sad/raptorq
1
0
Fork 0
mirror of https://github.com/cberner/raptorq.git synced 2024-06-29 18:21:43 +00:00
Code Issues Packages Projects Releases Wiki Activity

Reuse scratch memory for graph

Browse Source
This commit is contained in:
Christopher Berner 2020-01-05 15:51:39 -08:00
parent 9d0af2dcad
commit 55d42fdee2
2 changed files with 31 additions and 15 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

15
src/arraymap.rs
View File

@ -12,6 +12,21 @@ impl<T: std::clone::Clone> ArrayMap<T> {
}
}
pub fn reset<F: Fn(&mut T) -> ()>(
&mut self,
new_start: usize,
new_end: usize,
reset_value_fn: F,
) {
self.offset = new_start;
self.elements.resize(new_end - new_start, None);
for value in self.elements.iter_mut() {
if let Some(ref mut x) = value {
reset_value_fn(x);
}
}
}
pub fn insert(&mut self, key: usize, value: T) {
self.elements[key - self.offset] = Some(value);
}

31
src/pi_solver.rs
View File

@ -19,6 +19,8 @@ struct FirstPhaseRowSelectionStats {
end_col: usize,
start_row: usize,
rows_with_single_nonzero: Vec<usize>,
// Scratch data struct that is reused across calls because it's expensive to construct
scratch_adjacent_nodes: ArrayMap<Vec<(usize, usize)>>,
}
impl FirstPhaseRowSelectionStats {
@ -48,6 +50,7 @@ impl FirstPhaseRowSelectionStats {
end_col,
start_row: 0,
rows_with_single_nonzero: vec![],
scratch_adjacent_nodes: ArrayMap::new(0, end_col),
};
for row in 0..matrix.height() {
@ -156,11 +159,12 @@ impl FirstPhaseRowSelectionStats {
#[inline(never)]
fn first_phase_graph_substep_build_adjacency<T: OctetMatrix>(
&self,
&mut self,
rows_with_two_ones: &[usize],
matrix: &T,
) -> ArrayMap<Vec<(usize, usize)>> {
let mut adjacent_nodes = ArrayMap::new(self.start_col, self.end_col);
) {
self.scratch_adjacent_nodes
.reset(self.start_col, self.end_col, |nodes| nodes.clear());
for row in rows_with_two_ones.iter() {
if self.hdpc_rows[*row] {
@ -184,44 +188,41 @@ impl FirstPhaseRowSelectionStats {
}
}
assert_eq!(found, 2);
let first = adjacent_nodes.get_mut(ones[0]);
let first = self.scratch_adjacent_nodes.get_mut(ones[0]);
if first == None {
let mut new_nodes = Vec::with_capacity(10);
new_nodes.push((ones[1], *row));
adjacent_nodes.insert(ones[0], new_nodes);
self.scratch_adjacent_nodes.insert(ones[0], new_nodes);
} else {
first.unwrap().push((ones[1], *row));
}
let second = adjacent_nodes.get_mut(ones[1]);
let second = self.scratch_adjacent_nodes.get_mut(ones[1]);
if second == None {
let mut new_nodes = Vec::with_capacity(10);
new_nodes.push((ones[0], *row));
adjacent_nodes.insert(ones[1], new_nodes);
self.scratch_adjacent_nodes.insert(ones[1], new_nodes);
} else {
second.unwrap().push((ones[0], *row));
}
}
return adjacent_nodes;
}
#[inline(never)]
fn first_phase_graph_substep<T: OctetMatrix>(
&self,
&mut self,
start_row: usize,
end_row: usize,
rows_with_two_ones: &[usize],
matrix: &T,
) -> usize {
let adjacent_nodes =
self.first_phase_graph_substep_build_adjacency(rows_with_two_ones, matrix);
self.first_phase_graph_substep_build_adjacency(rows_with_two_ones, matrix);
let mut visited = BoolArrayMap::new(start_row, end_row);
let mut examplar_largest_component_row = None;
let mut largest_component_size = 0;
let mut node_queue = Vec::with_capacity(10);
for key in adjacent_nodes.keys() {
for key in self.scratch_adjacent_nodes.keys() {
let mut component_size = 0;
let mut examplar_row = None;
// Pick arbitrary node (column) to start
@ -233,7 +234,7 @@ impl FirstPhaseRowSelectionStats {
continue;
}
visited.insert(node, true);
let next_nodes = adjacent_nodes.get(node).unwrap();
let next_nodes = self.scratch_adjacent_nodes.get(node).unwrap();
component_size += 1;
for &(next_node, row) in next_nodes.iter() {
node_queue.push(next_node);
@ -323,7 +324,7 @@ impl FirstPhaseRowSelectionStats {
// selects from [start_row, end_row) reading [start_col, end_col)
// Returns (the chosen row, and "r" number of non-zero values the row has, is_HDPC)
pub fn first_phase_selection<T: OctetMatrix>(
&self,
&mut self,
start_row: usize,
end_row: usize,
matrix: &T,