pub const DIFFICULTY_BOMB_DIVISOR: f64 = 1024f64;
pub fn naive_retarget(
block_timestamp: i64,
parent_timestamp: i64,
target_block_time: i64,
parent_difficulty: u64,
) -> u64 {
let time_elapsed = block_timestamp - parent_timestamp;
if time_elapsed == target_block_time || time_elapsed == 0 {
parent_difficulty
} else {
let parent_diff = parent_difficulty as f64;
let mut x: f64;
x = (target_block_time - time_elapsed) as f64;
x /= target_block_time as f64;
x *= parent_diff;
x = parent_diff - x;
trace!("old difficulty {:#x}", parent_difficulty);
trace!("new difficulty {:#x}", x as u64);
x as u64
}
}
pub fn bitcoin_retarget(
block_timestamp: i64,
parent_timestamp: i64,
target_block_time: i64,
parent_difficulty: u64,
) -> u64 {
let mut time_elapsed = block_timestamp - parent_timestamp;
if time_elapsed < target_block_time / 2 {
time_elapsed = target_block_time / 2
} else if time_elapsed > target_block_time * 2 {
time_elapsed = target_block_time * 2
}
let mut x: u64;
x = match parent_difficulty.checked_mul(time_elapsed as u64) {
Some(x) => x,
None => u64::max_value(),
};
x /= target_block_time as u64;
x
}
pub fn ethereum_retarget(block_timestamp: i64, parent_timestamp: i64, parent_difficulty: u64) -> u64 {
let parent_diff = parent_difficulty as f64;
let mut x: f64;
let y: f64;
x = (block_timestamp - parent_timestamp) as f64;
x /= 10f64;
x = 1f64 - x;
x = f64::max(x, -99f64);
y = parent_diff / DIFFICULTY_BOMB_DIVISOR;
x *= y;
x += parent_diff;
trace!("old difficulty {:#x}", parent_difficulty);
trace!("new difficulty {:#x}", x as u64);
x as u64
}