Chain 구조체 정의

Author: leejaeseung

jaeseung-blockchain/src/block/block.rs

@@ -4,7 +4,7 @@ use sha256::digest;
 
 use rs_merkle::{algorithms::Sha256, Hasher, MerkleTree};
 
-#[derive(Debug, PartialEq)]
+#[derive(Debug, PartialEq, Clone)] // TODO : Copy 와 Clone 의 차이점?
 pub struct Block {
     header: BlockHeader,
     data: Vec<String>,
@@ -32,7 +32,7 @@ impl Block {
     }
 }
 
-#[derive(Debug, PartialEq)]
+#[derive(Debug, PartialEq, Clone)]
 struct BlockHeader {
     version: String,
     height: i32, // 블록의 높이. 블록 체인에 연결된 블록의 수

jaeseung-blockchain/src/chain/chain.rs

@@ -0,0 +1,83 @@
+use crate::block::Block;
+
+#[derive(Debug)]
+pub struct Chain {
+    block_chain: Vec<Block>,
+}
+
+impl Chain {
+    pub fn new() -> Result<Chain, String> {
+        Block::new_genesis().map(|b| Chain {
+            block_chain: vec![b],
+        })
+    }
+
+    pub fn get_length(&self) -> usize {
+        self.block_chain.len()
+    }
+
+    pub fn get_lastest_block(&self) -> Option<&Block> {
+        self.block_chain.last()
+    }
+
+    pub fn add_block(&mut self, data: &Vec<String>) -> Result<&Chain, String> {
+        let previous_block = self
+            .get_lastest_block()
+            .ok_or("previous_block not exist.")?;
+        let new_block = Block::new(previous_block, 0, data)?;
+
+        self.block_chain.push(new_block); // TODO : 안전할까?
+        Ok(self)
+    }
+}
+
+#[cfg(test)]
+mod tests {
+
+    use super::*;
+
+    #[test]
+    fn create_chain() {
+        let chain = Chain::new().unwrap();
+
+        assert_eq!(chain.block_chain.len(), 1);
+    }
+
+    #[test]
+    fn get_length() {
+        let chain = Chain::new().unwrap();
+
+        assert_eq!(chain.get_length(), 1);
+    }
+
+    #[test]
+    fn get_lastest_block() {
+        let first_block = Block::new_genesis().unwrap();
+        let second_block = Block::new(&first_block, 0, &vec!["data".to_string()]).unwrap();
+
+        let chain = Chain {
+            block_chain: vec![first_block, second_block.clone()],
+        };
+
+        assert_eq!(*chain.get_lastest_block().unwrap(), second_block);
+    }
+
+    #[test]
+    fn add_block_to_empty_chain() {
+        let mut empty_chain = Chain {
+            block_chain: Vec::new(),
+        };
+        let result = empty_chain.add_block(&vec!["data".to_string()]);
+
+        assert_eq!(result.is_err(), true);
+        assert_eq!(empty_chain.block_chain.len(), 0);
+    }
+
+    #[test]
+    fn add_block() {
+        let mut chain = Chain::new().unwrap();
+        let added_chain = chain.add_block(&vec!["data".to_string()]).unwrap();
+
+        assert_eq!(added_chain.block_chain.len(), 2);
+    }
+}

jaeseung-blockchain/src/chain/mod.rs

@@ -0,0 +1,2 @@
+pub mod chain;
+pub use chain::*;

jaeseung-blockchain/src/main.rs

@@ -1,4 +1,5 @@
 mod block;
+mod chain;
 
 use block::Block;