Use BLOB and consensus encoding for the entire header type

.gitignore

@@ -1,5 +1,6 @@
 /target
 /data
+/light_client_data
 /kyoto
 .DS_Store
 .idea/

Cargo.toml

@@ -33,8 +33,8 @@ tokio = { version = "1", default-features = false, features = [
 rusqlite = { version = "0.31.0", features = ["bundled"], optional = true }
 
 [features]
-default = ["database"]
-database = ["rusqlite"]
+default = ["rusqlite"]
+rusqlite = ["dep:rusqlite"]
 filter-control = []
 
 [dev-dependencies]

src/builder.rs

@@ -6,9 +6,9 @@ use bitcoin::Network;
 use bitcoin::ScriptBuf;
 
 use super::{client::Client, config::NodeConfig, node::Node};
-#[cfg(feature = "database")]
+#[cfg(feature = "rusqlite")]
 use crate::db::error::SqlInitializationError;
-#[cfg(feature = "database")]
+#[cfg(feature = "rusqlite")]
 use crate::db::sqlite::{headers::SqliteHeaderDb, peers::SqlitePeerDb};
 use crate::network::dns::{DnsResolver, DNS_RESOLVER_PORT};
 use crate::network::ConnectionType;
@@ -18,7 +18,7 @@ use crate::{
 };
 use crate::{FilterSyncPolicy, LogLevel, PeerStoreSizeConfig, TrustedPeer};
 
-#[cfg(feature = "database")]
+#[cfg(feature = "rusqlite")]
 /// The default node returned from the [`NodeBuilder`](crate::core).
 pub type NodeDefault = Node<SqliteHeaderDb, SqlitePeerDb>;
 
@@ -210,7 +210,7 @@ impl NodeBuilder {
     /// # Errors
     ///
     /// Building a node and client will error if a database connection is denied or cannot be found.
-    #[cfg(feature = "database")]
+    #[cfg(feature = "rusqlite")]
     pub fn build(&mut self) -> Result<(NodeDefault, Client), SqlInitializationError> {
         let peer_store = SqlitePeerDb::new(self.network, self.config.data_path.clone())?;
         let header_store = SqliteHeaderDb::new(self.network, self.config.data_path.clone())?;

src/db/error.rs

@@ -1,7 +1,7 @@
 use std::fmt::Debug;
 
 /// Errors when initializing a SQL-based backend.
-#[cfg(feature = "database")]
+#[cfg(feature = "rusqlite")]
 #[derive(Debug)]
 pub enum SqlInitializationError {
     /// A file or directory could not be opened or created.
@@ -10,7 +10,7 @@ pub enum SqlInitializationError {
     SQL(rusqlite::Error),
 }
 
-#[cfg(feature = "database")]
+#[cfg(feature = "rusqlite")]
 impl core::fmt::Display for SqlInitializationError {
     fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
         match self {
@@ -24,7 +24,7 @@ impl core::fmt::Display for SqlInitializationError {
     }
 }
 
-#[cfg(feature = "database")]
+#[cfg(feature = "rusqlite")]
 impl std::error::Error for SqlInitializationError {
     fn source(&self) -> Option<&(dyn std::error::Error + 'static)> {
         match self {
@@ -34,22 +34,22 @@ impl std::error::Error for SqlInitializationError {
     }
 }
 
-#[cfg(feature = "database")]
+#[cfg(feature = "rusqlite")]
 impl From<rusqlite::Error> for SqlInitializationError {
     fn from(value: rusqlite::Error) -> Self {
         Self::SQL(value)
     }
 }
 
-#[cfg(feature = "database")]
+#[cfg(feature = "rusqlite")]
 impl From<std::io::Error> for SqlInitializationError {
     fn from(value: std::io::Error) -> Self {
         Self::IO(value)
     }
 }
 
 /// Errors while reading or writing to and from a SQL-based peer backend.
-#[cfg(feature = "database")]
+#[cfg(feature = "rusqlite")]
 #[derive(Debug)]
 pub enum SqlPeerStoreError {
     /// A consensus critical data structure is malformed.
@@ -60,7 +60,7 @@ pub enum SqlPeerStoreError {
     SQL(rusqlite::Error),
 }
 
-#[cfg(feature = "database")]
+#[cfg(feature = "rusqlite")]
 impl core::fmt::Display for SqlPeerStoreError {
     fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
         match self {
@@ -80,7 +80,7 @@ impl core::fmt::Display for SqlPeerStoreError {
     }
 }
 
-#[cfg(feature = "database")]
+#[cfg(feature = "rusqlite")]
 impl std::error::Error for SqlPeerStoreError {
     fn source(&self) -> Option<&(dyn std::error::Error + 'static)> {
         match self {
@@ -91,66 +91,70 @@ impl std::error::Error for SqlPeerStoreError {
     }
 }
 
-#[cfg(feature = "database")]
+#[cfg(feature = "rusqlite")]
 impl From<rusqlite::Error> for SqlPeerStoreError {
     fn from(value: rusqlite::Error) -> Self {
         Self::SQL(value)
     }
 }
 
-#[cfg(feature = "database")]
+#[cfg(feature = "rusqlite")]
 impl From<bitcoin::consensus::encode::Error> for SqlPeerStoreError {
     fn from(value: bitcoin::consensus::encode::Error) -> Self {
         Self::Deserialize(value)
     }
 }
 
 /// Errors while reading or writing to and from a SQL-based block header backend.
-#[cfg(feature = "database")]
+#[cfg(feature = "rusqlite")]
 #[derive(Debug)]
 pub enum SqlHeaderStoreError {
-    /// A consensus critical data structure is malformed.
+    /// The headers do not link together.
     Corruption,
-    /// A string could not be deserialized into a known datatype.
-    StringConversion,
+    /// Consensus deserialization failed.
+    Deserialize(bitcoin::consensus::encode::Error),
     /// An error occured performing a SQL operation.
     SQL(rusqlite::Error),
 }
 
-#[cfg(feature = "database")]
+#[cfg(feature = "rusqlite")]
 impl core::fmt::Display for SqlHeaderStoreError {
     fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
         match self {
-            SqlHeaderStoreError::StringConversion => {
-                write!(
-                    f,
-                    "a string could not be deserialized into a known datatype."
-                )
-            }
             SqlHeaderStoreError::SQL(e) => {
                 write!(f, "reading or writing from the database failed: {e}")
             }
+            SqlHeaderStoreError::Deserialize(e) => {
+                write!(f, "consensus decoding failed {e}")
+            }
             SqlHeaderStoreError::Corruption => {
                 write!(f, "a consensus critical data structure is malformed.")
             }
         }
     }
 }
 
-#[cfg(feature = "database")]
+#[cfg(feature = "rusqlite")]
 impl std::error::Error for SqlHeaderStoreError {
     fn source(&self) -> Option<&(dyn std::error::Error + 'static)> {
         match self {
             SqlHeaderStoreError::Corruption => None,
-            SqlHeaderStoreError::StringConversion => None,
             SqlHeaderStoreError::SQL(error) => Some(error),
+            SqlHeaderStoreError::Deserialize(error) => Some(error),
         }
     }
 }
 
-#[cfg(feature = "database")]
+#[cfg(feature = "rusqlite")]
 impl From<rusqlite::Error> for SqlHeaderStoreError {
     fn from(value: rusqlite::Error) -> Self {
         Self::SQL(value)
     }
 }
+
+#[cfg(feature = "rusqlite")]
+impl From<bitcoin::consensus::encode::Error> for SqlHeaderStoreError {
+    fn from(value: bitcoin::consensus::encode::Error) -> Self {
+        Self::Deserialize(value)
+    }
+}

src/db/mod.rs

@@ -15,7 +15,7 @@ use crate::chain::IndexedHeader;
 /// Errors a database backend may produce.
 pub mod error;
 /// Persistence traits defined with SQL Lite to store data between sessions.
-#[cfg(feature = "database")]
+#[cfg(feature = "rusqlite")]
 pub mod sqlite;
 /// Traits that define the header and peer databases.
 pub mod traits;