1 files changed, 58 insertions, 0 deletions
diff --git a/third_party/rust/cubeb-pulse/src/backend/intern.rs b/third_party/rust/cubeb-pulse/src/backend/intern.rs
new file mode 100644
index 0000000000..222e78cb93
--- /dev/null
+++ b/third_party/rust/cubeb-pulse/src/backend/intern.rs
@@ -0,0 +1,58 @@
+// 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<Box<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(Box::new(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")));
+    }
+}