Trait transact::database::DatabaseReader
source · pub trait DatabaseReader {
// Required methods
fn get(&self, key: &[u8]) -> Result<Option<Vec<u8>>, DatabaseError>;
fn index_get(
&self,
index: &str,
key: &[u8]
) -> Result<Option<Vec<u8>>, DatabaseError>;
fn cursor(&self) -> Result<DatabaseCursor<'_>, DatabaseError>;
fn index_cursor(
&self,
index: &str
) -> Result<DatabaseCursor<'_>, DatabaseError>;
fn count(&self) -> Result<usize, DatabaseError>;
fn index_count(&self, index: &str) -> Result<usize, DatabaseError>;
}Expand description
A DatabaseReader provides read access to a database instance.
Required Methods§
sourcefn get(&self, key: &[u8]) -> Result<Option<Vec<u8>>, DatabaseError>
fn get(&self, key: &[u8]) -> Result<Option<Vec<u8>>, DatabaseError>
Returns the bytes stored at the given key, if found.
sourcefn index_get(
&self,
index: &str,
key: &[u8]
) -> Result<Option<Vec<u8>>, DatabaseError>
fn index_get( &self, index: &str, key: &[u8] ) -> Result<Option<Vec<u8>>, DatabaseError>
Returns the bytes stored at the given key on a specified index, if found.
sourcefn cursor(&self) -> Result<DatabaseCursor<'_>, DatabaseError>
fn cursor(&self) -> Result<DatabaseCursor<'_>, DatabaseError>
Returns a cursor against the main database. The cursor iterates over the entries in the natural key order.
sourcefn index_cursor(&self, index: &str) -> Result<DatabaseCursor<'_>, DatabaseError>
fn index_cursor(&self, index: &str) -> Result<DatabaseCursor<'_>, DatabaseError>
Returns a cursor against the given index. The cursor iterates over the entries in the index’s natural key order.
sourcefn count(&self) -> Result<usize, DatabaseError>
fn count(&self) -> Result<usize, DatabaseError>
Returns the number of entries in the main database.
sourcefn index_count(&self, index: &str) -> Result<usize, DatabaseError>
fn index_count(&self, index: &str) -> Result<usize, DatabaseError>
Returns the number of entries in the given index.