Struct rocksdb::WriteBatch

pub struct WriteBatch { /* fields omitted */ }

An atomic batch of write operations.

Making an atomic commit of several writes:

use rocksdb::{DB, Options, WriteBatch};

let path = "_path_for_rocksdb_storage1";
{
    let db = DB::open_default(path).unwrap();
    let mut batch = WriteBatch::default();
    batch.put(b"my key", b"my value");
    batch.put(b"key2", b"value2");
    batch.put(b"key3", b"value3");
    db.write(batch); // Atomically commits the batch
}
let _ = DB::destroy(&Options::default(), path);

Methods

impl WriteBatch

pub fn len(&self) -> usize

pub fn size_in_bytes(&self) -> usize

Return WriteBatch serialized size (in bytes).

pub fn is_empty(&self) -> bool

pub fn iterate(&self, callbacks: &mut dyn WriteBatchIterator)

Iterate the put and delete operations within this write batch. Note that this does not return an Iterator but instead will invoke the put() and delete() member functions of the provided WriteBatchIterator trait implementation.

pub fn put<K, V>(&mut self, key: K, value: V) -> Result<(), Error> where
    K: AsRef<[u8]>,
    V: AsRef<[u8]>, 

Insert a value into the database under the given key.

pub fn put_cf<K, V>(
    &mut self,
    cf: &ColumnFamily,
    key: K,
    value: V
) -> Result<(), Error> where
    K: AsRef<[u8]>,
    V: AsRef<[u8]>, 

pub fn merge<K, V>(&mut self, key: K, value: V) -> Result<(), Error> where
    K: AsRef<[u8]>,
    V: AsRef<[u8]>, 

pub fn merge_cf<K, V>(
    &mut self,
    cf: &ColumnFamily,
    key: K,
    value: V
) -> Result<(), Error> where
    K: AsRef<[u8]>,
    V: AsRef<[u8]>, 

pub fn delete<K: AsRef<[u8]>>(&mut self, key: K) -> Result<(), Error>

Remove the database entry for key.

Returns an error if the key was not found.

pub fn delete_cf<K: AsRef<[u8]>>(
    &mut self,
    cf: &ColumnFamily,
    key: K
) -> Result<(), Error>

pub fn delete_range<K: AsRef<[u8]>>(
    &mut self,
    from: K,
    to: K
) -> Result<(), Error>

Remove database entries from start key to end key.

Removes the database entries in the range ["begin_key", "end_key"), i.e., including "begin_key" and excluding "end_key". It is not an error if no keys exist in the range ["begin_key", "end_key").

pub fn delete_range_cf<K: AsRef<[u8]>>(
    &mut self,
    cf: &ColumnFamily,
    from: K,
    to: K
) -> Result<(), Error>

Remove database entries in column family from start key to end key.

Removes the database entries in the range ["begin_key", "end_key"), i.e., including "begin_key" and excluding "end_key". It is not an error if no keys exist in the range ["begin_key", "end_key").

pub fn clear(&mut self) -> Result<(), Error>

Clear all updates buffered in this batch.

Trait Implementations

impl Drop for WriteBatch

fn drop(&mut self)

Executes the destructor for this type.

impl Default for WriteBatch

fn default() -> WriteBatch

Returns the "default value" for a type.