Rust implementation of NextGraph, a Decentralized and local-first web 3.0 ecosystem https://nextgraph.org
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nextgraph-rs/stores-lmdb/src/repo_store.rs

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// Copyright (c) 2022-2023 Niko Bonnieure, Par le Peuple, NextGraph.org developers
// All rights reserved.
// Licensed under the Apache License, Version 2.0
// <LICENSE-APACHE2 or http://www.apache.org/licenses/LICENSE-2.0>
// or the MIT license <LICENSE-MIT or http://opensource.org/licenses/MIT>,
// at your option. All files in the project carrying such
// notice may not be copied, modified, or distributed except
// according to those terms.
use p2p_repo::store::*;
use p2p_repo::types::*;
use p2p_repo::utils::*;
use debug_print::*;
use std::path::Path;
use std::sync::{Arc, RwLock};
use rkv::backend::{
BackendDatabaseFlags, BackendFlags, BackendIter, BackendWriteFlags, DatabaseFlags, Lmdb,
LmdbDatabase, LmdbDatabaseFlags, LmdbEnvironment, LmdbRwTransaction, LmdbWriteFlags,
};
use rkv::{
Manager, MultiIntegerStore, Rkv, SingleStore, StoreError, StoreOptions, Value, WriteFlags,
Writer,
};
use serde::{Deserialize, Serialize};
use serde_bare::error::Error;
#[derive(Debug)]
pub struct LmdbRepoStore {
/// the main store where all the repo blocks are stored
main_store: SingleStore<LmdbDatabase>,
/// store for the pin boolean, recently_used timestamp, and synced boolean
meta_store: SingleStore<LmdbDatabase>,
/// store for the expiry timestamp
expiry_store: MultiIntegerStore<LmdbDatabase, u32>,
/// store for the LRU list
recently_used_store: MultiIntegerStore<LmdbDatabase, u32>,
/// the opened environment so we can create new transactions
environment: Arc<RwLock<Rkv<LmdbEnvironment>>>,
}
// TODO: versioning V0
#[derive(Clone, Debug, Serialize, Deserialize, PartialEq)]
struct BlockMeta {
pub pin: bool,
pub last_used: Timestamp,
pub synced: bool,
}
impl RepoStore for LmdbRepoStore {
/// Retrieves a block from the storage backend.
fn get(&self, block_id: &BlockId) -> Result<Block, StorageError> {
let lock = self.environment.read().unwrap();
let reader = lock.read().unwrap();
let block_id_ser = serde_bare::to_vec(&block_id).unwrap();
let block_ser_res = self.main_store.get(&reader, block_id_ser.clone());
match block_ser_res {
Err(e) => Err(StorageError::BackendError),
Ok(None) => Err(StorageError::NotFound),
Ok(Some(block_ser)) => {
// updating recently_used
// first getting the meta for this BlockId
let meta_ser = self.meta_store.get(&reader, block_id_ser.clone()).unwrap();
match meta_ser {
Some(meta_value) => {
let mut meta =
serde_bare::from_slice::<BlockMeta>(&meta_value.to_bytes().unwrap())
.unwrap();
if meta.synced {
let mut writer = lock.write().unwrap();
let now = now_timestamp();
if !meta.pin {
// we remove the previous timestamp (last_used) from recently_used_store
self.remove_from_lru(&mut writer, &block_id_ser, &meta.last_used)
.unwrap();
// we add an entry to recently_used_store with now
self.add_to_lru(&mut writer, &block_id_ser, &now).unwrap();
}
// we save the new meta (with last_used:now)
meta.last_used = now;
let new_meta_ser = serde_bare::to_vec(&meta).unwrap();
self.meta_store
.put(
&mut writer,
block_id_ser,
&Value::Blob(new_meta_ser.as_slice()),
)
.unwrap();
// commit
writer.commit().unwrap();
}
}
_ => {} // there is no meta. we do nothing since we start to record LRU only once synced == true.
}
match serde_bare::from_slice::<Block>(&block_ser.to_bytes().unwrap()) {
Err(_e) => Err(StorageError::InvalidValue),
Ok(o) => {
if o.id() != *block_id {
debug_println!(
"Invalid ObjectId.\nExp: {:?}\nGot: {:?}\nContent: {:?}",
block_id,
o.id(),
o
);
panic!("CORRUPTION OF DATA !");
}
Ok(o)
}
}
}
}
}
/// Adds a block in the storage backend.
/// The block is persisted to disk.
/// Returns the BlockId of the Block.
fn put(&self, block: &Block) -> Result<BlockId, StorageError> {
let block_ser = serde_bare::to_vec(&block).unwrap();
let block_id = block.id();
let block_id_ser = serde_bare::to_vec(&block_id).unwrap();
let lock = self.environment.read().unwrap();
let mut writer = lock.write().unwrap();
// TODO: check if the block is already in store? if yes, don't put it again.
// I didnt do it yet because it is extra cost. surely a get on the store is lighter than a put
// but doing a get in additing to a put for every call, is probably even costlier. better to deal with that at the higher level
self.main_store
.put(
&mut writer,
&block_id_ser,
&Value::Blob(block_ser.as_slice()),
)
.unwrap();
// if it has an expiry, adding the BlockId to the expiry_store
match block.expiry() {
Some(expiry) => {
self.expiry_store
.put(&mut writer, expiry, &Value::Blob(block_id_ser.as_slice()))
.unwrap();
}
_ => {}
}
writer.commit().unwrap();
Ok(block_id)
}
/// Removes the block from the storage backend.
/// The removed block is returned, so it can be inspected.
/// Also returned is the approximate size of of free space that was reclaimed.
fn del(&self, block_id: &BlockId) -> Result<(Block, usize), StorageError> {
let lock = self.environment.read().unwrap();
let mut writer = lock.write().unwrap();
let block_id_ser = serde_bare::to_vec(&block_id).unwrap();
// retrieving the block itself (we need the expiry)
let block_ser = self
.main_store
.get(&writer, block_id_ser.clone())
.unwrap()
.ok_or(StorageError::NotFound)?;
let slice = block_ser.to_bytes().unwrap();
let block = serde_bare::from_slice::<Block>(&slice).unwrap(); //FIXME propagate error?
let meta_res = self.meta_store.get(&writer, block_id_ser.clone()).unwrap();
if meta_res.is_some() {
let meta = serde_bare::from_slice::<BlockMeta>(&meta_res.unwrap().to_bytes().unwrap())
.unwrap();
if meta.last_used != 0 {
self.remove_from_lru(&mut writer, &block_id_ser.clone(), &meta.last_used)
.unwrap();
}
// removing the meta
self.meta_store
.delete(&mut writer, block_id_ser.clone())
.unwrap();
}
// delete block from main_store
self.main_store
.delete(&mut writer, block_id_ser.clone())
.unwrap();
// remove BlockId from expiry_store, if any expiry
match block.expiry() {
Some(expiry) => {
self.expiry_store
.delete(
&mut writer,
expiry,
&Value::Blob(block_id_ser.clone().as_slice()),
)
.unwrap();
}
_ => {}
}
writer.commit().unwrap();
Ok((block, slice.len()))
}
}
impl LmdbRepoStore {
/// Opens the store and returns a RepoStore object that should be kept and used to call put/get/delete/pin
/// The key is the encryption key for the data at rest.
pub fn open<'a>(path: &Path, key: [u8; 32]) -> LmdbRepoStore {
let mut manager = Manager::<LmdbEnvironment>::singleton().write().unwrap();
let shared_rkv = manager
.get_or_create(path, |path| {
//Rkv::new::<Lmdb>(path) // use this instead to disable encryption
Rkv::with_encryption_key_and_mapsize::<Lmdb>(path, key, 2 * 1024 * 1024 * 1024)
})
.unwrap();
let env = shared_rkv.read().unwrap();
println!(
"created env with LMDB Version: {} key: {}",
env.version(),
hex::encode(&key)
);
let main_store = env.open_single("main", StoreOptions::create()).unwrap();
let meta_store = env.open_single("meta", StoreOptions::create()).unwrap();
let mut opts = StoreOptions::<LmdbDatabaseFlags>::create();
opts.flags.set(DatabaseFlags::DUP_FIXED, true);
let expiry_store = env.open_multi_integer("expiry", opts).unwrap();
let recently_used_store = env.open_multi_integer("recently_used", opts).unwrap();
LmdbRepoStore {
environment: shared_rkv.clone(),
main_store,
meta_store,
expiry_store,
recently_used_store,
}
}
//FIXME: use BlockId, not ObjectId. this is a block level operation
/// Pins the object
pub fn pin(&self, object_id: &ObjectId) -> Result<(), StorageError> {
self.set_pin(object_id, true)
}
//FIXME: use BlockId, not ObjectId. this is a block level operation
/// Unpins the object
pub fn unpin(&self, object_id: &ObjectId) -> Result<(), StorageError> {
self.set_pin(object_id, false)
}
//FIXME: use BlockId, not ObjectId. this is a block level operation
/// Sets the pin for that Object. if add is true, will add the pin. if false, will remove the pin.
/// A pin on an object prevents it from being removed when the store is making some disk space by using the LRU.
/// A pin does not override the expiry. If expiry is set and is reached, the obejct will be deleted, no matter what.
pub fn set_pin(&self, object_id: &ObjectId, add: bool) -> Result<(), StorageError> {
let lock = self.environment.read().unwrap();
let mut writer = lock.write().unwrap();
let obj_id_ser = serde_bare::to_vec(&object_id).unwrap();
let meta_ser = self.meta_store.get(&writer, &obj_id_ser).unwrap();
let mut meta;
// if adding a pin, if there is a meta (if already pinned, return) and is synced, remove the last_used timestamp from recently_used_store
// if no meta, create it with pin:true, synced: false
// if removing a pin (if pin already removed, return), if synced, add an entry to recently_used_store with the last_used timestamp (as found in meta, dont use now)
match meta_ser {
Some(meta_value) => {
meta =
serde_bare::from_slice::<BlockMeta>(&meta_value.to_bytes().unwrap()).unwrap();
if add == meta.pin {
// pinning while already pinned, or unpinning while already unpinned. NOP
return Ok(());
};
meta.pin = add;
if meta.synced {
if add {
// we remove the previous timestamp (last_used) from recently_used_store
self.remove_from_lru(&mut writer, &obj_id_ser, &meta.last_used)
.unwrap();
} else {
// we add an entry to recently_used_store with last_used
self.add_to_lru(&mut writer, &obj_id_ser, &meta.last_used)
.unwrap();
}
}
}
None => {
if add {
meta = BlockMeta {
pin: true,
synced: false,
last_used: 0,
}
} else {
// there is no meta, and user wants to unpin, so let's leave everything as it is.
return Ok(());
}
}
}
let new_meta_ser = serde_bare::to_vec(&meta).unwrap();
self.meta_store
.put(
&mut writer,
obj_id_ser,
&Value::Blob(new_meta_ser.as_slice()),
)
.unwrap();
// commit
writer.commit().unwrap();
Ok(())
}
//FIXME: use BlockId, not ObjectId. this is a block level operation
/// the broker calls this method when the block has been retrieved/synced by enough peers and it
/// can now be included in the LRU for potential garbage collection.
/// If this method has not been called on a block, it will be kept in the store and will not enter LRU.
pub fn has_been_synced(&self, block_id: &BlockId, when: Option<u32>) -> Result<(), Error> {
let lock = self.environment.read().unwrap();
let mut writer = lock.write().unwrap();
let block_id_ser = serde_bare::to_vec(&block_id).unwrap();
let meta_ser = self.meta_store.get(&writer, block_id_ser.clone()).unwrap();
let mut meta;
let now = match when {
None => now_timestamp(),
Some(w) => w,
};
// get the meta. if no meta, it is ok, we will create it after (with pin:false and synced:true)
// if already synced, return
// update the meta with last_used:now and synced:true
// if pinned, save and return
// otherwise add an entry to recently_used_store with now
match meta_ser {
Some(meta_value) => {
meta =
serde_bare::from_slice::<BlockMeta>(&meta_value.to_bytes().unwrap()).unwrap();
if meta.synced {
// already synced. NOP
return Ok(());
};
meta.synced = true;
meta.last_used = now;
if !meta.pin {
// we add an entry to recently_used_store with now
println!("adding to LRU");
self.add_to_lru(&mut writer, &block_id_ser, &now).unwrap();
}
}
None => {
meta = BlockMeta {
pin: false,
synced: true,
last_used: now,
};
println!("adding to LRU also");
self.add_to_lru(&mut writer, &block_id_ser, &now).unwrap();
}
}
let new_meta_ser = serde_bare::to_vec(&meta).unwrap();
self.meta_store
.put(
&mut writer,
block_id_ser,
&Value::Blob(new_meta_ser.as_slice()),
)
.unwrap();
// commit
writer.commit().unwrap();
Ok(())
}
/// Removes all the blocks that have expired.
/// The broker should call this method periodically.
pub fn remove_expired(&self) -> Result<(), Error> {
let mut block_ids: Vec<BlockId> = vec![];
{
let lock = self.environment.read().unwrap();
let reader = lock.read().unwrap();
let mut iter = self
.expiry_store
.iter_prev_dup_from(&reader, now_timestamp())
.unwrap();
while let Some(Ok(mut sub_iter)) = iter.next() {
while let Some(Ok(k)) = sub_iter.next() {
//println!("removing {:?} {:?}", k.0, k.1);
let block_id = serde_bare::from_slice::<ObjectId>(k.1).unwrap();
block_ids.push(block_id);
}
}
}
for block_id in block_ids {
self.del(&block_id).unwrap();
}
Ok(())
}
/// Removes some blocks that haven't been used for a while, reclaiming some space on disk.
/// The oldest are removed first, until the total amount of data removed is at least equal to size,
/// or the LRU list became empty. The approximate size of the storage space that was reclaimed is returned.
pub fn remove_least_used(&self, size: usize) -> usize {
let mut block_ids: Vec<BlockId> = vec![];
let mut total: usize = 0;
{
let lock = self.environment.read().unwrap();
let reader = lock.read().unwrap();
let mut iter = self.recently_used_store.iter_start(&reader).unwrap();
while let Some(Ok(entry)) = iter.next() {
let block_id =
serde_bare::from_slice::<ObjectId>(entry.1.to_bytes().unwrap().as_slice())
.unwrap();
block_ids.push(block_id);
}
}
for block_id in block_ids {
let (block, block_size) = self.del(&block_id).unwrap();
println!("removed {:?}", block_id);
total += block_size;
if total >= size {
break;
}
}
total
}
fn remove_from_lru(
&self,
writer: &mut Writer<LmdbRwTransaction>,
block_id_ser: &Vec<u8>,
time: &Timestamp,
) -> Result<(), StoreError> {
self.recently_used_store
.delete(writer, *time, &Value::Blob(block_id_ser.as_slice()))
}
fn add_to_lru(
&self,
writer: &mut Writer<LmdbRwTransaction>,
block_id_ser: &Vec<u8>,
time: &Timestamp,
) -> Result<(), StoreError> {
let mut flag = LmdbWriteFlags::empty();
flag.set(WriteFlags::APPEND_DUP, true);
self.recently_used_store.put_with_flags(
writer,
*time,
&Value::Blob(block_id_ser.as_slice()),
flag,
)
}
fn list_all(&self) {
let lock = self.environment.read().unwrap();
let reader = lock.read().unwrap();
println!("MAIN");
let mut iter = self.main_store.iter_start(&reader).unwrap();
while let Some(Ok(entry)) = iter.next() {
println!("{:?} {:?}", entry.0, entry.1)
}
println!("META");
let mut iter2 = self.meta_store.iter_start(&reader).unwrap();
while let Some(Ok(entry)) = iter2.next() {
println!("{:?} {:?}", entry.0, entry.1)
}
println!("EXPIRY");
let mut iter3 = self.expiry_store.iter_start(&reader).unwrap();
while let Some(Ok(entry)) = iter3.next() {
println!("{:?} {:?}", entry.0, entry.1)
}
println!("LRU");
let mut iter4 = self.recently_used_store.iter_start(&reader).unwrap();
while let Some(Ok(entry)) = iter4.next() {
println!("{:?} {:?}", entry.0, entry.1)
}
}
}
#[cfg(test)]
mod test {
use crate::repo_store::LmdbRepoStore;
use p2p_repo::store::*;
use p2p_repo::types::*;
use p2p_repo::utils::*;
use rkv::backend::{BackendInfo, BackendStat, Lmdb, LmdbEnvironment};
use rkv::{Manager, Rkv, StoreOptions, Value};
#[allow(unused_imports)]
use std::time::Duration;
#[allow(unused_imports)]
use std::{fs, thread};
use tempfile::Builder;
#[test]
pub fn test_remove_least_used() {
let path_str = "test-env";
let root = Builder::new().prefix(path_str).tempdir().unwrap();
let key: [u8; 32] = [0; 32];
fs::create_dir_all(root.path()).unwrap();
println!("{}", root.path().to_str().unwrap());
let mut store = LmdbRepoStore::open(root.path(), key);
let mut now = now_timestamp();
now -= 200;
// TODO: fix the LMDB bug that is triggered with x max set to 86 !!!
for x in 1..85 {
let block = Block::new(
Vec::new(),
ObjectDeps::ObjectIdList(Vec::new()),
None,
vec![x; 10],
None,
);
let block_id = store.put(&block).unwrap();
println!("#{} -> objId {:?}", x, block_id);
store
.has_been_synced(&block_id, Some(now + x as u32))
.unwrap();
}
let ret = store.remove_least_used(200);
println!("removed {}", ret);
assert_eq!(ret, 208)
//store.list_all();
}
#[test]
pub fn test_set_pin() {
let path_str = "test-env";
let root = Builder::new().prefix(path_str).tempdir().unwrap();
let key: [u8; 32] = [0; 32];
fs::create_dir_all(root.path()).unwrap();
println!("{}", root.path().to_str().unwrap());
let mut store = LmdbRepoStore::open(root.path(), key);
let mut now = now_timestamp();
now -= 200;
// TODO: fix the LMDB bug that is triggered with x max set to 86 !!!
for x in 1..100 {
let block = Block::new(
Vec::new(),
ObjectDeps::ObjectIdList(Vec::new()),
None,
vec![x; 10],
None,
);
let obj_id = store.put(&block).unwrap();
println!("#{} -> objId {:?}", x, obj_id);
store.set_pin(&obj_id, true).unwrap();
store
.has_been_synced(&obj_id, Some(now + x as u32))
.unwrap();
}
let ret = store.remove_least_used(200);
println!("removed {}", ret);
assert_eq!(ret, 0);
store.list_all();
}
#[test]
pub fn test_get_valid_value_size() {
assert_eq!(store_valid_value_size(0), 4072);
assert_eq!(store_valid_value_size(2), 4072);
assert_eq!(store_valid_value_size(4072), 4072);
assert_eq!(store_valid_value_size(4072 + 1), 4072 + 4096);
assert_eq!(store_valid_value_size(4072 + 4096), 4072 + 4096);
assert_eq!(store_valid_value_size(4072 + 4096 + 1), 4072 + 4096 + 4096);
assert_eq!(
store_valid_value_size(4072 + 4096 + 4096),
4072 + 4096 + 4096
);
assert_eq!(
store_valid_value_size(4072 + 4096 + 4096 + 1),
4072 + 4096 + 4096 + 4096
);
assert_eq!(store_valid_value_size(4072 + 4096 * 511), 4072 + 4096 * 511);
assert_eq!(
store_valid_value_size(4072 + 4096 * 511 + 1),
4072 + 4096 * 511
);
}
#[test]
pub fn test_remove_expired() {
let path_str = "test-env";
let root = Builder::new().prefix(path_str).tempdir().unwrap();
let key: [u8; 32] = [0; 32];
fs::create_dir_all(root.path()).unwrap();
println!("{}", root.path().to_str().unwrap());
let mut store = LmdbRepoStore::open(root.path(), key);
let now = now_timestamp();
let list = [
now - 10,
now - 6,
now - 6,
now - 3,
now - 2,
now - 1, //#5 should be removed, and above
now + 3,
now + 4,
now + 4,
now + 5,
now + 10,
];
let mut block_ids: Vec<ObjectId> = Vec::with_capacity(11);
println!("now {}", now);
let mut i = 0u8;
for expiry in list {
//let i: u8 = (expiry + 10 - now).try_into().unwrap();
let block = Block::new(
Vec::new(),
ObjectDeps::ObjectIdList(Vec::new()),
Some(expiry),
[i].to_vec(),
None,
);
let block_id = store.put(&block).unwrap();
println!("#{} -> objId {:?}", i, block_id);
block_ids.push(block_id);
i += 1;
}
store.remove_expired().unwrap();
assert!(store.get(block_ids.get(0).unwrap()).is_err());
assert!(store.get(block_ids.get(1).unwrap()).is_err());
assert!(store.get(block_ids.get(2).unwrap()).is_err());
assert!(store.get(block_ids.get(5).unwrap()).is_err());
assert!(store.get(block_ids.get(6).unwrap()).is_ok());
assert!(store.get(block_ids.get(7).unwrap()).is_ok());
//store.list_all();
}
#[test]
pub fn test_remove_all_expired() {
let path_str = "test-env";
let root = Builder::new().prefix(path_str).tempdir().unwrap();
let key: [u8; 32] = [0; 32];
fs::create_dir_all(root.path()).unwrap();
println!("{}", root.path().to_str().unwrap());
let mut store = LmdbRepoStore::open(root.path(), key);
let now = now_timestamp();
let list = [
now - 10,
now - 6,
now - 6,
now - 3,
now - 2,
now - 2, //#5 should be removed, and above
];
let mut block_ids: Vec<ObjectId> = Vec::with_capacity(6);
println!("now {}", now);
let mut i = 0u8;
for expiry in list {
//let i: u8 = (expiry + 10 - now).try_into().unwrap();
let block = Block::new(
Vec::new(),
ObjectDeps::ObjectIdList(Vec::new()),
Some(expiry),
[i].to_vec(),
None,
);
let block_id = store.put(&block).unwrap();
println!("#{} -> objId {:?}", i, block_id);
block_ids.push(block_id);
i += 1;
}
store.remove_expired().unwrap();
assert!(store.get(block_ids.get(0).unwrap()).is_err());
assert!(store.get(block_ids.get(1).unwrap()).is_err());
assert!(store.get(block_ids.get(2).unwrap()).is_err());
assert!(store.get(block_ids.get(3).unwrap()).is_err());
assert!(store.get(block_ids.get(4).unwrap()).is_err());
assert!(store.get(block_ids.get(5).unwrap()).is_err());
}
#[test]
pub fn test_remove_empty_expired() {
let path_str = "test-env";
let root = Builder::new().prefix(path_str).tempdir().unwrap();
let key: [u8; 32] = [0; 32];
fs::create_dir_all(root.path()).unwrap();
println!("{}", root.path().to_str().unwrap());
let store = LmdbRepoStore::open(root.path(), key);
store.remove_expired().unwrap();
}
#[test]
pub fn test_store_block() {
let path_str = "test-env";
let root = Builder::new().prefix(path_str).tempdir().unwrap();
let key: [u8; 32] = [0; 32];
fs::create_dir_all(root.path()).unwrap();
println!("{}", root.path().to_str().unwrap());
let mut store = LmdbRepoStore::open(root.path(), key);
let block = Block::new(
Vec::new(),
ObjectDeps::ObjectIdList(Vec::new()),
None,
b"abc".to_vec(),
None,
);
let block_id = store.put(&block).unwrap();
assert_eq!(block_id, block.id());
println!("ObjectId: {:?}", block_id);
assert_eq!(
block_id,
Digest::Blake3Digest32([
155, 83, 186, 17, 95, 10, 80, 31, 111, 24, 250, 64, 8, 145, 71, 193, 103, 246, 202,
28, 202, 144, 63, 65, 85, 229, 136, 85, 202, 34, 13, 85
])
);
let block_res = store.get(&block_id).unwrap();
println!("Block: {:?}", block_res);
assert_eq!(block_res.id(), block.id());
}
#[test]
pub fn test_lmdb() {
let path_str = "test-env";
let root = Builder::new().prefix(path_str).tempdir().unwrap();
// we set an encryption key with all zeros... for test purpose only ;)
let key: [u8; 32] = [0; 32];
{
fs::create_dir_all(root.path()).unwrap();
println!("{}", root.path().to_str().unwrap());
let mut manager = Manager::<LmdbEnvironment>::singleton().write().unwrap();
let shared_rkv = manager
.get_or_create(root.path(), |path| {
// Rkv::new::<Lmdb>(path) // use this instead to disable encryption
Rkv::with_encryption_key_and_mapsize::<Lmdb>(path, key, 2 * 1024 * 1024 * 1024)
})
.unwrap();
let env = shared_rkv.read().unwrap();
println!("LMDB Version: {}", env.version());
let store = env.open_single("testdb", StoreOptions::create()).unwrap();
{
// Use a write transaction to mutate the store via a `Writer`. There can be only
// one writer for a given environment, so opening a second one will block until
// the first completes.
let mut writer = env.write().unwrap();
// Keys are `AsRef<[u8]>`, while values are `Value` enum instances. Use the `Blob`
// variant to store arbitrary collections of bytes. Putting data returns a
// `Result<(), StoreError>`, where StoreError is an enum identifying the reason
// for a failure.
// store.put(&mut writer, "int", &Value::I64(1234)).unwrap();
// store
// .put(&mut writer, "uint", &Value::U64(1234_u64))
// .unwrap();
// store
// .put(&mut writer, "float", &Value::F64(1234.0.into()))
// .unwrap();
// store
// .put(&mut writer, "instant", &Value::Instant(1528318073700))
// .unwrap();
// store
// .put(&mut writer, "boolean", &Value::Bool(true))
// .unwrap();
// store
// .put(&mut writer, "string", &Value::Str("Héllo, wörld!"))
// .unwrap();
// store
// .put(
// &mut writer,
// "json",
// &Value::Json(r#"{"foo":"bar", "number": 1}"#),
// )
// .unwrap();
const EXTRA: usize = 2095; // + 4096 * 524280 + 0;
let key: [u8; 33] = [0; 33];
let key2: [u8; 33] = [2; 33];
let key3: [u8; 33] = [3; 33];
let key4: [u8; 33] = [4; 33];
//let value: [u8; 1977 + EXTRA] = [1; 1977 + EXTRA];
let value = vec![1; 1977 + EXTRA];
let value2: [u8; 1977 + 1] = [1; 1977 + 1];
let value4: [u8; 953 + 0] = [1; 953 + 0];
store.put(&mut writer, key, &Value::Blob(&value2)).unwrap();
store.put(&mut writer, key2, &Value::Blob(&value2)).unwrap();
// store.put(&mut writer, key3, &Value::Blob(&value)).unwrap();
// store.put(&mut writer, key4, &Value::Blob(&value4)).unwrap();
// You must commit a write transaction before the writer goes out of scope, or the
// transaction will abort and the data won't persist.
writer.commit().unwrap();
let reader = env.read().expect("reader");
let stat = store.stat(&reader).unwrap();
println!("LMDB stat page_size : {}", stat.page_size());
println!("LMDB stat depth : {}", stat.depth());
println!("LMDB stat branch_pages : {}", stat.branch_pages());
println!("LMDB stat leaf_pages : {}", stat.leaf_pages());
println!("LMDB stat overflow_pages : {}", stat.overflow_pages());
println!("LMDB stat entries : {}", stat.entries());
}
// {
// // Use a read transaction to query the store via a `Reader`. There can be multiple
// // concurrent readers for a store, and readers never block on a writer nor other
// // readers.
// let reader = env.read().expect("reader");
// // Keys are `AsRef<u8>`, and the return value is `Result<Option<Value>, StoreError>`.
// // println!("Get int {:?}", store.get(&reader, "int").unwrap());
// // println!("Get uint {:?}", store.get(&reader, "uint").unwrap());
// // println!("Get float {:?}", store.get(&reader, "float").unwrap());
// // println!("Get instant {:?}", store.get(&reader, "instant").unwrap());
// // println!("Get boolean {:?}", store.get(&reader, "boolean").unwrap());
// // println!("Get string {:?}", store.get(&reader, "string").unwrap());
// // println!("Get json {:?}", store.get(&reader, "json").unwrap());
// println!("Get blob {:?}", store.get(&reader, "blob").unwrap());
// // Retrieving a non-existent value returns `Ok(None)`.
// println!(
// "Get non-existent value {:?}",
// store.get(&reader, "non-existent").unwrap()
// );
// // A read transaction will automatically close once the reader goes out of scope,
// // so isn't necessary to close it explicitly, although you can do so by calling
// // `Reader.abort()`.
// }
// {
// // Aborting a write transaction rolls back the change(s).
// let mut writer = env.write().unwrap();
// store.put(&mut writer, "foo", &Value::Blob(b"bar")).unwrap();
// writer.abort();
// let reader = env.read().expect("reader");
// println!(
// "It should be None! ({:?})",
// store.get(&reader, "foo").unwrap()
// );
// }
// {
// // Explicitly aborting a transaction is not required unless an early abort is
// // desired, since both read and write transactions will implicitly be aborted once
// // they go out of scope.
// {
// let mut writer = env.write().unwrap();
// store.put(&mut writer, "foo", &Value::Blob(b"bar")).unwrap();
// }
// let reader = env.read().expect("reader");
// println!(
// "It should be None! ({:?})",
// store.get(&reader, "foo").unwrap()
// );
// }
// {
// // Deleting a key/value pair also requires a write transaction.
// let mut writer = env.write().unwrap();
// store.put(&mut writer, "foo", &Value::Blob(b"bar")).unwrap();
// store.put(&mut writer, "bar", &Value::Blob(b"baz")).unwrap();
// store.delete(&mut writer, "foo").unwrap();
// // A write transaction also supports reading, and the version of the store that it
// // reads includes the changes it has made regardless of the commit state of that
// // transaction.
// // In the code above, "foo" and "bar" were put into the store, then "foo" was
// // deleted so only "bar" will return a result when the database is queried via the
// // writer.
// println!(
// "It should be None! ({:?})",
// store.get(&writer, "foo").unwrap()
// );
// println!("Get bar ({:?})", store.get(&writer, "bar").unwrap());
// // But a reader won't see that change until the write transaction is committed.
// {
// let reader = env.read().expect("reader");
// println!("Get foo {:?}", store.get(&reader, "foo").unwrap());
// println!("Get bar {:?}", store.get(&reader, "bar").unwrap());
// }
// writer.commit().unwrap();
// {
// let reader = env.read().expect("reader");
// println!(
// "It should be None! ({:?})",
// store.get(&reader, "foo").unwrap()
// );
// println!("Get bar {:?}", store.get(&reader, "bar").unwrap());
// }
// // Committing a transaction consumes the writer, preventing you from reusing it by
// // failing at compile time with an error. This line would report "error[E0382]:
// // borrow of moved value: `writer`".
// // store.put(&mut writer, "baz", &Value::Str("buz")).unwrap();
// }
// {
// // Clearing all the entries in the store with a write transaction.
// {
// let mut writer = env.write().unwrap();
// store.put(&mut writer, "foo", &Value::Blob(b"bar")).unwrap();
// store.put(&mut writer, "bar", &Value::Blob(b"baz")).unwrap();
// writer.commit().unwrap();
// }
// // {
// // let mut writer = env.write().unwrap();
// // store.clear(&mut writer).unwrap();
// // writer.commit().unwrap();
// // }
// // {
// // let reader = env.read().expect("reader");
// // println!(
// // "It should be None! ({:?})",
// // store.get(&reader, "foo").unwrap()
// // );
// // println!(
// // "It should be None! ({:?})",
// // store.get(&reader, "bar").unwrap()
// // );
// // }
// }
let stat = env.stat().unwrap();
let info = env.info().unwrap();
println!("LMDB info map_size : {}", info.map_size());
println!("LMDB info last_pgno : {}", info.last_pgno());
println!("LMDB info last_txnid : {}", info.last_txnid());
println!("LMDB info max_readers : {}", info.max_readers());
println!("LMDB info num_readers : {}", info.num_readers());
println!("LMDB stat page_size : {}", stat.page_size());
println!("LMDB stat depth : {}", stat.depth());
println!("LMDB stat branch_pages : {}", stat.branch_pages());
println!("LMDB stat leaf_pages : {}", stat.leaf_pages());
println!("LMDB stat overflow_pages : {}", stat.overflow_pages());
println!("LMDB stat entries : {}", stat.entries());
}
// We reopen the env and data to see if it was well saved to disk.
{
let mut manager = Manager::<LmdbEnvironment>::singleton().write().unwrap();
let shared_rkv = manager
.get_or_create(root.path(), |path| {
//Rkv::new::<Lmdb>(path) // use this instead to disable encryption
Rkv::with_encryption_key_and_mapsize::<Lmdb>(path, key, 2 * 1024 * 1024 * 1024)
})
.unwrap();
let env = shared_rkv.read().unwrap();
println!("LMDB Version: {}", env.version());
let mut store = env.open_single("testdb", StoreOptions::default()).unwrap(); //StoreOptions::create()
{
let reader = env.read().expect("reader");
println!(
"It should be baz! ({:?})",
store.get(&reader, "bar").unwrap()
);
}
}
// Here the database and environment is closed, but the files are still present in the temp directory.
// uncomment this if you need time to copy them somewhere for analysis, before the temp folder get destroyed
//thread::sleep(Duration::from_millis(20000));
}
}