feat: add ec

__misc/erasure-coding/src/main.rs

@@ -0,0 +1,38 @@
+#[macro_use(shards)]
+extern crate reed_solomon_erasure;
+
+use reed_solomon_erasure::galois_8::ReedSolomon;
+// or use the following for Galois 2^16 backend
+// use reed_solomon_erasure::galois_16::ReedSolomon;
+
+fn main () {
+    let r = ReedSolomon::new(3, 2).unwrap(); // 3 data shards, 2 parity shards
+
+    let mut master_copy = shards!(
+        [0, 1,  2,  3],
+        [4, 5,  6,  7],
+        [8, 9, 10, 11],
+        [0, 0,  0,  0], // last 2 rows are parity shards
+        [0, 0,  0,  0]
+    );
+
+    // Construct the parity shards
+    r.encode(&mut master_copy).unwrap();
+
+    // Make a copy and transform it into option shards arrangement
+    // for feeding into reconstruct_shards
+    let mut shards: Vec<_> = master_copy.iter().cloned().map(Some).collect();
+
+    // We can remove up to 2 shards, which may be data or parity shards
+    shards[0] = None;
+    shards[4] = None;
+
+    // Try to reconstruct missing shards
+    r.reconstruct(&mut shards).unwrap();
+
+    // Convert back to normal shard arrangement
+    let result: Vec<_> = shards.into_iter().filter_map(|x| x).collect();
+
+    assert!(r.verify(&result).unwrap());
+    assert_eq!(master_copy, result);
+}