From a43eb70ebe7844db0a4ffece47c22ae12384781b Mon Sep 17 00:00:00 2001
From: quou <quou@disroot.org>
Date: Sat, 13 Jul 2024 23:45:08 +1000
Subject: Add file API

---
 plat.c | 91 ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
 plat.h | 23 +++++++++++++++++
 2 files changed, 114 insertions(+)

diff --git a/plat.c b/plat.c
index f0d60ba..09c9444 100644
--- a/plat.c
+++ b/plat.c
@@ -8,11 +8,15 @@
 
 #define _POSIX_SOURCE
 #define _GNU_SOURCE
+#include <fcntl.h>
 #include <stdarg.h>
 #include <stdio.h>
+#include <stdlib.h>
+#include <sys/stat.h>
 #include <sys/time.h>
 #include <sys/types.h>
 #include <time.h>
+#include <unistd.h>
 
 extern int isatty(int);
 extern int fileno(FILE*);
@@ -86,16 +90,103 @@ void pbreak(Error code) {
 #endif
 }
 
+struct File {
+	int handle;
+	int cursor;
+	int size;
+};
+
+File* file_open(const char* name, File_Flags flags) {
+	File* file;
+	int handle, f = 0;
+	struct stat info;
+
+	if (flags & file_flags_write) {
+		f |= O_WRONLY | O_TRUNC;
+	}
+
+	if (flags & file_flags_read) {
+		f |= O_RDONLY;
+	}
+
+	if (flags & file_flags_read_write) {
+		f |= O_RDWR;
+	}
+
+	if (stat(name, &info) < 0) {
+		info.st_size = 0;
+		if (flags & file_flags_create) {
+			f |= O_CREAT | S_IRUSR | S_IWUSR;
+		}
+	}
+
+	handle = open(name, f);
+	if (handle < 0) {
+		return 0;
+	}
+
+	file = (File*)malloc(sizeof *file);
+	file->handle = handle;
+	file->cursor = 0;
+	file->size = (int)info.st_size;
+
+	return file;
+}
+
+void file_close(File* file) {
+	close(file->handle);
+	free(file);
+}
+
+void file_read(File* file, void* buffer, int size) {
+	lseek(file->handle, (off_t)file->cursor, SEEK_SET);
+	read(file->handle, buffer, size);
+	file->cursor += size;
+}
+
+void file_write(File* file, const void* buffer, int size) {
+	lseek(file->handle, (off_t)file->cursor, SEEK_SET);
+	write(file->handle, buffer, size);
+	file->cursor += size;
+}
+
+void file_seek(File* file, int offset, File_Whence whence) {
+	switch (whence) {
+		case file_whence_begin:
+			file->cursor = offset;
+			break;
+		case file_whence_end:
+			file->cursor = file->size - offset;
+			break;
+		case file_whence_cur:
+			file->cursor += offset;
+			break;
+	}
+}
+
+int file_size(File* file) {
+	return file->size;
+}
+
+int file_exists(const char* name) {
+	struct stat info;
+	return stat(name, &info) == 0;
+}
+
+
 static clockid_t global_clock;
 static unsigned long global_freq;
 
 void init_timer(void) {
+	struct timespec ts;
 	global_clock = CLOCK_REALTIME;
 	global_freq = 1000000000;
 #if defined(_POSIX_MONOTONIC_CLOCK)
 	if (clock_gettime(CLOCK_MONOTONIC, &ts) == 0) {
 		global_clock = CLOCK_MONOTONIC;
 	}
+#else
+	(void)ts;
 #endif
 }
 
diff --git a/plat.h b/plat.h
index 7e4f445..419d7fe 100644
--- a/plat.h
+++ b/plat.h
@@ -29,6 +29,29 @@ void print_err(const char* fmt, ...);
 void print_war(const char* fmt, ...);
 void pbreak(Error code);
 
+typedef struct File File;
+
+typedef enum {
+	file_flags_write       = 1 << 0,
+	file_flags_read        = 1 << 1,
+	file_flags_read_write  = 1 << 2,
+	file_flags_create      = 1 << 3
+} File_Flags;
+
+typedef enum {
+	file_whence_begin,
+	file_whence_end,
+	file_whence_cur
+} File_Whence;
+
+File* file_open(const char* name, File_Flags flags);
+void file_close(File* file);
+void file_read(File* file, void* buffer, int size);
+void file_write(File* file, const void* buffer, int size);
+void file_seek(File* file, int offset, File_Whence whence);
+int file_size(File* file);
+int file_exists(const char* name);
+
 typedef struct {
 	int mpf;
 	int fps;
-- 
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