Switch from SHA-1 to SHA-512

Local benchmarking showed that the implementation of SHA-512 in the *ring* crate
is 3x faster than the implementation of SHA-1 in the `sha1` crate. I've also
noticed that 80%+ of sccache's runtime on a fully cached build is spent hashing.
With this change I noticed a decrease from 108s to 92s when building a fully
cached LLVM from the network. Not a huge win but if the network were faster
could perhaps add up!

Closes mozilla#108

Cargo.toml

@@ -29,12 +29,12 @@ number_prefix = "0.2.5"
 redis = { version = "0.8.0", optional = true }
 regex = "0.1.65"
 retry = "0.4.0"
+ring = "0.7.0"
 rust-crypto = { version = "0.2.36", optional = true }
 rustc-serialize = "0.3"
 serde = "0.9"
 serde_derive = "0.9"
 serde_json = { version = "0.9.0", optional = true }
-sha1 = "0.2.0"
 tempdir = "0.3.4"
 time = "0.1.35"
 tokio-core = "0.1.6"

src/compiler/c.rs

@@ -16,14 +16,13 @@ use compiler::{Cacheable, Compiler, CompilerArguments, CompilerHasher, CompilerK
 use futures::Future;
 use futures_cpupool::CpuPool;
 use mock_command::CommandCreatorSync;
-use sha1;
 use std::borrow::Cow;
 use std::collections::{HashMap, HashSet};
 use std::ffi::{OsStr, OsString};
 use std::fmt;
 use std::path::Path;
 use std::process;
-use util::{os_str_bytes, sha1_digest};
+use util::{os_str_bytes, Digest};
 
 use errors::*;
 
@@ -130,7 +129,7 @@ impl <I> CCompiler<I>
 {
     pub fn new(compiler: I, executable: String, pool: &CpuPool) -> SFuture<CCompiler<I>>
     {
-        Box::new(sha1_digest(executable.clone(), &pool).map(move |digest| {
+        Box::new(Digest::file(executable.clone(), &pool).map(move |digest| {
             CCompiler {
                 executable: executable,
                 executable_digest: digest,
@@ -271,7 +270,7 @@ pub fn hash_key(compiler_digest: &str, arguments: &str, env_vars: &[(OsString, O
                 preprocessor_output: &[u8]) -> String
 {
     // If you change any of the inputs to the hash, you should change `CACHE_VERSION`.
-    let mut m = sha1::Sha1::new();
+    let mut m = Digest::new();
     m.update(compiler_digest.as_bytes());
     m.update(CACHE_VERSION);
     m.update(arguments.as_bytes());
@@ -285,7 +284,7 @@ pub fn hash_key(compiler_digest: &str, arguments: &str, env_vars: &[(OsString, O
         }
     }
     m.update(preprocessor_output);
-    m.digest().to_string()
+    m.finish()
 }
 
 #[cfg(test)]

src/compiler/rust.rs

@@ -18,7 +18,6 @@ use futures::{Future, future};
 use futures_cpupool::CpuPool;
 use log::LogLevel::Trace;
 use mock_command::{CommandCreatorSync, RunCommand};
-use sha1;
 use std::borrow::Cow;
 use std::collections::{HashMap, HashSet};
 use std::env::consts::DLL_EXTENSION;
@@ -31,7 +30,7 @@ use std::process::{self, Stdio};
 use std::slice;
 use std::time::Instant;
 use tempdir::TempDir;
-use util::{fmt_duration_as_secs, os_str_bytes, run_input_output, sha1_digest};
+use util::{fmt_duration_as_secs, os_str_bytes, run_input_output, Digest};
 
 use errors::*;
 
@@ -137,7 +136,7 @@ fn hash_all(files: Vec<String>, pool: &CpuPool) -> SFuture<Vec<String>>
     let start = Instant::now();
     let count = files.len();
     let pool = pool.clone();
-    Box::new(future::join_all(files.into_iter().map(move |f| sha1_digest(f, &pool)))
+    Box::new(future::join_all(files.into_iter().map(move |f| Digest::file(f, &pool)))
              .map(move |hashes| {
                  trace!("Hashed {} files in {}", count, fmt_duration_as_secs(&start.elapsed()));
                  hashes
@@ -508,7 +507,7 @@ impl<T> CompilerHasher<T> for RustHasher
         let hashes = source_hashes.join(extern_hashes);
         Box::new(hashes.and_then(move |(source_hashes, extern_hashes)| -> SFuture<_> {
             // If you change any of the inputs to the hash, you should change `CACHE_VERSION`.
-            let mut m = sha1::Sha1::new();
+            let mut m = Digest::new();
             // Hash inputs:
             // 1. A version
             m.update(CACHE_VERSION);
@@ -572,7 +571,7 @@ impl<T> CompilerHasher<T> for RustHasher
                     outputs.insert(dep_info, p);
                 }
                 HashResult {
-                    key: m.digest().to_string(),
+                    key: m.finish(),
                     compilation: Box::new(RustCompilation {
                         executable: executable,
                         arguments: arguments,
@@ -629,7 +628,6 @@ mod test {
     use ::compiler::*;
     use itertools::Itertools;
     use mock_command::*;
-    use sha1;
     use std::fs::File;
     use std::io::Write;
     use std::sync::{Arc,Mutex};
@@ -842,7 +840,6 @@ bar.rs:
         drop(env_logger::init());
         let f = TestFixture::new();
         // SHA-1 digest of an empty file.
-        const EMPTY_DIGEST: &'static str = "da39a3ee5e6b4b0d3255bfef95601890afd80709";
         const FAKE_DIGEST: &'static str = "abcd1234";
         // We'll just use empty files for each of these.
         for s in ["foo.rs", "bar.rs", "bar.rlib"].iter() {
@@ -873,23 +870,26 @@ bar.rs:
                                              (OsString::from("FOO"), OsString::from("bar")),
                                              (OsString::from("CARGO_BLAH"), OsString::from("abc"))],
                                            &pool).wait().unwrap();
-        let mut m = sha1::Sha1::new();
+        let mut m = Digest::new();
+        let empty_digest = m.finish();
+
+        let mut m = Digest::new();
         // Version.
         m.update(CACHE_VERSION);
         // sysroot shlibs digests.
         m.update(FAKE_DIGEST.as_bytes());
         // Arguments, with externs sorted at the end.
         m.update(b"ab--externabc--externxyz");
         // bar.rs (source file, from dep-info)
-        m.update(EMPTY_DIGEST.as_bytes());
+        m.update(empty_digest.as_bytes());
         // foo.rs (source file, from dep-info)
-        m.update(EMPTY_DIGEST.as_bytes());
+        m.update(empty_digest.as_bytes());
         // bar.rlib (extern crate, from externs)
-        m.update(EMPTY_DIGEST.as_bytes());
+        m.update(empty_digest.as_bytes());
         // Env vars
         m.update(b"CARGO_BLAH=abc");
         m.update(b"CARGO_PKG_NAME=foo");
-        let digest = m.digest().to_string();
+        let digest = m.finish();
         assert_eq!(res.key, digest);
         let mut out = res.compilation.outputs().map(|(k, _)| k.to_owned()).collect::<Vec<_>>();
         out.sort();

src/main.rs

@@ -47,6 +47,7 @@ extern crate libc;
 #[cfg(windows)]
 extern crate mio_named_pipes;
 extern crate number_prefix;
+extern crate ring;
 #[cfg(feature = "redis")]
 extern crate redis;
 extern crate regex;
@@ -56,7 +57,6 @@ extern crate rustc_serialize;
 extern crate serde_json;
 #[macro_use]
 extern crate serde_derive;
-extern crate sha1;
 extern crate tempdir;
 extern crate time;
 extern crate tokio_core;