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Secondary PoW scaling factor dampening, cleanup (#1765)

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* Remove useless time median window
* Secondary PoW factor dampening
* Fix off-by-one in time window, cleanup dampening, fix tests
This commit is contained in:
Ignotus Peverell
2018-10-16 16:55:40 -07:00
committed by GitHub
parent 67bc891455
commit fffe5154d2
4 changed files with 37 additions and 93 deletions
Download Patch File Download Diff File Expand all files Collapse all files
core/tests/consensus.rs
+20 -43
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@@ -122,35 +122,13 @@ fn get_diff_stats(chain_sim: &Vec<HeaderInfo>) -> DiffStats {
let tip_height = chain_sim.len();
let earliest_block_height = tip_height as i64 - last_blocks.len() as i64;
// Obtain the median window for the earlier time period
// the first MEDIAN_TIME_WINDOW elements
let mut window_earliest: Vec<u64> = last_blocks
.clone()
.iter()
.take(MEDIAN_TIME_WINDOW as usize)
.map(|n| n.clone().timestamp)
.collect();
// pick median
window_earliest.sort();
let earliest_ts = window_earliest[MEDIAN_TIME_INDEX as usize];
// Obtain the median window for the latest time period
// i.e. the last MEDIAN_TIME_WINDOW elements
let mut window_latest: Vec<u64> = last_blocks
.clone()
.iter()
.skip(DIFFICULTY_ADJUST_WINDOW as usize)
.map(|n| n.clone().timestamp)
.collect();
// pick median
window_latest.sort();
let latest_ts = window_latest[MEDIAN_TIME_INDEX as usize];
let earliest_ts = last_blocks[0].timestamp;
let latest_ts = last_blocks[last_blocks.len()-1].timestamp;
let mut i = 1;
let sum_blocks: Vec<HeaderInfo> = global::difficulty_data_to_vector(diff_iter.iter().cloned())
.into_iter()
.skip(MEDIAN_TIME_WINDOW as usize)
.take(DIFFICULTY_ADJUST_WINDOW as usize)
.collect();
@@ -263,7 +241,6 @@ fn print_chain_sim(chain_sim: Vec<(HeaderInfo, DiffStats)>) {
println!("Constants");
println!("DIFFICULTY_ADJUST_WINDOW: {}", DIFFICULTY_ADJUST_WINDOW);
println!("BLOCK_TIME_WINDOW: {}", BLOCK_TIME_WINDOW);
println!("MEDIAN_TIME_WINDOW: {}", MEDIAN_TIME_WINDOW);
println!("UPPER_TIME_BOUND: {}", UPPER_TIME_BOUND);
println!("DAMP_FACTOR: {}", DAMP_FACTOR);
chain_sim.iter().enumerate().for_each(|(i, b)| {
@@ -338,7 +315,7 @@ fn adjustment_scenarios() {
println!("*********************************************************");
print_chain_sim(chain_sim);
println!("*********************************************************");
let just_enough = (DIFFICULTY_ADJUST_WINDOW + MEDIAN_TIME_WINDOW) as usize;
let just_enough = (DIFFICULTY_ADJUST_WINDOW) as usize;
// Steady difficulty for a good while, then a sudden drop
let chain_sim = create_chain_sim(global::initial_block_difficulty());
@@ -408,17 +385,17 @@ fn next_target_adjustment() {
let diff_one = Difficulty::one();
assert_eq!(
next_difficulty(1, vec![HeaderInfo::from_ts_diff(cur_time, diff_one)]),
HeaderInfo::from_diff_scaling(Difficulty::one(), 2),
HeaderInfo::from_diff_scaling(Difficulty::one(), 1),
);
assert_eq!(
next_difficulty(1, vec![HeaderInfo::new(cur_time, diff_one, 10, true)]),
HeaderInfo::from_diff_scaling(Difficulty::one(), 2),
HeaderInfo::from_diff_scaling(Difficulty::one(), 1),
);
let mut hi = HeaderInfo::from_diff_scaling(diff_one, 1);
assert_eq!(
next_difficulty(1, repeat(60, hi.clone(), DIFFICULTY_ADJUST_WINDOW, None)),
HeaderInfo::from_diff_scaling(Difficulty::one(), 2),
HeaderInfo::from_diff_scaling(Difficulty::one(), 1),
);
hi.is_secondary = true;
assert_eq!(
@@ -428,7 +405,7 @@ fn next_target_adjustment() {
hi.secondary_scaling = 100;
assert_eq!(
next_difficulty(1, repeat(60, hi.clone(), DIFFICULTY_ADJUST_WINDOW, None)),
HeaderInfo::from_diff_scaling(Difficulty::one(), 106),
HeaderInfo::from_diff_scaling(Difficulty::one(), 96),
);
// Check we don't get stuck on difficulty 1
@@ -439,7 +416,7 @@ fn next_target_adjustment() {
);
// just enough data, right interval, should stay constant
let just_enough = DIFFICULTY_ADJUST_WINDOW + MEDIAN_TIME_WINDOW;
let just_enough = DIFFICULTY_ADJUST_WINDOW + 1;
hi.difficulty = Difficulty::from_num(1000);
assert_eq!(
next_difficulty(1, repeat(60, hi.clone(), just_enough, None)).difficulty,
@@ -448,7 +425,7 @@ fn next_target_adjustment() {
// checking averaging works
hi.difficulty = Difficulty::from_num(500);
let sec = DIFFICULTY_ADJUST_WINDOW / 2 + MEDIAN_TIME_WINDOW;
let sec = DIFFICULTY_ADJUST_WINDOW / 2;
let mut s1 = repeat(60, hi.clone(), sec, Some(cur_time));
let mut s2 = repeat_offs(
cur_time + (sec * 60) as u64,
@@ -513,22 +490,22 @@ fn next_target_adjustment() {
#[test]
fn secondary_pow_scale() {
let window = DIFFICULTY_ADJUST_WINDOW + MEDIAN_TIME_WINDOW;
let window = DIFFICULTY_ADJUST_WINDOW;
let mut hi = HeaderInfo::from_diff_scaling(Difficulty::from_num(10), 100);
// all primary, factor should be multiplied by 4 (max adjustment) so it
// becomes easier to find a high difficulty block
// all primary, factor should increase so it becomes easier to find a high
// difficulty block
assert_eq!(
secondary_pow_scaling(1, &(0..window).map(|_| hi.clone()).collect()),
200
148
);
// all secondary on 90%, factor should lose 10%
// all secondary on 90%, factor should go down a bit
hi.is_secondary = true;
assert_eq!(
secondary_pow_scaling(1, &(0..window).map(|_| hi.clone()).collect()),
90
96
);
// all secondary on 1%, should be divided by 4 (max adjustment)
// all secondary on 1%, factor should go down to bound (divide by 2)
assert_eq!(
secondary_pow_scaling(890_000, &(0..window).map(|_| hi.clone()).collect()),
50
@@ -552,7 +529,7 @@ fn secondary_pow_scale() {
),
100
);
// 95% secondary, should come down
// 95% secondary, should come down based on 100 median
assert_eq!(
secondary_pow_scaling(
1,
@@ -561,9 +538,9 @@ fn secondary_pow_scale() {
.chain((0..(window * 95 / 100)).map(|_| hi.clone()))
.collect()
),
94
98
);
// 40% secondary, should come up
// 40% secondary, should come up based on 50 median
assert_eq!(
secondary_pow_scaling(
1,
@@ -572,7 +549,7 @@ fn secondary_pow_scale() {
.chain((0..(window * 4 / 10)).map(|_| hi.clone()))
.collect()
),
100
61
);
}