w

data_structures/src/error.rs

@@ -284,12 +284,34 @@ pub enum TransactionError {
         min_stake, stake
     )]
     StakeBelowMinimum { min_stake: u64, stake: u64 },
-    /// A stake output with zero value does not make sense
+    /// Unstaking more than the total staked
     #[fail(
-        display = "Transaction {} contains a stake output with zero value",
-        tx_hash
+        display = "Unstaking ({}) more than the total staked ({})",
+        unstake, stake
     )]
+    UnstakingMoreThanStaked { stake: u64, unstake: u64 },
+    /// An stake output with zero value does not make sense
+    #[fail(display = "Transaction {} has a zero value stake output", tx_hash)]
     ZeroValueStakeOutput { tx_hash: Hash },
+    /// Invalid unstake signature
+    #[fail(
+        display = "Invalid unstake signature: ({}), withdrawal ({}), operator ({})",
+        signature, withdrawal, operator
+    )]
+    InvalidUnstakeSignature {
+        signature: Hash,
+        withdrawal: Hash,
+        operator: Hash,
+    },
+    /// Invalid unstake time_lock
+    #[fail(
+        display = "The unstake timelock: ({}) is lower than the minimum unstaking delay ({})",
+        time_lock, unstaking_delay_seconds
+    )]
+    InvalidUnstakeTimelock {
+        time_lock: u64,
+        unstaking_delay_seconds: u32,
+    },
     #[fail(
         display = "The reward-to-collateral ratio for this data request is {}, but must be equal or less than {}",
         reward_collateral_ratio, required_reward_collateral_ratio
@@ -419,6 +441,12 @@ pub enum BlockError {
         weight, max_weight
     )]
     TotalStakeWeightLimitExceeded { weight: u32, max_weight: u32 },
+    /// Unstake weight limit exceeded
+    #[fail(
+        display = "Total weight of Unstake Transactions in a block ({}) exceeds the limit ({})",
+        weight, max_weight
+    )]
+    TotalUnstakeWeightLimitExceeded { weight: u32, max_weight: u32 },
     /// Repeated operator Stake
     #[fail(
         display = "A single operator is receiving stake more than once in a block: ({}) ",

data_structures/src/superblock.rs

@@ -807,6 +807,7 @@ mod tests {
                 reveal_hash_merkle_root: default_hash,
                 tally_hash_merkle_root: tally_merkle_root_1,
                 stake_hash_merkle_root: default_hash,
+                unstake_hash_merkle_root: default_hash,
             },
             proof: default_proof,
             bn256_public_key: None,
@@ -857,6 +858,7 @@ mod tests {
                 reveal_hash_merkle_root: default_hash,
                 tally_hash_merkle_root: tally_merkle_root_1,
                 stake_hash_merkle_root: default_hash,
+                unstake_hash_merkle_root: default_hash,
             },
             proof: default_proof.clone(),
             bn256_public_key: None,
@@ -873,6 +875,7 @@ mod tests {
                 reveal_hash_merkle_root: default_hash,
                 tally_hash_merkle_root: tally_merkle_root_2,
                 stake_hash_merkle_root: default_hash,
+                unstake_hash_merkle_root: default_hash,
             },
             proof: default_proof,
             bn256_public_key: None,

data_structures/src/transaction.rs

@@ -13,7 +13,7 @@ use crate::{
     proto::{schema::witnet, ProtobufConvert},
     vrf::DataRequestEligibilityClaim,
 };
-
+pub const UNSTAKE_TRANSACTION_WEIGHT: u32 = 153;
 // These constants were calculated in:
 // https://github.com/witnet/WIPs/blob/master/wip-0007.md
 pub const INPUT_SIZE: u32 = 133;
@@ -132,6 +132,7 @@ pub enum Transaction {
     Tally(TallyTransaction),
     Mint(MintTransaction),
     Stake(StakeTransaction),
+    Unstake(UnstakeTransaction),
 }
 
 impl From<VTTransaction> for Transaction {
@@ -176,6 +177,12 @@ impl From<StakeTransaction> for Transaction {
     }
 }
 
+impl From<UnstakeTransaction> for Transaction {
+    fn from(transaction: UnstakeTransaction) -> Self {
+        Self::Unstake(transaction)
+    }
+}
+
 impl AsRef<Transaction> for Transaction {
     fn as_ref(&self) -> &Self {
         self
@@ -762,6 +769,64 @@ impl StakeOutput {
     }
 }
 
+#[derive(Debug, Default, Eq, PartialEq, Clone, Serialize, Deserialize, ProtobufConvert, Hash)]
+#[protobuf_convert(pb = "witnet::UnstakeTransaction")]
+pub struct UnstakeTransaction {
+    pub body: UnstakeTransactionBody,
+    pub signature: KeyedSignature,
+}
+impl UnstakeTransaction {
+    // Creates a new unstake transaction.
+    pub fn new(body: UnstakeTransactionBody, signature: KeyedSignature) -> Self {
+        UnstakeTransaction { body, signature }
+    }
+
+    /// Returns the weight of a unstake transaction.
+    /// This is the weight that will be used to calculate
+    /// how many transactions can fit inside one block
+    pub fn weight(&self) -> u32 {
+        self.body.weight()
+    }
+}
+
+#[derive(Debug, Default, Eq, PartialEq, Clone, Serialize, Deserialize, ProtobufConvert, Hash)]
+#[protobuf_convert(pb = "witnet::UnstakeTransactionBody")]
+pub struct UnstakeTransactionBody {
+    pub operator: PublicKeyHash,
+    pub withdrawal: ValueTransferOutput,
+    pub change: Option<ValueTransferOutput>,
+
+    #[protobuf_convert(skip)]
+    #[serde(skip)]
+    hash: MemoHash,
+}
+
+impl UnstakeTransactionBody {
+    /// Creates a new stake transaction body.
+    pub fn new(
+        operator: PublicKeyHash,
+        withdrawal: ValueTransferOutput,
+        change: Option<ValueTransferOutput>,
+    ) -> Self {
+        UnstakeTransactionBody {
+            operator,
+            withdrawal,
+            change,
+            hash: MemoHash::new(),
+        }
+    }
+
+    /// Stake transaction weight. It is calculated as:
+    ///
+    /// ```text
+    /// ST_weight = 153
+    ///
+    /// ```
+    pub fn weight(&self) -> u32 {
+        UNSTAKE_TRANSACTION_WEIGHT
+    }
+}
+
 impl MemoizedHashable for VTTransactionBody {
     fn hashable_bytes(&self) -> Vec<u8> {
         self.to_pb_bytes().unwrap()
@@ -810,6 +875,15 @@ impl MemoizedHashable for StakeTransactionBody {
         &self.hash
     }
 }
+impl MemoizedHashable for UnstakeTransactionBody {
+    fn hashable_bytes(&self) -> Vec<u8> {
+        self.to_pb_bytes().unwrap()
+    }
+
+    fn memoized_hash(&self) -> &MemoHash {
+        &self.hash
+    }
+}
 impl MemoizedHashable for TallyTransaction {
     fn hashable_bytes(&self) -> Vec<u8> {
         let Hash::SHA256(data_bytes) = self.data_poi_hash();
@@ -858,6 +932,11 @@ impl Hashable for StakeTransaction {
         self.body.hash()
     }
 }
+impl Hashable for UnstakeTransaction {
+    fn hash(&self) -> Hash {
+        self.body.hash()
+    }
+}
 
 impl Hashable for Transaction {
     fn hash(&self) -> Hash {
@@ -869,6 +948,7 @@ impl Hashable for Transaction {
             Transaction::Tally(tx) => tx.hash(),
             Transaction::Mint(tx) => tx.hash(),
             Transaction::Stake(tx) => tx.hash(),
+            Transaction::Unstake(tx) => tx.hash(),
         }
     }
 }

data_structures/src/types.rs

@@ -76,6 +76,7 @@ impl fmt::Display for Command {
                     Transaction::Tally(_) => f.write_str("TALLY_TRANSACTION")?,
                     Transaction::Mint(_) => f.write_str("MINT_TRANSACTION")?,
                     Transaction::Stake(_) => f.write_str("STAKE_TRANSACTION")?,
+                    Transaction::Unstake(_) => f.write_str("UNSTAKE_TRANSACTION")?,
                 }
                 write!(f, ": {}", tx.hash())
             }

node/src/actors/chain_manager/mining.rs

@@ -841,6 +841,8 @@ pub fn build_block(
     let mut tally_txns = Vec::new();
     // TODO: handle stake tx
     let stake_txns = Vec::new();
+    // TODO: handle unstake tx
+    let unstake_txns = Vec::new();
 
     let min_vt_weight =
         VTTransactionBody::new(vec![Input::default()], vec![ValueTransferOutput::default()])
@@ -1003,6 +1005,7 @@ pub fn build_block(
     let reveal_hash_merkle_root = merkle_tree_root(&reveal_txns);
     let tally_hash_merkle_root = merkle_tree_root(&tally_txns);
     let stake_hash_merkle_root = merkle_tree_root(&stake_txns);
+    let unstake_hash_merkle_root = merkle_tree_root(&unstake_txns);
     let merkle_roots = BlockMerkleRoots {
         mint_hash: mint.hash(),
         vt_hash_merkle_root,
@@ -1011,6 +1014,7 @@ pub fn build_block(
         reveal_hash_merkle_root,
         tally_hash_merkle_root,
         stake_hash_merkle_root,
+        unstake_hash_merkle_root,
     };
 
     let block_header = BlockHeader {
@@ -1029,6 +1033,7 @@ pub fn build_block(
         reveal_txns,
         tally_txns,
         stake_txns,
+        unstake_txns,
     };
 
     (block_header, txns)

schemas/witnet/witnet.proto

@@ -60,6 +60,7 @@ message Block {
             Hash reveal_hash_merkle_root = 5;
             Hash tally_hash_merkle_root = 6;
             Hash stake_hash_merkle_root = 7;
+            Hash unstake_hash_merkle_root = 8;
         }
         uint32 signals = 1;
         CheckpointBeacon beacon = 2;
@@ -75,6 +76,7 @@ message Block {
         repeated RevealTransaction reveal_txns = 5;
         repeated TallyTransaction tally_txns = 6;
         repeated StakeTransaction stake_txns = 7; 
+        repeated UnstakeTransaction unstake_txns = 8; 
     }
 
     BlockHeader block_header = 1;
@@ -247,6 +249,17 @@ message StakeTransaction {
     repeated KeyedSignature signatures = 2;
 }
 
+message UnstakeTransactionBody {
+    PublicKeyHash operator = 1;
+    ValueTransferOutput withdrawal = 2;
+    ValueTransferOutput change = 3;
+}
+
+message UnstakeTransaction {
+    UnstakeTransactionBody body = 1 ;
+    KeyedSignature signature = 2;
+}
+
 message Transaction {
     oneof kind {
         VTTransaction ValueTransfer = 1;
@@ -256,6 +269,7 @@ message Transaction {
         TallyTransaction Tally = 5;
         MintTransaction Mint = 6;
         StakeTransaction Stake = 7;
+        UnstakeTransaction Unstake = 8;
     }
 }