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|
mod vector_clock;
use uuid::Uuid;
use crate::vector_clock::VectorClock;
#[derive(Default)]
pub struct Doc {
ops: Vec<Op>,
}
impl Doc {
pub fn append_op(&mut self, actor_id: &Uuid, payload: OpPayload) {
// Increment the last clock for the provided actor
let clock = self
.ops
.last()
.map(|Op { clock, .. }| clock.inc(actor_id))
// For an empty document, initialize a new clock
.unwrap_or_else(|| VectorClock::default().inc(actor_id));
self.ops.push(Op {
id: Uuid::now_v7(),
clock,
payload,
});
}
pub fn realize(&self) -> RealizedDoc {
let mut realized = RealizedDoc::default();
for op in &self.ops {
op.apply(&mut realized);
}
realized
}
}
pub struct Op {
id: Uuid,
payload: OpPayload,
clock: VectorClock,
}
impl Op {
fn apply(&self, realized: &mut RealizedDoc) {
match &self.payload {
OpPayload::CreateGrid {
rows,
base_cells_per_row,
} => {
let rows = (0..*rows)
.map(|row_idx| {
let cells = (0..*base_cells_per_row)
.map(|cell_idx| Cell {
id: self.id.derive_id("cell", cell_idx),
})
.collect();
Row {
id: self.id.derive_id("row", row_idx),
cells,
}
})
.collect();
realized.grids.push(Grid {
id: self.id.derive_id("grid", 0),
rows,
});
}
}
}
}
pub enum OpPayload {
CreateGrid {
rows: usize,
base_cells_per_row: usize,
},
}
#[derive(Default)]
pub struct RealizedDoc {
grids: Vec<Grid>,
}
pub struct Grid {
id: DerivedId,
rows: Vec<Row>,
}
pub struct Row {
id: DerivedId,
cells: Vec<Cell>,
}
pub struct Cell {
id: DerivedId,
}
pub struct DerivedId {
id: Uuid,
tag: &'static str,
index: usize,
}
trait DerivableId {
fn derive_id(&self, tag: &'static str, index: usize) -> DerivedId;
}
impl DerivableId for Uuid {
fn derive_id(&self, tag: &'static str, index: usize) -> DerivedId {
DerivedId {
id: self.clone(),
tag,
index,
}
}
}
#[cfg(test)]
mod tests {
use super::*;
#[test]
fn realize_doc() {
let actor_id = Uuid::now_v7();
let mut doc = Doc::default();
doc.append_op(
&actor_id,
OpPayload::CreateGrid {
rows: 4,
base_cells_per_row: 16,
},
);
let realized = doc.realize();
assert!(realized.grids.len() == 1);
let grid = realized.grids.first().unwrap();
assert!(grid.rows.len() == 4);
let row = grid.rows.first().unwrap();
assert!(row.cells.len() == 16);
}
}
|
