reth_snap_sync/common/
record.rs

1//! Versioned progress records kept in the metadata table.
2//!
3//! Account coverage and storage progress each implement [`SnapRecord`], so a record written by
4//! another build version is reported instead of misread when a download resumes.
5
6use crate::SnapSyncError;
7use reth_storage_api::{MetadataProvider, MetadataWriter};
8use reth_storage_errors::provider::ProviderError;
9use serde::{de::DeserializeOwned, Serialize};
10
11/// A progress record stored as JSON under its own metadata key.
12///
13/// The serialized record carries a `version` field, checked before the rest is decoded.
14pub(crate) trait SnapRecord: Serialize + DeserializeOwned {
15    /// Metadata key the record is stored under.
16    const KEY: &'static str;
17
18    /// Encoding version this build writes.
19    const VERSION: u32;
20
21    /// Reads the record, reporting one written at another version instead of misreading it.
22    fn read(provider: &impl MetadataProvider) -> Result<Option<Self>, SnapSyncError> {
23        let Some(bytes) = provider.get_metadata(Self::KEY)? else { return Ok(None) };
24        let value = serde_json::from_slice::<serde_json::Value>(&bytes)
25            .map_err(|source| SnapSyncError::UnreadableRecord { key: Self::KEY, source })?;
26        let version = value.get("version").and_then(serde_json::Value::as_u64);
27        if version != Some(u64::from(Self::VERSION)) {
28            return Err(SnapSyncError::UnsupportedRecord { key: Self::KEY, version })
29        }
30        serde_json::from_value(value)
31            .map(Some)
32            .map_err(|source| SnapSyncError::UnreadableRecord { key: Self::KEY, source })
33    }
34
35    /// Removes the record, whichever version wrote it.
36    fn clear(provider: &impl MetadataWriter) -> Result<(), SnapSyncError> {
37        provider.delete_metadata(Self::KEY)?;
38        Ok(())
39    }
40
41    /// Writes this record under its key.
42    fn write(&self, provider: &impl MetadataWriter) -> Result<(), SnapSyncError> {
43        provider
44            .write_metadata(Self::KEY, serde_json::to_vec(self).map_err(ProviderError::other)?)?;
45        Ok(())
46    }
47}
reth_snap_sync/common/record.rs

reth_snap_sync/common/
record.rs
