Struct Db

pub struct Db { /* private fields */ }

Database instance.

Implementations

impl Db

pub fn open(options: &Options) -> Result<Db>

Open the database with given options. An error will be returned if the database does not exist.

pub fn open_or_create(options: &Options) -> Result<Db>

Open the database using given options. If the database does not exist it will be created empty.

pub fn open_read_only(options: &Options) -> Result<Db>

Open an existing database in read-only mode.

pub fn get(&self, col: ColId, key: &[u8]) -> Result<Option<Value>>

Get a value in a specified column by key. Returns None if the key does not exist.

pub fn get_size(&self, col: ColId, key: &[u8]) -> Result<Option<u32>>

Get value size by key. Returns None if the key does not exist.

pub fn iter(&self, col: ColId) -> Result<BTreeIterator<'_>>

Iterate over all ordered key-value pairs. Only supported for columns configured with btree_indexed.

pub fn get_tree( &self, col: ColId, key: &[u8], ) -> Result<Option<Arc<RwLock<Box<dyn TreeReader + Send + Sync>>>>>

pub fn get_root( &self, col: ColId, key: &[u8], ) -> Result<Option<(Vec<u8>, Children)>>

pub fn get_node( &self, col: ColId, node_address: NodeAddress, ) -> Result<Option<(Vec<u8>, Children)>>

pub fn get_node_children( &self, col: ColId, node_address: NodeAddress, ) -> Result<Option<Children>>

pub fn commit<I, K>(&self, tx: I) -> Result<()>

where I: IntoIterator<Item = (ColId, K, Option<Value>)>, K: AsRef<[u8]>,

Commit a set of changes to the database.

pub fn commit_changes<I>(&self, tx: I) -> Result<()>

where I: IntoIterator<Item = (ColId, Operation<Vec<u8>, Vec<u8>>)>,

Commit a set of changes to the database.

pub fn commit_changes_shared<I>(&self, tx: I) -> Result<()>

where I: IntoIterator<Item = (ColId, Operation<Vec<u8>, Arc<Vec<u8>>>)>,

👎Deprecated: This method will be removed in future versions. Use commit_changes_bytes instead

Commit a set of changes to the database.

This method passes values as Arc<Vec<u8>> potentially eliminating an extra copy.

pub fn num_columns(&self) -> u8

Returns the number of columns in the database.

pub fn iter_column_while( &self, c: ColId, f: impl FnMut(ValueIterState) -> bool, ) -> Result<()>

Iterate a column and call a function for each value. This is only supported for columns with btree_index set to false. Iteration order is unspecified. Unlike get the iteration may not include changes made in recent commit calls.

pub fn write_stats_text( &self, writer: &mut impl Write, column: Option<u8>, ) -> Result<()>

Dump full database stats to the text output.

pub fn clear_stats(&self, column: Option<u8>) -> Result<()>

Reset internal database statistics for the database or specified column.

pub fn dump(&self, check_param: CheckOptions) -> Result<()>

Print database contents in text form to stderr.

pub fn stats(&self) -> StatSummary

Get database statistics.

pub fn get_num_column_value_entries(&self, col: ColId) -> Result<u64>

pub fn add_column( options: &mut Options, new_column_options: ColumnOptions, ) -> Result<()>

Add a new column with options specified by new_column_options.

pub fn drop_last_column(options: &mut Options) -> Result<()>

Remove last column from the database. Db must be close when called.

pub fn reset_column( options: &mut Options, index: u8, new_options: Option<ColumnOptions>, ) -> Result<()>

Truncate a column from the database, optionally changing its options. Db must be close when called.

Trait Implementations

impl Drop for Db

fn drop(&mut self)

Executes the destructor for this type.