Struct typed_store::rocks::DBBatch

pub struct DBBatch { /* private fields */ }

Provides a mutable struct to form a collection of database write operations, and execute them.

Batching write and delete operations is faster than performing them one by one and ensures their atomicity, ie. they are all written or none is. This is also true of operations across column families in the same database.

Serializations / Deserialization, and naming of column families is performed by passing a DBMap<K,V> with each operation.

use typed_store::rocks::*;
use tempfile::tempdir;
use typed_store::Map;
let rocks = open_cf(tempfile::tempdir().unwrap(), None, &["First_CF", "Second_CF"]).unwrap();

let db_cf_1 = DBMap::reopen(&rocks, Some("First_CF"))
    .expect("Failed to open storage");
let keys_vals_1 = (1..100).map(|i| (i, i.to_string()));

let db_cf_2 = DBMap::reopen(&rocks, Some("Second_CF"))
    .expect("Failed to open storage");
let keys_vals_2 = (1000..1100).map(|i| (i, i.to_string()));

let batch = db_cf_1
    .batch()
    .insert_batch(&db_cf_1, keys_vals_1.clone())
    .expect("Failed to batch insert")
    .insert_batch(&db_cf_2, keys_vals_2.clone())
    .expect("Failed to batch insert");

let _ = batch.write().expect("Failed to execute batch");
for (k, v) in keys_vals_1 {
    let val = db_cf_1.get(&k).expect("Failed to get inserted key");
    assert_eq!(Some(v), val);
}

for (k, v) in keys_vals_2 {
    let val = db_cf_2.get(&k).expect("Failed to get inserted key");
    assert_eq!(Some(v), val);
}

Implementations

impl DBBatch

pub fn new(dbref: &Arc<DBWithThreadMode<MultiThreaded>>) -> Self

Create a new batch associated with a DB reference.

Use open_cf to get the DB reference or an existing open database.

pub fn write(self) -> Result<(), TypedStoreError>

Consume the batch and write its operations to the database

impl DBBatch

pub fn delete_batch<J: Borrow<K>, K: Serialize, V>(
    self,
    db: &DBMap<K, V>,
    purged_vals: impl IntoIterator<Item = J>
) -> Result<Self, TypedStoreError>

Deletes a set of keys given as an iterator

pub fn delete_range<'a, K: Serialize, V>(
    self,
    db: &'a DBMap<K, V>,
    from: &K,
    to: &K
) -> Result<Self, TypedStoreError>

Deletes a range of keys between from (inclusive) and to (non-inclusive)

pub fn insert_batch<J: Borrow<K>, K: Serialize, U: Borrow<V>, V: Serialize>(
    self,
    db: &DBMap<K, V>,
    new_vals: impl IntoIterator<Item = (J, U)>
) -> Result<Self, TypedStoreError>

inserts a range of (key, value) pairs given as an iterator