refactor: dump database to json

sdgb-cli/src/cache/mod.rs

@@ -1,6 +1,6 @@
 use std::sync::LazyLock;
 
-use redb::{Table, TableDefinition, WriteTransaction};
+use redb::{ReadTransaction, Table, TableDefinition, WriteTransaction};
 
 static DATABASE: LazyLock<redb::Database> = LazyLock::new(|| {
     redb::Database::builder()
@@ -17,6 +17,16 @@ pub fn open_table(write: &WriteTransaction) -> Result<Table<'_, u32, Vec<u8>>, r
     Ok(write.open_table(DIFINITION)?)
 }
 
+pub fn read_txn() -> Result<ReadTransaction, redb::Error> {
+    Ok(DATABASE.begin_read()?)
+}
+
+pub fn open_table_read(
+    read: &ReadTransaction,
+) -> Result<redb::ReadOnlyTable<u32, Vec<u8>>, redb::Error> {
+    Ok(read.open_table(DIFINITION)?)
+}
+
 pub fn init_db() -> Result<(), redb::Error> {
     let write_txn = DATABASE.begin_write()?;
     write_txn.open_table(DIFINITION)?;