feat: feature gate incremental function

.github/workflows/linux.yml

@@ -42,7 +42,7 @@ jobs:
         uses: actions-rs/cargo@v1
         with:
           command: check
-          args: --all --bins --examples --tests
+          args: --all --bins --examples --tests --all-features
 
       - name: tests
         uses: actions-rs/cargo@v1
@@ -56,7 +56,7 @@ jobs:
         uses: actions-rs/tarpaulin@v0.1
         with:
           version: '0.15.0'
-          args: '-t 1200'
+          args: '-t 1200 --all-features'
 
       - name: Upload to Codecov
         if: matrix.version == 'stable' && (github.ref == 'refs/heads/master' || github.event_name == 'pull_request')

Cargo.toml

@@ -19,3 +19,7 @@ serde = { version = "1.0", features = ["derive"] }
 bincode = "1.3"
 derive_builder = "0.12"
 num = { version = "0.4.0", default-features = false, features = ["serde", "num-bigint"]}
+
+[features]
+default = []
+incremental = []

Makefile

@@ -2,7 +2,7 @@
 #
 # SPDX-License-Identifier: AGPL-3.0-or-later
 define test_core
-	cargo test --no-fail-fast
+	cargo test --no-fail-fast --all-features
 endef
 
 default: ## Build library in debug mode

src/lib.rs

@@ -50,19 +50,32 @@ pub struct Config {
     pub salt: String,
 }
 
-pub enum SteppedSolve<T> {
+/// Return value of incremental prooving. When proof  is ready, IncrementalSolve::Work is returned
+/// and when proof is not ready, IncrementalSolve::Intermediate is returned
+#[cfg(feature = "incremental")]
+pub enum IncrementalSolve<T> {
+    /// Intermediate result
     Intermediate(u128, u64, Sha256, u128),
+    /// Final result
     Work(PoW<T>),
 }
 
 impl Config {
+    ///
+    /// step is used to control the number of cycles after which the function should exit, even
+    /// when the proof isn't ready
+    /// inter is used to keep track of state and complete proof generation. Set inter to None
+    /// during first cyle and pass the returned value of the previous cycle to continue proof
+    /// generation
+
+    #[cfg(feature = "incremental")]
     pub fn stepped_prove_work<T>(
         &self,
         t: &T,
         difficulty: u32,
         step: usize,
-        inter: Option<SteppedSolve<T>>,
+        inter: Option<IncrementalSolve<T>>,
-    ) -> bincode::Result<SteppedSolve<T>>
+    ) -> bincode::Result<IncrementalSolve<T>>
     where
         T: Serialize,
     {
@@ -70,23 +83,34 @@ impl Config {
             .map(|v| self.stepped_prove_work_serialized(&v, difficulty, step, inter))
     }
 
-    /// Create Proof of Work on an already serialized item of type T.
+    #[cfg(feature = "incremental")]
+    /// Create Proof of Work over item of type T.
+    ///
+    /// Make sure difficulty is not too high. A 64 bit difficulty,
+    /// for example, takes a long time on a general purpose processor.
     /// The input is assumed to be serialized using network byte order.
     ///
     /// Make sure difficulty is not too high. A 64 bit difficulty,
     /// for example, takes a long time on a general purpose processor.
-    pub fn stepped_prove_work_serialized<T>(
+    /// step is used to control the number of cycles after which the function should exit, even
+    /// when the proof isn't ready
+    /// inter is used to keep track of state and complete proof generation. Set inter to None
+    /// during first cyle and pass the returned value of the previous cycle to continue proof
+    /// generation
+    /// Returns bincode::Error if serialization fails.
+    /// Create Proof of Work on an already serialized item of type T.
+    fn stepped_prove_work_serialized<T>(
         &self,
         prefix: &[u8],
         difficulty: u32,
         step: usize,
-        inter: Option<SteppedSolve<T>>,
+        inter: Option<IncrementalSolve<T>>,
-    ) -> SteppedSolve<T>
+    ) -> IncrementalSolve<T>
     where
         T: Serialize,
     {
         let (mut result, mut n, prefix_sha, difficulty) = match inter {
-            Some(SteppedSolve::Intermediate(result, nonce, prefix, difficulty)) => {
+            Some(IncrementalSolve::Intermediate(result, nonce, prefix, difficulty)) => {
                 (result, nonce, prefix, difficulty)
             }
             _ => {
@@ -98,20 +122,16 @@ impl Config {
             }
         };
         let mut count = 0;
-        //     let prefix_sha = Sha256::new().chain(&self.salt).chain(prefix);
-        //     let mut n = 0;
-        //     let mut result = 0;
-        //     let difficulty = get_difficulty(difficulty);
         while result < difficulty {
             if count > step {
-                return SteppedSolve::Intermediate(result, n, prefix_sha, difficulty);
+                return IncrementalSolve::Intermediate(result, n, prefix_sha, difficulty);
             } else {
                 count += 1;
             }
             n += 1;
             result = dev::score(prefix_sha.clone(), n);
         }
-        SteppedSolve::Work(PoW {
+        IncrementalSolve::Work(PoW {
             nonce: n,
             result: result.to_string(),
             _spook: PhantomData,
@@ -331,6 +351,7 @@ mod test {
     }
 
     #[test]
+    #[cfg(feature = "incremental")]
     fn stepped_solve() {
         let phrase = "Ex nihilo nihil fit.".to_owned();
         let config = get_config();
@@ -338,15 +359,15 @@ mod test {
         let mut inter = None;
         loop {
             match config.stepped_prove_work(&phrase, 50000, 1000, inter) {
-                Ok(SteppedSolve::Intermediate(result, nonce, prefix, difficulty)) => {
+                Ok(IncrementalSolve::Intermediate(result, nonce, prefix, difficulty)) => {
                     println!("Current nonce {nonce}");
-                    inter = Some(SteppedSolve::Intermediate(
+                    inter = Some(IncrementalSolve::Intermediate(
                         result, nonce, prefix, difficulty,
                     ));
                     continue;
                 }
 
-                Ok(SteppedSolve::Work(w)) => {
+                Ok(IncrementalSolve::Work(w)) => {
                     assert!(config.is_valid_proof(&w, &phrase));
                     assert!(config.is_sufficient_difficulty(&w, DIFFICULTY));
                     break;