Struct heed::EnvOpenOptions

pub struct EnvOpenOptions { /* fields omitted */ }

Methods

impl EnvOpenOptions

pub fn new() -> EnvOpenOptions

pub fn map_size(&mut self, size: usize) -> &mut Self

pub fn max_readers(&mut self, readers: u32) -> &mut Self

pub fn max_dbs(&mut self, dbs: u32) -> &mut Self

pub unsafe fn flag(&mut self, flag: Flags) -> &mut Self

Set one or more LMDB flags (see http://www.lmdb.tech/doc/group__mdb__env.html).

use std::fs;
use heed::{EnvOpenOptions, Database};
use heed::types::*;
use heed::flags::Flags;

fs::create_dir_all("target/zerocopy.mdb")?;
let mut env_builder = EnvOpenOptions::new();
unsafe {
    env_builder.flag(Flags::MdbNoSync);
    env_builder.flag(Flags::MdbNoMetaSync);
}
let env = env_builder.open("target/zerocopy.mdb")?;

// we will open the default unamed database
let db: Database<Str, OwnedType<i32>> = env.create_database(None)?;

// opening a write transaction
let mut wtxn = env.write_txn()?;
db.put(&mut wtxn, "seven", &7)?;
db.put(&mut wtxn, "zero", &0)?;
db.put(&mut wtxn, "five", &5)?;
db.put(&mut wtxn, "three", &3)?;
wtxn.commit()?;

// Force the OS to flush the buffers (see Flags::MdbNoSync and Flags::MdbNoMetaSync).
env.force_sync();

// opening a read transaction
// to check if those values are now available
let mut rtxn = env.read_txn()?;

let ret = db.get(&rtxn, "zero")?;
assert_eq!(ret, Some(0));

let ret = db.get(&rtxn, "five")?;
assert_eq!(ret, Some(5));

pub fn open<P: AsRef<Path>>(&self, path: P) -> Result<Env>

Trait Implementations

impl Clone for EnvOpenOptions

fn clone(&self) -> EnvOpenOptions

Returns a copy of the value.

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

Performs copy-assignment from source.

impl Debug for EnvOpenOptions

fn fmt(&self, f: &mut Formatter) -> Result

Formats the value using the given formatter.