Add and use `debug_skip_parameter_preload` config option (#3197)

* add and use a config option to skip groth16 parameters download

* correct doc

* enable parameters download in `sync_past_mandatory_checkpoint` test

* change logging location

* fix import

* add argument to `create_cached_database_height()`

Co-authored-by: teor <teor@riseup.net>

zebra-consensus/src/chain.rs

@@ -150,7 +150,8 @@ where
 }
 
 /// Initialize block and transaction verification services,
-/// and pre-download Groth16 parameters if needed.
+/// and pre-download Groth16 parameters if requested by the `debug_skip_parameter_preload`
+/// config parameter and if the download is not already started.
 ///
 /// Returns a block verifier, transaction verifier,
 /// and the Groth16 parameter download task [`JoinHandle`].
@@ -185,6 +186,7 @@ pub async fn init<S>(
     config: Config,
     network: Network,
     mut state_service: S,
+    debug_skip_parameter_preload: bool,
 ) -> (
     Buffer<BoxService<Arc<Block>, block::Hash, VerifyChainError>, Arc<Block>>,
     Buffer<
@@ -204,10 +206,13 @@ where
 
     // The parameter download thread must be launched before initializing any verifiers.
     // Otherwise, the download might happen on the startup thread.
-    let groth16_download_handle = spawn_blocking(|| {
-        // The lazy static initializer does the download, if needed,
-        // and the file hash checks.
-        lazy_static::initialize(&crate::groth16::GROTH16_PARAMETERS);
+    let groth16_download_handle = spawn_blocking(move || {
+        if !debug_skip_parameter_preload {
+            // The lazy static initializer does the download, if needed,
+            // and the file hash checks.
+            lazy_static::initialize(&crate::groth16::GROTH16_PARAMETERS);
+            tracing::info!("Groth16 pre-download and check task finished");
+        }
     });
 
     // transaction verification

zebra-consensus/src/chain/tests.rs

@@ -65,7 +65,7 @@ async fn verifiers_from_network(
 ) {
     let state_service = zs::init_test(network);
     let (chain_verifier, _transaction_verifier, _groth16_download_handle) =
-        crate::chain::init(Config::default(), network, state_service.clone()).await;
+        crate::chain::init(Config::default(), network, state_service.clone(), true).await;
 
     // We can drop the download task handle here, because:
     // - if the download task fails, the tests will panic, and
@@ -136,10 +136,12 @@ static STATE_VERIFY_TRANSCRIPT_GENESIS: Lazy<
 async fn verify_checkpoint_test() -> Result<(), Report> {
     verify_checkpoint(Config {
         checkpoint_sync: true,
+        debug_skip_parameter_preload: true,
     })
     .await?;
     verify_checkpoint(Config {
         checkpoint_sync: false,
+        debug_skip_parameter_preload: true,
     })
     .await?;
 
@@ -160,7 +162,7 @@ async fn verify_checkpoint(config: Config) -> Result<(), Report> {
     //
     // Download task panics and timeouts are propagated to the tests that use Groth16 verifiers.
     let (chain_verifier, _transaction_verifier, _groth16_download_handle) =
-        super::init(config.clone(), network, zs::init_test(network)).await;
+        super::init(config.clone(), network, zs::init_test(network), true).await;
 
     // Add a timeout layer
     let chain_verifier =

zebra-consensus/src/config.rs

@@ -12,6 +12,8 @@ pub struct Config {
     /// Future versions of Zebra may change the mandatory checkpoint
     /// height.
     pub checkpoint_sync: bool,
+    /// Skip the pre-download of Groth16 parameters if this option is true.
+    pub debug_skip_parameter_preload: bool,
 }
 
 // we like our default configs to be explicit
@@ -21,6 +23,7 @@ impl Default for Config {
     fn default() -> Self {
         Self {
             checkpoint_sync: false,
+            debug_skip_parameter_preload: false,
         }
     }
 }

zebrad/src/commands/start.rs

@@ -106,6 +106,7 @@ impl StartCmd {
                 config.consensus.clone(),
                 config.network.network,
                 state.clone(),
+                config.consensus.debug_skip_parameter_preload,
             )
             .await;
 
@@ -217,7 +218,6 @@ impl StartCmd {
                             zebra_consensus::groth16::Groth16Parameters::failure_hint())
                         );
 
-                    info!("Groth16 pre-download and check task finished");
                     exit_when_task_finishes = false;
                     Ok(())
                 }

zebrad/src/components/inbound/tests.rs

@@ -591,8 +591,13 @@ async fn setup(
 
     // Download task panics and timeouts are propagated to the tests that use Groth16 verifiers.
     let (block_verifier, _transaction_verifier, _groth16_download_handle) =
-        zebra_consensus::chain::init(consensus_config.clone(), network, state_service.clone())
-            .await;
+        zebra_consensus::chain::init(
+            consensus_config.clone(),
+            network,
+            state_service.clone(),
+            true,
+        )
+        .await;
 
     let mut peer_set = MockService::build()
         .with_max_request_delay(MAX_PEER_SET_REQUEST_DELAY)

zebrad/tests/acceptance.rs

@@ -83,11 +83,17 @@ fn default_test_config() -> Result<ZebradConfig> {
         ..mempool::Config::default()
     };
 
+    let consensus = zebra_consensus::Config {
+        debug_skip_parameter_preload: true,
+        ..zebra_consensus::Config::default()
+    };
+
     let config = ZebradConfig {
         network,
         state: zebra_state::Config::ephemeral(),
         sync,
         mempool,
+        consensus,
         ..ZebradConfig::default()
     };
 
@@ -990,6 +996,7 @@ fn cached_mandatory_checkpoint_test_config() -> Result<ZebradConfig> {
 fn create_cached_database_height<P>(
     network: Network,
     height: Height,
+    debug_skip_parameter_preload: bool,
     test_child_predicate: impl Into<Option<P>>,
 ) -> Result<()>
 where
@@ -1004,6 +1011,7 @@ where
     // TODO: add convenience methods?
     config.network.network = network;
     config.state.debug_stop_at_height = Some(height.0);
+    config.consensus.debug_skip_parameter_preload = debug_skip_parameter_preload;
 
     let dir = PathBuf::from("/zebrad-cache");
     let mut child = dir
@@ -1031,11 +1039,16 @@ where
 
 fn create_cached_database(network: Network) -> Result<()> {
     let height = network.mandatory_checkpoint_height();
-    create_cached_database_height(network, height, |test_child: &mut TestChild<PathBuf>| {
-        // make sure pre-cached databases finish before the mandatory checkpoint
-        test_child.expect_stdout_line_matches("CommitFinalized request")?;
-        Ok(())
-    })
+    create_cached_database_height(
+        network,
+        height,
+        true,
+        |test_child: &mut TestChild<PathBuf>| {
+            // make sure pre-cached databases finish before the mandatory checkpoint
+            test_child.expect_stdout_line_matches("CommitFinalized request")?;
+            Ok(())
+        },
+    )
 }
 
 fn sync_past_mandatory_checkpoint(network: Network) -> Result<()> {
@@ -1043,6 +1056,7 @@ fn sync_past_mandatory_checkpoint(network: Network) -> Result<()> {
     create_cached_database_height(
         network,
         height.unwrap(),
+        false,
         |test_child: &mut TestChild<PathBuf>| {
             // make sure cached database tests finish after the mandatory checkpoint,
             // using the non-finalized state (the checkpoint_sync config must be false)