Files
pirate-librustzcash/examples/long.rs
2019-09-24 15:28:34 +02:00

127 lines
3.5 KiB
Rust

use zcash_mmr::{Entry, EntryLink, NodeData, Tree};
#[path= "lib/shared.rs"]
mod share;
fn prepare_tree(vec: &Vec<NodeData>) -> Tree {
assert!(vec.len() > 0);
// integer log2 of (vec.len()+1), -1
let mut h = (32 - ((vec.len()+1) as u32).leading_zeros() - 1)-1;
let mut peak_pos = (1 << (h+1)) - 1;
let mut nodes = Vec::new();
// used later
let mut last_peak_pos = 0;
let mut last_peak_h = 0;
loop {
if peak_pos > vec.len() {
// left child, -2^h
peak_pos = peak_pos - (1<<h);
h = h - 1;
}
if peak_pos <= vec.len() {
let mut peak: Entry = vec[peak_pos-1].clone().into();
if h != 0 {
let left_idx = (peak_pos - (1<<h) - 1) as u32;
let right_idx = (peak_pos - 2) as u32;
peak.update_siblings(
EntryLink::Stored(left_idx),
EntryLink::Stored(right_idx),
);
println!("Peak #{}: ({}, {})", nodes.len(), left_idx, right_idx);
}
nodes.push(((peak_pos-1) as u32, peak));
// save to be used in next loop
last_peak_pos = peak_pos;
last_peak_h = h;
// right sibling
peak_pos = peak_pos + (1 << (h+1)) - 1;
}
if h == 0 {
break;
}
}
// for deletion, everything on the right slope of the last peak should be pre-loaded
let mut extra = Vec::new();
let mut h = last_peak_h;
let mut peak_pos = last_peak_pos;
while h > 0 {
let left_pos = peak_pos - (1<<h);
let right_pos = peak_pos - 1;
h = h - 1;
// drafting left child
let mut peak: Entry = vec[left_pos-1].clone().into();
if h != 0 {
let left_idx = (left_pos - (1<<h) - 1) as u32;
let right_idx = (left_pos - 2) as u32;
peak.update_siblings(
EntryLink::Stored(left_idx),
EntryLink::Stored(right_idx),
);
}
extra.push(((left_pos-1) as u32, peak));
// drafting right child
let mut peak: Entry = vec[right_pos-1].clone().into();
if h != 0 {
let left_idx = (right_pos - (1<<h) - 1) as u32;
let right_idx = (right_pos - 2) as u32;
peak.update_siblings(
EntryLink::Stored(left_idx),
EntryLink::Stored(right_idx),
);
}
extra.push(((right_pos-1) as u32, peak));
// continuing on right slope
peak_pos = right_pos;
}
println!("Total extra of {} required for deletion!", extra.len());
Tree::new(vec.len() as u32, nodes, extra)
}
fn main() {
let number= match std::env::args().skip(1).next() {
None => { eprintln!("writer <number of nodes> [<out_file>]"); std::process::exit(1); },
Some(number) => {
number.parse::<usize>().expect("invalid number")
}
};
let long_vec = share::NodeDataIterator::new().take(number)
.collect::<Vec<NodeData>>();
let now = std::time::Instant::now();
let tree = prepare_tree(&long_vec);
let elapsed = now.elapsed();
println!("Tree final root: {}-{}",
tree.root_node().expect("root").data().start_height,
tree.root_node().expect("root").data().end_height,
);
println!("Prepare tree of {} length: {} ns / {} mcs / {} ms",
number,
elapsed.as_nanos(), elapsed.as_micros(), elapsed.as_millis()
);
}