Strip out old code

All of these files have been moved to either:

- https://github.com/sigp/lighthouse-beacon
- https://github.com/sigp/lighthouse-validator
- https://github.com/sigp/lighthouse-common

For rationale, see: https://github.com/sigp/lighthouse/issues/197

eth2/utils/ssz/src/tree_hash.rs

@@ -1,83 +0,0 @@
-use hashing::hash;
-
-const SSZ_CHUNK_SIZE: usize = 128;
-const HASHSIZE: usize = 32;
-
-pub trait TreeHash {
-    fn hash_tree_root(&self) -> Vec<u8>;
-}
-
-/// Returns a 32 byte hash of 'list' - a vector of byte vectors.
-/// Note that this will consume 'list'.
-pub fn merkle_hash(list: &mut Vec<Vec<u8>>) -> Vec<u8> {
-    // flatten list
-    let (mut chunk_size, mut chunkz) = list_to_blob(list);
-
-    // get data_len as bytes. It will hashed will the merkle root
-    let datalen = list.len().to_le_bytes();
-
-    // Tree-hash
-    while chunkz.len() > HASHSIZE {
-        let mut new_chunkz: Vec<u8> = Vec::new();
-
-        for two_chunks in chunkz.chunks(chunk_size * 2) {
-            if two_chunks.len() == chunk_size {
-                // Odd number of chunks
-                let mut c = two_chunks.to_vec();
-                c.append(&mut vec![0; SSZ_CHUNK_SIZE]);
-                new_chunkz.append(&mut hash(&c));
-            } else {
-                // Hash two chuncks together
-                new_chunkz.append(&mut hash(two_chunks));
-            }
-        }
-
-        chunk_size = HASHSIZE;
-        chunkz = new_chunkz;
-    }
-
-    chunkz.append(&mut datalen.to_vec());
-    hash(&chunkz)
-}
-
-fn list_to_blob(list: &mut Vec<Vec<u8>>) -> (usize, Vec<u8>) {
-    let chunk_size = if list.is_empty() {
-        SSZ_CHUNK_SIZE
-    } else if list[0].len() < SSZ_CHUNK_SIZE {
-        let items_per_chunk = SSZ_CHUNK_SIZE / list[0].len();
-        items_per_chunk * list[0].len()
-    } else {
-        list[0].len()
-    };
-
-    let mut data = Vec::new();
-    if list.is_empty() {
-        // handle and empty list
-        data.append(&mut vec![0; SSZ_CHUNK_SIZE]);
-    } else {
-        // just create a blob here; we'll divide into
-        // chunked slices when we merklize
-        data.reserve(list[0].len() * list.len());
-        for item in list.iter_mut() {
-            data.append(item);
-        }
-    }
-    (chunk_size, data)
-}
-
-#[cfg(test)]
-mod tests {
-    use super::*;
-
-    #[test]
-    fn test_merkle_hash() {
-        let data1 = vec![1; 100];
-        let data2 = vec![2; 100];
-        let data3 = vec![3; 100];
-        let mut list = vec![data1, data2, data3];
-        let result = merkle_hash(&mut list);
-
-        //note: should test againt a known test hash value
-        assert_eq!(HASHSIZE, result.len());
-    }
-}