Update workcache to no longer use Sha1.

Author: Palmer Cox

src/libextra/workcache.rs

@@ -10,10 +10,8 @@
 
 #[allow(missing_doc)];
 
-use digest::Digest;
 use json;
 use json::ToJson;
-use sha1::Sha1;
 use serialize::{Encoder, Encodable, Decoder, Decodable};
 use arc::{Arc,RWArc};
 use treemap::TreeMap;
@@ -23,7 +21,6 @@ use std::{os, str, task};
 use std::rt::io;
 use std::rt::io::Writer;
 use std::rt::io::Decorator;
-use std::rt::io::extensions::ReaderUtil;
 use std::rt::io::mem::MemWriter;
 use std::rt::io::file::FileInfo;
 
@@ -276,19 +273,6 @@ fn json_decode<T:Decodable<json::Decoder>>(s: &str) -> T {
     Decodable::decode(&mut decoder)
 }
 
-fn digest<T:Encodable<json::Encoder>>(t: &T) -> ~str {
-    let mut sha = ~Sha1::new();
-    (*sha).input_str(json_encode(t));
-    (*sha).result_str()
-}
-
-fn digest_file(path: &Path) -> ~str {
-    let mut sha = ~Sha1::new();
-    let s = path.open_reader(io::Open).read_to_end();
-    (*sha).input(s);
-    (*sha).result_str()
-}
-
 impl Context {
 
     pub fn new(db: RWArc<Database>,
@@ -497,6 +481,8 @@ impl<'self, T:Send +
 #[test]
 fn test() {
     use std::{os, run};
+    use std::rt::io::ReaderUtil;
+    use std::str::from_utf8_owned;
 
     // Create a path to a new file 'filename' in the directory in which
     // this test is running.
@@ -524,8 +510,10 @@ fn test() {
         let subcx = cx.clone();
         let pth = pth.clone();
 
+        let file_content = from_utf8_owned(pth.open_reader(io::Open).read_to_end());
+
         // FIXME (#9639): This needs to handle non-utf8 paths
-        prep.declare_input("file", pth.as_str().unwrap(), digest_file(&pth));
+        prep.declare_input("file", pth.as_str().unwrap(), file_content);
         do prep.exec |_exe| {
             let out = make_path(~"foo.o");
             // FIXME (#9639): This needs to handle non-utf8 paths