Files
RedBear-OS/src/header/stdio/helpers.rs
T
Mateusz Tabaka 02f202ff83 Use BufWriter (instead of LineWriter) for FILEs other than stdout and stderr
BufWriter has more capacity (8k vs 1k) and doesn't flush the stream after '\n'.
That change helps to reduce the number of syscalls, especially when dealing with text files.

Since BufWriter has a different way of getting number of pending elements than LineWriter -
Pending trait was introduced to deal with that.
2021-01-14 18:45:14 +01:00

83 lines
2.0 KiB
Rust

use alloc::boxed::Box;
use super::{constants::*, Buffer, FILE};
use crate::{
fs::File,
header::{errno, fcntl::*, string::strchr},
io::BufWriter,
platform::{self, types::*},
sync::Mutex,
};
use alloc::vec::Vec;
/// Parse mode flags as a string and output a mode flags integer
pub unsafe fn parse_mode_flags(mode_str: *const c_char) -> i32 {
let mut flags = if !strchr(mode_str, b'+' as i32).is_null() {
O_RDWR
} else if (*mode_str) == b'r' as i8 {
O_RDONLY
} else {
O_WRONLY
};
if !strchr(mode_str, b'x' as i32).is_null() {
flags |= O_EXCL;
}
if !strchr(mode_str, b'e' as i32).is_null() {
flags |= O_CLOEXEC;
}
if (*mode_str) != b'r' as i8 {
flags |= O_CREAT;
}
if (*mode_str) == b'w' as i8 {
flags |= O_TRUNC;
} else if (*mode_str) == b'a' as i8 {
flags |= O_APPEND;
}
flags
}
/// Open a file with the file descriptor `fd` in the mode `mode`
pub unsafe fn _fdopen(fd: c_int, mode: *const c_char) -> Option<*mut FILE> {
if *mode != b'r' as i8 && *mode != b'w' as i8 && *mode != b'a' as i8 {
platform::errno = errno::EINVAL;
return None;
}
let mut flags = 0;
if strchr(mode, b'+' as i32).is_null() {
flags |= if *mode == b'r' as i8 { F_NOWR } else { F_NORD };
}
if !strchr(mode, b'e' as i32).is_null() {
sys_fcntl(fd, F_SETFD, FD_CLOEXEC);
}
if *mode == 'a' as i8 {
let f = sys_fcntl(fd, F_GETFL, 0);
if (f & O_APPEND) == 0 {
sys_fcntl(fd, F_SETFL, f | O_APPEND);
}
flags |= F_APP;
}
let file = File::new(fd);
let writer = Box::new(BufWriter::new(file.get_ref()));
Some(Box::into_raw(Box::new(FILE {
lock: Mutex::new(()),
file,
flags,
read_buf: Buffer::Owned(vec![0; BUFSIZ as usize]),
read_pos: 0,
read_size: 0,
unget: Vec::new(),
writer,
pid: None,
orientation: 0,
})))
}