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pub extern crate log;
use std::rc::Rc;
use std::sync::Arc;
use std::cell::RefCell;
use std::mem;
mod macros;
#[derive(Debug, Clone)]
pub enum Ndc {
Str(&'static str),
String(String),
Rc(Rc<String>),
Arc(Arc<String>),
}
impl Default for Ndc {
fn default() -> Self {
Ndc::Str("")
}
}
impl Ndc {
fn to_str(&self) -> &str {
match self {
Ndc::Str(s) => s,
Ndc::String(s) => &s,
Ndc::Rc(s) => &**s,
Ndc::Arc(s) => &**s,
}
}
}
impl From<&'static str> for Ndc {
fn from(s: &'static str) -> Self {
Ndc::Str(s)
}
}
impl From<String> for Ndc {
fn from(s: String) -> Self {
Ndc::String(s)
}
}
impl From<Rc<String>> for Ndc {
fn from(s: Rc<String>) -> Self {
Ndc::Rc(s)
}
}
impl From<Arc<String>> for Ndc {
fn from(s: Arc<String>) -> Self {
Ndc::Arc(s)
}
}
thread_local! {
static NDC: RefCell<Ndc> = RefCell::new(Ndc::Str(""));
}
#[must_use]
pub struct SetGuard {
ndc: Ndc,
}
impl Drop for SetGuard {
fn drop(&mut self) {
set(mem::replace(&mut self.ndc, Default::default()));
}
}
pub fn set<S: Into<Ndc>>(ndc: S) {
replace(ndc);
}
pub fn replace<S: Into<Ndc>>(ndc: S) -> Ndc {
NDC.with(|r| {
mem::replace(&mut *r.borrow_mut(), ndc.into())
})
}
pub fn clear() {
set("");
}
pub fn push<S: Into<Ndc>>(ndc: S) -> SetGuard {
SetGuard { ndc: replace(ndc) }
}
pub fn get_raw() -> Ndc {
NDC.with(|r| r.borrow().clone())
}
pub fn get_copy() -> String {
get(|s| s.to_owned())
}
pub fn get<R, F>(f: F) -> R where F: FnOnce(&str) -> R {
NDC.with(|r| f(r.borrow().to_str()))
}
#[cfg(test)]
mod test {
mod log_ndc {
pub use super::super::*;
}
#[test]
fn set_get() {
let _g = log_ndc::push("");
log_ndc::set("aa");
assert_eq!("aa", log_ndc::get_copy());
}
#[test]
fn push() {
let _g = log_ndc::push("");
let _g1 = log_ndc::push("aa");
assert_eq!("aa", log_ndc::get_copy());
let g2 = log_ndc::push("bb");
assert_eq!("bb", log_ndc::get_copy());
drop(g2);
assert_eq!("aa", log_ndc::get_copy());
}
}