1 files changed, 56 insertions, 0 deletions
diff --git a/crates/cargo-util/src/sha256.rs b/crates/cargo-util/src/sha256.rs
new file mode 100644
index 0000000..58821f4
--- /dev/null
+++ b/crates/cargo-util/src/sha256.rs
@@ -0,0 +1,56 @@
+use super::paths;
+use anyhow::{Context, Result};
+use crypto_hash::{Algorithm, Hasher};
+use std::fs::File;
+use std::io::{self, Read, Write};
+use std::path::Path;
+
+pub struct Sha256(Hasher);
+
+impl Sha256 {
+    pub fn new() -> Sha256 {
+        let hasher = Hasher::new(Algorithm::SHA256);
+        Sha256(hasher)
+    }
+
+    pub fn update(&mut self, bytes: &[u8]) -> &mut Sha256 {
+        let _ = self.0.write_all(bytes);
+        self
+    }
+
+    pub fn update_file(&mut self, mut file: &File) -> io::Result<&mut Sha256> {
+        let mut buf = [0; 64 * 1024];
+        loop {
+            let n = file.read(&mut buf)?;
+            if n == 0 {
+                break Ok(self);
+            }
+            self.update(&buf[..n]);
+        }
+    }
+
+    pub fn update_path<P: AsRef<Path>>(&mut self, path: P) -> Result<&mut Sha256> {
+        let path = path.as_ref();
+        let file = paths::open(path)?;
+        self.update_file(&file)
+            .with_context(|| format!("failed to read `{}`", path.display()))?;
+        Ok(self)
+    }
+
+    pub fn finish(&mut self) -> [u8; 32] {
+        let mut ret = [0u8; 32];
+        let data = self.0.finish();
+        ret.copy_from_slice(&data[..]);
+        ret
+    }
+
+    pub fn finish_hex(&mut self) -> String {
+        hex::encode(self.finish())
+    }
+}
+
+impl Default for Sha256 {
+    fn default() -> Self {
+        Self::new()
+    }
+}