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// Copyright © 2017-2018 Mozilla Foundation
//
// This program is made available under an ISC-style license. See the
// accompanying file LICENSE for details.
use std::os::raw::c_char;
/// Maximum length in bytes for a log message.
/// Longer messages are silently truncated. See `write_str`.
const LOG_LIMIT: usize = 1024;
struct StaticCString<const N: usize> {
buf: [std::mem::MaybeUninit<u8>; N],
len: usize,
}
impl<const N: usize> StaticCString<N> {
fn new() -> Self {
StaticCString {
buf: unsafe { std::mem::MaybeUninit::uninit().assume_init() },
len: 0,
}
}
fn as_cstr(&self) -> &std::ffi::CStr {
unsafe {
std::ffi::CStr::from_bytes_with_nul_unchecked(std::slice::from_raw_parts(
self.buf.as_ptr().cast::<u8>(),
self.len,
))
}
}
}
impl<const N: usize> std::fmt::Write for StaticCString<N> {
fn write_str(&mut self, s: &str) -> std::fmt::Result {
use std::convert::TryInto;
let s = s.as_bytes();
let end = s.len().min(N.checked_sub(1).unwrap() - self.len);
debug_assert_eq!(s.len(), end, "message truncated");
unsafe {
std::ptr::copy_nonoverlapping(
s[..end].as_ptr(),
self.buf
.as_mut_ptr()
.cast::<u8>()
.offset(self.len.try_into().unwrap()),
end,
)
};
self.len += end;
self.buf[self.len].write(0);
Ok(())
}
}
/// Formats `$file:line: $msg\n` into an on-stack buffer of size `LOG_LIMIT`,
/// then calls `log_callback` with a pointer to the formatted message.
pub fn cubeb_log_internal_buf_fmt(
log_callback: unsafe extern "C" fn(*const c_char, ...),
file: &str,
line: u32,
msg: std::fmt::Arguments,
) {
let filename = std::path::Path::new(file)
.file_name()
.unwrap()
.to_str()
.unwrap();
let mut buf = StaticCString::<LOG_LIMIT>::new();
let _ = std::fmt::write(&mut buf, format_args!("{}:{}: {}\n", filename, line, msg));
unsafe {
log_callback(buf.as_cstr().as_ptr());
};
}
#[macro_export]
macro_rules! cubeb_log_internal {
($log_callback: expr, $level: expr, $fmt: expr, $($arg: expr),+) => {
#[allow(unused_unsafe)]
unsafe {
if $level <= $crate::ffi::cubeb_log_get_level().into() {
if let Some(log_callback) = $log_callback {
$crate::log::cubeb_log_internal_buf_fmt(log_callback, file!(), line!(), format_args!($fmt, $($arg),+));
}
}
}
};
($log_callback: expr, $level: expr, $msg: expr) => {
cubeb_log_internal!($log_callback, $level, "{}", $msg);
};
}
#[macro_export]
macro_rules! cubeb_log {
($($arg: expr),+) => (cubeb_log_internal!($crate::ffi::cubeb_log_get_callback(), $crate::LogLevel::Normal, $($arg),+));
}
#[macro_export]
macro_rules! cubeb_logv {
($($arg: expr),+) => (cubeb_log_internal!($crate::ffi::cubeb_log_get_callback(), $crate::LogLevel::Verbose, $($arg),+));
}
#[macro_export]
macro_rules! cubeb_alog {
($($arg: expr),+) => (cubeb_log_internal!($crate::ffi::cubeb_async_log.into(), $crate::LogLevel::Normal, $($arg),+));
}
#[macro_export]
macro_rules! cubeb_alogv {
($($arg: expr),+) => (cubeb_log_internal!($crate::ffi::cubeb_async_log.into(), $crate::LogLevel::Verbose, $($arg),+));
}
#[cfg(test)]
mod tests {
#[test]
fn test_normal_logging_sync() {
cubeb_log!("This is synchronous log output at normal level");
cubeb_log!("{} Formatted log", 1);
cubeb_log!("{} Formatted {} log {}", 1, 2, 3);
}
#[test]
fn test_verbose_logging_sync() {
cubeb_logv!("This is synchronous log output at verbose level");
cubeb_logv!("{} Formatted log", 1);
cubeb_logv!("{} Formatted {} log {}", 1, 2, 3);
}
#[test]
fn test_normal_logging_async() {
cubeb_alog!("This is asynchronous log output at normal level");
cubeb_alog!("{} Formatted log", 1);
cubeb_alog!("{} Formatted {} log {}", 1, 2, 3);
}
#[test]
fn test_verbose_logging_async() {
cubeb_alogv!("This is asynchronous log output at verbose level");
cubeb_alogv!("{} Formatted log", 1);
cubeb_alogv!("{} Formatted {} log {}", 1, 2, 3);
}
}