Allow transferring raw futures over cbor (#4504)

Co-authored-by: Micha de Vries <micha@devrie.sh>

core/src/dbs/executor.rs

@@ -243,6 +243,13 @@ impl<'a> Executor<'a> {
 						} else {
 							Force::None
 						}),
+						"FUTURES" => {
+							if stm.what {
+								opt.with_futures(true)
+							} else {
+								opt.with_futures_never()
+							}
+						}
 						_ => break,
 					};
 					// Continue

core/src/dbs/options.rs

@@ -41,7 +41,7 @@ pub struct Options {
 	/// Should we process field queries?
 	pub import: bool,
 	/// Should we process function futures?
-	pub futures: bool,
+	pub futures: Futures,
 	/// Should we process variable field projections?
 	pub projections: bool,
 	/// The channel over which we send notifications
@@ -59,6 +59,13 @@ pub enum Force {
 	Index(Arc<[DefineIndexStatement]>),
 }
 
+#[derive(Clone, Debug)]
+pub enum Futures {
+	Disabled,
+	Enabled,
+	Never,
+}
+
 impl Default for Options {
 	fn default() -> Self {
 		Options::new()
@@ -78,7 +85,7 @@ impl Options {
 			force: Force::None,
 			strict: false,
 			import: false,
-			futures: false,
+			futures: Futures::Disabled,
 			projections: false,
 			auth_enabled: true,
 			sender: None,
@@ -189,7 +196,20 @@ impl Options {
 
 	/// Specify if we should process futures
 	pub fn with_futures(mut self, futures: bool) -> Self {
-		self.futures = futures;
+		if matches!(self.futures, Futures::Never) {
+			return self;
+		}
+
+		self.futures = match futures {
+			true => Futures::Enabled,
+			false => Futures::Disabled,
+		};
+		self
+	}
+
+	/// Specify if we should never process futures
+	pub fn with_futures_never(mut self) -> Self {
+		self.futures = Futures::Never;
 		self
 	}
 
@@ -221,6 +241,7 @@ impl Options {
 			ns: self.ns.clone(),
 			db: self.db.clone(),
 			force: self.force.clone(),
+			futures: self.futures.clone(),
 			perms,
 			..*self
 		}
@@ -233,6 +254,7 @@ impl Options {
 			auth: self.auth.clone(),
 			ns: self.ns.clone(),
 			db: self.db.clone(),
+			futures: self.futures.clone(),
 			force,
 			..*self
 		}
@@ -246,6 +268,7 @@ impl Options {
 			ns: self.ns.clone(),
 			db: self.db.clone(),
 			force: self.force.clone(),
+			futures: self.futures.clone(),
 			strict,
 			..*self
 		}
@@ -259,6 +282,7 @@ impl Options {
 			ns: self.ns.clone(),
 			db: self.db.clone(),
 			force: self.force.clone(),
+			futures: self.futures.clone(),
 			import,
 			..*self
 		}
@@ -272,7 +296,13 @@ impl Options {
 			ns: self.ns.clone(),
 			db: self.db.clone(),
 			force: self.force.clone(),
-			futures,
+			futures: match self.futures {
+				Futures::Never => Futures::Never,
+				_ => match futures {
+					true => Futures::Enabled,
+					false => Futures::Disabled,
+				},
+			},
 			..*self
 		}
 	}
@@ -285,6 +315,7 @@ impl Options {
 			ns: self.ns.clone(),
 			db: self.db.clone(),
 			force: self.force.clone(),
+			futures: self.futures.clone(),
 			projections,
 			..*self
 		}
@@ -297,6 +328,7 @@ impl Options {
 			ns: self.ns.clone(),
 			db: self.db.clone(),
 			force: self.force.clone(),
+			futures: self.futures.clone(),
 			sender: Some(sender),
 			..*self
 		}
@@ -326,6 +358,7 @@ impl Options {
 			ns: self.ns.clone(),
 			db: self.db.clone(),
 			force: self.force.clone(),
+			futures: self.futures.clone(),
 			dive: self.dive - cost as u32,
 			..*self
 		})
@@ -511,4 +544,21 @@ mod tests {
 				.unwrap();
 		}
 	}
+
+	#[test]
+	pub fn execute_futures() {
+		let mut opts = Options::default().with_futures(false);
+
+		// Futures should be disabled
+		assert!(matches!(opts.futures, Futures::Disabled));
+
+		// Allow setting to true
+		opts = opts.with_futures(true);
+		assert!(matches!(opts.futures, Futures::Enabled));
+
+		// Set to never and disallow setting to true
+		opts = opts.with_futures_never();
+		opts = opts.with_futures(true);
+		assert!(matches!(opts.futures, Futures::Never));
+	}
 }

core/src/rpc/format/cbor/convert.rs

@@ -11,6 +11,7 @@ use crate::sql::id::range::IdRange;
 use crate::sql::Array;
 use crate::sql::Datetime;
 use crate::sql::Duration;
+use crate::sql::Future;
 use crate::sql::Geometry;
 use crate::sql::Id;
 use crate::sql::Number;
@@ -35,6 +36,7 @@ const TAG_STRING_DECIMAL: u64 = 10;
 const TAG_CUSTOM_DATETIME: u64 = 12;
 const TAG_STRING_DURATION: u64 = 13;
 const TAG_CUSTOM_DURATION: u64 = 14;
+const TAG_FUTURE: u64 = 15;
 
 // Ranges
 const TAG_RANGE: u64 = 49;
@@ -193,6 +195,14 @@ impl TryFrom<Cbor> for Value {
 					},
 					// A range
 					TAG_RANGE => Ok(Value::Range(Box::new(Range::try_from(*v)?))),
+					TAG_FUTURE => match *v {
+						Data::Text(v) => {
+							let block = crate::syn::block(format!("{{{v}}}").as_str())
+								.map_err(|_| "Failed to parse block")?;
+							Ok(Value::Future(Box::new(Future(block))))
+						}
+						_ => Err("Expected a CBOR text data type"),
+					},
 					TAG_GEOMETRY_POINT => match *v {
 						Data::Array(mut v) if v.len() == 2 => {
 							let x = Value::try_from(Cbor(v.remove(0)))?;
@@ -395,6 +405,10 @@ impl TryFrom<Value> for Cbor {
 			Value::Table(v) => Ok(Cbor(Data::Tag(TAG_TABLE, Box::new(Data::Text(v.0))))),
 			Value::Geometry(v) => Ok(Cbor(encode_geometry(v)?)),
 			Value::Range(v) => Ok(Cbor(Data::try_from(*v)?)),
+			Value::Future(v) => {
+				let bin = Data::Text(format!("{}", (*v).0));
+				Ok(Cbor(Data::Tag(TAG_FUTURE, Box::new(bin))))
+			}
 			// We shouldn't reach here
 			_ => Err("Found unsupported SurrealQL value being encoded into a CBOR value"),
 		}

core/src/sql/future.rs

@@ -1,9 +1,9 @@
-use crate::ctx::Context;
 use crate::dbs::Options;
 use crate::doc::CursorDoc;
 use crate::err::Error;
 use crate::sql::block::Block;
 use crate::sql::value::Value;
+use crate::{ctx::Context, dbs::Futures};
 use reblessive::tree::Stk;
 use revision::revisioned;
 use serde::{Deserialize, Serialize};
@@ -35,8 +35,8 @@ impl Future {
 	) -> Result<Value, Error> {
 		// Process the future if enabled
 		match opt.futures {
-			true => stk.run(|stk| self.0.compute(stk, ctx, opt, doc)).await?.ok(),
+			Futures::Enabled => stk.run(|stk| self.0.compute(stk, ctx, opt, doc)).await?.ok(),
-			false => Ok(self.clone().into()),
+			_ => Ok(self.clone().into()),
 		}
 	}
 }

core/src/syn/mod.rs

@@ -2,7 +2,7 @@
 
 use crate::{
 	err::Error,
-	sql::{Datetime, Duration, Idiom, Query, Range, Subquery, Thing, Value},
+	sql::{Block, Datetime, Duration, Idiom, Query, Range, Subquery, Thing, Value},
 };
 
 pub mod common;
@@ -21,6 +21,7 @@ mod test;
 
 use parser::Parser;
 use reblessive::Stack;
+use token::t;
 
 /// Takes a string and returns if it could be a reserved keyword in certain contexts.
 pub fn could_be_reserved_keyword(s: &str) -> bool {
@@ -168,3 +169,32 @@ pub fn thing(input: &str) -> Result<Thing, Error> {
 		.map_err(|e| e.render_on(input))
 		.map_err(Error::InvalidQuery)
 }
+
+/// Parse a block, expects the value to be wrapped in `{}`.
+pub fn block(input: &str) -> Result<Block, Error> {
+	debug!("parsing block, input = {input}");
+
+	let mut parser = Parser::new(input.as_bytes());
+	let mut stack = Stack::new();
+
+	match parser.peek_kind() {
+		t!("{") => {
+			let start = parser.pop_peek().span;
+			stack
+				.enter(|stk| parser.parse_block(stk, start))
+				.finish()
+				.map_err(|e| e.render_on(input))
+				.map_err(Error::InvalidQuery)
+		}
+		found => Err(Error::InvalidQuery(
+			crate::syn::parser::ParseError::new(
+				crate::syn::parser::ParseErrorKind::Unexpected {
+					expected: "{",
+					found,
+				},
+				parser.last_span(),
+			)
+			.render_on(input),
+		)),
+	}
+}

core/src/syn/parser/object.rs

@@ -637,7 +637,7 @@ impl Parser<'_> {
 	/// # Parser State
 	/// Expects the starting `{` to have already been eaten and its span to be handed to this
 	/// functions as the `start` parameter.
-	pub(super) async fn parse_block(&mut self, ctx: &mut Stk, start: Span) -> ParseResult<Block> {
+	pub async fn parse_block(&mut self, ctx: &mut Stk, start: Span) -> ParseResult<Block> {
 		let mut statements = Vec::new();
 		loop {
 			while self.eat(t!(";")) {}

lib/tests/future.rs

@@ -67,6 +67,24 @@ async fn future_function_arguments() -> Result<(), Error> {
 	Ok(())
 }
 
+#[tokio::test]
+async fn future_disabled() -> Result<(), Error> {
+	let sql = "
+	    OPTION FUTURES = false;
+		<future> { 123 };
+	";
+	let dbs = new_ds().await?;
+	let ses = Session::owner().with_ns("test").with_db("test");
+	let res = &mut dbs.execute(sql, &ses, None).await?;
+	assert_eq!(res.len(), 1);
+	//
+	let tmp = res.remove(0).result?;
+	let val = Value::parse("<future> { 123 }");
+	assert_eq!(tmp, val);
+	//
+	Ok(())
+}
+
 #[tokio::test]
 async fn concurrency() -> Result<(), Error> {
 	// cargo test --package surrealdb --test future --features kv-mem --release -- concurrency --nocapture