Move drone into its own crate

sdk/src/hash.rs

@@ -0,0 +1,75 @@
+//! The `hash` module provides functions for creating SHA-256 hashes.
+
+use bs58;
+use generic_array::typenum::U32;
+use generic_array::GenericArray;
+use sha2::{Digest, Sha256};
+use std::fmt;
+
+#[derive(Serialize, Deserialize, Clone, Copy, Default, Eq, PartialEq, Ord, PartialOrd, Hash)]
+pub struct Hash(GenericArray<u8, U32>);
+
+#[derive(Clone, Default)]
+pub struct Hasher {
+    hasher: Sha256,
+}
+
+impl Hasher {
+    pub fn hash(&mut self, val: &[u8]) -> () {
+        self.hasher.input(val);
+    }
+    pub fn hashv(&mut self, vals: &[&[u8]]) -> () {
+        for val in vals {
+            self.hash(val);
+        }
+    }
+    pub fn result(self) -> Hash {
+        // At the time of this writing, the sha2 library is stuck on an old version
+        // of generic_array (0.9.0). Decouple ourselves with a clone to our version.
+        Hash(GenericArray::clone_from_slice(
+            self.hasher.result().as_slice(),
+        ))
+    }
+}
+
+impl AsRef<[u8]> for Hash {
+    fn as_ref(&self) -> &[u8] {
+        &self.0[..]
+    }
+}
+
+impl fmt::Debug for Hash {
+    fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
+        write!(f, "{}", bs58::encode(self.0).into_string())
+    }
+}
+
+impl fmt::Display for Hash {
+    fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
+        write!(f, "{}", bs58::encode(self.0).into_string())
+    }
+}
+
+impl Hash {
+    pub fn new(hash_slice: &[u8]) -> Self {
+        Hash(GenericArray::clone_from_slice(&hash_slice))
+    }
+}
+/// Return a Sha256 hash for the given data.
+pub fn hashv(vals: &[&[u8]]) -> Hash {
+    let mut hasher = Hasher::default();
+    hasher.hashv(vals);
+    hasher.result()
+}
+
+/// Return a Sha256 hash for the given data.
+pub fn hash(val: &[u8]) -> Hash {
+    hashv(&[val])
+}
+
+/// Return the hash of the given hash extended with the given value.
+pub fn extend_and_hash(id: &Hash, val: &[u8]) -> Hash {
+    let mut hash_data = id.as_ref().to_vec();
+    hash_data.extend_from_slice(val);
+    hash(&hash_data)
+}