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// (c) Copyright 2025 Helsing GmbH. All rights reserved.
use super::ValueDelta;
use crate::{
CausalContext, CausalDotStore, DotStore, Identifier, MvReg, OrArray, OrMap,
crdts::{
NoExtensionTypes, Value,
orarray::Position,
test_util::{ArbitraryDelta, Delta, KeyTracker},
},
};
use quickcheck::{Arbitrary, Gen};
use std::{fmt, ops::RangeBounds};
// NOTE: Box is needed here to allow arbitrary nesting, otherwise the type isn't Sized.
// This is because `ValueDelta` itself contains `ArrayOp`.
#[cfg_attr(feature = "serde", derive(::serde::Deserialize, ::serde::Serialize))]
#[derive(Debug, Clone)]
pub(crate) enum ArrayOp {
Insert(usize, Position, Box<ValueDelta>),
Update(usize, Position, Box<ValueDelta>),
Delete(usize),
Move(usize, Position),
Clear,
}
impl fmt::Display for ArrayOp {
fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
match self {
Self::Insert(keyi, _, _) => write!(f, "insert key #{keyi}"),
Self::Update(keyi, _, _) => write!(f, "updates key #{keyi}"),
Self::Delete(keyi) => write!(f, "deletes key #{keyi}"),
Self::Move(keyi, _) => write!(f, "moves key #{keyi}"),
Self::Clear => write!(f, "clears the map"),
}
}
}
impl Delta for ArrayOp {
type DS = OrArray<NoExtensionTypes>;
fn depends_on_keyi_in<R: RangeBounds<usize>>(&self, range: R) -> bool {
match *self {
Self::Insert(keyi, _, _)
| Self::Update(keyi, _, _)
| Self::Delete(keyi)
| Self::Move(keyi, _) => range.contains(&keyi),
Self::Clear => false,
}
}
fn into_crdt(
self,
ds: &Self::DS,
cc: &CausalContext,
id: Identifier,
keys: &mut KeyTracker,
) -> CausalDotStore<Self::DS> {
match self {
Self::Insert(expected_keyi, p, v) => {
assert_eq!(expected_keyi, keys.len());
let keyi = expected_keyi;
let cc = cc.clone();
let uid = cc.next_dot_for(id).into();
let mut inner_keys = KeyTracker::default();
let crdt = ds.insert(
uid,
|cc, id| match *v {
ValueDelta::Map(m) => m
.into_crdt(&<_>::default(), cc, id, &mut inner_keys)
.map_store(Value::Map),
ValueDelta::Array(a) => a
.into_crdt(&<_>::default(), cc, id, &mut inner_keys)
.map_store(Value::Array),
ValueDelta::Register(r) => r
.into_crdt(&<_>::default(), cc, id, &mut inner_keys)
.map_store(Value::Register),
},
p,
&cc,
id,
);
keys.inner_keys.push(inner_keys);
keys.array_keys.insert(uid, keyi);
crdt
}
Self::Update(keyi, p, v) => {
let inner_keys = &mut keys.inner_keys[keyi];
let uid = *keys.array_keys.get_by_right(&keyi).unwrap();
ds.apply(
uid,
|old, cc, id| match *v {
ValueDelta::Map(m) => m
.into_crdt(&old.map, cc, id, inner_keys)
.map_store(Value::Map),
ValueDelta::Array(a) => a
.into_crdt(&old.array, cc, id, inner_keys)
.map_store(Value::Array),
ValueDelta::Register(r) => r
.into_crdt(&old.reg, cc, id, inner_keys)
.map_store(Value::Register),
},
p,
cc,
id,
)
}
Self::Delete(keyi) => {
let uid = *keys.array_keys.get_by_right(&keyi).unwrap();
ds.delete(uid, cc, id)
}
Self::Move(keyi, p) => {
let uid = *keys.array_keys.get_by_right(&keyi).unwrap();
ds.mv(uid, p, cc, id)
}
Self::Clear => ds.clear(cc, id),
}
}
}
impl ArbitraryDelta for OrArray<NoExtensionTypes> {
type Delta = ArrayOp;
fn arbitrary_delta(
&self,
cc: &CausalContext,
id: Identifier,
keys: &mut KeyTracker,
g: &mut Gen,
depth: usize,
) -> (Self::Delta, CausalDotStore<Self>) {
// NOTE: see the outer_remove_vs_inner_mv test for why we need this
let valid_keys: Vec<_> = self
.0
.iter()
.filter_map(|(k, v)| (!v.value.is_bottom()).then_some(k))
.collect();
let op = if valid_keys.is_empty() && self.0.is_empty() {
g.choose(&["insert", "clear"])
} else if valid_keys.is_empty() {
g.choose(&["insert", "delete", "clear"])
} else {
g.choose(&["insert", "update", "delete", "move", "clear"])
};
let indent = " ".repeat(depth);
match op.copied().unwrap() {
"insert" => {
let uid = cc.next_dot_for(id).into();
let kind = if g.size() <= 1 {
"register"
} else {
g.choose(&["map", "array", "register"]).copied().unwrap()
};
let keyi = keys.add_array_key(uid);
eprintln!("{indent} -> inserting #{keyi} ({uid:?})");
let inner_keys = &mut keys.inner_keys[keyi];
let p = Position::arbitrary(g);
let mut value_delta = None;
let crdt = self.insert(
uid,
|cc, id| {
eprintln!("{indent} -> generating inner {kind} operation");
let (vd, value_crdt) = match kind {
"map" => {
let mut g = Gen::new(g.size() / 2);
let g = &mut g;
let (delta, crdt) = OrMap::arbitrary_delta(
&<_>::default(),
cc,
id,
inner_keys,
g,
depth + 1,
);
(ValueDelta::Map(delta), crdt.map_store(Value::Map))
}
"array" => {
let mut g = Gen::new(g.size() / 2);
let g = &mut g;
let (delta, crdt) = OrArray::arbitrary_delta(
&<_>::default(),
cc,
id,
inner_keys,
g,
depth + 1,
);
(ValueDelta::Array(delta), crdt.map_store(Value::Array))
}
"register" => {
let (delta, crdt) = MvReg::arbitrary_delta(
&<_>::default(),
cc,
id,
inner_keys,
g,
depth + 1,
);
(ValueDelta::Register(delta), crdt.map_store(Value::Register))
}
kind => unreachable!("need match arm for '{kind}'"),
};
value_delta = Some(vd);
value_crdt
},
p,
cc,
id,
);
(
ArrayOp::Insert(
keyi,
p,
Box::new(value_delta.expect("insert closure is always called")),
),
crdt,
)
}
"update" => {
let uid = **g
.choose(&valid_keys)
.expect("this arm is only taken if non-empty");
// TODO: how should this handle the case of concurrent inserts of the same
// key, which will imply that a single key has _multiple_ keyi.
let keyi = *keys.array_keys.get_by_left(&uid).unwrap();
eprintln!("{indent} -> updating #{keyi} ({uid:?})");
let inner_keys = &mut keys.inner_keys[keyi];
let p = Position::arbitrary(g);
// NOTE: this _may_ change the type -- that is intentional! test thoroughly.
let mut value_delta = None;
let crdt = self.apply(
uid,
|old, cc, id| {
let kind = if g.size() <= 1 {
"register"
} else {
g.choose(&["map", "array", "register"]).copied().unwrap()
};
eprintln!("{indent} -> generating inner {kind} operation");
let (vd, value_crdt) = match kind {
"map" => {
let mut g = Gen::new(g.size() / 2);
let g = &mut g;
let (delta, crdt) = OrMap::arbitrary_delta(
&old.map,
cc,
id,
inner_keys,
g,
depth + 1,
);
(ValueDelta::Map(delta), crdt.map_store(Value::Map))
}
"array" => {
let mut g = Gen::new(g.size() / 2);
let g = &mut g;
let (delta, crdt) = OrArray::arbitrary_delta(
&old.array,
cc,
id,
inner_keys,
g,
depth + 1,
);
(ValueDelta::Array(delta), crdt.map_store(Value::Array))
}
"register" => {
let (delta, crdt) = MvReg::arbitrary_delta(
&old.reg,
cc,
id,
inner_keys,
g,
depth + 1,
);
(ValueDelta::Register(delta), crdt.map_store(Value::Register))
}
kind => unreachable!("need match arm for '{kind}'"),
};
value_delta = Some(vd);
value_crdt
},
p,
cc,
id,
);
(
ArrayOp::Update(
keyi,
p,
Box::new(value_delta.expect("apply closure is always called")),
),
crdt,
)
}
"delete" => {
// NOTE: we specifically use the whole range of keys here, not just
// "valid_keys", since we want to test what happens if a bottom-value element is
// deleted.
let mut uids = self.0.keys();
let uidi = usize::arbitrary(g) % uids.len();
let uid = *uids
.nth(uidi)
.expect("this arm is only taken if non-empty, and n is % len");
let keyi = *keys.array_keys.get_by_left(&uid).unwrap();
eprintln!("{indent} -> deleting #{keyi} ({uid:?})");
(ArrayOp::Delete(keyi), self.delete(uid, cc, id))
}
"move" => {
let uid = **g
.choose(&valid_keys)
.expect("this arm is only taken if non-empty");
let keyi = *keys.array_keys.get_by_left(&uid).unwrap();
eprintln!("{indent} -> moving #{keyi} ({uid:?})");
let p = Position::arbitrary(g);
(ArrayOp::Move(keyi, p), self.mv(uid, p, cc, id))
}
"clear" => {
eprintln!("{indent} -> clearing array");
(ArrayOp::Clear, self.clear(cc, id))
}
op => unreachable!("need match arm for '{op}'"),
}
}
}