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#[allow(unused_imports)]
#[macro_use]
extern crate proptest;
pub mod constants;
pub mod math;
use constants::*;
use math::*;
const PANIC_OUT_OF_BOUNDS: &str = "Requested bits are out of bounds!";
#[derive(Default, Debug)]
pub struct Genestring {
pieces: Vec<u64>,
}
pub struct Writer<'a> {
parent: &'a mut Genestring,
offset: u64
}
pub struct Reader<'a> {
parent: &'a mut Genestring,
offset: u64
}
impl Genestring {
pub fn with_bits(count: u64) -> Genestring {
let mut result = Genestring {
pieces: Vec::with_capacity(count as usize),
};
result.pieces.resize(part_count_for_bits(count) as usize, 0);
result
}
pub fn writer(&mut self) -> Writer {
Writer { parent: self, offset: 0 }
}
pub fn reader(&mut self) -> Reader {
Reader { parent: self, offset: 0 }
}
pub fn bit_len(&self) -> usize {
self.pieces.len() * PIECE_SIZE_IN_BITS as usize
}
pub fn byte_len(&self) -> usize {
self.pieces.len() * PIECE_SIZE_IN_BYTES as usize
}
pub fn len(&self) -> usize {
self.pieces.len()
}
pub fn is_empty(&self) -> bool {
self.pieces.is_empty()
}
pub fn get(&self, offset: u64, bits: u64) -> u64 {
if bits == 0 {
return 0;
}
if bits > 64 {
panic!("Can only obtain 64 bits at a time!");
}
if bits + offset > self.bit_len() as u64 {
panic!(PANIC_OUT_OF_BOUNDS);
}
let first_half_idx = part_for_bit(offset) as usize;
let second_half_idx = part_for_bit(offset + (bits - 1)) as usize;
let offset_modulo = offset % PIECE_SIZE_IN_BITS;
let mut result: u64 = 0;
if first_half_idx != second_half_idx {
let mut acc: u64 = 0;
let p1_bits = PIECE_SIZE_IN_BITS - offset_modulo;
for i in 0..p1_bits {
acc += 1 << i;
}
let value_mask1 = acc;
let p2_bits = bits - p1_bits;
acc = 0;
for i in 0..p2_bits {
acc += 1 << i;
}
let piece_mask2 = acc;
let piece_mask1 = value_mask1 << offset_modulo;
result = (self.pieces[first_half_idx] & piece_mask1) >> offset_modulo;
result += (self.pieces[second_half_idx] & piece_mask2) << p1_bits;
} else {
let first_half = self.pieces[first_half_idx];
let piece = first_half;
for i in offset_modulo..(offset_modulo + bits) {
let mask = 1 << i;
result += piece & mask;
}
result >>= offset_modulo;
}
result
}
pub fn piece_iter(&self) -> std::slice::Iter<'_, u64> {
self.pieces.iter()
}
pub fn piece_iter_mut(&mut self) -> std::slice::IterMut<'_, u64> {
self.pieces.iter_mut()
}
pub fn set(&mut self, offset: u64, bits: u64, value: u64) {
if bits == 0 {
return;
}
if bits > 64 {
panic!("Can only write 64 bits at a time!");
}
if bits + offset > self.bit_len() as u64 {
panic!(PANIC_OUT_OF_BOUNDS);
}
let first_half_idx = part_for_bit(offset) as usize;
let second_half_idx = part_for_bit(offset + (bits - 1)) as usize;
let mut source_mask = 0;
let offset_modulo = offset % PIECE_SIZE_IN_BITS;
if first_half_idx == second_half_idx {
for i in 0..bits {
source_mask += 1 << i;
}
let destination_mask = source_mask << offset_modulo;
self.pieces[first_half_idx] = (self.pieces[first_half_idx] & !destination_mask)
+ ((value as u64 & source_mask) << offset_modulo);
} else {
let mut acc: u64 = 0;
let p1_bits = PIECE_SIZE_IN_BITS - offset_modulo;
for i in 0..p1_bits {
acc += 1 << i;
}
let value_mask1 = acc;
let p2_bits = bits - p1_bits;
acc = 0;
for i in 0..p2_bits {
acc += 1 << i;
}
let piece_mask2 = acc;
acc <<= p1_bits;
let value_mask2 = acc;
let piece_mask1 = value_mask1 << offset_modulo;
self.pieces[first_half_idx] = (self.pieces[first_half_idx] & !piece_mask1)
+ ((value & value_mask1) << offset_modulo);
self.pieces[second_half_idx] =
(self.pieces[second_half_idx] & !piece_mask2) + ((value & value_mask2) >> p1_bits);
}
}
pub fn transplant(&mut self, donor: &Genestring, offset: u64, bits: u64) {
let end = bits + offset;
if end > self.bit_len() as u64 || end > donor.bit_len() as u64 {
panic!(PANIC_OUT_OF_BOUNDS);
}
if bits <= 64 {
self.set(offset, bits, donor.get(offset, bits));
} else {
let mut offset = offset;
let bit_windows = bits / PIECE_SIZE_IN_BITS;
for _ in 0..bit_windows {
self.set(
offset,
PIECE_SIZE_IN_BITS,
donor.get(offset, PIECE_SIZE_IN_BITS),
);
offset += PIECE_SIZE_IN_BITS;
}
self.set(
offset,
bits % PIECE_SIZE_IN_BITS,
donor.get(offset, bits % PIECE_SIZE_IN_BITS),
);
}
}
}
impl<'a> Writer<'a> {
pub fn push(&mut self, bits: u64, value: u64) {
self.parent.set(self.offset, bits, value);
self.offset += bits;
}
}
impl<'a> Reader<'a> {
pub fn next(&mut self, bits: u64) -> u64 {
let result = self.parent.get(self.offset, bits);
self.offset += bits;
result
}
}
#[cfg(test)]
mod tests {
use *;
#[test]
fn assume_intdiv_rounds_down() {
assert_eq!(4 / 5, 0);
assert_eq!(7 / 5, 1);
}
#[test]
fn calculating_bi_offsets() {
let offset = 50;
let bits = 32;
let mut total = 0;
let start = offset % PIECE_SIZE_IN_BITS;
let stop = PIECE_SIZE_IN_BITS;
for _ in start..stop {
total += 1;
}
let stop = bits - (stop - start);
let start = 0;
for _ in start..stop {
total += 1;
}
assert_eq!(total, bits);
}
#[test]
fn get_set_same_chunk() {
assert_eq!(PIECE_SIZE_IN_BITS, 64);
let mut gs = Genestring::with_bits(32);
eprintln!("{:?}", gs);
gs.set(8, 12, 842);
eprintln!("{:?}", gs);
assert_eq!(gs.get(8, 12), 842);
}
#[test]
fn get_set_different_chunk() {
assert_eq!(PIECE_SIZE_IN_BITS, 64);
let mut gs = Genestring::with_bits(128);
eprintln!("{:?}", gs);
gs.set(60, 8, 0xFF);
eprintln!("{:?}", gs);
assert_eq!(gs.pieces[0], 0xF000000000000000);
assert_eq!(gs.pieces[1], 0x000000000000000F);
assert_eq!(gs.get(60, 8), 0xFF);
}
#[test]
fn string_size_minimum() {
assert_eq!(PIECE_SIZE_IN_BITS, 64);
assert_eq!(part_count_for_bits(0), 1);
}
proptest! {
#[test]
fn string_size_blocks(blocks in 1..10) {
assert_eq!(PIECE_SIZE_IN_BITS, 64);
assert_eq!(part_count_for_bits(blocks as u64 * PIECE_SIZE_IN_BITS), blocks as u64);
}
#[test]
fn string_size_subblocks(blocks in 1..10, subblock in 1..32) {
assert_eq!(PIECE_SIZE_IN_BITS, 64);
assert_eq!(part_count_for_bits((blocks as u64 * PIECE_SIZE_IN_BITS) + subblock as u64), blocks as u64 + 1);
}
#[test]
fn get_set_single(start in 0..256, len in 1..64, value: u64) {
prop_assume!((start + len) < 256, "Value must be within bit string boundaries.");
assert_eq!(PIECE_SIZE_IN_BITS, 64);
let mut gs = Genestring::with_bits(256);
let mut band: u64 = 0;
for i in 0..len {
band += 1 << i;
}
let banded_value = value as u64 & band;
gs.set(start as u64, len as u64, banded_value);
prop_assert_eq!(gs.get(start as u64, len as u64), banded_value);
}
#[test]
fn get_set_1piece_duo(a in 0..16, b in 32..48, value_a: u16, value_b: u16) {
assert_eq!(PIECE_SIZE_IN_BITS, 64);
let mut gs = Genestring::with_bits(64);
gs.set(a as u64, 16, value_a as u64);
gs.set(b as u64, 16, value_b as u64);
prop_assert_eq!(gs.get(a as u64, 16), value_a as u64);
prop_assert_eq!(gs.get(b as u64, 16), value_b as u64);
}
#[test]
fn get_set_multibinning(a in 0..16, b in 32..100, value_a: u16, value_b: u16) {
assert_eq!(PIECE_SIZE_IN_BITS, 64);
let mut gs = Genestring::with_bits(128);
gs.set(a as u64, 16, value_a as u64);
gs.set(b as u64, 16, value_b as u64);
prop_assert_eq!(gs.get(a as u64, 16), value_a as u64);
prop_assert_eq!(gs.get(b as u64, 16), value_b as u64);
}
#[test]
fn transplanting_small_ranges(a in 0..32, b in 64..100, value_a: u16, value_b: u16) {
assert_eq!(PIECE_SIZE_IN_BITS, 64);
let mut gs = Genestring::with_bits(128);
let mut gs2 = Genestring::with_bits(128);
gs.set(a as u64, 16, value_a as u64);
gs.set(b as u64, 16, value_b as u64);
gs2.transplant(&gs, a as u64, 16);
gs2.transplant(&gs, b as u64, 16);
prop_assert_eq!(gs2.get(a as u64, 16), value_a as u64);
prop_assert_eq!(gs2.get(b as u64, 16), value_b as u64);
}
#[test]
fn transplanting_small_ranges_blocked(a in 0..8, b in 0..8, value_a: u16, value_b: u16) {
assert_eq!(PIECE_SIZE_IN_BITS, 64);
prop_assume!(a != b, "Blocks cannot overlap.");
let mut gs = Genestring::with_bits(8 * 16);
let mut gs2 = Genestring::with_bits(8 * 16);
gs.set(a as u64 * 16, 16, value_a as u64);
gs.set(b as u64 * 16, 16, value_b as u64);
gs2.transplant(&gs, a as u64 * 16, 16);
gs2.transplant(&gs, b as u64 * 16, 16);
prop_assert_eq!(gs2.get(a as u64 * 16, 16), value_a as u64);
prop_assert_eq!(gs2.get(b as u64 * 16, 16), value_b as u64);
}
#[test]
fn transplanting_large_ranges(a in 0..16, b in 0..16, value_a: u16, value_b: u16) {
prop_assume!(a != b, "Overlapping is not allowed.");
assert_eq!(PIECE_SIZE_IN_BITS, 64);
let mut gs = Genestring::with_bits(16 * 16);
let mut gs2 = Genestring::with_bits(16 * 16);
gs.set((a * 16) as u64, 16, value_a as u64);
prop_assert_eq!(gs.get(a as u64 * 16, 16), value_a as u64);
gs.set((b * 16) as u64, 16, value_b as u64);
prop_assert_eq!(gs.get(a as u64 * 16, 16), value_a as u64);
prop_assert_eq!(gs.get(b as u64 * 16, 16), value_b as u64);
gs2.transplant(&gs, 0, 16 * 16);
prop_assert_eq!(gs.get(a as u64 * 16, 16), value_a as u64);
prop_assert_eq!(gs.get(b as u64 * 16, 16), value_b as u64);
prop_assert_eq!(gs2.get(a as u64 * 16, 16), value_a as u64);
prop_assert_eq!(gs2.get(b as u64 * 16, 16), value_b as u64);
}
}
}