +++++++++++++++++++++++++++++++++
1 file changed, 33 insertions(+)
diff --git a/src/file/SDL_iostream.c b/src/file/SDL_iostream.c
index 50f22dc3c6689..3622e9290c126 100644
--- a/src/file/SDL_iostream.c
+++ b/src/file/SDL_iostream.c
@@ -22,6 +22,8 @@
#if defined(SDL_PLATFORM_WINDOWS)
#include "../core/windows/SDL_windows.h"
+#else
+#include <unistd.h>
#endif
#ifdef HAVE_STDIO_H
@@ -33,6 +35,10 @@
#include <limits.h>
#endif
+#ifdef SDL_PLATFORM_APPLE
+#include <fcntl.h>
+#endif
+
#include "SDL_iostream_c.h"
/* This file provides a general interface for SDL to read and write
@@ -277,6 +283,15 @@ static size_t SDLCALL windows_file_write(void *userdata, const void *ptr, size_t
return bytes;
}
+static bool SDLCALL windows_file_flush(void *userdata, SDL_IOStatus *status)
+{
+ IOStreamWindowsData *iodata = (IOStreamWindowsData *) userdata;
+ if (!FlushFileBuffers(iodata->h)) {
+ return WIN_SetError("Error flushing datastream");
+ }
+ return true;
+}
+
static bool SDLCALL windows_file_close(void *userdata)
{
IOStreamWindowsData *iodata = (IOStreamWindowsData *) userdata;
@@ -309,6 +324,7 @@ SDL_IOStream *SDL_IOFromHandle(HANDLE handle, const char *mode, bool autoclose)
}
iface.read = windows_file_read;
iface.write = windows_file_write;
+ iface.flush = windows_file_flush;
iface.close = windows_file_close;
iodata->h = handle;
@@ -343,6 +359,7 @@ typedef struct IOStreamStdioData
{
FILE *fp;
bool autoclose;
+ bool regular_file;
} IOStreamStdioData;
#ifdef HAVE_FOPEN64
@@ -464,6 +481,19 @@ static bool SDLCALL stdio_flush(void *userdata, SDL_IOStatus *status)
return SDL_SetError("Error flushing datastream: %s", strerror(errno));
}
}
+
+ #if defined(SDL_PLATFORM_APPLE) // Apple doesn't have fdatasync (rather, the symbol exists as an incompatible system call).
+ if (fcntl(fileno(iodata->fp), F_FULLFSYNC) == -1) {
+ return SDL_SetError("Error flushing datastream: %s", strerror(errno));
+ }
+ #elif defined(_POSIX_SYNCHRONIZED_IO) // POSIX defines this if fdatasync() exists, so we don't need a CMake test.
+ #ifndef SDL_PLATFORM_RISCOS // !!! FIXME: however, RISCOS doesn't have the symbol...maybe we need to link to an extra library or something?
+ if (iodata->regular_file && (fdatasync(fileno(iodata->fp)) == -1)) {
+ return SDL_SetError("Error flushing datastream: %s", strerror(errno));
+ }
+ #endif
+ #endif
+
return true;
}
@@ -502,6 +532,9 @@ SDL_IOStream *SDL_IOFromFP(FILE *fp, bool autoclose)
iodata->fp = fp;
iodata->autoclose = autoclose;
+ struct stat st;
+ iodata->regular_file = ((fstat(fileno(fp), &st) == 0) && S_ISREG(st.st_mode));
+
SDL_IOStream *iostr = SDL_OpenIO(&iface, iodata);
if (!iostr) {
iface.close(iodata);