Struct tetsy_kvdb_rocksdb::Database

pub struct Database { /* fields omitted */ }

Key-Value database.

Implementations

impl Database

pub fn open(config: &DatabaseConfig, path: &str) -> Result<Database>

Open database file. Creates if it does not exist.

Safety

The number of config.columns must not be zero.

pub fn transaction(&self) -> DBTransaction

Helper to create new transaction for this database.

pub fn write_buffered(&self, tr: DBTransaction)

Commit transaction to database.

pub fn flush(&self) -> Result<()>

Commit buffered changes to database.

pub fn write(&self, tr: DBTransaction) -> Result<()>

Commit transaction to database.

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

Get value by key.

pub fn get_by_prefix(&self, col: u32, prefix: &[u8]) -> Option<Box<[u8]>>

Get value by partial key. Prefix size should match configured prefix size. Only searches flushed values.

pub fn iter<'a>(
    &'a self,
    col: u32
) -> impl Iterator<Item = (Box<[u8]>, Box<[u8]>)> + 'a

Get database iterator for flushed data. Will hold a lock until the iterator is dropped preventing the database from being closed.

pub fn restore(&self, new_db: &str) -> Result<()>

Restore the database from a copy at given path.

pub fn num_columns(&self) -> u32

The number of column families in the db.

pub fn num_keys(&self, col: u32) -> Result<u64>

The number of keys in a column (estimated). Does not take into account the unflushed data.

pub fn remove_last_column(&self) -> Result<()>

Remove the last column family in the database. The deletion is definitive.

pub fn add_column(&self) -> Result<()>

Add a new column family to the DB.

Trait Implementations

impl Drop for Database

fn drop(&mut self)

Executes the destructor for this type.

impl KeyValueDB for Database

fn get(&self, col: u32, key: &[u8]) -> Result<Option<DBValue>>

Get a value by key.

fn get_by_prefix(&self, col: u32, prefix: &[u8]) -> Option<Box<[u8]>>

Get a value by partial key. Only works for flushed data.

fn write_buffered(&self, transaction: DBTransaction)

Write a transaction of changes to the buffer.

fn write(&self, transaction: DBTransaction) -> Result<()>

Write a transaction of changes to the backing store.

fn flush(&self) -> Result<()>

Flush all buffered data.

fn iter<'a>(
    &'a self,
    col: u32
) -> Box<dyn Iterator<Item = (Box<[u8]>, Box<[u8]>)> + 'a>

Iterate over flushed data for a given column.

fn iter_from_prefix<'a>(
    &'a self,
    col: u32,
    prefix: &'a [u8]
) -> Box<dyn Iterator<Item = (Box<[u8]>, Box<[u8]>)> + 'a>

Iterate over flushed data for a given column, starting from a given prefix.

fn restore(&self, new_db: &str) -> Result<()>

Attempt to replace this database with a new one located at the given path.

fn io_stats(&self, kind: IoStatsKind) -> IoStats

Query statistics.

pub fn transaction(&self) -> DBTransaction

Helper to create a new transaction.

impl MallocSizeOf for Database

fn size_of(&self, ops: &mut MallocSizeOfOps) -> usize

Measure the heap usage of all descendant heap-allocated structures, but not the space taken up by the value itself.