Struct RocksDB

pub struct RocksDB { /* private fields */ }

RocksDB wrapper base on OptimisticTransactionDB

https://github.com/facebook/rocksdb/wiki/Transactions#optimistictransactiondb

Implementations

impl RocksDB

pub fn open(config: &DBConfig, columns: u32) -> Self

Open a database with the given configuration and columns count.

pub fn open_in<P: AsRef<Path>>(path: P, columns: u32) -> Self

Open a database in the given directory with the default configuration and columns count.

pub fn prepare_for_bulk_load_open<P: AsRef<Path>>( path: P, columns: u32, ) -> Result<Option<Self>>

Set appropriate parameters for bulk loading.

pub fn get_pinned( &self, col: Col, key: &[u8], ) -> Result<Option<DBPinnableSlice<'_>>>

Return the value associated with a key using RocksDB’s PinnableSlice from the given column so as to avoid unnecessary memory copy.

pub fn get_pinned_default( &self, key: &[u8], ) -> Result<Option<DBPinnableSlice<'_>>>

Return the value associated with a key using RocksDB’s PinnableSlice from the default column so as to avoid unnecessary memory copy.

pub fn put_default<K, V>(&self, key: K, value: V) -> Result<()>

where K: AsRef<[u8]>, V: AsRef<[u8]>,

Insert a value into the database under the given key.

pub fn full_traverse<F>(&self, col: Col, callback: &mut F) -> Result<()>

where F: FnMut(&[u8], &[u8]) -> Result<()>,

Traverse database column with the given callback function.

pub fn traverse<F>( &self, col: Col, callback: &mut F, mode: IteratorMode<'_>, limit: usize, ) -> Result<(usize, Vec<u8>)>

where F: FnMut(&[u8], &[u8]) -> Result<()>,

Traverse database column with the given callback function.

pub fn transaction(&self) -> RocksDBTransaction

Set a snapshot at start of transaction by setting set_snapshot=true

pub fn new_write_batch(&self) -> RocksDBWriteBatch

Construct RocksDBWriteBatch with default option.

pub fn write(&self, batch: &RocksDBWriteBatch) -> Result<()>

Write batch into transaction db.

pub fn write_sync(&self, batch: &RocksDBWriteBatch) -> Result<()>

WriteOptions set_sync true If true, the write will be flushed from the operating system buffer cache (by calling WritableFile::Sync()) before the write is considered complete. If this flag is true, writes will be slower.

If this flag is false, and the machine crashes, some recent writes may be lost. Note that if it is just the process that crashes (i.e., the machine does not reboot), no writes will be lost even if sync==false.

In other words, a DB write with sync==false has similar crash semantics as the “write()” system call. A DB write with sync==true has similar crash semantics to a “write()” system call followed by “fdatasync()”.

Default: false

pub fn compact_range( &self, col: Col, start: Option<&[u8]>, end: Option<&[u8]>, ) -> Result<()>

The begin and end arguments define the key range to be compacted. The behavior varies depending on the compaction style being used by the db. In case of universal and FIFO compaction styles, the begin and end arguments are ignored and all files are compacted. Also, files in each level are compacted and left in the same level. For leveled compaction style, all files containing keys in the given range are compacted to the last level containing files. If either begin or end are NULL, it is taken to mean the key before all keys in the db or the key after all keys respectively.

If more than one thread calls manual compaction, only one will actually schedule it while the other threads will simply wait for the scheduled manual compaction to complete.

CompactRange waits while compaction is performed on the background threads and thus is a blocking call.

pub fn get_snapshot(&self) -> RocksDBSnapshot

Return RocksDBSnapshot.

pub fn inner(&self) -> Arc<OptimisticTransactionDB>

Return rocksdb OptimisticTransactionDB.

pub fn create_cf(&mut self, col: Col) -> Result<()>

Create a new column family for the database.

pub fn drop_cf(&mut self, col: Col) -> Result<()>

Delete column family.

Trait Implementations

impl Clone for RocksDB

fn clone(&self) -> RocksDB

Returns a copy of the value.

fn clone_from(&mut self, source: &Self)

Performs copy-assignment from source.

impl DBIterator for RocksDB

fn iter_opt( &self, col: Col, mode: IteratorMode<'_>, readopts: &ReadOptions, ) -> Result<DBIter<'_>>

Opens an iterator using the provided IteratorMode and ReadOptions. This is used when you want to iterate over a specific ColumnFamily with a modified ReadOptions

fn iter(&self, col: Col, mode: IteratorMode<'_>) -> Result<DBIter<'_>>

Opens an iterator using the provided IteratorMode. This is used when you want to iterate over a specific ColumnFamily