Remove PoW consensus

Cargo.toml

@@ -31,7 +31,6 @@ codechain-sync = { path = "sync" }
 codechain-timer = { path = "util/timer" }
 codechain-types = { path = "types" }
 codechain-vm = { path = "vm" }
-codechain-stratum = { path = "stratum" }
 ctrlc = { git = "https://github.com/paritytech/rust-ctrlc.git" }
 fdlimit = "0.1"
 finally-block = "0.1"

core/Cargo.toml

@@ -17,10 +17,8 @@ codechain-network = { path = "../network" }
 codechain-state = { path = "../state" }
 codechain-timer = { path = "../util/timer" }
 codechain-types = { path = "../types" }
-codechain-stratum = { path = "../stratum" }
 codechain-vm = { path = "../vm" }
 crossbeam-channel = "0.3"
-cuckoo = { git = "https://github.com/CodeChain-io/rust-cuckoo.git", rev = "280cab9c" }
 hyper = { git = "https://github.com/paritytech/hyper", default-features = false }
 kvdb = "0.1"
 kvdb-rocksdb = "0.1"

core/src/block.rs

@@ -375,19 +375,11 @@ impl LockedBlock {
     /// Provide a valid seal in order to turn this into a `SealedBlock`.
     /// This does check the validity of `seal` with the engine.
     /// Returns the `ClosedBlock` back again if the seal is no good.
-    pub fn try_seal(
-        mut self,
-        engine: &dyn CodeChainEngine,
-        seal: Vec<Bytes>,
-    ) -> Result<SealedBlock, (Error, LockedBlock)> {
+    pub fn seal_block(mut self, seal: Vec<Bytes>) -> SealedBlock {
         self.block.header.set_seal(seal);
 
-        // TODO: passing state context to avoid engines owning it?
-        match engine.verify_local_seal(&self.block.header) {
-            Err(e) => Err((e, self)),
-            _ => Ok(SealedBlock {
-                block: self.block,
-            }),
+        SealedBlock {
+            block: self.block,
         }
     }
 

core/src/client/client.rs

@@ -315,21 +315,13 @@ impl Client {
     }
 }
 
-/// When RESEAL_MAX_TIMER invoked, a block is created although the block is empty.
-const RESEAL_MAX_TIMER_TOKEN: TimerToken = 0;
 /// The minimum time between blocks, the miner creates a block when RESEAL_MIN_TIMER is invoked.
 /// Do not create a block before RESEAL_MIN_TIMER event.
 const RESEAL_MIN_TIMER_TOKEN: TimerToken = 1;
 
 impl TimeoutHandler for Client {
     fn on_timeout(&self, token: TimerToken) {
         match token {
-            RESEAL_MAX_TIMER_TOKEN => {
-                // Working in PoW only
-                if self.engine().seals_internally().is_none() && !self.importer.miner.prepare_work_sealing(self) {
-                    self.update_sealing(BlockId::Latest, true);
-                }
-            }
             RESEAL_MIN_TIMER_TOKEN => {
                 // Checking self.ready_transactions() for efficiency
                 if !self.engine().engine_type().ignore_reseal_min_period() && !self.is_pending_queue_empty() {
@@ -552,18 +544,6 @@ impl EngineClient for Client {
         }
     }
 
-    /// Submit a seal for a block in the mining queue.
-    fn submit_seal(&self, block_hash: BlockHash, seal: Vec<Bytes>) {
-        if self.importer.miner.submit_seal(self, block_hash, seal).is_err() {
-            cwarn!(CLIENT, "Wrong internal seal submission!")
-        }
-    }
-
-    /// Convert PoW difficulty to target.
-    fn score_to_target(&self, score: &U256) -> U256 {
-        self.engine.score_to_target(score)
-    }
-
     /// Update the best block as the given block hash.
     ///
     /// Used in Tendermint, when going to the commit step.
@@ -690,20 +670,6 @@ impl ImportBlock for Client {
             Err(err) => unreachable!("Reseal min timer should not fail but failed with {:?}", err),
         }
     }
-
-    fn set_max_timer(&self) {
-        self.reseal_timer.cancel(RESEAL_MAX_TIMER_TOKEN).expect("Reseal max timer clear succeeds");
-        match self
-            .reseal_timer
-            .schedule_once(self.importer.miner.get_options().reseal_max_period, RESEAL_MAX_TIMER_TOKEN)
-        {
-            Ok(_) => {}
-            Err(TimerScheduleError::TokenAlreadyScheduled) => {
-                // Since set_max_timer could be called in multi thread, ignore the TokenAlreadyScheduled error
-            }
-            Err(err) => unreachable!("Reseal max timer should not fail but failed with {:?}", err),
-        }
-    }
 }