the same technique applies to fasta-redux

This commit is contained in:
Andre Bogus 2015-09-24 13:25:50 +02:00
parent 960e85c8ea
commit 12d990d385

View File

@ -39,199 +39,338 @@
// OF THE POSSIBILITY OF SUCH DAMAGE.
use std::cmp::min;
use std::env;
use std::io;
use std::io::BufWriter;
use std::io::prelude::*;
use std::io::{self, Write};
use std::sync::{Arc, Mutex};
use std::thread;
const LINE_LEN: usize = 60;
const BLOCK_LINES: usize = 512;
const BLOCK_THOROUGHPUT: usize = LINE_LEN * BLOCK_LINES;
const BLOCK_LEN: usize = BLOCK_THOROUGHPUT + BLOCK_LINES;
const STDIN_BUF: usize = (LINE_LEN + 1) * 1024;
const LOOKUP_SIZE: usize = 4 * 1024;
const LOOKUP_SCALE: f32 = (LOOKUP_SIZE - 1) as f32;
// Random number generator constants
const IM: u32 = 139968;
const IA: u32 = 3877;
const IC: u32 = 29573;
const ALU: &'static [u8] =
b"GGCCGGGCGCGGTGGCTCACGCCTGTAATCCCAGCACTTTGG\
GAGGCCGAGGCGGGCGGATCACCTGAGGTCAGGAGTTCGAGA\
CCAGCCTGGCCAACATGGTGAAACCCCGTCTCTACTAAAAAT\
ACAAAAATTAGCCGGGCGTGGTGGCGCGCGCCTGTAATCCCA\
GCTACTCGGGAGGCTGAGGCAGGAGAATCGCTTGAACCCGGG\
AGGCGGAGGTTGCAGTGAGCCGAGATCGCGCCACTGCACTCC\
AGCCTGGGCGACAGAGCGAGACTCCGTCTCAAAAA";
const ALU: &'static str = "GGCCGGGCGCGGTGGCTCACGCCTGTAATCCCAGCACTTTG\
GGAGGCCGAGGCGGGCGGATCACCTGAGGTCAGGAGTTCGA\
GACCAGCCTGGCCAACATGGTGAAACCCCGTCTCTACTAAA\
AATACAAAAATTAGCCGGGCGTGGTGGCGCGCGCCTGTAAT\
CCCAGCTACTCGGGAGGCTGAGGCAGGAGAATCGCTTGAAC\
CCGGGAGGCGGAGGTTGCAGTGAGCCGAGATCGCGCCACTG\
CACTCCAGCCTGGGCGACAGAGCGAGACTCCGTCTCAAAAA";
const IUB: &'static [(u8, f32)] =
&[(b'a', 0.27), (b'c', 0.12), (b'g', 0.12),
(b't', 0.27), (b'B', 0.02), (b'D', 0.02),
(b'H', 0.02), (b'K', 0.02), (b'M', 0.02),
(b'N', 0.02), (b'R', 0.02), (b'S', 0.02),
(b'V', 0.02), (b'W', 0.02), (b'Y', 0.02)];
const NULL_AMINO_ACID: AminoAcid = AminoAcid { c: ' ' as u8, p: 0.0 };
const HOMOSAPIENS: &'static [(u8, f32)] =
&[(b'a', 0.3029549426680),
(b'c', 0.1979883004921),
(b'g', 0.1975473066391),
(b't', 0.3015094502008)];
static IUB: [AminoAcid;15] = [
AminoAcid { c: 'a' as u8, p: 0.27 },
AminoAcid { c: 'c' as u8, p: 0.12 },
AminoAcid { c: 'g' as u8, p: 0.12 },
AminoAcid { c: 't' as u8, p: 0.27 },
AminoAcid { c: 'B' as u8, p: 0.02 },
AminoAcid { c: 'D' as u8, p: 0.02 },
AminoAcid { c: 'H' as u8, p: 0.02 },
AminoAcid { c: 'K' as u8, p: 0.02 },
AminoAcid { c: 'M' as u8, p: 0.02 },
AminoAcid { c: 'N' as u8, p: 0.02 },
AminoAcid { c: 'R' as u8, p: 0.02 },
AminoAcid { c: 'S' as u8, p: 0.02 },
AminoAcid { c: 'V' as u8, p: 0.02 },
AminoAcid { c: 'W' as u8, p: 0.02 },
AminoAcid { c: 'Y' as u8, p: 0.02 },
];
// We need a specific Rng,
// so implement this manually
static HOMO_SAPIENS: [AminoAcid;4] = [
AminoAcid { c: 'a' as u8, p: 0.3029549426680 },
AminoAcid { c: 'c' as u8, p: 0.1979883004921 },
AminoAcid { c: 'g' as u8, p: 0.1975473066391 },
AminoAcid { c: 't' as u8, p: 0.3015094502008 },
];
const MODULUS: u32 = 139968;
const MULTIPLIER: u32 = 3877;
const ADDITIVE: u32 = 29573;
fn sum_and_scale(a: &'static [AminoAcid]) -> Vec<AminoAcid> {
let mut p = 0f32;
let mut result: Vec<AminoAcid> = a.iter().map(|a_i| {
p += a_i.p;
AminoAcid { c: a_i.c, p: p * LOOKUP_SCALE }
}).collect();
let result_len = result.len();
result[result_len - 1].p = LOOKUP_SCALE;
result
}
// Why doesn't rust already have this?
// Algorithm directly taken from Wikipedia
fn powmod(mut base: u64, mut exponent: u32, modulus: u64) -> u64 {
let mut ret = 1;
base %= modulus;
#[derive(Copy, Clone)]
struct AminoAcid {
c: u8,
p: f32,
}
struct RepeatFasta<'a, W:'a> {
alu: &'static str,
out: &'a mut W
}
impl<'a, W: Write> RepeatFasta<'a, W> {
fn new(alu: &'static str, w: &'a mut W) -> RepeatFasta<'a, W> {
RepeatFasta { alu: alu, out: w }
while exponent > 0 {
if exponent & 1 == 1 {
ret *= base;
ret %= modulus;
}
exponent >>= 1;
base *= base;
base %= modulus;
}
fn make(&mut self, n: usize) -> io::Result<()> {
let alu_len = self.alu.len();
let mut buf = vec![0; alu_len + LINE_LEN];
let alu: &[u8] = self.alu.as_bytes();
ret
}
for (slot, val) in buf.iter_mut().zip(alu) {
*slot = *val;
}
let buf_len = buf.len();
for (slot, val) in buf[alu_len..buf_len].iter_mut().zip(&alu[..LINE_LEN]) {
*slot = *val;
}
// Just a typical LCRNG
pub struct Rng {
last: u32
}
let mut pos = 0;
let mut bytes;
let mut n = n;
while n > 0 {
bytes = min(LINE_LEN, n);
try!(self.out.write_all(&buf[pos..pos + bytes]));
try!(self.out.write_all(&[b'\n']));
pos += bytes;
if pos > alu_len {
pos -= alu_len;
impl Rng {
pub fn new() -> Rng {
Rng { last: 42 }
}
pub fn max_value() -> u32 {
MODULUS - 1
}
pub fn normalize(p: f32) -> u32 {
(p * MODULUS as f32).floor() as u32
}
pub fn gen(&mut self) -> u32 {
self.last = (self.last * MULTIPLIER + ADDITIVE) % MODULUS;
self.last
}
// This allows us to fast-forward the RNG,
// allowing us to run it in parallel.
pub fn future(&self, n: u32) -> Rng {
let a = MULTIPLIER as u64;
let b = ADDITIVE as u64;
let m = MODULUS as u64;
// (a^n - 1) mod (a-1) m
// x_k = ((a^n x_0 mod m) + --------------------- b) mod m
// a - 1
//
// Since (a - 1) divides (a^n - 1) mod (a-1) m,
// the subtraction does not overflow and thus can be non-modular.
//
let new_seed =
(powmod(a, n, m) * self.last as u64) % m +
(powmod(a, n, (a-1) * m) - 1) / (a-1) * b;
Rng { last: (new_seed % m) as u32 }
}
}
// This will end up keeping track of threads, like
// in the other multithreaded Rust version, in
// order to keep writes in order.
//
// This is stolen from another multithreaded Rust
// implementation, although that implementation
// was not able to parallelize the RNG itself.
struct BlockSubmitter<W: io::Write> {
writer: W,
pub waiting_on: usize,
}
impl<W: io::Write> BlockSubmitter<W> {
fn submit(&mut self, data: &[u8], block_num: usize) -> Option<io::Result<()>> {
if block_num == self.waiting_on {
self.waiting_on += 1;
Some(self.submit_async(data))
}
else {
None
}
}
fn submit_async(&mut self, data: &[u8]) -> io::Result<()> {
self.writer.write_all(data)
}
}
// For repeating strings as output
fn fasta_static<W: io::Write>(
writer: &mut W,
header: &[u8],
data: &[u8],
mut n: usize
) -> io::Result<()>
{
// The aim here is to print a short(ish) string cyclically
// with line breaks as appropriate.
//
// The secret technique is to repeat the string such that
// any wanted line is a single offset in the string.
//
// This technique is stolen from the Haskell version.
try!(writer.write_all(header));
// Maximum offset is data.len(),
// Maximum read len is LINE_LEN
let stream = data.iter().cloned().cycle();
let mut extended: Vec<u8> = stream.take(data.len() + LINE_LEN + 1).collect();
let mut offset = 0;
while n > 0 {
let write_len = min(LINE_LEN, n);
let end = offset + write_len;
n -= write_len;
let tmp = extended[end];
extended[end] = b'\n';
try!(writer.write_all(&extended[offset..end + 1]));
extended[end] = tmp;
offset = end;
offset %= data.len();
}
Ok(())
}
// For RNG streams as output
fn fasta<W: io::Write + Send + 'static>(
submitter: &Arc<Mutex<BlockSubmitter<W>>>,
header: &[u8],
table: &'static [(u8, f32)],
rng: &mut Rng,
n: usize
) -> io::Result<()>
{
// Here the lookup table is part of the algorithm and needs the
// original probabilities (scaled with the LOOKUP_SCALE), because
// Isaac says so :-)
fn sum_and_scale(a: &'static [(u8, f32)]) -> Vec<(u8, f32)> {
let mut p = 0f32;
let mut result: Vec<(u8, f32)> = a.iter().map(|e| {
p += e.1;
(e.0, p * LOOKUP_SCALE)
}).collect();
let result_len = result.len();
result[result_len - 1].1 = LOOKUP_SCALE;
result
}
fn make_lookup(a: &[(u8, f32)]) -> [(u8, f32); LOOKUP_SIZE] {
let mut lookup = [(0, 0f32); LOOKUP_SIZE];
let mut j = 0;
for (i, slot) in lookup.iter_mut().enumerate() {
while a[j].1 < (i as f32) {
j += 1;
}
n -= bytes;
*slot = a[j];
}
Ok(())
lookup
}
{
try!(submitter.lock().unwrap().submit_async(header));
}
let lookup_table = Arc::new(make_lookup(&sum_and_scale(table)));
let thread_count = 4;
let mut threads = Vec::new();
for block_num in (0..thread_count) {
let offset = BLOCK_THOROUGHPUT * block_num;
let local_submitter = submitter.clone();
let local_lookup_table = lookup_table.clone();
let local_rng = rng.future(offset as u32);
threads.push(thread::spawn(move || {
gen_block(
local_submitter,
local_lookup_table,
local_rng,
n.saturating_sub(offset),
block_num,
thread_count
)
}));
}
for thread in threads {
try!(thread.join().unwrap());
}
*rng = rng.future(n as u32);
Ok(())
}
fn make_lookup(a: &[AminoAcid]) -> [AminoAcid;LOOKUP_SIZE] {
let mut lookup = [ NULL_AMINO_ACID;LOOKUP_SIZE ];
let mut j = 0;
for (i, slot) in lookup.iter_mut().enumerate() {
while a[j].p < (i as f32) {
j += 1;
}
*slot = a[j];
}
lookup
}
// A very optimized writer.
// I have a feeling a simpler version wouldn't slow
// things down too much, though, since the RNG
// is the really heavy hitter.
fn gen_block<W: io::Write>(
submitter: Arc<Mutex<BlockSubmitter<W>>>,
lookup_table: Arc<[(u8, f32)]>,
mut rng: Rng,
mut length: usize,
mut block_num: usize,
block_stride: usize,
) -> io::Result<()>
{
// Include newlines in block
length += length / LINE_LEN;
let block: &mut [u8] = &mut [b'\n'; BLOCK_LEN];
struct RandomFasta<'a, W:'a> {
seed: u32,
lookup: [AminoAcid;LOOKUP_SIZE],
out: &'a mut W,
}
while length > 0 {
{
let gen_into = &mut block[..min(length, BLOCK_LEN)];
impl<'a, W: Write> RandomFasta<'a, W> {
fn new(w: &'a mut W, a: &[AminoAcid]) -> RandomFasta<'a, W> {
RandomFasta {
seed: 42,
out: w,
lookup: make_lookup(a),
}
}
fn rng(&mut self, max: f32) -> f32 {
self.seed = (self.seed * IA + IC) % IM;
(max * self.seed as f32) / (IM as f32)
}
fn nextc(&mut self) -> u8 {
let r = self.rng(LOOKUP_SCALE);
for i in (r as usize..LOOKUP_SIZE) {
if self.lookup[i].p >= r {
return self.lookup[i].c;
// Write random numbers, skipping newlines
for (i, byte) in gen_into.iter_mut().enumerate() {
if (i + 1) % (LINE_LEN + 1) != 0 {
let p = rng.gen() as f32 * (LOOKUP_SCALE / MODULUS as f32);
*byte = lookup_table[p as usize..LOOKUP_SIZE].iter().find(
|le| le.1 >= p).unwrap().0;
}
}
}
unreachable!();
}
fn make(&mut self, n: usize) -> io::Result<()> {
let lines = n / LINE_LEN;
let chars_left = n % LINE_LEN;
let mut buf = [0;LINE_LEN + 1];
let write_out = {
if length >= BLOCK_LEN { &mut *block }
else if length % (LINE_LEN + 1) == 0 { &mut block[..length] }
else { &mut block[..length + 1] }
};
for _ in 0..lines {
for i in 0..LINE_LEN {
buf[i] = self.nextc();
*write_out.last_mut().unwrap() = b'\n';
loop {
// Make sure to release lock before calling `yield_now`
let res = { submitter.lock().unwrap().submit(write_out, block_num) };
match res {
Some(result) => { try!(result); break; }
None => std::thread::yield_now()
}
buf[LINE_LEN] = '\n' as u8;
try!(self.out.write(&buf));
}
for i in 0..chars_left {
buf[i] = self.nextc();
}
self.out.write_all(&buf[..chars_left])
block_num += block_stride;
rng = rng.future((BLOCK_THOROUGHPUT * (block_stride - 1)) as u32);
length = length.saturating_sub(BLOCK_LEN * (block_stride - 1));
length = length.saturating_sub(BLOCK_LEN);
}
Ok(())
}
fn run<W: io::Write + Send + 'static>(writer: W) -> io::Result<()> {
let n = std::env::args_os().nth(1)
.and_then(|s| s.into_string().ok())
.and_then(|n| n.parse().ok())
.unwrap_or(1000);
let rng = &mut Rng::new();
// Use automatic buffering for the static version...
let mut writer = io::BufWriter::with_capacity(STDIN_BUF, writer);
try!(fasta_static(&mut writer, b">ONE Homo sapiens alu\n", ALU, n * 2));
// ...but the dynamic version does its own buffering already
let writer = try!(writer.into_inner());
let submitter = Arc::new(Mutex::new(BlockSubmitter { writer: writer, waiting_on: 0 }));
{ submitter.lock().unwrap().waiting_on = 0; }
try!(fasta(&submitter, b">TWO IUB ambiguity codes\n", &IUB, rng, n * 3));
{ submitter.lock().unwrap().waiting_on = 0; }
try!(fasta(&submitter, b">THREE Homo sapiens frequency\n", &HOMOSAPIENS, rng, n * 5));
Ok(())
}
fn main() {
let mut args = env::args();
let n = if args.len() > 1 {
args.nth(1).unwrap().parse::<usize>().unwrap()
} else {
5
};
let stdout = io::stdout();
let mut out = BufWriter::new(stdout.lock());
out.write_all(b">ONE Homo sapiens alu\n").unwrap();
{
let mut repeat = RepeatFasta::new(ALU, &mut out);
repeat.make(n * 2).unwrap();
}
out.write_all(b">TWO IUB ambiguity codes\n").unwrap();
let iub = sum_and_scale(&IUB);
let mut random = RandomFasta::new(&mut out, &iub);
random.make(n * 3).unwrap();
random.out.write_all(b">THREE Homo sapiens frequency\n").unwrap();
let homo_sapiens = sum_and_scale(&HOMO_SAPIENS);
random.lookup = make_lookup(&homo_sapiens);
random.make(n * 5).unwrap();
random.out.write_all(b"\n").unwrap();
run(io::stdout()).unwrap()
}