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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::ffi::{c_char, CStr};
use std::sync::RwLock;
use {ffi, Error, Result};
/// Level (verbosity) of logging for a particular cubeb context.
#[derive(PartialEq, Eq, Clone, Debug, Copy, PartialOrd, Ord)]
pub enum LogLevel {
/// Logging disabled
Disabled,
/// Logging lifetime operation (creation/destruction).
Normal,
/// Verbose logging of callbacks, can have performance implications.
Verbose,
}
impl From<ffi::cubeb_log_level> for LogLevel {
fn from(x: ffi::cubeb_log_level) -> Self {
use LogLevel::*;
match x {
ffi::CUBEB_LOG_NORMAL => Normal,
ffi::CUBEB_LOG_VERBOSE => Verbose,
_ => Disabled,
}
}
}
impl From<LogLevel> for ffi::cubeb_log_level {
fn from(x: LogLevel) -> Self {
use LogLevel::*;
match x {
Normal => ffi::CUBEB_LOG_NORMAL,
Verbose => ffi::CUBEB_LOG_VERBOSE,
Disabled => ffi::CUBEB_LOG_DISABLED,
}
}
}
pub fn log_enabled() -> bool {
unsafe { ffi::cubeb_log_get_level() != LogLevel::Disabled as _ }
}
static LOG_CALLBACK: RwLock<Option<fn(s: &CStr)>> = RwLock::new(None);
extern "C" {
fn cubeb_write_log(fmt: *const c_char, ...);
}
/// # Safety
///
/// |s| must be null, or a pointer to a valid, nul-terminated, array of chars.
#[no_mangle]
pub unsafe extern "C" fn rust_write_formatted_msg(s: *const c_char) {
if s.is_null() {
// Do nothing if the pointer is null.
return;
}
if let Ok(guard) = LOG_CALLBACK.read() {
if let Some(f) = *guard {
f(CStr::from_ptr(s));
}
// Do nothing if there is no callback.
}
// Silently fail if lock cannot be acquired.
}
pub fn set_logging(level: LogLevel, f: Option<fn(s: &CStr)>) -> Result<()> {
match LOG_CALLBACK.write() {
Ok(mut guard) => {
*guard = f;
}
Err(_) => return Err(Error::Error),
}
unsafe {
call!(ffi::cubeb_set_log_callback(
level.into(),
Some(cubeb_write_log)
))
}
}
#[cfg(test)]
mod tests {
use super::*;
#[test]
fn test_logging_disabled_by_default() {
assert!(!log_enabled());
}
}