Refactor obtaining of activation heights

zebra-chain/src/parameters/network.rs

@@ -129,6 +129,19 @@ impl Network {
     pub fn is_a_test_network(&self) -> bool {
         *self != Network::Mainnet
     }
+
+    /// Returns the minimum Sapling birthday height.
+    pub fn sapling_activation_height(self) -> Height {
+        // Assume that the genesis block never contains shielded inputs or outputs.
+        //
+        // # Consensus
+        //
+        // For Zcash mainnet and the public testnet, Sapling activates above genesis,
+        // so this is always true.
+        super::NetworkUpgrade::Sapling
+            .activation_height(self)
+            .expect("Sapling activation height needs to be set")
+    }
 }
 
 impl FromStr for Network {

zebra-scan/src/service.rs

@@ -86,7 +86,7 @@ impl Service<Request> for ScanService {
 
                 return async move {
                     Ok(Response::Info {
-                        min_sapling_birthday_height: db.min_sapling_birthday_height(),
+                        min_sapling_birthday_height: db.network().sapling_activation_height(),
                     })
                 }
                 .boxed();

zebra-scan/src/service/scan_task/commands.rs

@@ -12,7 +12,7 @@ use color_eyre::{eyre::eyre, Report};
 use tokio::sync::oneshot;
 
 use zcash_primitives::{sapling::SaplingIvk, zip32::DiversifiableFullViewingKey};
-use zebra_chain::{block::Height, transaction::Transaction};
+use zebra_chain::{block::Height, parameters::Network, transaction::Transaction};
 use zebra_state::SaplingScanningKey;
 
 use super::ScanTask;
@@ -61,11 +61,13 @@ impl ScanTask {
             SaplingScanningKey,
             (Vec<DiversifiableFullViewingKey>, Vec<SaplingIvk>),
         >,
+        network: Network,
     ) -> Result<
         HashMap<SaplingScanningKey, (Vec<DiversifiableFullViewingKey>, Vec<SaplingIvk>, Height)>,
         Report,
     > {
         let mut new_keys = HashMap::new();
+        let sapling_activation_height = network.sapling_activation_height();
 
         loop {
             let cmd = match cmd_receiver.try_recv() {

zebra-scan/src/service/scan_task/scan.rs

@@ -76,7 +76,7 @@ pub async fn start(
     cmd_receiver: Receiver<ScanTaskCommand>,
 ) -> Result<(), Report> {
     let network = storage.network();
-    let sapling_activation_height = storage.min_sapling_birthday_height();
+    let sapling_activation_height = network.sapling_activation_height();
 
     // Do not scan and notify if we are below sapling activation height.
     wait_for_height(
@@ -126,7 +126,7 @@ pub async fn start(
             }
         }
 
-        let new_keys = ScanTask::process_messages(&cmd_receiver, &mut parsed_keys)?;
+        let new_keys = ScanTask::process_messages(&cmd_receiver, &mut parsed_keys, network)?;
 
         // TODO: Check if the `start_height` is at or above the current height
         if !new_keys.is_empty() {

zebra-scan/src/service/scan_task/scan/scan_range.rs

@@ -71,7 +71,7 @@ pub async fn scan_range(
     state: State,
     storage: Storage,
 ) -> Result<(), BoxError> {
-    let sapling_activation_height = storage.min_sapling_birthday_height();
+    let sapling_activation_height = storage.network().sapling_activation_height();
     // Do not scan and notify if we are below sapling activation height.
     wait_for_height(
         sapling_activation_height,

zebra-scan/src/storage.rs

@@ -2,10 +2,7 @@
 
 use std::collections::{BTreeMap, HashMap};
 
-use zebra_chain::{
-    block::Height,
-    parameters::{Network, NetworkUpgrade},
-};
+use zebra_chain::{block::Height, parameters::Network};
 use zebra_state::TransactionIndex;
 
 use crate::config::Config;
@@ -126,19 +123,4 @@ impl Storage {
     ) -> BTreeMap<Height, Vec<SaplingScannedResult>> {
         self.sapling_results_for_key(sapling_key)
     }
-
-    // Parameters
-
-    /// Returns the minimum sapling birthday height for the configured network.
-    pub fn min_sapling_birthday_height(&self) -> Height {
-        // Assume that the genesis block never contains shielded inputs or outputs.
-        //
-        // # Consensus
-        //
-        // For Zcash mainnet and the public testnet, Sapling activates above genesis,
-        // so this is always true.
-        NetworkUpgrade::Sapling
-            .activation_height(self.network())
-            .unwrap_or(Height(0))
-    }
 }

zebra-scan/src/storage/db/sapling.rs

@@ -213,7 +213,7 @@ impl Storage {
         sapling_key: &SaplingScanningKey,
         birthday_height: Option<Height>,
     ) {
-        let min_birthday_height = self.min_sapling_birthday_height();
+        let min_birthday_height = self.network().sapling_activation_height();
 
         // The birthday height must be at least the minimum height for that pool.
         let birthday_height = birthday_height