Changed chain id to chain name (it will be a string). Implemented saving blockchain to sqlite DB.

Cargo.toml

@@ -21,6 +21,7 @@ groestl = "0.8.0"
 base64 = "0.11.0"
 chrono = "0.4.9"
 rand = "0.7.2"
+sqlite = "0.25.3"
 eventbus = "0.5.1"
 
 [build-dependencies]

alfis.cfg

@@ -1,5 +1,5 @@
 {
-    "chain_id": 42,
-    "version": 0,
+    "chain_name": "test",
+    "version_flags": 0,
     "key_file": "default.key"
 }

src/block.rs

@@ -17,8 +17,8 @@ use crate::keys::Bytes;
 pub struct Block {
     pub index: u64,
     pub timestamp: i64,
-    pub chain_id: u32,
-    pub version: u32,
+    pub chain_name: String,
+    pub version_flags: u32,
     pub difficulty: usize,
     pub random: u32,
     pub nonce: u64,
@@ -31,12 +31,12 @@ pub struct Block {
 }
 
 impl Block {
-    pub fn new(index: u64, timestamp: i64, chain_id: u32, version: u32, prev_block_hash: Bytes, transaction: Option<Transaction>) -> Self {
+    pub fn new(index: u64, timestamp: i64, chain_name: &str, version_flags: u32, prev_block_hash: Bytes, transaction: Option<Transaction>) -> Self {
         Block {
             index,
             timestamp,
-            chain_id,
-            version,
+            chain_name: chain_name.to_owned(),
+            version_flags,
             // TODO make difficulty parameter
             difficulty: 20,
             random: 0,
@@ -47,6 +47,21 @@ impl Block {
         }
     }
 
+    pub fn from_all_params(index: u64, timestamp: i64, chain_name: &str, version_flags: u32, difficulty: usize, random: u32, nonce: u64, prev_block_hash: Bytes, hash: Bytes, transaction: Option<Transaction>) -> Self {
+        Block {
+            index,
+            timestamp,
+            chain_name: chain_name.to_owned(),
+            version_flags,
+            difficulty,
+            random,
+            nonce,
+            transaction,
+            prev_block_hash,
+            hash,
+        }
+    }
+
     pub fn hash(data: &[u8]) -> Bytes {
         let mut buf: [u8; 32] = [0; 32];
         let mut digest = Sha256::new();

src/blockchain.rs

@@ -1,46 +1,124 @@
 use crate::{Block, Transaction, Bytes};
 use chrono::Utc;
+use sqlite::{Connection, State, Readable, Statement, Error};
+
+const DB_NAME: &str = "blockchain.db";
 
 pub struct Blockchain {
-    pub chain_id: u32,
-    pub version: u32,
+    pub chain_name: String,
+    pub version_flags: u32,
     pub blocks: Vec<Block>,
+    last_block: Option<Block>,
+    db: Connection,
 }
 
 impl Blockchain {
-    pub fn new(chain_id: u32, version: u32) -> Self {
-        let mut blockchain = Blockchain{chain_id, version, blocks: Vec::new()};
+    pub fn new(chain_name: &str, version_flags: u32) -> Self {
+        let db = sqlite::open(DB_NAME).expect("Unable to open blockchain DB");
+        let mut blockchain = Blockchain{ chain_name: chain_name.to_owned(), version_flags, blocks: Vec::new(), last_block: None, db};
+        blockchain.init_db();
         blockchain
     }
 
-    pub fn new_block(&self, transaction: Transaction) -> Block {
-        let prev_block = self.blocks.last().unwrap();
-        let block = Block::new(prev_block.index + 1,Utc::now().timestamp(), self.chain_id, self.version, prev_block.hash.clone(), Some(transaction));
-        block
+    /// Reads options from DB or initializes and writes them to DB if not found
+    fn init_db(&mut self) {
+        match self.db.prepare("SELECT * FROM blocks ORDER BY id DESC LIMIT 1;") {
+            Ok(mut statement) => {
+                while statement.next().unwrap() == State::Row {
+                    match Self::get_block(&mut statement) {
+                        None => { println!("Something wrong with block in DB!"); }
+                        Some(block) => {
+                            println!("Loaded last block: {:?}", &block);
+                            self.chain_name = block.chain_name.clone();
+                            self.version_flags = block.version_flags;
+                            self.last_block = Some(block);
+                        }
+                    }
+                    println!("Loaded from DB: chain_name = {}, version_flags = {}", self.chain_name, self.version_flags);
+                }
+            }
+            Err(_) => {
+                println!("No blockchain database found. Creating new.");
+                self.db.execute("
+                    CREATE TABLE blocks (
+                                         'id' BIGINT,
+                                         'timestamp' BIGINT,
+                                         'chain_name' TEXT,
+                                         'version_flags' TEXT,
+                                         'difficulty' INTEGER,
+                                         'random' INTEGER,
+                                         'nonce' INTEGER,
+                                         'transaction' TEXT,
+                                         'prev_block_hash' BINARY,
+                                         'hash' BINARY
+                                         );
+                    CREATE INDEX block_index ON blocks (id);"
+                ).expect("Error creating blocks table");
+            }
+        }
+    }
+
+    fn get_block(statement: &mut Statement) -> Option<Block> {
+        let index = statement.read::<i64>(0).unwrap() as u64;
+        let timestamp = statement.read::<i64>(1).unwrap();
+        let chain_name = statement.read::<String>(2).unwrap();
+        let version_flags = statement.read::<i64>(3).unwrap() as u32;
+        let difficulty = statement.read::<i64>(4).unwrap() as usize;
+        let random = statement.read::<i64>(5).unwrap() as u32;
+        let nonce = statement.read::<i64>(6).unwrap() as u64;
+        let transaction = Transaction::from_json(&statement.read::<String>(7).unwrap());
+        let prev_block_hash = Bytes::from_bytes(statement.read::<Vec<u8>>(8).unwrap().as_slice());
+        let hash = Bytes::from_bytes(statement.read::<Vec<u8>>(9).unwrap().as_slice());
+        Some(Block::from_all_params(index, timestamp, &chain_name, version_flags, difficulty, random, nonce, prev_block_hash, hash, transaction))
     }
 
     pub fn add_block(&mut self, block: Block) {
-        if self.check_block(&block, None) {
+        if self.check_block(&block, &self.last_block) {
             println!("Adding block:\n{:?}", &block);
-            self.blocks.push(block);
+            self.blocks.push(block.clone());
+            self.last_block = Some(block.clone());
+
+            // Adding block to DB
+            let mut statement = self.db.prepare("INSERT INTO blocks (\
+            id, timestamp, chain_name, version_flags, difficulty,\
+            random, nonce, 'transaction', prev_block_hash, hash)\
+            VALUES (?, ?, ?, ?, ?, ?, ?, ?, ?, ?)").unwrap();
+            statement.bind(1, block.index as i64);
+            statement.bind(2, block.timestamp as i64);
+            statement.bind(3, &*block.chain_name);
+            statement.bind(4, block.version_flags as i64);
+            statement.bind(5, block.difficulty as i64);
+            statement.bind(6, block.random as i64);
+            statement.bind(7, block.nonce as i64);
+            match block.transaction {
+                None => { statement.bind(8, ""); }
+                Some(transaction) => { statement.bind(8, &*transaction.to_string()); }
+            }
+            statement.bind(9, block.prev_block_hash.as_bytes());
+            statement.bind(10, block.hash.as_bytes());
+            statement.next().expect("Error adding block to DB");
         } else {
             println!("Bad block found, ignoring:\n{:?}", &block);
         }
     }
 
-    pub fn check(&self) -> bool {
+    pub fn get_last_block(&self) -> Option<Block> {
+        self.last_block.clone()
+    }
+
+    /*pub fn check(&self) -> bool {
         let mut prev_block = None;
         for block in self.blocks.iter() {
-            if !self.check_block(block, prev_block) {
+            if !self.check_block(block, &prev_block) {
                 println!("Block {:?} is bad", block);
                 return false;
             }
             prev_block = Some(block);
         }
         true
-    }
+    }*/
 
-    fn check_block(&self, block: &Block, prev_block: Option<&Block>) -> bool {
+    fn check_block(&self, block: &Block, prev_block: &Option<Block>) -> bool {
         if !Self::check_block_hash(block) {
             return false;
         }
@@ -48,7 +126,7 @@ impl Blockchain {
             return true;
         }
 
-        return block.prev_block_hash == prev_block.unwrap().hash;
+        return block.prev_block_hash == prev_block.as_ref().unwrap().hash;
     }
 
     pub fn check_block_hash(block: &Block) -> bool {

src/context.rs

@@ -46,8 +46,8 @@ impl Context {
 
 #[derive(Clone, Debug, Serialize, Deserialize)]
 pub struct Settings {
-    pub chain_id: u32,
-    pub version: u32,
+    pub chain_name: String,
+    pub version_flags: u32,
     pub key_file: String
 }
 

src/main.rs

@@ -27,7 +27,7 @@ fn main() {
         None => { generate_key(KEYSTORE_DIFFICULTY, Arc::new(AtomicBool::new(true))).expect("Could not load or generate keypair") }
         Some(keystore) => { keystore }
     };
-    let blockchain: Blockchain = Blockchain::new(settings.chain_id, settings.version);
+    let blockchain: Blockchain = Blockchain::new(&settings.chain_name, settings.version_flags);
     let context: Arc<Mutex<Context>> = Arc::new(Mutex::new(Context::new(settings, keystore, blockchain)));
 
     let mut miner_obj = Miner::new(context.clone());
@@ -40,19 +40,10 @@ fn main() {
 
 fn create_genesis_if_needed(context: &Arc<Mutex<Context>>, miner: &Arc<Mutex<Miner>>) {
     // TODO check settings and if there is no mention of bootstrap nodes, generate genesis block
-    let keystore = {
-        // This code block makes it possible to contain quick lock here, and let the miner below work
-        let context_guard = context.lock().unwrap();
-        if context_guard.get_blockchain().blocks.is_empty() {
-            // If blockchain is empty, we are going to mine a Genesis block
-            Some(context_guard.get_keystore())
-        } else {
-            None
-        }
-    };
-
-    if keystore.is_some() {
-        create_genesis(miner.clone(), GENESIS_ZONE, &keystore.unwrap(), GENESIS_ZONE_DIFFICULTY);
+    let context_guard = context.lock().unwrap();
+    if context_guard.get_blockchain().get_last_block().is_none() {
+        // If blockchain is empty, we are going to mine a Genesis block
+        create_genesis(miner.clone(), GENESIS_ZONE, &context_guard.get_keystore(), GENESIS_ZONE_DIFFICULTY);
     }
 }
 
@@ -192,30 +183,3 @@ fn inline_style(s: &str) -> String {
 fn inline_script(s: &str) -> String {
     format!(r#"<script type="text/javascript">{}</script>"#, s)
 }
-
-fn test_blockchain() -> () {
-    let mut blockchain = Blockchain::new(42, 0);
-    println!("Blockchain with genesis block has been created");
-    let keystore = Keystore::from_file("default.key", "").unwrap();
-
-    /*let mut block = create_transaction(&mut blockchain, keystore.clone(), "test.zz", vec!["AAAA IN 301:2925::1".to_owned()], vec!["testing".to_owned(), "example".to_owned()], 365);
-
-    // Mining the nonce
-    block.mine();
-
-    // Our block is ready, we can print it and add to Blockchain
-    let s = serde_json::to_string(&block).unwrap();
-    println!("Serialized block:\n{}", s);
-    blockchain.add_block(block);
-    println!("Second block added");
-
-    let block2: Block = serde_json::from_str(&s).unwrap();
-    println!("DeSerialized block:\n{:?}", block2);*/
-
-    // Let's check if the blockchain is valid
-    if blockchain.check() {
-        println!("Blockchain is correct");
-    } else {
-        println!("Blockchain is corrupted, aborting");
-    }
-}

src/miner.rs

@@ -11,8 +11,8 @@ use num_cpus;
 pub struct Miner {
     context: Arc<Mutex<Context>>,
     keystore: Keystore,
-    chain_id: u32,
-    version: u32,
+    chain_name: String,
+    version_flags: u32,
     transactions: Arc<Mutex<Vec<Transaction>>>,
     last_block: Option<Block>,
     running: Arc<AtomicBool>,
@@ -26,8 +26,8 @@ impl Miner {
         Miner {
             context: context.clone(),
             keystore: c.keystore.clone(),
-            chain_id: c.settings.chain_id,
-            version: c.settings.version,
+            chain_name: c.settings.chain_name.clone(),
+            version_flags: c.settings.version_flags,
             transactions: Arc::new(Mutex::new(Vec::new())),
             last_block: c.blockchain.blocks.last().cloned(),
             running: Arc::new(AtomicBool::new(false)),
@@ -83,12 +83,12 @@ impl Miner {
 
     fn mine_internal(context: Arc<Mutex<Context>>, transactions: Arc<Mutex<Vec<Transaction>>>, mut transaction: Transaction, mining: Arc<AtomicBool>, cond_var: Arc<Condvar>) {
         let mut last_block_time = 0i64;
-        let mut chain_id = 0u32;
-        let mut version = 0u32;
+        let mut chain_name= String::new();
+        let mut version_flags= 0u32;
         {
             let c = context.lock().unwrap();
-            chain_id = c.settings.chain_id;
-            version = c.settings.version;
+            chain_name = c.settings.chain_name.clone();
+            version_flags = c.settings.version_flags;
         }
         let block = {
             if transaction.signature.is_zero() {
@@ -99,17 +99,17 @@ impl Miner {
             }
 
             // Get last block for mining
-            let last_block = { context.lock().unwrap().blockchain.blocks.last().cloned() };
+            let last_block = { context.lock().unwrap().blockchain.get_last_block() };
             match last_block {
                 None => {
                     println!("Mining genesis block");
                     // Creating a block with that signed transaction
-                    Block::new(0, Utc::now().timestamp(), chain_id, version, Bytes::zero32(), Some(transaction.clone()))
+                    Block::new(0, Utc::now().timestamp(), &chain_name, version_flags, Bytes::zero32(), Some(transaction.clone()))
                 },
                 Some(block) => {
                     last_block_time = block.timestamp;
                     // Creating a block with that signed transaction
-                    Block::new(block.index + 1, Utc::now().timestamp(), chain_id, version, block.hash.clone(), Some(transaction.clone()))
+                    Block::new(block.index + 1, Utc::now().timestamp(), &chain_name, version_flags, block.hash.clone(), Some(transaction.clone()))
                 },
             }
         };
@@ -149,11 +149,6 @@ impl Miner {
             });
         }
     }
-
-    fn get_last_block(&self) -> Option<Block> {
-        let context = self.context.lock().unwrap();
-        context.blockchain.blocks.last().cloned()
-    }
 }
 
 fn find_hash(digest: &mut dyn Digest, mut block: Block, prev_block_time: i64, running: Arc<AtomicBool>) -> Option<Block> {

src/transaction.rs

@@ -31,6 +31,13 @@ impl Transaction {
         Transaction { identity, method, data, pub_key, signature: Bytes::zero64() }
     }
 
+    pub fn from_json(json: &str) -> Option<Self> {
+        match serde_json::from_str(json) {
+            Ok(transaction) => Some(transaction),
+            Err(_) => None
+        }
+    }
+
     pub fn set_signature(&mut self, hash: Bytes) {
         self.signature = hash;
     }
@@ -39,6 +46,11 @@ impl Transaction {
         // Let it panic if something is not okay
         serde_json::to_vec(&self).unwrap()
     }
+
+    pub fn to_string(&self) -> String {
+        // Let it panic if something is not okay
+        serde_json::to_string(&self).unwrap()
+    }
 }
 
 impl fmt::Debug for Transaction {