surrealpatch/core/src/kvs/ds.rs
2024-03-05 15:26:14 +00:00

1548 lines
51 KiB
Rust

use std::collections::{BTreeMap, BTreeSet};
use std::fmt;
use std::sync::Arc;
use std::time::Duration;
#[cfg(not(target_arch = "wasm32"))]
use std::time::{SystemTime, UNIX_EPOCH};
use channel::{Receiver, Sender};
use futures::{lock::Mutex, Future};
use tokio::sync::RwLock;
use tracing::instrument;
use tracing::trace;
#[cfg(target_arch = "wasm32")]
use wasmtimer::std::{SystemTime, UNIX_EPOCH};
use crate::cf;
use crate::cf::{ChangeSet, TableMutation};
use crate::ctx::Context;
#[cfg(feature = "jwks")]
use crate::dbs::capabilities::NetTarget;
use crate::dbs::{
node::Timestamp, Attach, Capabilities, Executor, Notification, Options, Response, Session,
Statement, Variables, Workable,
};
use crate::doc::Document;
use crate::err::Error;
use crate::fflags::FFLAGS;
use crate::iam::{Action, Auth, Error as IamError, Resource, Role};
use crate::idx::trees::store::IndexStores;
use crate::key::root::hb::Hb;
use crate::kvs::clock::SizedClock;
#[allow(unused_imports)]
use crate::kvs::clock::SystemClock;
use crate::kvs::lq_structs::{
LqEntry, LqIndexKey, LqIndexValue, LqSelector, LqValue, TrackedResult, UnreachableLqType,
};
use crate::kvs::{LockType, LockType::*, TransactionType, TransactionType::*};
use crate::options::EngineOptions;
use crate::sql::statements::show::ShowSince;
use crate::sql::{self, statements::DefineUserStatement, Base, Query, Uuid, Value};
use crate::syn;
use crate::vs::{conv, Oracle, Versionstamp};
use super::tx::Transaction;
// If there are an infinite number of heartbeats, then we want to go batch-by-batch spread over several checks
const HEARTBEAT_BATCH_SIZE: u32 = 1000;
const LQ_CHANNEL_SIZE: usize = 100;
// The batch size used for non-paged operations (i.e. if there are more results, they are ignored)
const NON_PAGED_BATCH_SIZE: u32 = 100_000;
/// The underlying datastore instance which stores the dataset.
#[allow(dead_code)]
pub struct Datastore {
// The inner datastore type
inner: Inner,
// The unique id of this datastore, used in notifications
id: Uuid,
// Whether this datastore runs in strict mode by default
strict: bool,
// Whether authentication is enabled on this datastore.
auth_enabled: bool,
// Whether authentication level is enabled on this datastore.
// TODO(gguillemas): Remove this field once the legacy authentication is deprecated in v2.0.0
auth_level_enabled: bool,
// The maximum duration timeout for running multiple statements in a query
query_timeout: Option<Duration>,
// The maximum duration timeout for running multiple statements in a transaction
transaction_timeout: Option<Duration>,
// Capabilities for this datastore
capabilities: Capabilities,
engine_options: EngineOptions,
// The versionstamp oracle for this datastore.
// Used only in some datastores, such as tikv.
versionstamp_oracle: Arc<Mutex<Oracle>>,
// Whether this datastore enables live query notifications to subscribers
notification_channel: Option<(Sender<Notification>, Receiver<Notification>)>,
// Map of Live Query identifier (ns+db+tb) for change feed tracking
// the mapping is to a list of affected live queries
local_live_queries: Arc<RwLock<BTreeMap<LqIndexKey, Vec<LqIndexValue>>>>,
// Set of tracked change feeds with associated watermarks
// This is updated with new/removed live queries and improves cf request performance
cf_watermarks: Arc<RwLock<BTreeMap<LqSelector, Versionstamp>>>,
// Clock for tracking time. It is read only and accessible to all transactions. It is behind a mutex as tests may write to it.
clock: Arc<SizedClock>,
// The index store cache
index_stores: IndexStores,
}
/// We always want to be circulating the live query information
/// And we will sometimes have an error attached but still not want to lose the LQ.
pub(crate) type BootstrapOperationResult = (LqValue, Option<Error>);
#[allow(clippy::large_enum_variant)]
pub(super) enum Inner {
#[cfg(feature = "kv-mem")]
Mem(super::mem::Datastore),
#[cfg(feature = "kv-rocksdb")]
RocksDB(super::rocksdb::Datastore),
#[cfg(feature = "kv-speedb")]
SpeeDB(super::speedb::Datastore),
#[cfg(feature = "kv-indxdb")]
IndxDB(super::indxdb::Datastore),
#[cfg(feature = "kv-tikv")]
TiKV(super::tikv::Datastore),
#[cfg(feature = "kv-fdb")]
FoundationDB(super::fdb::Datastore),
#[cfg(feature = "kv-surrealkv")]
SurrealKV(super::surrealkv::Datastore),
}
impl fmt::Display for Datastore {
fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
#![allow(unused_variables)]
match &self.inner {
#[cfg(feature = "kv-mem")]
Inner::Mem(_) => write!(f, "memory"),
#[cfg(feature = "kv-rocksdb")]
Inner::RocksDB(_) => write!(f, "rocksdb"),
#[cfg(feature = "kv-speedb")]
Inner::SpeeDB(_) => write!(f, "speedb"),
#[cfg(feature = "kv-indxdb")]
Inner::IndxDB(_) => write!(f, "indxdb"),
#[cfg(feature = "kv-tikv")]
Inner::TiKV(_) => write!(f, "tikv"),
#[cfg(feature = "kv-fdb")]
Inner::FoundationDB(_) => write!(f, "fdb"),
#[cfg(feature = "kv-surrealkv")]
Inner::SurrealKV(_) => write!(f, "surrealkv"),
#[allow(unreachable_patterns)]
_ => unreachable!(),
}
}
}
impl Datastore {
/// Creates a new datastore instance
///
/// # Examples
///
/// ```rust,no_run
/// # use surrealdb_core::kvs::Datastore;
/// # use surrealdb_core::err::Error;
/// # #[tokio::main]
/// # async fn main() -> Result<(), Error> {
/// let ds = Datastore::new("memory").await?;
/// # Ok(())
/// # }
/// ```
///
/// Or to create a file-backed store:
///
/// ```rust,no_run
/// # use surrealdb_core::kvs::Datastore;
/// # use surrealdb_core::err::Error;
/// # #[tokio::main]
/// # async fn main() -> Result<(), Error> {
/// let ds = Datastore::new("file://temp.db").await?;
/// # Ok(())
/// # }
/// ```
///
/// Or to connect to a tikv-backed distributed store:
///
/// ```rust,no_run
/// # use surrealdb_core::kvs::Datastore;
/// # use surrealdb_core::err::Error;
/// # #[tokio::main]
/// # async fn main() -> Result<(), Error> {
/// let ds = Datastore::new("tikv://127.0.0.1:2379").await?;
/// # Ok(())
/// # }
/// ```
pub async fn new(path: &str) -> Result<Datastore, Error> {
Self::new_full_impl(path, None).await
}
#[allow(dead_code)]
#[cfg(test)]
pub async fn new_full(
path: &str,
clock_override: Option<Arc<SizedClock>>,
) -> Result<Datastore, Error> {
Self::new_full_impl(path, clock_override).await
}
#[allow(dead_code)]
async fn new_full_impl(
path: &str,
#[allow(unused_variables)] clock_override: Option<Arc<SizedClock>>,
) -> Result<Datastore, Error> {
#[allow(unused_variables)]
let default_clock: Arc<SizedClock> = Arc::new(SizedClock::System(SystemClock::new()));
// removes warning if no storage is enabled.
#[cfg(not(any(
feature = "kv-mem",
feature = "kv-rocksdb",
feature = "kv-speedb",
feature = "kv-indxdb",
feature = "kv-tikv",
feature = "kv-fdb",
feature = "kv-surrealkv"
)))]
let _ = (clock_override, default_clock);
// Initiate the desired datastore
let (inner, clock): (Result<Inner, Error>, Arc<SizedClock>) = match path {
"memory" => {
#[cfg(feature = "kv-mem")]
{
info!("Starting kvs store in {}", path);
let v = super::mem::Datastore::new().await.map(Inner::Mem);
let default_clock = Arc::new(SizedClock::System(SystemClock::new()));
let clock = clock_override.unwrap_or(default_clock);
info!("Started kvs store in {}", path);
Ok((v, clock))
}
#[cfg(not(feature = "kv-mem"))]
return Err(Error::Ds("Cannot connect to the `memory` storage engine as it is not enabled in this build of SurrealDB".to_owned()));
}
// Parse and initiate an File database
s if s.starts_with("file:") => {
#[cfg(feature = "kv-rocksdb")]
{
info!("Starting kvs store at {}", path);
let s = s.trim_start_matches("file://");
let s = s.trim_start_matches("file:");
let v = super::rocksdb::Datastore::new(s).await.map(Inner::RocksDB);
let default_clock = Arc::new(SizedClock::System(SystemClock::new()));
let clock = clock_override.unwrap_or(default_clock);
info!("Started kvs store at {}", path);
Ok((v, clock))
}
#[cfg(not(feature = "kv-rocksdb"))]
return Err(Error::Ds("Cannot connect to the `rocksdb` storage engine as it is not enabled in this build of SurrealDB".to_owned()));
}
// Parse and initiate an RocksDB database
s if s.starts_with("rocksdb:") => {
#[cfg(feature = "kv-rocksdb")]
{
info!("Starting kvs store at {}", path);
let s = s.trim_start_matches("rocksdb://");
let s = s.trim_start_matches("rocksdb:");
let v = super::rocksdb::Datastore::new(s).await.map(Inner::RocksDB);
info!("Started kvs store at {}", path);
let default_clock = Arc::new(SizedClock::System(SystemClock::new()));
let clock = clock_override.unwrap_or(default_clock);
Ok((v, clock))
}
#[cfg(not(feature = "kv-rocksdb"))]
return Err(Error::Ds("Cannot connect to the `rocksdb` storage engine as it is not enabled in this build of SurrealDB".to_owned()));
}
// Parse and initiate an SpeeDB database
s if s.starts_with("speedb:") => {
#[cfg(feature = "kv-speedb")]
{
info!("Starting kvs store at {}", path);
let s = s.trim_start_matches("speedb://");
let s = s.trim_start_matches("speedb:");
let v = super::speedb::Datastore::new(s).await.map(Inner::SpeeDB);
info!("Started kvs store at {}", path);
let default_clock = Arc::new(SizedClock::System(SystemClock::new()));
let clock = clock_override.unwrap_or(default_clock);
Ok((v, clock))
}
#[cfg(not(feature = "kv-speedb"))]
return Err(Error::Ds("Cannot connect to the `speedb` storage engine as it is not enabled in this build of SurrealDB".to_owned()));
}
// Parse and initiate an IndxDB database
s if s.starts_with("indxdb:") => {
#[cfg(feature = "kv-indxdb")]
{
info!("Starting kvs store at {}", path);
let s = s.trim_start_matches("indxdb://");
let s = s.trim_start_matches("indxdb:");
let v = super::indxdb::Datastore::new(s).await.map(Inner::IndxDB);
info!("Started kvs store at {}", path);
let default_clock = Arc::new(SizedClock::System(SystemClock::new()));
let clock = clock_override.unwrap_or(default_clock);
Ok((v, clock))
}
#[cfg(not(feature = "kv-indxdb"))]
return Err(Error::Ds("Cannot connect to the `indxdb` storage engine as it is not enabled in this build of SurrealDB".to_owned()));
}
// Parse and initiate a TiKV database
s if s.starts_with("tikv:") => {
#[cfg(feature = "kv-tikv")]
{
info!("Connecting to kvs store at {}", path);
let s = s.trim_start_matches("tikv://");
let s = s.trim_start_matches("tikv:");
let v = super::tikv::Datastore::new(s).await.map(Inner::TiKV);
info!("Connected to kvs store at {}", path);
let default_clock = Arc::new(SizedClock::System(SystemClock::new()));
let clock = clock_override.unwrap_or(default_clock);
Ok((v, clock))
}
#[cfg(not(feature = "kv-tikv"))]
return Err(Error::Ds("Cannot connect to the `tikv` storage engine as it is not enabled in this build of SurrealDB".to_owned()));
}
// Parse and initiate a FoundationDB database
s if s.starts_with("fdb:") => {
#[cfg(feature = "kv-fdb")]
{
info!("Connecting to kvs store at {}", path);
let s = s.trim_start_matches("fdb://");
let s = s.trim_start_matches("fdb:");
let v = super::fdb::Datastore::new(s).await.map(Inner::FoundationDB);
info!("Connected to kvs store at {}", path);
let default_clock = Arc::new(SizedClock::System(SystemClock::new()));
let clock = clock_override.unwrap_or(default_clock);
Ok((v, clock))
}
#[cfg(not(feature = "kv-fdb"))]
return Err(Error::Ds("Cannot connect to the `foundationdb` storage engine as it is not enabled in this build of SurrealDB".to_owned()));
}
// Parse and initiate a SurrealKV database
s if s.starts_with("surrealkv:") => {
#[cfg(feature = "kv-surrealkv")]
{
info!("Starting kvs store at {}", path);
let s = s.trim_start_matches("surrealkv://");
let s = s.trim_start_matches("surrealkv:");
let v = super::surrealkv::Datastore::new(s).await.map(Inner::SurrealKV);
info!("Started to kvs store at {}", path);
let default_clock = Arc::new(SizedClock::System(SystemClock::new()));
let clock = clock_override.unwrap_or(default_clock);
Ok((v, clock))
}
#[cfg(not(feature = "kv-surrealkv"))]
return Err(Error::Ds("Cannot connect to the `surrealkv` storage engine as it is not enabled in this build of SurrealDB".to_owned()));
}
// The datastore path is not valid
_ => {
// use clock_override and default_clock to remove warning when no kv is enabled.
let _ = default_clock;
info!("Unable to load the specified datastore {}", path);
Err(Error::Ds("Unable to load the specified datastore".into()))
}
}?;
// Set the properties on the datastore
inner.map(|inner| Self {
id: Uuid::new_v4(),
inner,
strict: false,
auth_enabled: false,
// TODO(gguillemas): Remove this field once the legacy authentication is deprecated in v2.0.0
auth_level_enabled: false,
query_timeout: None,
transaction_timeout: None,
notification_channel: None,
capabilities: Capabilities::default(),
engine_options: EngineOptions::default(),
versionstamp_oracle: Arc::new(Mutex::new(Oracle::systime_counter())),
clock,
index_stores: IndexStores::default(),
local_live_queries: Arc::new(RwLock::new(BTreeMap::new())),
cf_watermarks: Arc::new(RwLock::new(BTreeMap::new())),
})
}
/// Specify whether this Datastore should run in strict mode
pub fn with_node_id(mut self, id: Uuid) -> Self {
self.id = id;
self
}
/// Specify whether this Datastore should run in strict mode
pub fn with_strict_mode(mut self, strict: bool) -> Self {
self.strict = strict;
self
}
/// Specify whether this datastore should enable live query notifications
pub fn with_notifications(mut self) -> Self {
self.notification_channel = Some(channel::bounded(LQ_CHANNEL_SIZE));
self
}
/// Set a global query timeout for this Datastore
pub fn with_query_timeout(mut self, duration: Option<Duration>) -> Self {
self.query_timeout = duration;
self
}
/// Set a global transaction timeout for this Datastore
pub fn with_transaction_timeout(mut self, duration: Option<Duration>) -> Self {
self.transaction_timeout = duration;
self
}
/// Set whether authentication is enabled for this Datastore
pub fn with_auth_enabled(mut self, enabled: bool) -> Self {
self.auth_enabled = enabled;
self
}
/// Set whether authentication levels are enabled for this Datastore
/// TODO(gguillemas): Remove this method once the legacy authentication is deprecated in v2.0.0
pub fn with_auth_level_enabled(mut self, enabled: bool) -> Self {
self.auth_level_enabled = enabled;
self
}
/// Set specific capabilities for this Datastore
pub fn with_capabilities(mut self, caps: Capabilities) -> Self {
self.capabilities = caps;
self
}
/// Set the engine options for the datastore
pub fn with_engine_options(mut self, engine_options: EngineOptions) -> Self {
self.engine_options = engine_options;
self
}
pub fn index_store(&self) -> &IndexStores {
&self.index_stores
}
/// Is authentication enabled for this Datastore?
pub fn is_auth_enabled(&self) -> bool {
self.auth_enabled
}
/// Is authentication level enabled for this Datastore?
/// TODO(gguillemas): Remove this method once the legacy authentication is deprecated in v2.0.0
pub fn is_auth_level_enabled(&self) -> bool {
self.auth_level_enabled
}
/// Does the datastore allow connections to a network target?
#[cfg(feature = "jwks")]
pub(crate) fn allows_network_target(&self, net_target: &NetTarget) -> bool {
self.capabilities.allows_network_target(net_target)
}
/// Setup the initial credentials
/// Trigger the `unreachable definition` compilation error, probably due to this issue:
/// https://github.com/rust-lang/rust/issues/111370
#[allow(unreachable_code, unused_variables)]
pub async fn setup_initial_creds(&self, username: &str, password: &str) -> Result<(), Error> {
// Start a new writeable transaction
let txn = self.transaction(Write, Optimistic).await?.rollback_with_panic().enclose();
// Fetch the root users from the storage
let users = txn.lock().await.all_root_users().await;
// Process credentials, depending on existing users
match users {
Ok(v) if v.is_empty() => {
// Display information in the logs
info!("Credentials were provided, and no root users were found. The root user '{}' will be created", username);
// Create and save a new root users
let stm = DefineUserStatement::from((Base::Root, username, password));
let ctx = Context::default();
let opt = Options::new().with_auth(Arc::new(Auth::for_root(Role::Owner)));
let _ = stm.compute(&ctx, &opt, &txn, None).await?;
// We added a new user, so commit the transaction
txn.lock().await.commit().await?;
// Everything ok
Ok(())
}
Ok(_) => {
// Display warnings in the logs
warn!("Credentials were provided, but existing root users were found. The root user '{}' will not be created", username);
warn!("Consider removing the --user and --pass arguments from the server start command");
// We didn't write anything, so just rollback
txn.lock().await.cancel().await?;
// Everything ok
Ok(())
}
Err(e) => {
// There was an unexpected error, so rollback
txn.lock().await.cancel().await?;
// Return any error
Err(e)
}
}
}
// Initialise bootstrap with implicit values intended for runtime
// An error indicates that a failure happened, but that does not mean that the bootstrap
// completely failed. It may have partially completed. It certainly has side-effects
// that weren't reversed, as it tries to bootstrap and garbage collect to the best of its
// ability.
// NOTE: If you get rust mutex deadlocks, check your transactions around this method.
// This should be called before any transactions are made in release mode
// In tests, it should be outside any other transaction - in isolation.
// We cannot easily systematise this, since we aren't counting transactions created.
pub async fn bootstrap(&self) -> Result<(), Error> {
// First we clear unreachable state that could exist by upgrading from
// previous beta versions
trace!("Clearing unreachable state");
let mut tx = self.transaction(Write, Optimistic).await?;
match self.clear_unreachable_state(&mut tx).await {
Ok(_) => tx.commit().await,
Err(e) => {
let msg = format!("Error clearing unreachable cluster state at bootstrap: {:?}", e);
error!(msg);
tx.cancel().await?;
Err(Error::Tx(msg))
}
}?;
trace!("Bootstrapping {}", self.id);
let mut tx = self.transaction(Write, Optimistic).await?;
let archived = match self.register_remove_and_archive(&mut tx, &self.id).await {
Ok(archived) => {
tx.commit().await?;
archived
}
Err(e) => {
error!("Error bootstrapping mark phase: {:?}", e);
tx.cancel().await?;
return Err(e);
}
};
// Filtered includes all lqs that should be used in subsequent step
// Currently that is all of them, no matter the error encountered
let mut filtered: Vec<LqValue> = vec![];
// err is used to aggregate all errors across all stages
let mut err = vec![];
for res in archived {
match res {
(lq, Some(e)) => {
filtered.push(lq);
err.push(e);
}
(lq, None) => {
filtered.push(lq);
}
}
}
let mut tx = self.transaction(Write, Optimistic).await?;
let val = self.remove_archived(&mut tx, filtered).await;
let resolve_err = match val {
Ok(_) => tx.commit().await,
Err(e) => {
error!("Error bootstrapping sweep phase: {:?}", e);
match tx.cancel().await {
Ok(_) => Err(e),
Err(e) => {
// We have a nested error
Err(Error::Tx(format!("Error bootstrapping sweep phase: {:?} and error cancelling transaction: {:?}", e, e)))
}
}
}
};
if let Err(e) = resolve_err {
err.push(e);
}
if !err.is_empty() {
error!("Error bootstrapping sweep phase: {:?}", err);
return Err(Error::Tx(format!("Error bootstrapping sweep phase: {:?}", err)));
}
Ok(())
}
// Node registration + "mark" stage of mark-and-sweep gc
pub async fn register_remove_and_archive(
&self,
tx: &mut Transaction,
node_id: &Uuid,
) -> Result<Vec<BootstrapOperationResult>, Error> {
trace!("Registering node {}", node_id);
let timestamp = tx.clock().await;
self.register_membership(tx, node_id, timestamp).await?;
// Determine the timeout for when a cluster node is expired
let ts_expired = (&timestamp - &sql::duration::Duration::from_secs(5))?;
let dead = self.remove_dead_nodes(tx, &ts_expired).await?;
trace!("Archiving dead nodes: {:?}", dead);
self.archive_dead_lqs(tx, &dead, node_id).await
}
// Adds entries to the KV store indicating membership information
pub async fn register_membership(
&self,
tx: &mut Transaction,
node_id: &Uuid,
timestamp: Timestamp,
) -> Result<(), Error> {
tx.set_nd(node_id.0).await?;
tx.set_hb(timestamp, node_id.0).await?;
Ok(())
}
/// Delete dead heartbeats and nodes
/// Returns node IDs
pub async fn remove_dead_nodes(
&self,
tx: &mut Transaction,
ts: &Timestamp,
) -> Result<Vec<Uuid>, Error> {
let hbs = self.delete_dead_heartbeats(tx, ts).await?;
trace!("Found {} expired heartbeats", hbs.len());
let mut nodes = vec![];
for hb in hbs {
trace!("Deleting node {}", &hb.nd);
// TODO should be delr in case of nested entries
tx.del_nd(hb.nd).await?;
nodes.push(crate::sql::uuid::Uuid::from(hb.nd));
}
Ok(nodes)
}
/// Accepts cluster IDs
/// Archives related live queries
/// Returns live query keys that can be used for deletes
///
/// The reason we archive first is to stop other nodes from picking it up for further updates
/// This means it will be easier to wipe the range in a subsequent transaction
pub async fn archive_dead_lqs(
&self,
tx: &mut Transaction,
nodes: &[Uuid],
this_node_id: &Uuid,
) -> Result<Vec<BootstrapOperationResult>, Error> {
let mut archived = vec![];
for nd in nodes.iter() {
trace!("Archiving node {}", &nd);
// Scan on node prefix for LQ space
let node_lqs = tx.scan_ndlq(nd, NON_PAGED_BATCH_SIZE).await?;
trace!("Found {} LQ entries for {:?}", node_lqs.len(), nd);
for lq in node_lqs {
trace!("Archiving query {:?}", &lq);
let node_archived_lqs =
match self.archive_lv_for_node(tx, &lq.nd, *this_node_id).await {
Ok(lq) => lq,
Err(e) => {
error!("Error archiving lqs during bootstrap phase: {:?}", e);
vec![]
}
};
// We need to add lv nodes not found so that they can be deleted in second stage
for lq_value in node_archived_lqs {
archived.push(lq_value);
}
}
}
Ok(archived)
}
pub async fn remove_archived(
&self,
tx: &mut Transaction,
archived: Vec<LqValue>,
) -> Result<(), Error> {
trace!("Gone into removing archived: {:?}", archived.len());
for lq in archived {
// Delete the cluster key, used for finding LQ associated with a node
let key = crate::key::node::lq::new(lq.nd.0, lq.lq.0, &lq.ns, &lq.db);
tx.del(key).await?;
// Delete the table key, used for finding LQ associated with a table
let key = crate::key::table::lq::new(&lq.ns, &lq.db, &lq.tb, lq.lq.0);
tx.del(key).await?;
}
Ok(())
}
pub async fn clear_unreachable_state(&self, tx: &mut Transaction) -> Result<(), Error> {
// Scan nodes
let cluster = tx.scan_nd(NON_PAGED_BATCH_SIZE).await?;
trace!("Found {} nodes", cluster.len());
let mut unreachable_nodes = BTreeMap::new();
for cl in &cluster {
unreachable_nodes.insert(cl.name.clone(), cl.clone());
}
// Scan all heartbeats
let end_of_time = Timestamp {
// We remove one, because the scan range adds one
value: u64::MAX - 1,
};
let hbs = tx.scan_hb(&end_of_time, NON_PAGED_BATCH_SIZE).await?;
trace!("Found {} heartbeats", hbs.len());
for hb in hbs {
match unreachable_nodes.remove(&hb.nd.to_string()) {
None => {
// Didnt exist in cluster and should be deleted
tx.del_hb(hb.hb, hb.nd).await?;
}
Some(_) => {}
}
}
// Remove unreachable nodes
for (_, cl) in unreachable_nodes {
trace!("Removing unreachable node {}", cl.name);
tx.del_nd(
uuid::Uuid::parse_str(&cl.name).map_err(|e| {
Error::Unimplemented(format!("cluster id was not uuid: {:?}", e))
})?,
)
.await?;
}
// Scan node live queries for every node
let mut nd_lq_set: BTreeSet<UnreachableLqType> = BTreeSet::new();
for cl in &cluster {
let nds = tx.scan_ndlq(&uuid::Uuid::parse_str(&cl.name).map_err(|e| {
Error::Unimplemented(format!("cluster id was not uuid when parsing to aggregate cluster live queries: {:?}", e))
})?, NON_PAGED_BATCH_SIZE).await?;
nd_lq_set.extend(nds.into_iter().map(UnreachableLqType::Nd));
}
trace!("Found {} node live queries", nd_lq_set.len());
// Scan tables for all live queries
// let mut tb_lqs: Vec<LqValue> = vec![];
let mut tb_lq_set: BTreeSet<UnreachableLqType> = BTreeSet::new();
for ndlq in &nd_lq_set {
let lq = ndlq.get_inner();
let tbs = tx.scan_tblq(&lq.ns, &lq.db, &lq.tb, NON_PAGED_BATCH_SIZE).await?;
tb_lq_set.extend(tbs.into_iter().map(UnreachableLqType::Tb));
}
trace!("Found {} table live queries", tb_lq_set.len());
// Find and delete missing
for missing in nd_lq_set.symmetric_difference(&tb_lq_set) {
match missing {
UnreachableLqType::Nd(ndlq) => {
warn!("Deleting ndlq {:?}", &ndlq);
tx.del_ndlq(ndlq.nd.0, ndlq.lq.0, &ndlq.ns, &ndlq.db).await?;
}
UnreachableLqType::Tb(tblq) => {
warn!("Deleting tblq {:?}", &tblq);
tx.del_tblq(&tblq.ns, &tblq.db, &tblq.tb, tblq.lq.0).await?;
}
}
}
trace!("Successfully cleared cluster of unreachable state");
Ok(())
}
// Garbage collection task to run when a client disconnects from a surrealdb node
// i.e. we know the node, we are not performing a full wipe on the node
// and the wipe must be fully performed by this node
pub async fn garbage_collect_dead_session(
&self,
live_queries: &[uuid::Uuid],
) -> Result<(), Error> {
let mut tx = self.transaction(Write, Optimistic).await?;
// Find all the LQs we own, so that we can get the ns/ds from provided uuids
// We may improve this in future by tracking in web layer
let lqs = tx.scan_ndlq(&self.id, NON_PAGED_BATCH_SIZE).await?;
let mut hits = vec![];
for lq_value in lqs {
if live_queries.contains(&lq_value.lq) {
hits.push(lq_value.clone());
let lq = crate::key::node::lq::Lq::new(
lq_value.nd.0,
lq_value.lq.0,
lq_value.ns.as_str(),
lq_value.db.as_str(),
);
tx.del(lq).await?;
trace!("Deleted lq {:?} as part of session garbage collection", lq_value.clone());
}
}
// Now delete the table entries for the live queries
for lq in hits {
let lv =
crate::key::table::lq::new(lq.ns.as_str(), lq.db.as_str(), lq.tb.as_str(), lq.lq.0);
tx.del(lv.clone()).await?;
trace!("Deleted lv {:?} as part of session garbage collection", lv);
}
tx.commit().await
}
// Returns a list of live query IDs
pub async fn archive_lv_for_node(
&self,
tx: &mut Transaction,
nd: &Uuid,
this_node_id: Uuid,
) -> Result<Vec<BootstrapOperationResult>, Error> {
let lqs = tx.all_lq(nd).await?;
trace!("Archiving lqs and found {} LQ entries for {}", lqs.len(), nd);
let mut ret: Vec<BootstrapOperationResult> = vec![];
for lq in lqs {
let lv_res =
tx.get_tb_live(lq.ns.as_str(), lq.db.as_str(), lq.tb.as_str(), &lq.lq).await;
if let Err(e) = lv_res {
error!("Error getting live query for node {}: {:?}", nd, e);
ret.push((lq, Some(e)));
continue;
}
let lv = lv_res.unwrap();
let archived_lvs = lv.clone().archive(this_node_id);
tx.putc_tblq(&lq.ns, &lq.db, &lq.tb, archived_lvs, Some(lv)).await?;
ret.push((lq, None));
}
Ok(ret)
}
/// Given a timestamp, delete all the heartbeats that have expired
/// Return the removed heartbeats as they will contain node information
pub async fn delete_dead_heartbeats(
&self,
tx: &mut Transaction,
ts: &Timestamp,
) -> Result<Vec<Hb>, Error> {
let dead = tx.scan_hb(ts, HEARTBEAT_BATCH_SIZE).await?;
// Delete the heartbeat and everything nested
tx.delr_hb(dead.clone(), NON_PAGED_BATCH_SIZE).await?;
for dead_node in dead.clone() {
tx.del_nd(dead_node.nd).await?;
}
Ok::<Vec<Hb>, Error>(dead)
}
// tick is called periodically to perform maintenance tasks.
// This is called every TICK_INTERVAL.
pub async fn tick(&self) -> Result<(), Error> {
let now = SystemTime::now().duration_since(UNIX_EPOCH).map_err(|e| {
Error::Internal(format!("Clock may have gone backwards: {:?}", e.duration()))
})?;
let ts = now.as_secs();
self.tick_at(ts).await?;
Ok(())
}
// tick_at is the utility function that is called by tick.
// It is handy for testing, because it allows you to specify the timestamp,
// without depending on a system clock.
pub async fn tick_at(&self, ts: u64) -> Result<(), Error> {
let _vs = self.save_timestamp_for_versionstamp(ts).await?;
self.garbage_collect_stale_change_feeds(ts).await?;
// TODO Add LQ GC
// TODO Add Node GC?
Ok(())
}
// save_timestamp_for_versionstamp saves the current timestamp for the each database's current versionstamp.
pub(crate) async fn save_timestamp_for_versionstamp(
&self,
ts: u64,
) -> Result<Option<Versionstamp>, Error> {
let mut tx = self.transaction(Write, Optimistic).await?;
match self.save_timestamp_for_versionstamp_impl(ts, &mut tx).await {
Ok(vs) => Ok(vs),
Err(e) => {
match tx.cancel().await {
Ok(_) => {
Err(e)
}
Err(txe) => {
Err(Error::Tx(format!("Error saving timestamp for versionstamp: {:?} and error cancelling transaction: {:?}", e, txe)))
}
}
}
}
}
/// Poll change feeds for live query notifications
pub async fn process_lq_notifications(&self, opt: &Options) -> Result<(), Error> {
// Runtime feature gate, as it is not production-ready
if !FFLAGS.change_feed_live_queries.enabled() {
return Ok(());
}
// Return if there are no live queries
if self.notification_channel.is_none() {
trace!("Channels is none, short-circuiting");
return Ok(());
}
if self.local_live_queries.read().await.is_empty() {
trace!("No live queries, short-circuiting");
return Ok(());
}
// Change map includes a mapping of selector to changesets, ordered by versionstamp
let mut change_map: BTreeMap<LqSelector, Vec<ChangeSet>> = BTreeMap::new();
let mut tx = self.transaction(Read, Optimistic).await?;
let mut tracked_cfs = self.cf_watermarks.write().await;
let mut tracked_cfs_updates = Vec::with_capacity(tracked_cfs.len());
for (selector, vs) in tracked_cfs.iter() {
// Read the change feed for the selector
let res = cf::read(
&mut tx,
&selector.ns,
&selector.db,
// Technically, we can not fetch by table and do the per-table filtering this side.
// That is an improvement though
Some(&selector.tb),
ShowSince::versionstamp(vs),
Some(self.engine_options.live_query_catchup_size),
)
.await?;
// Confirm we do need to change watermark - this is technically already handled by the cf range scan
if res.is_empty() {
trace!(
"There were no changes in the change feed for {:?} from versionstamp {:?}",
selector,
vs
)
}
if let Some(change_set) = res.last() {
if conv::versionstamp_to_u64(&change_set.0) > conv::versionstamp_to_u64(vs) {
trace!("Adding a change set for lq notification processing");
// Update the cf watermark so we can progress scans
// If the notifications fail from here-on, they are lost
// this is a separate vec that we later insert to because we are iterating immutably
// We shouldn't use a read lock because of consistency between watermark scans
tracked_cfs_updates.push((selector.clone(), change_set.0));
// This does not guarantee a notification, as a changeset an include many tables and many changes
change_map.insert(selector.clone(), res);
}
}
}
tx.cancel().await?;
// Now we update since we are no longer iterating immutably
for (selector, vs) in tracked_cfs_updates {
tracked_cfs.insert(selector, vs);
}
for (selector, change_sets) in change_map {
// find matching live queries
let lq_pairs: Vec<(LqIndexKey, LqIndexValue)> = {
let lq_lock = self.local_live_queries.read().await;
lq_lock
.iter()
.filter(|(k, _)| k.selector == selector)
.flat_map(|(lq_index, lq_values)| {
lq_values.iter().cloned().map(|x| (lq_index.clone(), x))
})
.to_owned()
.collect()
};
// Find relevant changes
let tx = Arc::new(Mutex::new(self.transaction(Read, Optimistic).await?));
for change_set in change_sets {
// TODO(phughk): this loop can be on the inside so we are only checking lqs relavant to cf change
for (lq_key, lq_value) in lq_pairs.iter() {
trace!(
"Processing live query for notification key={:?} and value={:?}",
lq_key,
lq_value
);
let change_vs = change_set.0;
let database_mutation = &change_set.1;
for table_mutations in database_mutation.0.iter() {
if table_mutations.0 == lq_key.selector.tb {
// Create a doc of the table value
// Run the 'lives' logic on the doc, while providing live queries instead of reading from storage
// This will generate and send notifications
for mutation in table_mutations.1.iter() {
if let Some(doc) = Self::construct_document(mutation) {
// We know we are only processing a single LQ at a time, so we can limit notifications to 1
let notification_capacity = 1;
// We track notifications as a separate channel in case we want to process
// for the current state we only forward
let (sender, receiver) =
channel::bounded(notification_capacity);
doc.check_lqs_and_send_notifications(
opt,
&Statement::Live(&lq_value.stm),
&tx,
[&lq_value.stm].as_slice(),
&sender,
)
.await
.map_err(|e| {
Error::Internal(format!(
"Error checking lqs for notifications: {:?}",
e
))
})?;
// Send the notifications to driver or api
// TODO: evaluate if we want channel directly instead of proxy
while let Ok(notification) = receiver.try_recv() {
trace!("Sending notification to client");
self.notification_channel
.as_ref()
.unwrap()
.0
.send(notification)
.await
.unwrap();
}
trace!("Ended notification sending")
}
// Update watermarks
trace!(
"Updating watermark to {:?} for index key {:?}",
change_vs,
lq_key
);
// For each live query we have processed we update the watermarks
self.local_live_queries.write().await.insert(
(*lq_key).clone(),
vec![LqIndexValue {
vs: change_vs,
..lq_value.clone()
}],
);
// We also update the tracked_cfs with a minimum watermark
}
}
}
}
}
}
Ok(())
}
/// Construct a document from a Change Feed mutation
/// This is required to perform document operations such as live query notifications
fn construct_document(mutation: &TableMutation) -> Option<Document> {
match mutation {
TableMutation::Set(a, b) => {
let doc = Document::new(None, Some(a), None, b, Workable::Normal);
Some(doc)
}
TableMutation::Del(a) => {
let doc = Document::new(None, Some(a), None, &Value::None, Workable::Normal);
Some(doc)
}
TableMutation::Def(_) => None,
TableMutation::SetPrevious(id, _old, new) => {
let doc = Document::new(None, Some(id), None, new, Workable::Normal);
// TODO set previous value
Some(doc)
}
}
}
/// Add live queries to track on the datastore
/// These get polled by the change feed tick
pub(crate) async fn track_live_queries(&self, lqs: &Vec<TrackedResult>) -> Result<(), Error> {
// Lock the local live queries
let mut lq_map = self.local_live_queries.write().await;
let mut cf_watermarks = self.cf_watermarks.write().await;
for lq in lqs {
match lq {
TrackedResult::LiveQuery(lq) => {
let lq_index_key: LqIndexKey = lq.as_key();
let m = lq_map.get_mut(&lq_index_key);
match m {
Some(lq_index_value) => lq_index_value.push(lq.as_value()),
None => {
let lq_vec = vec![lq.as_value()];
lq_map.insert(lq_index_key.clone(), lq_vec);
}
}
let selector = lq_index_key.selector;
// TODO(phughk): - read watermark for catchup
// We insert the current watermark.
cf_watermarks.entry(selector).or_insert_with(Versionstamp::default);
}
TrackedResult::KillQuery(_lq) => {
unimplemented!("Cannot kill queries yet")
}
}
}
Ok(())
}
async fn save_timestamp_for_versionstamp_impl(
&self,
ts: u64,
tx: &mut Transaction,
) -> Result<Option<Versionstamp>, Error> {
let mut vs: Option<Versionstamp> = None;
let nses = tx.all_ns().await?;
let nses = nses.as_ref();
for ns in nses {
let ns = ns.name.as_str();
let dbs = tx.all_db(ns).await?;
let dbs = dbs.as_ref();
for db in dbs {
let db = db.name.as_str();
vs = Some(tx.set_timestamp_for_versionstamp(ts, ns, db, true).await?);
}
}
tx.commit().await?;
Ok(vs)
}
// garbage_collect_stale_change_feeds deletes all change feed entries that are older than the watermarks.
pub(crate) async fn garbage_collect_stale_change_feeds(&self, ts: u64) -> Result<(), Error> {
let mut tx = self.transaction(Write, Optimistic).await?;
if let Err(e) = self.garbage_collect_stale_change_feeds_impl(ts, &mut tx).await {
return match tx.cancel().await {
Ok(_) => {
Err(e)
}
Err(txe) => {
Err(Error::Tx(format!("Error garbage collecting stale change feeds: {:?} and error cancelling transaction: {:?}", e, txe)))
}
};
}
Ok(())
}
async fn garbage_collect_stale_change_feeds_impl(
&self,
ts: u64,
tx: &mut Transaction,
) -> Result<(), Error> {
// TODO Make gc batch size/limit configurable?
cf::gc_all_at(tx, ts, Some(100)).await?;
tx.commit().await?;
Ok(())
}
// Creates a heartbeat entry for the member indicating to the cluster
// that the node is alive.
// This is the preferred way of creating heartbeats inside the database, so try to use this.
pub async fn heartbeat(&self) -> Result<(), Error> {
let mut tx = self.transaction(Write, Optimistic).await?;
let timestamp = tx.clock().await;
self.heartbeat_full(&mut tx, timestamp, self.id).await?;
tx.commit().await
}
// Creates a heartbeat entry for the member indicating to the cluster
// that the node is alive. Intended for testing.
// This includes all dependencies that are hard to control and is done in such a way for testing.
// Inside the database, try to use the heartbeat() function instead.
pub async fn heartbeat_full(
&self,
tx: &mut Transaction,
timestamp: Timestamp,
node_id: Uuid,
) -> Result<(), Error> {
tx.set_hb(timestamp, node_id.0).await
}
// -----
// End cluster helpers, storage functions here
// -----
/// Create a new transaction on this datastore
///
/// ```rust,no_run
/// use surrealdb_core::kvs::{Datastore, TransactionType::*, LockType::*};
/// use surrealdb_core::err::Error;
///
/// #[tokio::main]
/// async fn main() -> Result<(), Error> {
/// let ds = Datastore::new("file://database.db").await?;
/// let mut tx = ds.transaction(Write, Optimistic).await?;
/// tx.cancel().await?;
/// Ok(())
/// }
/// ```
pub async fn transaction(
&self,
write: TransactionType,
lock: LockType,
) -> Result<Transaction, Error> {
#![allow(unused_variables)]
let write = match write {
TransactionType::Read => false,
TransactionType::Write => true,
};
let lock = match lock {
LockType::Pessimistic => true,
LockType::Optimistic => false,
};
let inner = match &self.inner {
#[cfg(feature = "kv-mem")]
Inner::Mem(v) => {
let tx = v.transaction(write, lock).await?;
super::tx::Inner::Mem(tx)
}
#[cfg(feature = "kv-rocksdb")]
Inner::RocksDB(v) => {
let tx = v.transaction(write, lock).await?;
super::tx::Inner::RocksDB(tx)
}
#[cfg(feature = "kv-speedb")]
Inner::SpeeDB(v) => {
let tx = v.transaction(write, lock).await?;
super::tx::Inner::SpeeDB(tx)
}
#[cfg(feature = "kv-indxdb")]
Inner::IndxDB(v) => {
let tx = v.transaction(write, lock).await?;
super::tx::Inner::IndxDB(tx)
}
#[cfg(feature = "kv-tikv")]
Inner::TiKV(v) => {
let tx = v.transaction(write, lock).await?;
super::tx::Inner::TiKV(tx)
}
#[cfg(feature = "kv-fdb")]
Inner::FoundationDB(v) => {
let tx = v.transaction(write, lock).await?;
super::tx::Inner::FoundationDB(tx)
}
#[cfg(feature = "kv-surrealkv")]
Inner::SurrealKV(v) => {
let tx = v.transaction(write, lock).await?;
super::tx::Inner::SurrealKV(tx)
}
#[allow(unreachable_patterns)]
_ => unreachable!(),
};
let (send, recv): (Sender<LqEntry>, Receiver<LqEntry>) = channel::bounded(LQ_CHANNEL_SIZE);
#[allow(unreachable_code)]
Ok(Transaction {
inner,
cache: super::cache::Cache::default(),
cf: cf::Writer::new(),
vso: self.versionstamp_oracle.clone(),
clock: self.clock.clone(),
prepared_live_queries: (Arc::new(send), Arc::new(recv)),
engine_options: self.engine_options,
})
}
/// Parse and execute an SQL query
///
/// ```rust,no_run
/// use surrealdb_core::kvs::Datastore;
/// use surrealdb_core::err::Error;
/// use surrealdb_core::dbs::Session;
///
/// #[tokio::main]
/// async fn main() -> Result<(), Error> {
/// let ds = Datastore::new("memory").await?;
/// let ses = Session::owner();
/// let ast = "USE NS test DB test; SELECT * FROM person;";
/// let res = ds.execute(ast, &ses, None).await?;
/// Ok(())
/// }
/// ```
#[instrument(level = "debug", skip_all)]
pub async fn execute(
&self,
txt: &str,
sess: &Session,
vars: Variables,
) -> Result<Vec<Response>, Error> {
// Parse the SQL query text
let ast = syn::parse(txt)?;
// Process the AST
self.process(ast, sess, vars).await
}
/// Execute a pre-parsed SQL query
///
/// ```rust,no_run
/// use surrealdb_core::kvs::Datastore;
/// use surrealdb_core::err::Error;
/// use surrealdb_core::dbs::Session;
/// use surrealdb_core::sql::parse;
///
/// #[tokio::main]
/// async fn main() -> Result<(), Error> {
/// let ds = Datastore::new("memory").await?;
/// let ses = Session::owner();
/// let ast = parse("USE NS test DB test; SELECT * FROM person;")?;
/// let res = ds.process(ast, &ses, None).await?;
/// Ok(())
/// }
/// ```
#[instrument(level = "debug", skip_all)]
pub async fn process(
&self,
ast: Query,
sess: &Session,
vars: Variables,
) -> Result<Vec<Response>, Error> {
// Check if the session has expired
if sess.expired() {
return Err(Error::ExpiredSession);
}
// Check if anonymous actors can execute queries when auth is enabled
// TODO(sgirones): Check this as part of the authorisation layer
if self.auth_enabled && sess.au.is_anon() && !self.capabilities.allows_guest_access() {
return Err(IamError::NotAllowed {
actor: "anonymous".to_string(),
action: "process".to_string(),
resource: "query".to_string(),
}
.into());
}
// Create a new query options
let opt = Options::default()
.with_id(self.id.0)
.with_ns(sess.ns())
.with_db(sess.db())
.with_live(sess.live())
.with_auth(sess.au.clone())
.with_strict(self.strict)
.with_auth_enabled(self.auth_enabled);
// Create a new query executor
let mut exe = Executor::new(self);
// Create a default context
let mut ctx = Context::from_ds(
self.query_timeout,
self.capabilities.clone(),
self.index_stores.clone(),
)?;
// Setup the notification channel
if let Some(channel) = &self.notification_channel {
ctx.add_notifications(Some(&channel.0));
}
// Start an execution context
let ctx = sess.context(ctx);
// Store the query variables
let ctx = vars.attach(ctx)?;
// Process all statements
let res = exe.execute(ctx, opt, ast).await;
match res {
Ok((responses, lives)) => {
// Register live queries
self.track_live_queries(&lives).await?;
Ok(responses)
}
Err(e) => Err(e),
}
}
/// Ensure a SQL [`Value`] is fully computed
///
/// ```rust,no_run
/// use surrealdb_core::kvs::Datastore;
/// use surrealdb_core::err::Error;
/// use surrealdb_core::dbs::Session;
/// use surrealdb_core::sql::Future;
/// use surrealdb_core::sql::Value;
///
/// #[tokio::main]
/// async fn main() -> Result<(), Error> {
/// let ds = Datastore::new("memory").await?;
/// let ses = Session::owner();
/// let val = Value::Future(Box::new(Future::from(Value::Bool(true))));
/// let res = ds.compute(val, &ses, None).await?;
/// Ok(())
/// }
/// ```
#[instrument(level = "debug", skip_all)]
pub async fn compute(
&self,
val: Value,
sess: &Session,
vars: Variables,
) -> Result<Value, Error> {
// Check if the session has expired
if sess.expired() {
return Err(Error::ExpiredSession);
}
// Check if anonymous actors can compute values when auth is enabled
// TODO(sgirones): Check this as part of the authorisation layer
if self.auth_enabled && !self.capabilities.allows_guest_access() {
return Err(IamError::NotAllowed {
actor: "anonymous".to_string(),
action: "compute".to_string(),
resource: "value".to_string(),
}
.into());
}
// Create a new query options
let opt = Options::default()
.with_id(self.id.0)
.with_ns(sess.ns())
.with_db(sess.db())
.with_live(sess.live())
.with_auth(sess.au.clone())
.with_strict(self.strict)
.with_auth_enabled(self.auth_enabled);
// Create a default context
let mut ctx = Context::default();
// Set context capabilities
ctx.add_capabilities(self.capabilities.clone());
// Set the global query timeout
if let Some(timeout) = self.query_timeout {
ctx.add_timeout(timeout)?;
}
// Setup the notification channel
if let Some(channel) = &self.notification_channel {
ctx.add_notifications(Some(&channel.0));
}
// Start an execution context
let ctx = sess.context(ctx);
// Store the query variables
let ctx = vars.attach(ctx)?;
// Start a new transaction
let txn = self.transaction(val.writeable().into(), Optimistic).await?.enclose();
// Compute the value
let res = val.compute(&ctx, &opt, &txn, None).await;
// Store any data
match (res.is_ok(), val.writeable()) {
// If the compute was successful, then commit if writeable
(true, true) => txn.lock().await.commit().await?,
// Cancel if the compute was an error, or if readonly
(_, _) => txn.lock().await.cancel().await?,
};
// Return result
res
}
/// Evaluates a SQL [`Value`] without checking authenticating config
/// This is used in very specific cases, where we do not need to check
/// whether authentication is enabled, or guest access is disabled.
/// For example, this is used when processing a SCOPE SIGNUP or SCOPE
/// SIGNIN clause, which still needs to work without guest access.
///
/// ```rust,no_run
/// use surrealdb_core::kvs::Datastore;
/// use surrealdb_core::err::Error;
/// use surrealdb_core::dbs::Session;
/// use surrealdb_core::sql::Future;
/// use surrealdb_core::sql::Value;
///
/// #[tokio::main]
/// async fn main() -> Result<(), Error> {
/// let ds = Datastore::new("memory").await?;
/// let ses = Session::owner();
/// let val = Value::Future(Box::new(Future::from(Value::Bool(true))));
/// let res = ds.evaluate(val, &ses, None).await?;
/// Ok(())
/// }
/// ```
#[instrument(level = "debug", skip_all)]
pub async fn evaluate(
&self,
val: Value,
sess: &Session,
vars: Variables,
) -> Result<Value, Error> {
// Check if the session has expired
if sess.expired() {
return Err(Error::ExpiredSession);
}
// Create a new query options
let opt = Options::default()
.with_id(self.id.0)
.with_ns(sess.ns())
.with_db(sess.db())
.with_live(sess.live())
.with_auth(sess.au.clone())
.with_strict(self.strict)
.with_auth_enabled(self.auth_enabled);
// Create a default context
let mut ctx = Context::default();
// Set context capabilities
ctx.add_capabilities(self.capabilities.clone());
// Set the global query timeout
if let Some(timeout) = self.query_timeout {
ctx.add_timeout(timeout)?;
}
// Setup the notification channel
if let Some(channel) = &self.notification_channel {
ctx.add_notifications(Some(&channel.0));
}
// Start an execution context
let ctx = sess.context(ctx);
// Store the query variables
let ctx = vars.attach(ctx)?;
// Start a new transaction
let txn = self.transaction(val.writeable().into(), Optimistic).await?.enclose();
// Compute the value
let res = val.compute(&ctx, &opt, &txn, None).await;
// Store any data
match (res.is_ok(), val.writeable()) {
// If the compute was successful, then commit if writeable
(true, true) => txn.lock().await.commit().await?,
// Cancel if the compute was an error, or if readonly
(_, _) => txn.lock().await.cancel().await?,
};
// Return result
res
}
/// Subscribe to live notifications
///
/// ```rust,no_run
/// use surrealdb_core::kvs::Datastore;
/// use surrealdb_core::err::Error;
/// use surrealdb_core::dbs::Session;
///
/// #[tokio::main]
/// async fn main() -> Result<(), Error> {
/// let ds = Datastore::new("memory").await?.with_notifications();
/// let ses = Session::owner();
/// if let Some(channel) = ds.notifications() {
/// while let Ok(v) = channel.recv().await {
/// println!("Received notification: {v}");
/// }
/// }
/// Ok(())
/// }
/// ```
#[instrument(level = "debug", skip_all)]
pub fn notifications(&self) -> Option<Receiver<Notification>> {
self.notification_channel.as_ref().map(|v| v.1.clone())
}
/// Performs a database import from SQL
#[instrument(level = "debug", skip(self, sess, sql))]
pub async fn import(&self, sql: &str, sess: &Session) -> Result<Vec<Response>, Error> {
// Execute the SQL import
self.execute(sql, sess, None).await
}
/// Performs a full database export as SQL
#[instrument(level = "debug", skip(self, sess, chn))]
pub async fn export(
&self,
sess: &Session,
chn: Sender<Vec<u8>>,
) -> Result<impl Future<Output = Result<(), Error>>, Error> {
// Check if the session has expired
if sess.expired() {
return Err(Error::ExpiredSession);
}
// Retrieve the provided NS and DB
let (ns, db) = crate::iam::check::check_ns_db(sess)?;
// Create a new readonly transaction
let mut txn = self.transaction(Read, Optimistic).await?;
// Return an async export job
Ok(async move {
// Process the export
txn.export(&ns, &db, chn).await?;
// Everything ok
Ok(())
})
}
/// Checks the required permissions level for this session
#[instrument(level = "debug", skip(self, sess))]
pub fn check(&self, sess: &Session, action: Action, resource: Resource) -> Result<(), Error> {
// Check if the session has expired
if sess.expired() {
return Err(Error::ExpiredSession);
}
// Skip auth for Anonymous users if auth is disabled
let skip_auth = !self.is_auth_enabled() && sess.au.is_anon();
if !skip_auth {
sess.au.is_allowed(action, &resource)?;
}
// All ok
Ok(())
}
}