VFS: VFileOpen can now have a swappable backend

src/util/vfs.c

@@ -5,6 +5,36 @@
  * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
 #include "vfs.h"
 
+struct VFile* VFileOpen(const char* path, int flags) {
+#ifdef USE_VFS_FILE
+	const char* chflags;
+	switch (flags & O_ACCMODE) {
+	case O_WRONLY:
+		if (flags & O_APPEND) {
+			chflags = "ab";
+		} else {
+			chflags = "wb";
+		}
+		break;
+	case O_RDWR:
+		if (flags & O_APPEND) {
+			chflags = "a+b";
+		} else if (flags & O_TRUNC) {
+			chflags = "w+b";
+		} else {
+			chflags = "r+b";
+		}
+		break;
+	case O_RDONLY:
+		chflags = "rb";
+		break;
+	}
+	return VFileFOpen(path, chflags);
+#else
+	return VFileOpenFD(path, flags);
+#endif
+}
+
 ssize_t VFileReadline(struct VFile* vf, char* buffer, size_t size) {
 	ssize_t bytesRead = 0;
 	while (bytesRead < size - 1) {

src/util/vfs.h

@@ -53,6 +53,8 @@ struct VDir {
 };
 
 struct VFile* VFileOpen(const char* path, int flags);
+
+struct VFile* VFileOpenFD(const char* path, int flags);
 struct VFile* VFileFOpen(const char* path, const char* mode);
 struct VFile* VFileFromFD(int fd);
 struct VFile* VFileFromMemory(void* mem, size_t size);

src/util/vfs/vfs-fd.c

@@ -29,7 +29,7 @@ static void _vfdUnmap(struct VFile* vf, void* memory, size_t size);
 static void _vfdTruncate(struct VFile* vf, size_t size);
 static ssize_t _vfdSize(struct VFile* vf);
 
-struct VFile* VFileOpen(const char* path, int flags) {
+struct VFile* VFileOpenFD(const char* path, int flags) {
 	if (!path) {
 		return 0;
 	}

src/util/vfs/vfs-file.c

@@ -7,6 +7,7 @@
 
 #include "util/memory.h"
 
+#include <errno.h>
 #include <stdio.h>
 
 struct VFileFILE {
@@ -28,6 +29,9 @@ struct VFile* VFileFOpen(const char* path, const char* mode) {
 		return 0;
 	}
 	FILE* file = fopen(path, mode);
+	if (!file && errno == ENOENT && strcmp(mode, "r+b") == 0) {
+		file = fopen(path, "w+b");
+	}
 	return VFileFromFILE(file);
 }