Optimize cmstring parser a bit.

Stop parsing at terminating null instead of searching for it afterwards.

1 files changed, 6 insertions, 4 deletions

diff --git a/src/main.rs b/src/main.rs
index 6eb105b..dfeea93 100644
--- a/src/main.rs
+++ b/src/main.rs
@@ -21,7 +21,8 @@ use cubase_project::*;
 
 use nom::{
     bytes::complete::*,
-    multi::{length_data, many1},
+    combinator::map,
+    multi::{length_data, length_value, many1},
     number::complete::*,
     sequence::tuple,
     Finish,
@@ -37,10 +38,11 @@ use std::{
 /// Cubase uses a string format where the length of the string is given as a 32 bit big endian word
 /// before the actual string data. The string may also be zero terminated, with the zero term char
 /// included in the length. In that case, we trim off the ending zero bytes.
+///
+/// We assume strings to be UTF-8 encoded.
 fn cmstring(data: &[u8]) -> IResult<&[u8], &str> {
-    let (r, s) = length_data(be_u32)(data)?;
-    let end = s.iter().rposition(|b| b != &0u8).unwrap() + 1;
-    Ok((r, std::str::from_utf8(&s[0..end]).unwrap()))
+    let strdata = length_value(be_u32, take_till(|c| c == b'\0'));
+    map(strdata, |s| std::str::from_utf8(s).unwrap())(data)
 }
 
 /**