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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::{CStr, CString};
use std::os::raw::c_char;
#[derive(Debug)]
pub struct Intern {
vec: Vec<CString>,
}
impl Intern {
pub fn new() -> Intern {
Intern { vec: Vec::new() }
}
pub fn add(&mut self, string: &CStr) -> *const c_char {
fn eq(s1: &CStr, s2: &CStr) -> bool {
s1 == s2
}
for s in &self.vec {
if eq(s, string) {
return s.as_ptr();
}
}
self.vec.push(string.to_owned());
self.vec.last().unwrap().as_ptr()
}
}
#[cfg(test)]
mod tests {
use super::Intern;
use std::ffi::CStr;
#[test]
fn intern() {
fn cstr(str: &[u8]) -> &CStr {
CStr::from_bytes_with_nul(str).unwrap()
}
let mut intern = Intern::new();
let foo_ptr = intern.add(cstr(b"foo\0"));
let bar_ptr = intern.add(cstr(b"bar\0"));
assert!(!foo_ptr.is_null());
assert!(!bar_ptr.is_null());
assert!(foo_ptr != bar_ptr);
assert!(foo_ptr == intern.add(cstr(b"foo\0")));
assert!(foo_ptr != intern.add(cstr(b"fo\0")));
assert!(foo_ptr != intern.add(cstr(b"fool\0")));
assert!(foo_ptr != intern.add(cstr(b"not foo\0")));
}
}