espresso_node/persistence/

fs.rs

use std::{
    collections::BTreeMap,
    fs::{self, File, OpenOptions},
    io::{BufReader, BufWriter, Read, Seek, SeekFrom, Write},
    ops::RangeInclusive,
    path::{Path, PathBuf},
    sync::Arc,
    time::Instant,
};

use alloy::primitives::Address;
use anyhow::{Context, anyhow, bail};
use async_lock::RwLock;
use async_trait::async_trait;
use clap::Parser;
use espresso_types::{
    AuthenticatedValidatorMap, Header, Leaf2, NetworkConfig, Payload, PubKey,
    RegisteredValidatorMap, SeqTypes, StakeTableHash,
    traits::{EventsPersistenceRead, MembershipPersistence, StakeTuple},
    v0::traits::{EventConsumer, PersistenceOptions, SequencerPersistence, StateCertPersistence},
    v0_3::{
        AuthenticatedValidator, EventKey, IndexedStake, RegisteredValidator, RewardAmount,
        StakeTableEvent,
    },
};
use hotshot_new_protocol::message::Certificate2;
use hotshot_types::{
    data::{
        DaProposal, DaProposal2, EpochNumber, QuorumProposalWrapper, QuorumProposalWrapperLegacy,
        VidCommitment, VidDisperseShare,
    },
    drb::{DrbInput, DrbResult},
    event::{HotShotAction, LeafInfo},
    initializer::InitializerEpochInfo,
    message::{Proposal, convert_proposal},
    new_protocol::CoordinatorEvent,
    simple_certificate::{
        CertificatePair, LightClientStateUpdateCertificateV1, LightClientStateUpdateCertificateV2,
        NextEpochQuorumCertificate2, QuorumCertificate2, UpgradeCertificate,
    },
    simple_vote::LockView,
    traits::{
        block_contents::{BlockHeader, BlockPayload},
        metrics::Metrics,
        node_implementation::NodeType,
    },
    vote::HasViewNumber,
};
use itertools::Itertools;

use super::{
    RegisteredValidatorNoX25519, RegisteredValidatorPreOption, RegisteredValidatorPreSchnorrOption,
};
use crate::{
    RECENT_STAKE_TABLES_LIMIT, ViewNumber,
    persistence::{
        migrate_network_config,
        persistence_metrics::PersistenceMetricsValue,
        storage_probe::{self, StorageProbe},
    },
};

/// Deserialize a stake table from bytes, trying current and legacy formats.
/// Returns (stake_tuple, needs_rewrite) where needs_rewrite=true means legacy format was used.
fn deserialize_stake_table(bytes: &[u8]) -> anyhow::Result<(StakeTuple, bool)> {
    // Try current format (both keys as Option<KEY>).
    if let Ok(stake) = bincode::deserialize::<StakeTuple>(bytes) {
        return Ok((stake, false));
    }

    // Pre-Schnorr-Option: stake_table_key as Option<KEY>, state_ver_key as raw KEY.
    type PreSchnorrMap = indexmap::IndexMap<Address, RegisteredValidatorPreSchnorrOption>;
    type PreSchnorrTuple = (PreSchnorrMap, Option<RewardAmount>, Option<StakeTableHash>);
    if let Ok(pre_schnorr) = bincode::deserialize::<PreSchnorrTuple>(bytes) {
        let migrated: AuthenticatedValidatorMap = pre_schnorr
            .0
            .into_iter()
            .map(|(addr, v)| {
                let registered = v.migrate();
                let authenticated = AuthenticatedValidator::try_from(registered)?;
                Ok((addr, authenticated))
            })
            .collect::<anyhow::Result<_>>()?;
        return Ok(((migrated, pre_schnorr.1, pre_schnorr.2), true));
    }

    // Pre-Option: both keys raw, x25519/p2p fields present.
    type PreOptionMap = indexmap::IndexMap<Address, RegisteredValidatorPreOption>;
    type PreOptionTuple = (PreOptionMap, Option<RewardAmount>, Option<StakeTableHash>);
    if let Ok(pre_option) = bincode::deserialize::<PreOptionTuple>(bytes) {
        let migrated: AuthenticatedValidatorMap = pre_option
            .0
            .into_iter()
            .map(|(addr, v)| {
                let registered = v.migrate();
                let authenticated = AuthenticatedValidator::try_from(registered)?;
                Ok((addr, authenticated))
            })
            .collect::<anyhow::Result<_>>()?;
        return Ok(((migrated, pre_option.1, pre_option.2), true));
    }

    // Pre-x25519: RegisteredValidator without x25519_key/p2p_addr.
    type LegacyMap = indexmap::IndexMap<Address, RegisteredValidatorNoX25519>;
    type LegacyTuple = (LegacyMap, Option<RewardAmount>, Option<StakeTableHash>);
    let legacy: LegacyTuple = bincode::deserialize(bytes)
        .context("failed to deserialize stake table (tried current and legacy formats)")?;
    let migrated: AuthenticatedValidatorMap = legacy
        .0
        .into_iter()
        .map(|(addr, v)| {
            let registered = v.migrate();
            (
                addr,
                AuthenticatedValidator::try_from(registered)
                    .expect("stake tables only contain authenticated validators"),
            )
        })
        .collect();
    Ok(((migrated, legacy.1, legacy.2), true))
}

/// Options for file system backed persistence.
#[derive(Parser, Clone, Debug)]
pub struct Options {
    /// Storage path for persistent data.
    #[clap(long, env = "ESPRESSO_NODE_STORAGE_PATH")]
    pub(crate) path: PathBuf,

    /// Number of views to retain in consensus storage before data that hasn't been archived is
    /// garbage collected.
    ///
    /// The longer this is, the more certain that all data will eventually be archived, even if
    /// there are temporary problems with archive storage or partially missing data. This can be set
    /// very large, as most data is garbage collected as soon as it is finalized by consensus. This
    /// setting only applies to views which never get decided (ie forks in consensus) and views for
    /// which this node is partially offline. These should be exceptionally rare.
    ///
    /// The default of 130000 views equates to approximately 3 days (259200 seconds) at an average
    /// view time of 2s.
    #[clap(
        long,
        env = "ESPRESSO_NODE_CONSENSUS_VIEW_RETENTION",
        default_value = "130000"
    )]
    pub(crate) consensus_view_retention: u64,

    #[clap(skip)]
    pub(crate) consensus_only: bool,
}

impl Default for Options {
    fn default() -> Self {
        Self::parse_from(std::iter::empty::<String>())
    }
}

impl Options {
    pub fn new(path: PathBuf) -> Self {
        Self {
            path,
            consensus_view_retention: 130000,
            consensus_only: false,
        }
    }

    pub(crate) fn path(&self) -> &Path {
        &self.path
    }
}

#[async_trait]
impl PersistenceOptions for Options {
    type Persistence = Persistence;

    fn set_view_retention(&mut self, view_retention: u64) {
        self.consensus_view_retention = view_retention;
    }

    fn set_consensus_only(&mut self) {
        self.consensus_only = true;
    }

    async fn create(&mut self) -> anyhow::Result<Self::Persistence> {
        let path = self.path.clone();
        let view_retention = self.consensus_view_retention;
        // Fail fast if the data directory can't be created: every writer would fail on it later
        // anyway, and the fsync probe below needs it to exist.
        fs::create_dir_all(&path).context("creating storage directory")?;
        let probe = storage_probe::probe(&path, None).await?;

        Ok(Persistence {
            inner: Arc::new(RwLock::new(Inner {
                path,
                view_retention,
            })),
            metrics: Arc::new(PersistenceMetricsValue::default()),
            probe,
            consensus_only: self.consensus_only,
        })
    }

    async fn reset(self) -> anyhow::Result<()> {
        todo!()
    }
}

/// File system backed persistence.
#[derive(Clone, Debug)]
pub struct Persistence {
    // We enforce mutual exclusion on access to the data source, as the current file system
    // implementation does not support transaction isolation for concurrent reads and writes. We can
    // improve this in the future by switching to a SQLite-based file system implementation.
    inner: Arc<RwLock<Inner>>,
    /// A reference to the metrics trait
    metrics: Arc<PersistenceMetricsValue>,
    /// Startup findings about the filesystem backing the data directory.
    probe: StorageProbe,
    consensus_only: bool,
}

#[derive(Debug)]
struct Inner {
    path: PathBuf,
    view_retention: u64,
}

impl Inner {
    fn config_path(&self) -> PathBuf {
        self.path.join("hotshot.cfg")
    }

    fn voted_view_path(&self) -> PathBuf {
        self.path.join("highest_voted_view")
    }

    fn restart_view_path(&self) -> PathBuf {
        self.path.join("restart_view")
    }

    fn decided_leaf2_path(&self) -> PathBuf {
        self.path.join("decided_leaves2")
    }

    /// The path from previous versions where there was only a single file for anchor leaves.
    fn legacy_anchor_leaf_path(&self) -> PathBuf {
        self.path.join("anchor_leaf")
    }

    fn vid2_dir_path(&self) -> PathBuf {
        self.path.join("vid2")
    }

    fn da_dir_path(&self) -> PathBuf {
        self.path.join("da")
    }

    fn drb_dir_path(&self) -> PathBuf {
        self.path.join("drb")
    }

    fn da2_dir_path(&self) -> PathBuf {
        self.path.join("da2")
    }

    fn quorum_proposals2_dir_path(&self) -> PathBuf {
        self.path.join("quorum_proposals2")
    }

    fn upgrade_certificate_dir_path(&self) -> PathBuf {
        self.path.join("upgrade_certificate")
    }

    fn stake_table_dir_path(&self) -> PathBuf {
        self.path.join("stake_table")
    }

    fn next_epoch_qc(&self) -> PathBuf {
        self.path.join("next_epoch_quorum_certificate")
    }

    fn eqc(&self) -> PathBuf {
        self.path.join("eqc")
    }

    fn high_qc2(&self) -> PathBuf {
        self.path.join("high_qc2")
    }

    fn boundary_qc2(&self) -> PathBuf {
        self.path.join("boundary_qc2")
    }

    fn epoch_drb_result_dir_path(&self) -> PathBuf {
        self.path.join("epoch_drb_result")
    }

    fn epoch_root_block_header_dir_path(&self) -> PathBuf {
        self.path.join("epoch_root_block_header")
    }

    fn finalized_state_cert_dir_path(&self) -> PathBuf {
        self.path.join("finalized_state_cert")
    }

    fn state_cert_dir_path(&self) -> PathBuf {
        self.path.join("state_cert")
    }

    fn decided_cert2_dir_path(&self) -> PathBuf {
        self.path.join("decided_cert2")
    }

    /// cert2 is only persisted for the view that is directly finalized
    /// (the newest leaf in a decided chain). Ancestor views finalized
    /// indirectly have no cert2 file on disk
    /// for those, this returns `Ok(None)`
    fn load_cert2(&self, view: ViewNumber) -> anyhow::Result<Option<Certificate2<SeqTypes>>> {
        let file_path = self
            .decided_cert2_dir_path()
            .join(view.u64().to_string())
            .with_extension("bin");
        if !file_path.is_file() {
            return Ok(None);
        }
        let bytes = fs::read(&file_path).context("read cert2")?;
        Ok(Some(
            bincode::deserialize(&bytes).context("deserialize cert2")?,
        ))
    }

    fn append_cert2(
        &mut self,
        view: ViewNumber,
        cert2: &Certificate2<SeqTypes>,
    ) -> anyhow::Result<()> {
        let dir_path = self.decided_cert2_dir_path();
        fs::create_dir_all(&dir_path).context("failed to create decided_cert2 dir")?;
        let file_path = dir_path.join(view.u64().to_string()).with_extension("bin");
        self.replace(
            &file_path,
            |_| Ok(true),
            |mut file| {
                let bytes = bincode::serialize(cert2).context("serialize cert2")?;
                file.write_all(&bytes)?;
                Ok(())
            },
        )
    }

    /// Overwrite a file if a condition is met.
    ///
    /// The file at `path`, if it exists, is opened in read mode and passed to `pred`. If `pred`
    /// returns `true`, or if there was no existing file, then `write` is called to update the
    /// contents of the file. `write` receives a truncated file open in write mode and sets the
    /// contents of the file.
    ///
    /// The final replacement of the original file is atomic; that is, `path` will be modified only
    /// if the entire update succeeds.
    fn replace(
        &mut self,
        path: &Path,
        pred: impl FnOnce(File) -> anyhow::Result<bool>,
        write: impl FnOnce(File) -> anyhow::Result<()>,
    ) -> anyhow::Result<()> {
        if path.is_file() {
            // If there is an existing file, check if it is suitable to replace. Note that this
            // check is not atomic with respect to the subsequent write at the file system level,
            // but this object is the only one which writes to this file, and we have a mutable
            // reference, so this should be safe.
            if !pred(File::open(path)?)? {
                // If we are not overwriting the file, we are done and consider the whole operation
                // successful.
                return Ok(());
            }
        }

        // Either there is no existing file or we have decided to overwrite the file. Write the new
        // contents into a temporary file so we can update `path` atomically using `rename`.
        let mut swap_path = path.to_owned();
        swap_path.set_extension("swp");
        let swap = OpenOptions::new()
            .write(true)
            .truncate(true)
            .create(true)
            .open(&swap_path)?;
        write(swap)?;

        // Now we can replace the original file.
        fs::rename(swap_path, path)?;

        Ok(())
    }

    fn collect_garbage(
        &mut self,
        decided_view: ViewNumber,
        prune_intervals: &[RangeInclusive<ViewNumber>],
    ) -> anyhow::Result<()> {
        let prune_view = ViewNumber::new(decided_view.saturating_sub(self.view_retention));

        self.prune_files(self.da2_dir_path(), prune_view, None, prune_intervals)?;
        self.prune_files(self.vid2_dir_path(), prune_view, None, prune_intervals)?;
        self.prune_files(
            self.quorum_proposals2_dir_path(),
            prune_view,
            None,
            prune_intervals,
        )?;
        self.prune_files(
            self.state_cert_dir_path(),
            prune_view,
            None,
            prune_intervals,
        )?;
        self.prune_files(
            self.decided_cert2_dir_path(),
            prune_view,
            Some(decided_view),
            prune_intervals,
        )?;

        // Save the most recent leaf as it will be our anchor point if the node restarts.
        self.prune_files(
            self.decided_leaf2_path(),
            prune_view,
            Some(decided_view),
            prune_intervals,
        )?;

        Ok(())
    }

    fn prune_files(
        &mut self,
        dir_path: PathBuf,
        prune_view: ViewNumber,
        keep_decided_view: Option<ViewNumber>,
        prune_intervals: &[RangeInclusive<ViewNumber>],
    ) -> anyhow::Result<()> {
        if !dir_path.is_dir() {
            return Ok(());
        }

        for (file_view, path) in view_files(dir_path)? {
            // If the view is the anchor view, keep it no matter what.
            if let Some(decided_view) = keep_decided_view
                && decided_view == file_view
            {
                continue;
            }
            // Otherwise, delete it if it is time to prune this view _or_ if the given intervals,
            // which we've already successfully processed, contain the view; in this case we simply
            // don't need it anymore.
            if file_view < prune_view || prune_intervals.iter().any(|i| i.contains(&file_view)) {
                fs::remove_file(&path)?;
            }
        }

        Ok(())
    }

    fn parse_decided_leaf(
        &self,
        bytes: &[u8],
    ) -> anyhow::Result<(Leaf2, CertificatePair<SeqTypes>)> {
        // Old versions of the software did not store the next epoch QC. Without knowing which
        // version this file was created with, we can simply try parsing both ways and then
        // reconstruct a certificate pair with or without the next epoch QC.
        match bincode::deserialize(bytes) {
            Ok((leaf, cert)) => Ok((leaf, cert)),
            Err(err) => {
                tracing::info!(
                    "error parsing decided leaf, maybe file was created without next epoch QC? \
                     {err}"
                );
                let (leaf, qc) =
                    bincode::deserialize::<(Leaf2, QuorumCertificate2<SeqTypes>)>(bytes)
                        .context("parsing decided leaf")?;
                Ok((leaf, CertificatePair::non_epoch_change(qc)))
            },
        }
    }

    /// Generate events based on persisted decided leaves.
    ///
    /// Returns a list of closed intervals of views which can be safely deleted, as all leaves
    /// within these view ranges have been processed by the event consumer.
    async fn generate_decide_events(
        &mut self,
        view: ViewNumber,
        consumer: &impl EventConsumer,
    ) -> anyhow::Result<Vec<RangeInclusive<ViewNumber>>> {
        // Generate a decide event for each leaf, to be processed by the event consumer. We make a
        // separate event for each leaf because it is possible we have non-consecutive leaves in our
        // storage, which would not be valid as a single decide with a single leaf chain.
        let mut leaves = BTreeMap::new();
        for (v, path) in view_files(self.decided_leaf2_path())? {
            if v > view {
                continue;
            }

            let bytes =
                fs::read(&path).context(format!("reading decided leaf {}", path.display()))?;
            let (mut leaf, cert) = self.parse_decided_leaf(&bytes)?;

            // Include the VID share if available.
            let vid_proposal = self.load_vid_share(v)?;
            if vid_proposal.is_none() {
                tracing::debug!(?v, "VID share not available at decide");
            }
            let vid_share = vid_proposal.as_ref().map(|proposal| proposal.data.clone());

            // Move the state cert to the finalized dir if it exists.
            let state_cert = self.store_finalized_state_cert(v)?;

            // Fill in the full block payload using the DA proposals we had persisted.
            if let Some(proposal) = self.load_da_proposal(v)? {
                let payload = Payload::from_bytes(
                    &proposal.data.encoded_transactions,
                    &proposal.data.metadata,
                );
                leaf.fill_block_payload_unchecked(payload);
            } else {
                tracing::debug!(?v, "DA proposal not available at decide");
            }

            let info = LeafInfo {
                leaf,
                vid_share,
                state_cert,
                // Note: the following fields are not used in Decide event processing, and should be
                // removed. For now, we just default them.
                state: Default::default(),
                delta: Default::default(),
            };

            leaves.insert(v, (info, cert));
        }

        // The invariant is that the oldest existing leaf in the `anchor_leaf` table -- if there is
        // one -- was always included in the _previous_ decide event...but not removed from the
        // database, because we always persist the most recent anchor leaf.
        if let Some((oldest_view, _)) = leaves.first_key_value() {
            // The only exception is when the oldest leaf is the genesis leaf; then there was no
            // previous decide event.
            if *oldest_view > ViewNumber::genesis() {
                leaves.pop_first();
            }
        }

        let mut intervals = vec![];
        let mut current_interval = None;
        for (view, (leaf, cert)) in leaves {
            let height = leaf.leaf.block_header().block_number();

            // cert2 is stored only for the directly finalized view; ancestors get `None`, which
            // is what update() expects for indirectly decided leaves.
            let event = CoordinatorEvent::NewDecide {
                leaf_infos: vec![leaf],
                cert1: cert.qc().clone(),
                cert2: self.load_cert2(view)?,
            };
            consumer.handle_event(&event).await?;

            if let Some((start, end, current_height)) = current_interval.as_mut() {
                if height == *current_height + 1 {
                    // If we have a chain of consecutive leaves, extend the current interval of
                    // views which are safe to delete.
                    *current_height += 1;
                    *end = view;
                } else {
                    // Otherwise, end the current interval and start a new one.
                    intervals.push(*start..=*end);
                    current_interval = Some((view, view, height));
                }
            } else {
                // Start a new interval.
                current_interval = Some((view, view, height));
            }
        }
        if let Some((start, end, _)) = current_interval {
            intervals.push(start..=end);
        }

        Ok(intervals)
    }

    fn skip_decide_events(
        &mut self,
        view: ViewNumber,
    ) -> anyhow::Result<Vec<RangeInclusive<ViewNumber>>> {
        for (leaf_view, _) in view_files(self.decided_leaf2_path())? {
            if leaf_view <= view {
                self.store_finalized_state_cert(leaf_view)?;
            }
        }
        Ok(Vec::from([ViewNumber::genesis()..=view]))
    }

    fn load_da_proposal(
        &self,
        view: ViewNumber,
    ) -> anyhow::Result<Option<Proposal<SeqTypes, DaProposal2<SeqTypes>>>> {
        let dir_path = self.da2_dir_path();

        let file_path = dir_path.join(view.u64().to_string()).with_extension("txt");

        if !file_path.exists() {
            return Ok(None);
        }

        let da_bytes = fs::read(file_path)?;

        let da_proposal: Proposal<SeqTypes, DaProposal2<SeqTypes>> =
            bincode::deserialize(&da_bytes)?;
        Ok(Some(da_proposal))
    }

    fn load_vid_share(
        &self,
        view: ViewNumber,
    ) -> anyhow::Result<Option<Proposal<SeqTypes, VidDisperseShare<SeqTypes>>>> {
        let dir_path = self.vid2_dir_path();

        let file_path = dir_path.join(view.u64().to_string()).with_extension("txt");

        if !file_path.exists() {
            return Ok(None);
        }

        let vid_share_bytes = fs::read(file_path)?;
        let vid_share: Proposal<SeqTypes, VidDisperseShare<SeqTypes>> =
            bincode::deserialize(&vid_share_bytes)?;
        Ok(Some(vid_share))
    }

    fn load_anchor_leaf(&self) -> anyhow::Result<Option<(Leaf2, CertificatePair<SeqTypes>)>> {
        tracing::info!("Checking `Leaf2` to load the anchor leaf.");
        if self.decided_leaf2_path().is_dir() {
            let mut anchor: Option<(Leaf2, CertificatePair<SeqTypes>)> = None;

            // Return the latest decided leaf.
            for (_, path) in view_files(self.decided_leaf2_path())? {
                let bytes =
                    fs::read(&path).context(format!("reading decided leaf {}", path.display()))?;
                let (leaf, cert) = self.parse_decided_leaf(&bytes)?;
                if let Some((anchor_leaf, _)) = &anchor {
                    if leaf.view_number() > anchor_leaf.view_number() {
                        anchor = Some((leaf, cert));
                    }
                } else {
                    anchor = Some((leaf, cert));
                }
            }

            return Ok(anchor);
        }

        tracing::warn!(
            "Failed to find an anchor leaf in `Leaf2` storage. Checking legacy `Leaf` storage. \
             This is very likely to fail."
        );
        if self.legacy_anchor_leaf_path().is_file() {
            // We may have an old version of storage, where there is just a single file for the
            // anchor leaf. Read it and return the contents.
            let mut file = BufReader::new(File::open(self.legacy_anchor_leaf_path())?);

            // The first 8 bytes just contain the height of the leaf. We can skip this.
            file.seek(SeekFrom::Start(8)).context("seek")?;
            let bytes = file
                .bytes()
                .collect::<Result<Vec<_>, _>>()
                .context("read")?;
            let (leaf2, qc2): (Leaf2, QuorumCertificate2<SeqTypes>) =
                bincode::deserialize(&bytes).context("deserialize")?;
            let cert_pair = CertificatePair::new(qc2, None);
            return Ok(Some((leaf2, cert_pair)));
        }

        Ok(None)
    }

    fn store_finalized_state_cert(
        &mut self,
        view: ViewNumber,
    ) -> anyhow::Result<Option<LightClientStateUpdateCertificateV2<SeqTypes>>> {
        let dir_path = self.state_cert_dir_path();
        let file_path = dir_path.join(view.u64().to_string()).with_extension("txt");

        if !file_path.exists() {
            return Ok(None);
        }

        let bytes = fs::read(&file_path)?;

        let state_cert: LightClientStateUpdateCertificateV2<SeqTypes> =
            bincode::deserialize(&bytes).or_else(|err_v2| {
                tracing::info!(
                    error = %err_v2,
                    path = %file_path.display(),
                    "Failed to deserialize state certificate, attempting with v1"
                );

                bincode::deserialize::<LightClientStateUpdateCertificateV1<SeqTypes>>(&bytes)
                    .map(Into::into)
                    .with_context(|| {
                        format!(
                            "Failed to deserialize with both v2 and v1 from file '{}'. error: \
                             {err_v2}",
                            file_path.display()
                        )
                    })
            })?;

        let epoch = state_cert.epoch.u64();
        let finalized_dir_path = self.finalized_state_cert_dir_path();
        fs::create_dir_all(&finalized_dir_path).context("creating finalized state cert dir")?;

        let finalized_file_path = finalized_dir_path
            .join(epoch.to_string())
            .with_extension("txt");

        self.replace(
            &finalized_file_path,
            |_| Ok(true),
            |mut file| {
                file.write_all(&bytes)?;
                Ok(())
            },
        )
        .context(format!(
            "finalizing light client state update certificate file for epoch {epoch:?}"
        ))?;

        Ok(Some(state_cert))
    }
}

#[async_trait]
impl SequencerPersistence for Persistence {
    async fn load_config(&self) -> anyhow::Result<Option<NetworkConfig>> {
        let inner = self.inner.read().await;
        let path = inner.config_path();
        if !path.is_file() {
            tracing::info!("config not found at {}", path.display());
            return Ok(None);
        }
        tracing::info!("loading config from {}", path.display());

        let bytes =
            fs::read(&path).context(format!("unable to read config from {}", path.display()))?;
        let json = serde_json::from_slice(&bytes).context("config file is not valid JSON")?;
        let json = migrate_network_config(json).context("migration of network config failed")?;
        let config = serde_json::from_value(json).context("malformed config file")?;
        Ok(Some(config))
    }

    async fn save_config(&self, cfg: &NetworkConfig) -> anyhow::Result<()> {
        let inner = self.inner.write().await;
        let path = inner.config_path();
        tracing::info!("saving config to {}", path.display());
        Ok(cfg.to_file(path.display().to_string())?)
    }

    async fn load_latest_acted_view(&self) -> anyhow::Result<Option<ViewNumber>> {
        let inner = self.inner.read().await;
        let path = inner.voted_view_path();
        if !path.is_file() {
            return Ok(None);
        }
        let bytes = fs::read(inner.voted_view_path())?
            .try_into()
            .map_err(|bytes| anyhow!("malformed voted view file: {bytes:?}"))?;
        Ok(Some(ViewNumber::new(u64::from_le_bytes(bytes))))
    }

    async fn load_restart_view(&self) -> anyhow::Result<Option<ViewNumber>> {
        let inner = self.inner.read().await;
        let path = inner.restart_view_path();
        if !path.is_file() {
            return Ok(None);
        }
        let bytes = fs::read(path)?
            .try_into()
            .map_err(|bytes| anyhow!("malformed restart view file: {bytes:?}"))?;
        Ok(Some(ViewNumber::new(u64::from_le_bytes(bytes))))
    }

    async fn persist_decided_leaves(
        &self,
        leaf_chain: impl IntoIterator<Item = (&LeafInfo<SeqTypes>, CertificatePair<SeqTypes>)> + Send,
        cert2: Option<&Certificate2<SeqTypes>>,
        _consumer: &(impl EventConsumer + 'static),
    ) -> anyhow::Result<()> {
        let leaf_chain: Vec<_> = leaf_chain.into_iter().collect();
        let mut inner = self.inner.write().await;
        // Written before the leaves and under the same lock as the decide replay, so the replay
        // can never find the newest leaf on disk without its cert2. Keyed by that leaf's view,
        // which a re-vote's cert2 is later than.
        let newest = leaf_chain
            .iter()
            .map(|(info, _)| info.leaf.view_number())
            .max();
        if let Some(cert2) = cert2
            && newest.is_none()
        {
            tracing::warn!(view = %cert2.view_number, "cert2 without a decided leaf; not stored");
        }
        if let Some(cert2) = cert2
            && let Some(newest) = newest
        {
            inner.append_cert2(newest, cert2)?;
        }
        let path = inner.decided_leaf2_path();

        // Ensure the anchor leaf directory exists.
        fs::create_dir_all(&path).context("creating anchor leaf directory")?;

        // Earlier versions stored only a single decided leaf in a regular file. If our storage is
        // still on this version, migrate to a directory structure storing (possibly) many leaves.
        let legacy_path = inner.legacy_anchor_leaf_path();
        if !path.is_dir() && legacy_path.is_file() {
            tracing::info!("migrating to multi-leaf storage");

            // Move the existing data into the new directory.
            let (leaf, qc) = inner
                .load_anchor_leaf()?
                .context("anchor leaf file exists but unable to load contents")?;
            let view = leaf.view_number().u64();
            let bytes = bincode::serialize(&(leaf, qc))?;
            let new_file = path.join(view.to_string()).with_extension("txt");
            inner
                .replace(
                    &new_file,
                    |_| Ok(true),
                    |mut file| {
                        file.write_all(&bytes)?;
                        Ok(())
                    },
                )
                .context(format!("writing anchor leaf file {view}"))?;

            // Now we can remove the old file.
            fs::remove_file(&legacy_path).context("removing legacy anchor leaf file")?;
        }

        for (info, cert) in leaf_chain {
            let view = info.leaf.view_number().u64();
            let file_path = path.join(view.to_string()).with_extension("txt");
            inner.replace(
                &file_path,
                |_| {
                    // Don't overwrite an existing leaf, but warn about it as this is likely not
                    // intended behavior from HotShot.
                    tracing::warn!(view, "duplicate decided leaf");
                    Ok(false)
                },
                |mut file| {
                    let bytes = bincode::serialize(&(&info.leaf, cert))?;
                    file.write_all(&bytes)?;
                    Ok(())
                },
            )?;
        }

        Ok(())
    }

    async fn process_decided_events(
        &self,
        view: ViewNumber,
        consumer: &(impl EventConsumer + 'static),
    ) -> anyhow::Result<Option<ViewNumber>> {
        // Started before the lock acquisition: this pass holds the exclusive write lock, so the
        // metric must include the wait to reflect how long appends can block behind it.
        let now = Instant::now();
        // On error, GC does not run over the failed range, so the leaves stay on disk and are
        // retried; no data is lost.
        let mut inner = self.inner.write().await;
        let intervals = if self.consensus_only {
            inner.skip_decide_events(view)?
        } else {
            inner.generate_decide_events(view, consumer).await?
        };
        drop(inner);

        // Highest view we generated an event for; unprocessed leaves stay on disk (the cursor).
        let processed = intervals.iter().map(|i| *i.end()).max();

        // Best-effort GC; runs again at the next decide.
        let res = self.inner.write().await.collect_garbage(view, &intervals);
        if let Err(err) = res {
            tracing::warn!(?view, "GC failed: {err:#}");
        }
        self.metrics
            .internal_process_decided_events_duration
            .add_point(now.elapsed().as_secs_f64());

        Ok(processed)
    }

    async fn load_anchor_leaf(&self) -> anyhow::Result<Option<(Leaf2, CertificatePair<SeqTypes>)>> {
        self.inner.read().await.load_anchor_leaf()
    }

    async fn load_da_proposal(
        &self,
        view: ViewNumber,
    ) -> anyhow::Result<Option<Proposal<SeqTypes, DaProposal2<SeqTypes>>>> {
        self.inner.read().await.load_da_proposal(view)
    }

    async fn load_vid_share(
        &self,
        view: ViewNumber,
    ) -> anyhow::Result<Option<Proposal<SeqTypes, VidDisperseShare<SeqTypes>>>> {
        self.inner.read().await.load_vid_share(view)
    }

    async fn append_vid(
        &self,
        proposal: &Proposal<SeqTypes, VidDisperseShare<SeqTypes>>,
    ) -> anyhow::Result<()> {
        let mut inner = self.inner.write().await;
        let view_number = proposal.data.view_number().u64();
        let dir_path = inner.vid2_dir_path();

        fs::create_dir_all(dir_path.clone()).context("failed to create vid dir")?;

        let file_path = dir_path.join(view_number.to_string()).with_extension("txt");
        inner.replace(
            &file_path,
            |_| {
                // Don't overwrite an existing share, but warn about it as this is likely not intended
                // behavior from HotShot.
                tracing::warn!(view_number, "duplicate VID share");
                Ok(false)
            },
            |mut file| {
                let proposal_bytes = bincode::serialize(proposal).context("serialize proposal")?;
                let now = Instant::now();
                file.write_all(&proposal_bytes)?;
                self.metrics
                    .internal_append_vid_duration
                    .add_point(now.elapsed().as_secs_f64());
                Ok(())
            },
        )
    }

    async fn append_da(
        &self,
        proposal: &Proposal<SeqTypes, DaProposal<SeqTypes>>,
        _vid_commit: VidCommitment,
    ) -> anyhow::Result<()> {
        let mut inner = self.inner.write().await;
        let view_number = proposal.data.view_number().u64();
        let dir_path = inner.da_dir_path();

        fs::create_dir_all(dir_path.clone()).context("failed to create da dir")?;

        let file_path = dir_path.join(view_number.to_string()).with_extension("txt");
        inner.replace(
            &file_path,
            |_| {
                // Don't overwrite an existing proposal, but warn about it as this is likely not
                // intended behavior from HotShot.
                tracing::warn!(view_number, "duplicate DA proposal");
                Ok(false)
            },
            |mut file| {
                let proposal_bytes = bincode::serialize(&proposal).context("serialize proposal")?;
                let now = Instant::now();
                file.write_all(&proposal_bytes)?;
                self.metrics
                    .internal_append_da_duration
                    .add_point(now.elapsed().as_secs_f64());
                Ok(())
            },
        )
    }
    async fn record_action(&self, view: ViewNumber, action: HotShotAction) -> anyhow::Result<()> {
        // Todo Remove this after https://github.com/EspressoSystems/espresso-network/issues/1931
        //
        // A timeout vote counts: a restarted node must not vote2 at a view it
        // sent a timeout vote for.
        if !matches!(
            action,
            HotShotAction::Propose | HotShotAction::Vote | HotShotAction::TimeoutVote
        ) {
            return Ok(());
        }
        let mut inner = self.inner.write().await;
        let path = &inner.voted_view_path();
        inner.replace(
            path,
            |mut file| {
                let mut bytes = vec![];
                file.read_to_end(&mut bytes)?;
                let bytes = bytes
                    .try_into()
                    .map_err(|bytes| anyhow!("malformed voted view file: {bytes:?}"))?;
                let saved_view = ViewNumber::new(u64::from_le_bytes(bytes));

                // Overwrite the file if the saved view is older than the new view.
                Ok(saved_view < view)
            },
            |mut file| {
                file.write_all(&view.u64().to_le_bytes())?;
                Ok(())
            },
        )?;

        if matches!(action, HotShotAction::Vote) {
            let restart_view_path = &inner.restart_view_path();
            let restart_view = view + 1;
            inner.replace(
                restart_view_path,
                |mut file| {
                    let mut bytes = vec![];
                    file.read_to_end(&mut bytes)?;
                    let bytes = bytes
                        .try_into()
                        .map_err(|bytes| anyhow!("malformed voted view file: {bytes:?}"))?;
                    let saved_view = ViewNumber::new(u64::from_le_bytes(bytes));

                    // Overwrite the file if the saved view is older than the new view.
                    Ok(saved_view < restart_view)
                },
                |mut file| {
                    file.write_all(&restart_view.u64().to_le_bytes())?;
                    Ok(())
                },
            )?;
        }
        Ok(())
    }

    async fn append_quorum_proposal2(
        &self,
        proposal: &Proposal<SeqTypes, QuorumProposalWrapper<SeqTypes>>,
    ) -> anyhow::Result<()> {
        let mut inner = self.inner.write().await;
        let view_number = proposal.data.view_number().u64();
        let dir_path = inner.quorum_proposals2_dir_path();

        fs::create_dir_all(dir_path.clone()).context("failed to create proposals dir")?;

        let file_path = dir_path.join(view_number.to_string()).with_extension("txt");
        inner.replace(
            &file_path,
            |_| {
                // Always overwrite the previous file
                Ok(true)
            },
            |mut file| {
                let proposal_bytes = bincode::serialize(&proposal).context("serialize proposal")?;
                let now = Instant::now();
                file.write_all(&proposal_bytes)?;
                self.metrics
                    .internal_append_quorum2_duration
                    .add_point(now.elapsed().as_secs_f64());
                Ok(())
            },
        )
    }

    async fn append_cert2(
        &self,
        view: ViewNumber,
        cert2: Certificate2<SeqTypes>,
    ) -> anyhow::Result<()> {
        self.inner.write().await.append_cert2(view, &cert2)
    }

    async fn load_cert2(&self, view: ViewNumber) -> anyhow::Result<Option<Certificate2<SeqTypes>>> {
        let inner = self.inner.read().await;
        let dir_path = inner.decided_cert2_dir_path();
        let file_path = dir_path.join(view.u64().to_string()).with_extension("bin");
        if !file_path.is_file() {
            return Ok(None);
        }
        let bytes = fs::read(&file_path).context("read cert2")?;
        Ok(Some(
            bincode::deserialize(&bytes).context("deserialize cert2")?,
        ))
    }
    async fn load_quorum_proposals(
        &self,
    ) -> anyhow::Result<BTreeMap<ViewNumber, Proposal<SeqTypes, QuorumProposalWrapper<SeqTypes>>>>
    {
        let inner = self.inner.read().await;

        // First, get the proposal directory.
        let dir_path = inner.quorum_proposals2_dir_path();
        if !dir_path.is_dir() {
            return Ok(Default::default());
        }

        // Read quorum proposals from every data file in this directory.
        let mut map = BTreeMap::new();
        for (view, path) in view_files(&dir_path)? {
            let proposal_bytes = fs::read(path)?;
            let Some(proposal) = bincode::deserialize::<
                Proposal<SeqTypes, QuorumProposalWrapper<SeqTypes>>,
            >(&proposal_bytes)
            .or_else(|error| {
                bincode::deserialize::<Proposal<SeqTypes, QuorumProposalWrapperLegacy<SeqTypes>>>(
                    &proposal_bytes,
                )
                .map(convert_proposal)
                .inspect_err(|err_v3| {
                    // At this point, if the file contents are invalid, it is most likely an
                    // error rather than a miscellaneous file somehow ending up in the
                    // directory. However, we continue on, because it is better to collect as
                    // many proposals as we can rather than letting one bad proposal cause the
                    // entire operation to fail, and it is still possible that this was just
                    // some unintended file whose name happened to match the naming convention.

                    tracing::warn!(
                        ?view,
                        %error,
                        error_v3 = %err_v3,
                        "ignoring malformed quorum proposal file"
                    );
                })
            })
            .ok() else {
                continue;
            };

            let proposal2 = convert_proposal(proposal);

            // Push to the map and we're done.
            map.insert(view, proposal2);
        }

        Ok(map)
    }

    async fn load_quorum_proposal(
        &self,
        view: ViewNumber,
    ) -> anyhow::Result<Proposal<SeqTypes, QuorumProposalWrapper<SeqTypes>>> {
        let inner = self.inner.read().await;
        let dir_path = inner.quorum_proposals2_dir_path();
        let file_path = dir_path.join(view.to_string()).with_extension("txt");
        let bytes = fs::read(file_path)?;
        let proposal: Proposal<SeqTypes, QuorumProposalWrapper<SeqTypes>> =
            bincode::deserialize(&bytes).or_else(|error| {
                bincode::deserialize::<Proposal<SeqTypes, QuorumProposalWrapperLegacy<SeqTypes>>>(
                    &bytes,
                )
                .map(convert_proposal)
                .context(format!(
                    "Failed to deserialize quorum proposal for view {view:?}: {error}."
                ))
            })?;
        Ok(proposal)
    }

    async fn load_upgrade_certificate(
        &self,
    ) -> anyhow::Result<Option<UpgradeCertificate<SeqTypes>>> {
        let inner = self.inner.read().await;
        let path = inner.upgrade_certificate_dir_path();
        if !path.is_file() {
            return Ok(None);
        }
        let bytes = fs::read(&path).context("read")?;
        Ok(Some(
            bincode::deserialize(&bytes).context("deserialize upgrade certificate")?,
        ))
    }

    async fn store_upgrade_certificate(
        &self,
        decided_upgrade_certificate: Option<UpgradeCertificate<SeqTypes>>,
    ) -> anyhow::Result<()> {
        let mut inner = self.inner.write().await;
        let path = &inner.upgrade_certificate_dir_path();
        let certificate = match decided_upgrade_certificate {
            Some(cert) => cert,
            None => return Ok(()),
        };
        inner.replace(
            path,
            |_| {
                // Always overwrite the previous file.
                Ok(true)
            },
            |mut file| {
                let bytes =
                    bincode::serialize(&certificate).context("serializing upgrade certificate")?;
                file.write_all(&bytes)?;
                Ok(())
            },
        )
    }

    async fn append_next_epoch_high_qc2(
        &self,
        next_epoch_high_qc: NextEpochQuorumCertificate2<SeqTypes>,
    ) -> anyhow::Result<()> {
        let mut inner = self.inner.write().await;
        let path = &inner.next_epoch_qc();
        let view = next_epoch_high_qc.view_number();
        inner.replace(
            path,
            |mut file| {
                // Overwrite only when the new QC is newer. The whole replace runs under the inner
                // write lock, so this compare-and-set is atomic and a stale concurrent write cannot
                // regress the stored view (mirrors `append_high_qc2`).
                let mut bytes = vec![];
                file.read_to_end(&mut bytes)?;
                let existing: NextEpochQuorumCertificate2<SeqTypes> = bincode::deserialize(&bytes)
                    .context("deserializing existing next epoch high_qc2")?;
                Ok(existing.view_number() < view)
            },
            |mut file| {
                let bytes = bincode::serialize(&next_epoch_high_qc)
                    .context("serializing next epoch high_qc2")?;
                file.write_all(&bytes)?;
                Ok(())
            },
        )
    }

    async fn store_eqc(
        &self,
        high_qc: QuorumCertificate2<SeqTypes>,
        next_epoch_high_qc: NextEpochQuorumCertificate2<SeqTypes>,
    ) -> anyhow::Result<()> {
        let mut inner = self.inner.write().await;
        let path = &inner.eqc();

        inner.replace(
            path,
            |_| {
                // Always overwrite the previous file.
                Ok(true)
            },
            |mut file| {
                let bytes = bincode::serialize(&(high_qc, next_epoch_high_qc))
                    .context("serializing next epoch qc")?;
                file.write_all(&bytes)?;
                Ok(())
            },
        )
    }

    async fn load_eqc(
        &self,
    ) -> Option<(
        QuorumCertificate2<SeqTypes>,
        NextEpochQuorumCertificate2<SeqTypes>,
    )> {
        let inner = self.inner.read().await;
        let path = inner.eqc();
        if !path.is_file() {
            return None;
        }
        let bytes = fs::read(&path).ok()?;

        bincode::deserialize(&bytes).ok()
    }

    async fn append_high_qc2(&self, high_qc: QuorumCertificate2<SeqTypes>) -> anyhow::Result<()> {
        let mut inner = self.inner.write().await;
        let path = &inner.high_qc2();
        // Locks are ordered by epoch, then view.
        let lock = LockView::of(&high_qc);
        inner.replace(
            path,
            |mut file| {
                // Overwrite only when the new lock is newer. The whole replace
                // runs under the inner write lock, so this compare-and-set is
                // atomic and a stale concurrent write cannot regress the lock.
                let mut bytes = vec![];
                file.read_to_end(&mut bytes)?;
                let existing: QuorumCertificate2<SeqTypes> =
                    bincode::deserialize(&bytes).context("deserializing existing high_qc2")?;
                Ok(LockView::of(&existing) < lock)
            },
            |mut file| {
                let bytes = bincode::serialize(&high_qc).context("serializing high_qc2")?;
                file.write_all(&bytes)?;
                Ok(())
            },
        )
    }

    async fn load_high_qc2(&self) -> anyhow::Result<Option<QuorumCertificate2<SeqTypes>>> {
        let inner = self.inner.read().await;
        let path = inner.high_qc2();
        if !path.is_file() {
            return Ok(None);
        }
        let bytes = fs::read(&path).context("reading high_qc2")?;
        Ok(Some(
            bincode::deserialize(&bytes).context("deserializing high_qc2")?,
        ))
    }

    async fn append_boundary_qc2(&self, qc: QuorumCertificate2<SeqTypes>) -> anyhow::Result<()> {
        let mut inner = self.inner.write().await;
        let path = &inner.boundary_qc2();
        let lock = LockView::of(&qc);
        inner.replace(
            path,
            |mut file| {
                // Overwrite only when the new certificate is later, under the
                // inner write lock, as for `high_qc2`.
                let mut bytes = vec![];
                file.read_to_end(&mut bytes)?;
                let existing: QuorumCertificate2<SeqTypes> =
                    bincode::deserialize(&bytes).context("deserializing existing boundary_qc2")?;
                Ok(LockView::of(&existing) < lock)
            },
            |mut file| {
                let bytes = bincode::serialize(&qc).context("serializing boundary_qc2")?;
                file.write_all(&bytes)?;
                Ok(())
            },
        )
    }

    async fn load_boundary_qc2(&self) -> anyhow::Result<Option<QuorumCertificate2<SeqTypes>>> {
        let inner = self.inner.read().await;
        let path = inner.boundary_qc2();
        if !path.is_file() {
            return Ok(None);
        }
        let bytes = fs::read(&path).context("reading boundary_qc2")?;
        Ok(Some(
            bincode::deserialize(&bytes).context("deserializing boundary_qc2")?,
        ))
    }

    async fn append_da2(
        &self,
        proposal: &Proposal<SeqTypes, DaProposal2<SeqTypes>>,
        _vid_commit: VidCommitment,
    ) -> anyhow::Result<()> {
        if self.consensus_only {
            return Ok(());
        }
        let mut inner = self.inner.write().await;
        let view_number = proposal.data.view_number().u64();
        let dir_path = inner.da2_dir_path();

        fs::create_dir_all(dir_path.clone()).context("failed to create da dir")?;

        let file_path = dir_path.join(view_number.to_string()).with_extension("txt");
        inner.replace(
            &file_path,
            |_| {
                // Don't overwrite an existing proposal, but warn about it as this is likely not
                // intended behavior from HotShot.
                tracing::warn!(view_number, "duplicate DA proposal");
                Ok(false)
            },
            |mut file| {
                let proposal_bytes = bincode::serialize(&proposal).context("serialize proposal")?;
                let now = Instant::now();
                file.write_all(&proposal_bytes)?;
                self.metrics
                    .internal_append_da2_duration
                    .add_point(now.elapsed().as_secs_f64());
                Ok(())
            },
        )
    }

    async fn store_drb_input(&self, drb_input: DrbInput) -> anyhow::Result<()> {
        if let Ok(loaded_drb_input) = self.load_drb_input(drb_input.epoch).await {
            if loaded_drb_input.difficulty_level != drb_input.difficulty_level {
                tracing::error!("Overwriting {loaded_drb_input:?} in storage with {drb_input:?}");
            } else if loaded_drb_input.iteration >= drb_input.iteration {
                anyhow::bail!(
                    "DrbInput in storage {:?} is more recent than {:?}, refusing to update",
                    loaded_drb_input,
                    drb_input
                )
            }
        }

        let mut inner = self.inner.write().await;
        let dir_path = inner.drb_dir_path();

        fs::create_dir_all(dir_path.clone()).context("failed to create drb dir")?;

        let drb_input_bytes =
            bincode::serialize(&drb_input).context("failed to serialize drb_input")?;

        let file_path = dir_path
            .join(drb_input.epoch.to_string())
            .with_extension("bin");

        inner.replace(
            &file_path,
            |_| {
                // Always overwrite the previous file.
                Ok(true)
            },
            |mut file| {
                file.write_all(&drb_input_bytes).context(format!(
                    "writing epoch drb_input file for epoch {:?} at {:?}",
                    drb_input.epoch, file_path
                ))
            },
        )
    }

    async fn load_drb_input(&self, epoch: u64) -> anyhow::Result<DrbInput> {
        let inner = self.inner.read().await;
        let path = &inner.drb_dir_path();
        let file_path = path.join(epoch.to_string()).with_extension("bin");
        let bytes = fs::read(&file_path).context("read")?;
        Ok(bincode::deserialize(&bytes)
            .context(format!("failed to deserialize DrbInput for epoch {epoch}"))?)
    }

    async fn store_drb_result(
        &self,
        epoch: EpochNumber,
        drb_result: DrbResult,
    ) -> anyhow::Result<()> {
        let mut inner = self.inner.write().await;
        let dir_path = inner.epoch_drb_result_dir_path();

        fs::create_dir_all(dir_path.clone()).context("failed to create epoch drb result dir")?;

        let drb_result_bytes = bincode::serialize(&drb_result).context("serialize drb result")?;

        let file_path = dir_path.join(epoch.to_string()).with_extension("txt");

        inner.replace(
            &file_path,
            |_| {
                // Always overwrite the previous file.
                Ok(true)
            },
            |mut file| {
                file.write_all(&drb_result_bytes)
                    .context(format!("writing epoch drb result file for epoch {epoch:?}"))
            },
        )
    }

    async fn add_state_cert(
        &self,
        state_cert: LightClientStateUpdateCertificateV2<SeqTypes>,
    ) -> anyhow::Result<()> {
        let mut inner = self.inner.write().await;
        // let epoch = state_cert.epoch;
        let view = state_cert.light_client_state.view_number;
        let dir_path = inner.state_cert_dir_path();

        fs::create_dir_all(dir_path.clone())
            .context("failed to create light client state update certificate dir")?;

        let bytes = bincode::serialize(&state_cert)
            .context("serialize light client state update certificate")?;

        let file_path = dir_path.join(view.to_string()).with_extension("txt");
        inner
            .replace(
                &file_path,
                |_| Ok(true),
                |mut file| {
                    file.write_all(&bytes)?;
                    Ok(())
                },
            )
            .context(format!(
                "writing light client state update certificate file for view {view:?}"
            ))?;

        Ok(())
    }

    async fn load_start_epoch_info(&self) -> anyhow::Result<Vec<InitializerEpochInfo<SeqTypes>>> {
        let inner = self.inner.read().await;
        let drb_dir_path = inner.epoch_drb_result_dir_path();
        let block_header_dir_path = inner.epoch_root_block_header_dir_path();

        let mut result = Vec::new();

        if !drb_dir_path.is_dir() {
            return Ok(Vec::new());
        }
        for (epoch, path) in epoch_files(drb_dir_path)? {
            let bytes =
                fs::read(&path).context(format!("reading epoch drb result {}", path.display()))?;
            let drb_result = bincode::deserialize::<DrbResult>(&bytes)
                .context(format!("parsing epoch drb result {}", path.display()))?;

            let block_header_path = block_header_dir_path
                .join(epoch.to_string())
                .with_extension("txt");
            let block_header = if block_header_path.is_file() {
                let bytes = fs::read(&block_header_path).context(format!(
                    "reading epoch root block header {}",
                    block_header_path.display()
                ))?;
                Some(
                    bincode::deserialize::<<SeqTypes as NodeType>::BlockHeader>(&bytes).context(
                        format!(
                            "parsing epoch root block header {}",
                            block_header_path.display()
                        ),
                    )?,
                )
            } else {
                None
            };

            result.push(InitializerEpochInfo::<SeqTypes> {
                epoch,
                drb_result,
                block_header,
            });
        }

        result.sort_by_key(|a| a.epoch);

        // Keep only the most recent epochs
        let start = result
            .len()
            .saturating_sub(RECENT_STAKE_TABLES_LIMIT as usize);
        let recent = result[start..].to_vec();

        Ok(recent)
    }

    async fn load_state_cert(
        &self,
    ) -> anyhow::Result<Option<LightClientStateUpdateCertificateV2<SeqTypes>>> {
        let inner = self.inner.read().await;
        let dir_path = inner.finalized_state_cert_dir_path();

        if !dir_path.is_dir() {
            return Ok(None);
        }

        let mut result: Option<LightClientStateUpdateCertificateV2<SeqTypes>> = None;

        for (epoch, path) in epoch_files(dir_path)? {
            if result.as_ref().is_some_and(|cert| epoch <= cert.epoch) {
                continue;
            }
            let bytes = fs::read(&path).context(format!(
                "reading light client state update certificate {}",
                path.display()
            ))?;
            let cert =
                bincode::deserialize::<LightClientStateUpdateCertificateV2<SeqTypes>>(&bytes)
                    .or_else(|error| {
                        tracing::info!(
                            %error,
                            path = %path.display(),
                            "Failed to deserialize LightClientStateUpdateCertificateV2"
                        );

                        bincode::deserialize::<LightClientStateUpdateCertificateV1<SeqTypes>>(
                            &bytes,
                        )
                        .map(Into::into)
                        .with_context(|| {
                            format!(
                                "Failed to deserialize with v1 and v2. path='{}'. error: {error}",
                                path.display()
                            )
                        })
                    })?;

            result = Some(cert);
        }

        Ok(result)
    }

    fn enable_metrics(&mut self, metrics: &dyn Metrics) {
        self.metrics = Arc::new(PersistenceMetricsValue::new(metrics));
        self.probe.register(&*metrics.subgroup("disk".into()));
    }
}

#[async_trait]
impl StateCertPersistence for Persistence {
    async fn get_state_cert_by_epoch(
        &self,
        epoch: u64,
    ) -> anyhow::Result<Option<LightClientStateUpdateCertificateV2<SeqTypes>>> {
        let inner = self.inner.read().await;
        let dir_path = inner.finalized_state_cert_dir_path();

        let file_path = dir_path.join(epoch.to_string()).with_extension("txt");

        if !file_path.exists() {
            return Ok(None);
        }

        let bytes = fs::read(&file_path).context(format!(
            "reading light client state update certificate {}",
            file_path.display()
        ))?;

        let cert = bincode::deserialize::<LightClientStateUpdateCertificateV2<SeqTypes>>(&bytes)
            .or_else(|error| {
                tracing::info!(
                    %error,
                    path = %file_path.display(),
                    "Failed to deserialize LightClientStateUpdateCertificateV2"
                );

                bincode::deserialize::<LightClientStateUpdateCertificateV1<SeqTypes>>(&bytes)
                    .map(Into::into)
                    .with_context(|| {
                        format!(
                            "Failed to deserialize with v1 and v2. path='{}'. error: {error}",
                            file_path.display()
                        )
                    })
            })?;

        Ok(Some(cert))
    }

    async fn insert_state_cert(
        &self,
        epoch: u64,
        cert: LightClientStateUpdateCertificateV2<SeqTypes>,
    ) -> anyhow::Result<()> {
        let inner = self.inner.read().await;
        let dir_path = inner.finalized_state_cert_dir_path();

        fs::create_dir_all(&dir_path)
            .context(format!("creating state cert dir {}", dir_path.display()))?;

        let file_path = dir_path.join(epoch.to_string()).with_extension("txt");
        let bytes = bincode::serialize(&cert)
            .context("serializing light client state update certificate")?;

        fs::write(&file_path, bytes).context(format!(
            "writing light client state update certificate {}",
            file_path.display()
        ))?;

        Ok(())
    }
}

#[async_trait]
impl MembershipPersistence for Persistence {
    async fn load_stake(&self, epoch: EpochNumber) -> anyhow::Result<Option<StakeTuple>> {
        let inner = self.inner.read().await;
        let path = &inner.stake_table_dir_path();
        let file_path = path.join(epoch.to_string()).with_extension("txt");

        if !file_path.exists() {
            return Ok(None);
        }

        let bytes = fs::read(&file_path).with_context(|| {
            format!("failed to read stake table file at {}", file_path.display())
        })?;

        let (stake, _needs_rewrite) = deserialize_stake_table(&bytes).with_context(|| {
            format!(
                "failed to deserialize stake table at {}",
                file_path.display()
            )
        })?;
        Ok(Some(stake))
    }

    async fn load_drb_result(&self, epoch: EpochNumber) -> anyhow::Result<Option<DrbResult>> {
        let inner = self.inner.read().await;
        let file_path = inner
            .epoch_drb_result_dir_path()
            .join(epoch.to_string())
            .with_extension("txt");

        if !file_path.is_file() {
            return Ok(None);
        }

        let bytes = fs::read(&file_path)
            .context(format!("reading epoch drb result {}", file_path.display()))?;
        let drb_result = bincode::deserialize::<DrbResult>(&bytes)
            .context(format!("parsing epoch drb result {}", file_path.display()))?;
        Ok(Some(drb_result))
    }

    async fn load_epoch_root(&self, epoch: EpochNumber) -> anyhow::Result<Option<Header>> {
        let inner = self.inner.read().await;
        let file_path = inner
            .epoch_root_block_header_dir_path()
            .join(epoch.to_string())
            .with_extension("txt");

        if !file_path.is_file() {
            return Ok(None);
        }

        let bytes = fs::read(&file_path).context(format!(
            "reading epoch root block header {}",
            file_path.display()
        ))?;
        let header = bincode::deserialize::<Header>(&bytes).context(format!(
            "parsing epoch root block header {}",
            file_path.display()
        ))?;
        Ok(Some(header))
    }

    async fn store_epoch_root(
        &self,
        epoch: EpochNumber,
        block_header: Header,
    ) -> anyhow::Result<()> {
        let mut inner = self.inner.write().await;
        let dir_path = inner.epoch_root_block_header_dir_path();

        fs::create_dir_all(dir_path.clone())
            .context("failed to create epoch root block header dir")?;

        let block_header_bytes =
            bincode::serialize(&block_header).context("serialize block header")?;

        let file_path = dir_path.join(epoch.to_string()).with_extension("txt");
        inner
            .replace(
                &file_path,
                |_| Ok(true),
                |mut file| {
                    file.write_all(&block_header_bytes)?;
                    Ok(())
                },
            )
            .context(format!(
                "writing epoch root block header file for epoch {epoch:?}"
            ))?;

        Ok(())
    }

    async fn load_latest_stake(&self, limit: u64) -> anyhow::Result<Option<Vec<IndexedStake>>> {
        let limit = limit as usize;
        let inner = self.inner.read().await;
        let path = &inner.stake_table_dir_path();
        let sorted_files = epoch_files(path)?
            .sorted_by(|(e1, _), (e2, _)| e2.cmp(e1))
            .take(limit);
        let mut validator_sets: Vec<IndexedStake> = Vec::new();

        for (epoch, file_path) in sorted_files {
            let bytes = fs::read(&file_path).with_context(|| {
                format!("failed to read stake table file at {}", file_path.display())
            })?;

            let (stake, _needs_rewrite) = deserialize_stake_table(&bytes).with_context(|| {
                format!(
                    "failed to deserialize stake table at {}",
                    file_path.display()
                )
            })?;
            validator_sets.push((epoch, (stake.0, stake.1), stake.2));
        }

        Ok(Some(validator_sets))
    }

    async fn store_stake(
        &self,
        epoch: EpochNumber,
        stake: AuthenticatedValidatorMap,
        block_reward: Option<RewardAmount>,
        stake_table_hash: Option<StakeTableHash>,
    ) -> anyhow::Result<()> {
        let mut inner = self.inner.write().await;
        let dir_path = &inner.stake_table_dir_path();

        fs::create_dir_all(dir_path.clone()).context("failed to create stake table dir")?;

        let file_path = dir_path.join(epoch.to_string()).with_extension("txt");

        inner.replace(
            &file_path,
            |_| {
                // Always overwrite the previous file.
                Ok(true)
            },
            |mut file| {
                let data: StakeTuple = (stake, block_reward, stake_table_hash);
                let bytes =
                    bincode::serialize(&data).context("serializing combined stake table")?;
                file.write_all(&bytes)?;
                Ok(())
            },
        )
    }

    /// store stake table events upto the l1 block
    async fn store_events(
        &self,
        to_l1_block: u64,
        events: Vec<(EventKey, StakeTableEvent)>,
    ) -> anyhow::Result<()> {
        let mut inner = self.inner.write().await;
        let dir_path = &inner.stake_table_dir_path();
        let events_dir = dir_path.join("events");

        fs::create_dir_all(events_dir.clone()).context("failed to create events dir")?;
        // Read the last l1 finalized for which events has been stored
        let last_l1_finalized_path = events_dir.join("last_l1_finalized").with_extension("bin");

        // check if the last l1 events is higher than the incoming one
        if last_l1_finalized_path.exists() {
            let bytes = fs::read(&last_l1_finalized_path).with_context(|| {
                format!("Failed to read file at path: {last_l1_finalized_path:?}")
            })?;
            let mut buf = [0; 8];
            bytes
                .as_slice()
                .read_exact(&mut buf[..8])
                .with_context(|| {
                    format!("Failed to read 8 bytes from file at path: {last_l1_finalized_path:?}")
                })?;
            let persisted_l1_block = u64::from_le_bytes(buf);
            if persisted_l1_block > to_l1_block {
                tracing::debug!(?persisted_l1_block, ?to_l1_block, "stored l1 is greater");
                return Ok(());
            }
        }

        // stores each event in a separate file
        // this can cause performance issue when, for example, reading all the files
        // However, the plan is to remove file system completely in future
        for (event_key, event) in events {
            let (block_number, event_index) = event_key;
            // file name is like block_index.json
            let filename = format!("{block_number}_{event_index}");
            let file_path = events_dir.join(filename).with_extension("json");

            if file_path.exists() {
                continue;
            }

            inner
                .replace(
                    &file_path,
                    |_| Ok(true),
                    |file| {
                        let writer = BufWriter::new(file);

                        serde_json::to_writer_pretty(writer, &event)?;
                        Ok(())
                    },
                )
                .context("Failed to write event to file")?;
        }

        // update the l1 block for which we have processed events
        inner.replace(
            &last_l1_finalized_path,
            |_| Ok(true),
            |mut file| {
                let bytes = to_l1_block.to_le_bytes();

                file.write_all(&bytes)?;
                tracing::debug!("updated l1 finalized ={to_l1_block:?}");
                Ok(())
            },
        )
    }

    /// Loads all events from persistent storage up to the specified L1 block.
    ///
    /// # Returns
    ///
    /// Returns a tuple containing:
    /// - `Option<u64>` - The queried L1 block for which all events have been successfully fetched.
    /// - `Vec<(EventKey, StakeTableEvent)>` - A list of events, where each entry is a tuple of the event key
    /// event key is (l1 block number, log index)
    ///   and the corresponding StakeTable event.
    ///
    async fn load_events(
        &self,
        from_l1_block: u64,
        to_l1_block: u64,
    ) -> anyhow::Result<(
        Option<EventsPersistenceRead>,
        Vec<(EventKey, StakeTableEvent)>,
    )> {
        let inner = self.inner.read().await;
        let dir_path = inner.stake_table_dir_path();
        let events_dir = dir_path.join("events");

        // check if we have any events in storage
        // we can do this by checking last l1 finalized block for which we processed events
        let last_l1_finalized_path = events_dir.join("last_l1_finalized").with_extension("bin");

        if !last_l1_finalized_path.exists() || !events_dir.exists() {
            return Ok((None, Vec::new()));
        }

        let mut events = Vec::new();

        let bytes = fs::read(&last_l1_finalized_path)
            .with_context(|| format!("Failed to read file at path: {last_l1_finalized_path:?}"))?;
        let mut buf = [0; 8];
        bytes
            .as_slice()
            .read_exact(&mut buf[..8])
            .with_context(|| {
                format!("Failed to read 8 bytes from file at path: {last_l1_finalized_path:?}")
            })?;

        let last_processed_l1_block = u64::from_le_bytes(buf);

        // Determine the L1 block for querying events.
        // If the last stored L1 block is greater than the requested block, limit the query to the requested block.
        // Otherwise, query up to the last stored block.
        let query_l1_block = if last_processed_l1_block > to_l1_block {
            to_l1_block
        } else {
            last_processed_l1_block
        };

        for entry in fs::read_dir(&events_dir).context("events directory")? {
            let entry = entry?;
            let path = entry.path();

            if !entry.file_type()?.is_file() {
                continue;
            }

            if path
                .extension()
                .context(format!("extension for path={path:?}"))?
                != "json"
            {
                continue;
            }

            let filename = path
                .file_stem()
                .and_then(|f| f.to_str())
                .unwrap_or_default();

            let parts: Vec<&str> = filename.split('_').collect();
            if parts.len() != 2 {
                continue;
            }

            let block_number = parts[0].parse::<u64>()?;
            let log_index = parts[1].parse::<u64>()?;

            if block_number < from_l1_block || block_number > query_l1_block {
                continue;
            }

            let file =
                File::open(&path).context(format!("Failed to open event file. path={path:?}"))?;
            let reader = BufReader::new(file);

            let event: StakeTableEvent = serde_json::from_reader(reader)
                .context(format!("Failed to deserialize event at path={path:?}"))?;

            events.push(((block_number, log_index), event));
        }

        events.sort_by_key(|(key, _)| *key);

        if query_l1_block == to_l1_block {
            Ok((Some(EventsPersistenceRead::Complete), events))
        } else {
            Ok((
                Some(EventsPersistenceRead::UntilL1Block(query_l1_block)),
                events,
            ))
        }
    }

    async fn delete_stake_tables(&self) -> anyhow::Result<()> {
        let inner = self.inner.write().await;
        let events_dir = inner.stake_table_dir_path().join("events");
        if events_dir.exists() {
            fs::remove_dir_all(&events_dir)
                .with_context(|| format!("Failed to remove events dir: {events_dir:?}"))?;
        }
        let validators_dir = inner.stake_table_dir_path().join("validators");
        if validators_dir.exists() {
            fs::remove_dir_all(&validators_dir)
                .with_context(|| format!("Failed to remove validators dir: {validators_dir:?}"))?;
        }
        let drb_dir = inner.epoch_drb_result_dir_path();
        if drb_dir.exists() {
            fs::remove_dir_all(&drb_dir)
                .with_context(|| format!("Failed to remove epoch DRB result dir: {drb_dir:?}"))?;
        }
        Ok(())
    }

    async fn store_all_validators(
        &self,
        epoch: EpochNumber,
        all_validators: RegisteredValidatorMap,
    ) -> anyhow::Result<()> {
        let mut inner = self.inner.write().await;
        let dir_path = inner.stake_table_dir_path();
        let validators_dir = dir_path.join("validators");

        // Ensure validators directory exists
        fs::create_dir_all(&validators_dir)
            .with_context(|| format!("Failed to create validators dir: {validators_dir:?}"))?;

        // Path = validators/epoch_<number>.json
        let file_path = validators_dir.join(format!("epoch_{epoch}.json"));

        inner
            .replace(
                &file_path,
                |_| Ok(true),
                |file| {
                    let writer = BufWriter::new(file);

                    serde_json::to_writer_pretty(writer, &all_validators).with_context(|| {
                        format!("Failed to serialize validators for epoch {epoch}")
                    })?;
                    Ok(())
                },
            )
            .with_context(|| format!("Failed to write validator file: {file_path:?}"))?;

        Ok(())
    }

    async fn load_all_validators(
        &self,
        epoch: EpochNumber,
        offset: u64,
        limit: u64,
    ) -> anyhow::Result<Vec<RegisteredValidator<PubKey>>> {
        let inner = self.inner.read().await;
        let dir_path = inner.stake_table_dir_path();
        let validators_dir = dir_path.join("validators");
        let file_path = validators_dir.join(format!("epoch_{epoch}.json"));

        if !file_path.exists() {
            bail!("Validator file not found for epoch {epoch}");
        }

        let file = File::open(&file_path)
            .with_context(|| format!("Failed to open validator file: {file_path:?}"))?;
        let reader = BufReader::new(file);

        let map: RegisteredValidatorMap = serde_json::from_reader(reader).with_context(|| {
            format!("Failed to deserialize validators at {file_path:?}. epoch = {epoch}")
        })?;

        let mut values: Vec<RegisteredValidator<PubKey>> = map.into_values().collect();
        values.sort_by_key(|v| v.account);

        let start = offset as usize;
        let end = (start + limit as usize).min(values.len());

        if start >= values.len() {
            return Ok(vec![]);
        }

        Ok(values[start..end].to_vec())
    }
}

/// Get all paths under `dir` whose name is of the form <view number>.txt.
fn view_files(
    dir: impl AsRef<Path>,
) -> anyhow::Result<impl Iterator<Item = (ViewNumber, PathBuf)>> {
    Ok(fs::read_dir(dir.as_ref())?.filter_map(move |entry| {
        let dir = dir.as_ref().display();
        let entry = entry.ok()?;
        if !entry.file_type().ok()?.is_file() {
            tracing::debug!(%dir, ?entry, "ignoring non-file in data directory");
            return None;
        }
        let path = entry.path();
        // Most view-keyed files use a `.txt` extension; cert2 files use `.bin`. Both hold bincode.
        let ext = path.extension()?;
        if ext != "txt" && ext != "bin" {
            tracing::debug!(%dir, ?entry, "ignoring file with unrecognized extension in data directory");
            return None;
        }
        let file_name = path.file_stem()?;
        let Ok(view_number) = file_name.to_string_lossy().parse::<u64>() else {
            tracing::debug!(%dir, ?file_name, "ignoring extraneous file in data directory");
            return None;
        };
        Some((ViewNumber::new(view_number), entry.path().to_owned()))
    }))
}

/// Get all paths under `dir` whose name is of the form <epoch number>.txt.
/// Should probably be made generic and merged with view_files.
fn epoch_files(
    dir: impl AsRef<Path>,
) -> anyhow::Result<impl Iterator<Item = (EpochNumber, PathBuf)>> {
    Ok(fs::read_dir(dir.as_ref())?.filter_map(move |entry| {
        let dir = dir.as_ref().display();
        let entry = entry.ok()?;
        if !entry.file_type().ok()?.is_file() {
            tracing::debug!(%dir, ?entry, "ignoring non-file in data directory");
            return None;
        }
        let path = entry.path();
        if path.extension()? != "txt" {
            tracing::debug!(%dir, ?entry, "ignoring non-text file in data directory");
            return None;
        }
        let file_name = path.file_stem()?;
        let Ok(epoch_number) = file_name.to_string_lossy().parse::<u64>() else {
            tracing::debug!(%dir, ?file_name, "ignoring extraneous file in data directory");
            return None;
        };
        Some((EpochNumber::new(epoch_number), entry.path().to_owned()))
    }))
}

#[cfg(test)]
mod test {
    use std::marker::PhantomData;

    use committable::Committable;
    use espresso_types::{Leaf, NodeState, PubKey};
    use hotshot_example_types::node_types::TEST_VERSIONS;
    use hotshot_query_service::{metrics::PrometheusMetrics, testing::mocks::MOCK_UPGRADE};
    use hotshot_types::{
        data::QuorumProposal2, simple_vote::Vote2Data, traits::signature_key::SignatureKey,
    };
    use serde_json::json;
    use tempfile::TempDir;

    use super::*;
    use crate::{BLSPubKey, persistence::tests::TestablePersistence};

    #[async_trait]
    impl TestablePersistence for Persistence {
        type Storage = TempDir;

        async fn tmp_storage() -> Self::Storage {
            TempDir::new().unwrap()
        }

        fn options(storage: &Self::Storage) -> impl PersistenceOptions<Persistence = Self> {
            Options::new(storage.path().into())
        }
    }

    #[test]
    fn test_config_migrations_add_builder_urls() {
        let before = json!({
            "config": {
                "builder_url": "https://test:8080",
                "start_proposing_view": 1,
                "stop_proposing_view": 2,
                "start_voting_view": 1,
                "stop_voting_view": 2,
                "start_proposing_time": 1,
                "stop_proposing_time": 2,
                "start_voting_time": 1,
                "stop_voting_time": 2
            }
        });
        let after = json!({
            "config": {
                "builder_urls": ["https://test:8080"],
                "start_proposing_view": 1,
                "stop_proposing_view": 2,
                "start_voting_view": 1,
                "stop_voting_view": 2,
                "start_proposing_time": 1,
                "stop_proposing_time": 2,
                "start_voting_time": 1,
                "stop_voting_time": 2,
                "epoch_height": 0,
                "drb_difficulty": 0,
                "drb_upgrade_difficulty": 0,
                "da_committees": [],
            }
        });

        assert_eq!(migrate_network_config(before).unwrap(), after);
    }

    #[test]
    fn test_config_migrations_existing_builder_urls() {
        let before = json!({
            "config": {
                "builder_urls": ["https://test:8080", "https://test:8081"],
                "start_proposing_view": 1,
                "stop_proposing_view": 2,
                "start_voting_view": 1,
                "stop_voting_view": 2,
                "start_proposing_time": 1,
                "stop_proposing_time": 2,
                "start_voting_time": 1,
                "stop_voting_time": 2,
                "epoch_height": 0,
                "drb_difficulty": 0,
                "drb_upgrade_difficulty": 0,
                "da_committees": [],
            }
        });

        assert_eq!(migrate_network_config(before.clone()).unwrap(), before);
    }

    #[test]
    fn test_config_migrations_add_upgrade_params() {
        let before = json!({
            "config": {
                "builder_urls": ["https://test:8080", "https://test:8081"]
            }
        });
        let after = json!({
            "config": {
                "builder_urls": ["https://test:8080", "https://test:8081"],
                "start_proposing_view": 9007199254740991u64,
                "stop_proposing_view": 0,
                "start_voting_view": 9007199254740991u64,
                "stop_voting_view": 0,
                "start_proposing_time": 9007199254740991u64,
                "stop_proposing_time": 0,
                "start_voting_time": 9007199254740991u64,
                "stop_voting_time": 0,
                "epoch_height": 0,
                "drb_difficulty": 0,
                "drb_upgrade_difficulty": 0,
                "da_committees": [],
            }
        });

        assert_eq!(migrate_network_config(before).unwrap(), after);
    }

    #[test]
    fn test_config_migrations_existing_upgrade_params() {
        let before = json!({
            "config": {
                "builder_urls": ["https://test:8080", "https://test:8081"],
                "start_proposing_view": 1,
                "stop_proposing_view": 2,
                "start_voting_view": 1,
                "stop_voting_view": 2,
                "start_proposing_time": 1,
                "stop_proposing_time": 2,
                "start_voting_time": 1,
                "stop_voting_time": 2,
                "epoch_height": 0,
                "drb_difficulty": 0,
                "drb_upgrade_difficulty": 0,
                "da_committees": [],
            }
        });

        assert_eq!(migrate_network_config(before.clone()).unwrap(), before);
    }

    #[test_log::test(tokio::test(flavor = "multi_thread"))]
    async fn test_load_quorum_proposals_invalid_extension() {
        let tmp = Persistence::tmp_storage().await;
        let storage = Persistence::connect(&tmp).await;

        // Generate a couple of valid quorum proposals.
        let leaf = Leaf2::genesis(&Default::default(), &NodeState::mock(), MOCK_UPGRADE.base).await;
        let privkey = PubKey::generated_from_seed_indexed([0; 32], 1).1;
        let signature = PubKey::sign(&privkey, &[]).unwrap();
        let mut quorum_proposal = Proposal {
            data: QuorumProposalWrapper::<SeqTypes> {
                proposal: QuorumProposal2::<SeqTypes> {
                    epoch: None,
                    block_header: leaf.block_header().clone(),
                    view_number: ViewNumber::genesis(),
                    justify_qc: QuorumCertificate2::genesis(
                        &Default::default(),
                        &NodeState::mock(),
                        TEST_VERSIONS.test,
                    )
                    .await,
                    upgrade_certificate: None,
                    view_change_evidence: None,
                    next_drb_result: None,
                    next_epoch_justify_qc: None,
                    state_cert: None,
                },
            },
            signature,
            _pd: Default::default(),
        };

        // Store quorum proposals.
        let quorum_proposal1 = quorum_proposal.clone();
        storage
            .append_quorum_proposal2(&quorum_proposal1)
            .await
            .unwrap();
        quorum_proposal.data.proposal.view_number = ViewNumber::new(1);
        let quorum_proposal2 = quorum_proposal.clone();
        storage
            .append_quorum_proposal2(&quorum_proposal2)
            .await
            .unwrap();

        // Change one of the file extensions. It can happen that we end up with files with the wrong
        // extension if, for example, the node is killed before cleaning up a swap file.
        fs::rename(
            tmp.path().join("quorum_proposals2/1.txt"),
            tmp.path().join("quorum_proposals2/1.swp"),
        )
        .unwrap();

        // Loading should simply ignore the unrecognized extension.
        assert_eq!(
            storage.load_quorum_proposals().await.unwrap(),
            [(ViewNumber::genesis(), quorum_proposal1)]
                .into_iter()
                .collect::<BTreeMap<_, _>>()
        );
    }

    #[test_log::test(tokio::test(flavor = "multi_thread"))]
    async fn test_cert2_persisted_as_bin() {
        let tmp = Persistence::tmp_storage().await;
        let storage = Persistence::connect(&tmp).await;
        let view = ViewNumber::new(7);
        let leaf = Leaf2::genesis(&Default::default(), &NodeState::mock(), MOCK_UPGRADE.base).await;
        let data = Vote2Data {
            leaf_commit: leaf.commit(),
            epoch: EpochNumber::new(1),
            block_number: leaf.height(),
        };
        let cert2 = Certificate2::new(data.clone(), data.commit(), view, None, PhantomData);

        storage.append_cert2(view, cert2.clone()).await.unwrap();

        assert!(tmp.path().join("decided_cert2/7.bin").is_file());
        assert!(!tmp.path().join("decided_cert2/7.txt").exists());
        assert_eq!(storage.load_cert2(view).await.unwrap(), Some(cert2));
    }

    #[test_log::test(tokio::test(flavor = "multi_thread"))]
    async fn test_load_quorum_proposals_malformed_data() {
        let tmp = Persistence::tmp_storage().await;
        let storage = Persistence::connect(&tmp).await;

        // Generate a valid quorum proposal.
        let leaf: Leaf2 = Leaf::genesis(&Default::default(), &NodeState::mock(), MOCK_UPGRADE.base)
            .await
            .into();
        let privkey = PubKey::generated_from_seed_indexed([0; 32], 1).1;
        let signature = PubKey::sign(&privkey, &[]).unwrap();
        let quorum_proposal = Proposal {
            data: QuorumProposalWrapper::<SeqTypes> {
                proposal: QuorumProposal2::<SeqTypes> {
                    epoch: None,
                    block_header: leaf.block_header().clone(),
                    view_number: ViewNumber::new(1),
                    justify_qc: QuorumCertificate2::genesis(
                        &Default::default(),
                        &NodeState::mock(),
                        TEST_VERSIONS.test,
                    )
                    .await,
                    upgrade_certificate: None,
                    view_change_evidence: None,
                    next_drb_result: None,
                    next_epoch_justify_qc: None,
                    state_cert: None,
                },
            },
            signature,
            _pd: Default::default(),
        };

        // First store an invalid quorum proposal.
        fs::create_dir_all(tmp.path().join("quorum_proposals2")).unwrap();
        fs::write(
            tmp.path().join("quorum_proposals2/0.txt"),
            "invalid data".as_bytes(),
        )
        .unwrap();

        // Store valid quorum proposal.
        storage
            .append_quorum_proposal2(&quorum_proposal)
            .await
            .unwrap();

        // Loading should ignore the invalid data and return the valid proposal.
        assert_eq!(
            storage.load_quorum_proposals().await.unwrap(),
            [(ViewNumber::new(1), quorum_proposal)]
                .into_iter()
                .collect::<BTreeMap<_, _>>()
        );
    }

    #[test_log::test(tokio::test(flavor = "multi_thread"))]
    async fn test_store_events_empty() {
        let tmp = Persistence::tmp_storage().await;
        let mut opt = Persistence::options(&tmp);
        let storage = opt.create().await.unwrap();

        assert_eq!(storage.load_events(0, 100).await.unwrap(), (None, vec![]));

        // Storing an empty events list still updates the latest L1 block.
        for i in 1..=2 {
            tracing::info!(i, "update l1 height");
            storage.store_events(i, vec![]).await.unwrap();
            assert_eq!(
                storage.load_events(0, 100).await.unwrap(),
                (Some(EventsPersistenceRead::UntilL1Block(i)), vec![])
            );
        }
    }

    #[test_log::test(tokio::test(flavor = "multi_thread"))]
    async fn test_store_all_validators_authenticated_and_unauthenticated() {
        use std::collections::HashMap;

        use alloy::primitives::{Address, U256};
        use espresso_types::v0_3::RegisteredValidator;
        use indexmap::IndexMap;

        let tmp = Persistence::tmp_storage().await;
        let mut opt = Persistence::options(&tmp);
        let storage = opt.create().await.unwrap();

        // Create an authenticated validator
        let authenticated_validator = RegisteredValidator {
            account: Address::random(),
            stake_table_key: Some(BLSPubKey::generated_from_seed_indexed([0u8; 32], 0).0),
            state_ver_key: Some(hotshot_types::light_client::StateVerKey::default()),
            stake: U256::from(1000),
            commission: 100,
            delegators: HashMap::new(),
            authenticated: true,
            x25519_key: None,
            p2p_addr: None,
        };

        // Create an unauthenticated validator
        let unauthenticated_validator = RegisteredValidator {
            account: Address::random(),
            stake_table_key: Some(BLSPubKey::generated_from_seed_indexed([0u8; 32], 1).0),
            state_ver_key: Some(hotshot_types::light_client::StateVerKey::default()),
            stake: U256::from(2000),
            commission: 200,
            delegators: HashMap::new(),
            authenticated: false,
            x25519_key: None,
            p2p_addr: None,
        };

        let mut validators: IndexMap<Address, RegisteredValidator<BLSPubKey>> = IndexMap::new();
        validators.insert(
            authenticated_validator.account,
            authenticated_validator.clone(),
        );
        validators.insert(
            unauthenticated_validator.account,
            unauthenticated_validator.clone(),
        );

        // Store both validators
        storage
            .store_all_validators(EpochNumber::new(1), validators)
            .await
            .unwrap();

        // Load and verify
        let loaded = storage
            .load_all_validators(EpochNumber::new(1), 0, 100)
            .await
            .unwrap();
        assert_eq!(loaded.len(), 2);

        // Find each validator and verify authenticated state is preserved
        let loaded_auth = loaded
            .iter()
            .find(|v| v.account == authenticated_validator.account)
            .unwrap();
        assert!(
            loaded_auth.authenticated,
            "authenticated validator should remain authenticated"
        );

        let loaded_unauth = loaded
            .iter()
            .find(|v| v.account == unauthenticated_validator.account)
            .unwrap();
        assert!(
            !loaded_unauth.authenticated,
            "unauthenticated validator should remain unauthenticated"
        );
    }

    fn write_legacy_stake_file(
        path: &std::path::Path,
        epoch: u64,
        validator: RegisteredValidatorPreOption,
    ) {
        use indexmap::IndexMap;

        let mut map: IndexMap<Address, RegisteredValidatorPreOption> = IndexMap::new();
        map.insert(validator.account, validator);
        type PreOptionTuple = (
            IndexMap<Address, RegisteredValidatorPreOption>,
            Option<RewardAmount>,
            Option<StakeTableHash>,
        );
        let data: PreOptionTuple = (map, None, None);
        let bytes = bincode::serialize(&data).unwrap();
        fs::create_dir_all(path).unwrap();
        fs::write(path.join(format!("{epoch}.txt")), &bytes).unwrap();
    }

    fn pre_option_validator(seed: u8, stake: u64) -> RegisteredValidatorPreOption {
        use std::collections::HashMap;

        use alloy::primitives::U256;

        RegisteredValidatorPreOption {
            account: Address::random(),
            stake_table_key: BLSPubKey::generated_from_seed_indexed([seed; 32], 0).0,
            state_ver_key: hotshot_types::light_client::StateVerKey::default(),
            stake: U256::from(stake),
            commission: 0,
            delegators: HashMap::new(),
            authenticated: true,
            x25519_key: None,
            p2p_addr: None,
        }
    }

    #[test_log::test(tokio::test(flavor = "multi_thread"))]
    async fn test_load_stake_legacy_storage() {
        let tmp = Persistence::tmp_storage().await;
        let mut opt = Persistence::options(&tmp);
        let storage = opt.create().await.unwrap();

        let v1 = pre_option_validator(1, 100);
        let v2 = pre_option_validator(2, 200);
        let v1_addr = v1.account;
        let v2_addr = v2.account;

        let path = {
            let inner = storage.inner.read().await;
            inner.stake_table_dir_path()
        };
        write_legacy_stake_file(&path, 1, v1);
        write_legacy_stake_file(&path, 2, v2);

        let (loaded1, ..) = storage
            .load_stake(EpochNumber::new(1))
            .await
            .unwrap()
            .unwrap();
        assert_eq!(loaded1.len(), 1);
        assert!(loaded1.get(&v1_addr).unwrap().stake_table_key.is_some());

        let (loaded2, ..) = storage
            .load_stake(EpochNumber::new(2))
            .await
            .unwrap()
            .unwrap();
        assert_eq!(loaded2.len(), 1);
        assert!(loaded2.get(&v2_addr).unwrap().stake_table_key.is_some());

        let latest = storage.load_latest_stake(10).await.unwrap().unwrap();
        assert_eq!(latest.len(), 2);
        let epochs: Vec<_> = latest.iter().map(|(e, ..)| *e).collect();
        assert!(epochs.contains(&EpochNumber::new(1)));
        assert!(epochs.contains(&EpochNumber::new(2)));
    }

    #[test_log::test(tokio::test(flavor = "multi_thread"))]
    async fn test_load_stake_mixed_storage() {
        use indexmap::IndexMap;

        let tmp = Persistence::tmp_storage().await;
        let mut opt = Persistence::options(&tmp);
        let storage = opt.create().await.unwrap();

        let legacy_v = pre_option_validator(3, 300);
        let legacy_addr = legacy_v.account;
        let path = {
            let inner = storage.inner.read().await;
            inner.stake_table_dir_path()
        };
        write_legacy_stake_file(&path, 5, legacy_v);

        let current_v = espresso_types::v0_3::AuthenticatedValidator::mock();
        let current_addr = current_v.account;
        let mut current_map = IndexMap::new();
        current_map.insert(current_addr, current_v);
        storage
            .store_stake(EpochNumber::new(6), current_map, None, None)
            .await
            .unwrap();

        let latest = storage.load_latest_stake(10).await.unwrap().unwrap();
        assert_eq!(latest.len(), 2);
        let by_epoch: std::collections::HashMap<_, _> = latest
            .into_iter()
            .map(|(e, (map, _), _)| (e, map))
            .collect();
        assert!(
            by_epoch
                .get(&EpochNumber::new(5))
                .unwrap()
                .contains_key(&legacy_addr)
        );
        assert!(
            by_epoch
                .get(&EpochNumber::new(6))
                .unwrap()
                .contains_key(&current_addr)
        );
    }

    /// The probe is taken in `create()` and only reaches the exported registry through
    /// `enable_metrics`, mirroring the sqlite backend's `test_storage_probe_reaches_exported_registry`.
    #[test_log::test(tokio::test(flavor = "multi_thread"))]
    async fn test_storage_probe_reaches_exported_registry() {
        let tmp = Persistence::tmp_storage().await;
        let mut persistence = Persistence::options(&tmp).create().await.unwrap();

        let metrics = PrometheusMetrics::default();
        persistence.enable_metrics(&*Metrics::subgroup(&metrics, "consensus".to_string()));

        let exported = metrics.export().unwrap();
        assert!(exported.contains("consensus_disk_info"), "{exported}");
        assert!(exported.contains("backend=\"fs\""), "{exported}");
        assert!(
            exported.contains("consensus_disk_fsync_micros"),
            "{exported}"
        );
    }
}