consensus: move verify::block to its own file

Part of #477.

zebra-consensus/src/verify.rs

@@ -20,6 +20,7 @@ use tower::{buffer::Buffer, Service};
 
 use zebra_chain::block::{Block, BlockHeaderHash};
 
+mod block;
 mod script;
 mod transaction;
 
@@ -31,50 +32,6 @@ struct BlockVerifier<S> {
 // TODO(jlusby): Error = Report ?
 type Error = Box<dyn error::Error + Send + Sync + 'static>;
 
-/// Block validity checks
-mod block {
-    use super::Error;
-
-    use chrono::{DateTime, Duration, Utc};
-    use std::sync::Arc;
-
-    use zebra_chain::block::Block;
-
-    /// Helper function for `node_time_check()`, see that function for details.
-    fn node_time_check_helper(
-        block_header_time: DateTime<Utc>,
-        now: DateTime<Utc>,
-    ) -> Result<(), Error> {
-        let two_hours_in_the_future = now
-            .checked_add_signed(Duration::hours(2))
-            .ok_or("overflow when calculating 2 hours in the future")?;
-
-        if block_header_time <= two_hours_in_the_future {
-            Ok(())
-        } else {
-            Err("block header time is more than 2 hours in the future".into())
-        }
-    }
-
-    /// Check if the block header time is less than or equal to
-    /// 2 hours in the future, according to the node's local clock.
-    ///
-    /// This is a non-deterministic rule, as clocks vary over time, and
-    /// between different nodes.
-    ///
-    /// "In addition, a full validator MUST NOT accept blocks with nTime
-    /// more than two hours in the future according to its clock. This
-    /// is not strictly a consensus rule because it is nondeterministic,
-    /// and clock time varies between nodes. Also note that a block that
-    /// is rejected by this rule at a given point in time may later be
-    /// accepted."[S 7.5][7.5]
-    ///
-    /// [7.5]: https://zips.z.cash/protocol/protocol.pdf#blockheader
-    pub(super) fn node_time_check(block: Arc<Block>) -> Result<(), Error> {
-        node_time_check_helper(block.header.time, Utc::now())
-    }
-}
-
 /// The BlockVerifier service implementation.
 ///
 /// After verification, blocks are added to the underlying state service.

zebra-consensus/src/verify/block.rs

@@ -0,0 +1,42 @@
+//! Block validity checks
+
+use super::Error;
+
+use chrono::{DateTime, Duration, Utc};
+use std::sync::Arc;
+
+use zebra_chain::block::Block;
+
+/// Helper function for `node_time_check()`, see that function for details.
+fn node_time_check_helper(
+    block_header_time: DateTime<Utc>,
+    now: DateTime<Utc>,
+) -> Result<(), Error> {
+    let two_hours_in_the_future = now
+        .checked_add_signed(Duration::hours(2))
+        .ok_or("overflow when calculating 2 hours in the future")?;
+
+    if block_header_time <= two_hours_in_the_future {
+        Ok(())
+    } else {
+        Err("block header time is more than 2 hours in the future".into())
+    }
+}
+
+/// Check if the block header time is less than or equal to
+/// 2 hours in the future, according to the node's local clock.
+///
+/// This is a non-deterministic rule, as clocks vary over time, and
+/// between different nodes.
+///
+/// "In addition, a full validator MUST NOT accept blocks with nTime
+/// more than two hours in the future according to its clock. This
+/// is not strictly a consensus rule because it is nondeterministic,
+/// and clock time varies between nodes. Also note that a block that
+/// is rejected by this rule at a given point in time may later be
+/// accepted."[S 7.5][7.5]
+///
+/// [7.5]: https://zips.z.cash/protocol/protocol.pdf#blockheader
+pub(super) fn node_time_check(block: Arc<Block>) -> Result<(), Error> {
+    node_time_check_helper(block.header.time, Utc::now())
+}