feat!: adding fee output type

- Adding a Token::is_zero API.
- Re-adding workflow file for automatic releases.

.github/workflows/auto_merge_prs.yml

@@ -0,0 +1,38 @@
+# auto merge workflow.
+#
+# Auto merge PR if commit msg begins with `chore(release):`,
+# or if it has been raised by Dependabot.
+# Uses https://github.com/ridedott/merge-me-action.
+
+name: Merge Version Change and Dependabot PRs automatically
+
+on: pull_request
+
+jobs:
+  merge:
+    runs-on: ubuntu-20.04
+    steps:
+    - uses: actions/checkout@v2
+      with:
+        fetch-depth: '0'
+
+    - name: get commit message
+      run: |
+          commitmsg=$(git log --format=%s -n 1 ${{ github.event.pull_request.head.sha }})
+          echo "commitmsg=${commitmsg}" >> $GITHUB_ENV
+    - name: show commit message
+      run : echo $commitmsg
+
+    - name: Merge Version change PR
+      if: startsWith( env.commitmsg, 'chore(release):')
+      uses: ridedott/merge-me-action@81667e6ae186ddbe6d3c3186d27d91afa7475e2c
+      with:
+        GITHUB_LOGIN: dirvine
+        GITHUB_TOKEN: ${{ secrets.MERGE_BUMP_BRANCH_TOKEN }}
+        MERGE_METHOD: REBASE
+
+    - name: Dependabot Merge
+      uses: ridedott/merge-me-action@v2
+      with:
+        GITHUB_TOKEN: ${{ secrets.GITHUB_TOKEN }}
+        MERGE_METHOD: REBASE

src/builder.rs

@@ -8,7 +8,7 @@
 
 use crate::{
     transaction::{DbcTransaction, Output},
-    DbcId, DerivationIndex, DerivedKey, Input, PublicAddress, Spend,
+    DbcId, DerivationIndex, DerivedKey, FeeOutput, Input, PublicAddress, Spend,
 };
 use crate::{Dbc, DbcCiphers, Error, Hash, Result, SignedSpend, Token};
 #[cfg(feature = "serde")]
@@ -24,6 +24,7 @@ pub type InputSrcTx = DbcTransaction;
 pub struct TransactionBuilder {
     inputs: Vec<Input>,
     outputs: Vec<Output>,
+    fee: FeeOutput,
     input_details: BTreeMap<DbcId, (DerivedKey, InputSrcTx)>,
     output_details: BTreeMap<DbcId, (PublicAddress, DerivationIndex)>,
 }
@@ -100,6 +101,12 @@ impl TransactionBuilder {
         self
     }
 
+    /// Sets the given fee output.
+    pub fn set_fee_output(mut self, output: FeeOutput) -> Self {
+        self.fee = output;
+        self
+    }
+
     /// Get a list of input ids.
     pub fn input_ids(&self) -> Vec<DbcId> {
         self.inputs.iter().map(|i| i.dbc_id()).collect()
@@ -113,7 +120,12 @@ impl TransactionBuilder {
 
     /// Get sum of output Tokens.
     pub fn outputs_tokens_sum(&self) -> Token {
-        let amount = self.outputs.iter().map(|o| o.token.as_nano()).sum();
+        let amount = self
+            .outputs
+            .iter()
+            .map(|o| o.token.as_nano())
+            .chain(std::iter::once(self.fee.token.as_nano()))
+            .sum();
         Token::from_nano(amount)
     }
 
@@ -132,6 +144,7 @@ impl TransactionBuilder {
         let spent_tx = DbcTransaction {
             inputs: self.inputs.clone(),
             outputs: self.outputs.clone(),
+            fee: self.fee.clone(),
         };
         let signed_spends: BTreeSet<_> = self
             .inputs

src/dbc.rs

@@ -8,7 +8,7 @@
 
 use crate::{
     dbc_id::PublicAddress, transaction::DbcTransaction, DbcCiphers, DbcId, DerivationIndex,
-    DerivedKey, Error, Hash, MainKey, Result, SignedSpend, Token,
+    DerivedKey, Error, FeeOutput, Hash, MainKey, Result, SignedSpend, Token,
 };
 #[cfg(feature = "serde")]
 use serde::{Deserialize, Serialize};
@@ -96,6 +96,11 @@ impl Dbc {
         self.ciphers.derivation_index(main_key)
     }
 
+    /// Return the fee output used in the source transaction
+    pub fn fee_output(&self) -> &FeeOutput {
+        &self.src_tx.fee
+    }
+
     /// Return the reason why this Dbc was spent.
     /// Will be the default Hash (empty) if reason is none.
     pub fn reason(&self) -> Hash {
@@ -194,7 +199,7 @@ pub(crate) mod tests {
         mock,
         rand::{CryptoRng, RngCore},
         transaction::Output,
-        Hash, Token,
+        FeeOutput, Hash, Token,
     };
     use blsttc::{PublicKey, SecretKey};
     use std::convert::TryInto;
@@ -209,6 +214,7 @@ pub(crate) mod tests {
         let tx = DbcTransaction {
             inputs: vec![],
             outputs: vec![Output::new(derived_key.dbc_id(), amount)],
+            fee: FeeOutput::new(Hash::default(), 3_500, Hash::default()),
         };
         let ciphers = DbcCiphers::from((&main_key.public_address(), &derivation_index));
         let dbc = Dbc {
@@ -222,6 +228,10 @@ pub(crate) mod tests {
 
         let dbc = Dbc::from_hex(&hex)?;
         assert_eq!(dbc.token()?.as_nano(), 1_530_000_000);
+
+        let fee_amount = dbc.fee_output().token;
+        assert_eq!(fee_amount, Token::from_nano(3_500));
+
         Ok(())
     }
 
@@ -235,6 +245,7 @@ pub(crate) mod tests {
         let tx = DbcTransaction {
             inputs: vec![],
             outputs: vec![Output::new(derived_key.dbc_id(), amount)],
+            fee: FeeOutput::new(Hash::default(), 2_500, Hash::default()),
         };
         let ciphers = DbcCiphers::from((&main_key.public_address(), &derivation_index));
         let dbc = Dbc {
@@ -249,6 +260,9 @@ pub(crate) mod tests {
 
         assert_eq!(dbc.token()?, dbc_from_hex.token()?);
 
+        let fee_amount = dbc.fee_output().token;
+        assert_eq!(fee_amount, Token::from_nano(2_500));
+
         Ok(())
     }
 
@@ -286,6 +300,7 @@ pub(crate) mod tests {
         let tx = DbcTransaction {
             inputs: vec![],
             outputs: vec![Output::new(derived_key.dbc_id(), amount)],
+            fee: FeeOutput::default(),
         };
 
         let ciphers = DbcCiphers::from((&main_key.public_address(), &derivation_index));

src/fee_output.rs

@@ -0,0 +1,56 @@
+// Copyright (c) 2023, MaidSafe.
+// All rights reserved.
+//
+// This SAFE Network Software is licensed under the BSD-3-Clause license.
+// Please see the LICENSE file for more details.
+
+use crate::{Hash, Token};
+
+#[cfg(feature = "serde")]
+use serde::{Deserialize, Serialize};
+
+#[cfg_attr(feature = "serde", derive(Serialize, Deserialize))]
+#[derive(Debug, Clone, Eq, PartialEq)]
+pub struct FeeOutput {
+    /// The id is expected (in order to be accepted by the network) to be built from: hash(root_hash + inputs' ids).
+    /// This requirement makes it possible for this output to be used as an input in a rewards/farming
+    /// claiming Tx, by making its spend location deterministic, analogous to how any other output
+    /// is spent using its id to determine the location to store the signed spend.
+    pub id: Hash,
+    /// Amount being paid as storage fee to the network.
+    pub token: Token,
+    /// The root hash of the proof's Merkletree corresponding to the content being paid for.
+    pub root_hash: Hash,
+}
+
+impl Default for FeeOutput {
+    fn default() -> Self {
+        Self {
+            id: Hash::default(),
+            token: Token::zero(),
+            root_hash: Hash::default(),
+        }
+    }
+}
+
+impl FeeOutput {
+    pub fn new(id: Hash, amount: u64, root_hash: Hash) -> Self {
+        Self {
+            id,
+            token: Token::from_nano(amount),
+            root_hash,
+        }
+    }
+
+    pub fn is_free(&self) -> bool {
+        self.token.is_zero()
+    }
+
+    pub fn to_bytes(&self) -> Vec<u8> {
+        let mut v = Vec::<u8>::new();
+        v.extend(self.id.slice());
+        v.extend(self.token.to_bytes());
+        v.extend(self.root_hash.slice());
+        v
+    }
+}

src/lib.rs

@@ -13,6 +13,7 @@ mod dbc;
 mod dbc_ciphers;
 mod dbc_id;
 mod error;
+mod fee_output;
 mod signed_spend;
 mod spentbook;
 mod token;
@@ -27,6 +28,7 @@ pub use crate::{
     dbc_ciphers::DbcCiphers,
     dbc_id::{random_derivation_index, DbcId, DerivationIndex, DerivedKey, MainKey, PublicAddress},
     error::{Error, Result},
+    fee_output::FeeOutput,
     signed_spend::{SignedSpend, Spend},
     token::Token,
     transaction::{DbcTransaction, Input, Output},

src/mock/genesis_material.rs

@@ -8,7 +8,7 @@
 
 use crate::{
     builder::InputSrcTx, transaction::Output, DbcId, DbcTransaction, DerivationIndex, DerivedKey,
-    Input, MainKey,
+    FeeOutput, Input, MainKey,
 };
 use blsttc::IntoFr;
 
@@ -51,12 +51,10 @@ impl Default for GenesisMaterial {
         let genesis_tx = DbcTransaction {
             inputs: vec![input],
             outputs: vec![output],
+            fee: FeeOutput::default(),
         };
 
-        let input_src_tx = DbcTransaction {
-            inputs: vec![],
-            outputs: vec![],
-        };
+        let input_src_tx = DbcTransaction::empty();
 
         Self {
             input_dbc_id: input_derived_key.dbc_id(), // the id of the fictional dbc being reissued to genesis dbc

src/token.rs

@@ -31,6 +31,11 @@ impl Token {
         Self(0)
     }
 
+    /// Returns whether it's a representation of zero Token.
+    pub const fn is_zero(&self) -> bool {
+        self.0 == 0
+    }
+
     /// New value from a number of nano tokens.
     pub const fn from_nano(value: u64) -> Self {
         Self(value)

src/transaction.rs

@@ -4,7 +4,7 @@
 // This SAFE Network Software is licensed under the BSD-3-Clause license.
 // Please see the LICENSE file for more details.
 
-use crate::{DbcId, SignedSpend, Token};
+use crate::{DbcId, FeeOutput, SignedSpend, Token};
 #[cfg(feature = "serde")]
 use serde::{Deserialize, Serialize};
 use std::{cmp::Ordering, collections::BTreeSet};
@@ -73,6 +73,7 @@ impl Output {
 pub struct DbcTransaction {
     pub inputs: Vec<Input>,
     pub outputs: Vec<Output>,
+    pub fee: FeeOutput,
 }
 
 impl PartialEq for DbcTransaction {
@@ -96,6 +97,14 @@ impl Ord for DbcTransaction {
 }
 
 impl DbcTransaction {
+    pub fn empty() -> Self {
+        Self {
+            inputs: vec![],
+            outputs: vec![],
+            fee: FeeOutput::default(),
+        }
+    }
+
     pub fn to_bytes(&self) -> Vec<u8> {
         let mut v: Vec<u8> = Default::default();
         v.extend("inputs".as_bytes());
@@ -106,6 +115,8 @@ impl DbcTransaction {
         for o in self.outputs.iter() {
             v.extend(&o.to_bytes());
         }
+        v.extend("fee".as_bytes());
+        v.extend(&self.fee.to_bytes());
         v.extend("end".as_bytes());
         v
     }
@@ -145,6 +156,7 @@ impl DbcTransaction {
             .outputs
             .iter()
             .map(|o| o.token)
+            .chain(std::iter::once(self.fee.token))
             .try_fold(0, |acc: u64, o| {
                 acc.checked_add(o.as_nano()).ok_or(Error::NumericOverflow)
             })?;