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actix-extras/actix-http/src/helpers.rs
2019-06-28 14:34:26 +06:00

236 lines
6.9 KiB
Rust

use std::{io, mem, ptr, slice};
use bytes::{BufMut, BytesMut};
use http::Version;
use crate::extensions::Extensions;
const DEC_DIGITS_LUT: &[u8] = b"0001020304050607080910111213141516171819\
2021222324252627282930313233343536373839\
4041424344454647484950515253545556575859\
6061626364656667686970717273747576777879\
8081828384858687888990919293949596979899";
pub(crate) const STATUS_LINE_BUF_SIZE: usize = 13;
pub(crate) fn write_status_line(version: Version, mut n: u16, bytes: &mut BytesMut) {
let mut buf: [u8; STATUS_LINE_BUF_SIZE] = [
b'H', b'T', b'T', b'P', b'/', b'1', b'.', b'1', b' ', b' ', b' ', b' ', b' ',
];
match version {
Version::HTTP_2 => buf[5] = b'2',
Version::HTTP_10 => buf[7] = b'0',
Version::HTTP_09 => {
buf[5] = b'0';
buf[7] = b'9';
}
_ => (),
}
let mut curr: isize = 12;
let buf_ptr = buf.as_mut_ptr();
let lut_ptr = DEC_DIGITS_LUT.as_ptr();
let four = n > 999;
// decode 2 more chars, if > 2 chars
let d1 = (n % 100) << 1;
n /= 100;
curr -= 2;
unsafe {
ptr::copy_nonoverlapping(lut_ptr.offset(d1 as isize), buf_ptr.offset(curr), 2);
}
// decode last 1 or 2 chars
if n < 10 {
curr -= 1;
unsafe {
*buf_ptr.offset(curr) = (n as u8) + b'0';
}
} else {
let d1 = n << 1;
curr -= 2;
unsafe {
ptr::copy_nonoverlapping(
lut_ptr.offset(d1 as isize),
buf_ptr.offset(curr),
2,
);
}
}
bytes.put_slice(&buf);
if four {
bytes.put(b' ');
}
}
/// NOTE: bytes object has to contain enough space
pub fn write_content_length(mut n: usize, bytes: &mut BytesMut) {
if n < 10 {
let mut buf: [u8; 21] = [
b'\r', b'\n', b'c', b'o', b'n', b't', b'e', b'n', b't', b'-', b'l', b'e',
b'n', b'g', b't', b'h', b':', b' ', b'0', b'\r', b'\n',
];
buf[18] = (n as u8) + b'0';
bytes.put_slice(&buf);
} else if n < 100 {
let mut buf: [u8; 22] = [
b'\r', b'\n', b'c', b'o', b'n', b't', b'e', b'n', b't', b'-', b'l', b'e',
b'n', b'g', b't', b'h', b':', b' ', b'0', b'0', b'\r', b'\n',
];
let d1 = n << 1;
unsafe {
ptr::copy_nonoverlapping(
DEC_DIGITS_LUT.as_ptr().add(d1),
buf.as_mut_ptr().offset(18),
2,
);
}
bytes.put_slice(&buf);
} else if n < 1000 {
let mut buf: [u8; 23] = [
b'\r', b'\n', b'c', b'o', b'n', b't', b'e', b'n', b't', b'-', b'l', b'e',
b'n', b'g', b't', b'h', b':', b' ', b'0', b'0', b'0', b'\r', b'\n',
];
// decode 2 more chars, if > 2 chars
let d1 = (n % 100) << 1;
n /= 100;
unsafe {
ptr::copy_nonoverlapping(
DEC_DIGITS_LUT.as_ptr().add(d1),
buf.as_mut_ptr().offset(19),
2,
)
};
// decode last 1
buf[18] = (n as u8) + b'0';
bytes.put_slice(&buf);
} else {
bytes.put_slice(b"\r\ncontent-length: ");
convert_usize(n, bytes);
}
}
pub(crate) fn convert_usize(mut n: usize, bytes: &mut BytesMut) {
let mut curr: isize = 39;
let mut buf: [u8; 41] = unsafe { mem::uninitialized() };
buf[39] = b'\r';
buf[40] = b'\n';
let buf_ptr = buf.as_mut_ptr();
let lut_ptr = DEC_DIGITS_LUT.as_ptr();
// eagerly decode 4 characters at a time
while n >= 10_000 {
let rem = (n % 10_000) as isize;
n /= 10_000;
let d1 = (rem / 100) << 1;
let d2 = (rem % 100) << 1;
curr -= 4;
unsafe {
ptr::copy_nonoverlapping(lut_ptr.offset(d1), buf_ptr.offset(curr), 2);
ptr::copy_nonoverlapping(lut_ptr.offset(d2), buf_ptr.offset(curr + 2), 2);
}
}
// if we reach here numbers are <= 9999, so at most 4 chars long
let mut n = n as isize; // possibly reduce 64bit math
// decode 2 more chars, if > 2 chars
if n >= 100 {
let d1 = (n % 100) << 1;
n /= 100;
curr -= 2;
unsafe {
ptr::copy_nonoverlapping(lut_ptr.offset(d1), buf_ptr.offset(curr), 2);
}
}
// decode last 1 or 2 chars
if n < 10 {
curr -= 1;
unsafe {
*buf_ptr.offset(curr) = (n as u8) + b'0';
}
} else {
let d1 = n << 1;
curr -= 2;
unsafe {
ptr::copy_nonoverlapping(lut_ptr.offset(d1), buf_ptr.offset(curr), 2);
}
}
unsafe {
bytes.extend_from_slice(slice::from_raw_parts(
buf_ptr.offset(curr),
41 - curr as usize,
));
}
}
pub(crate) struct Writer<'a>(pub &'a mut BytesMut);
impl<'a> io::Write for Writer<'a> {
fn write(&mut self, buf: &[u8]) -> io::Result<usize> {
self.0.extend_from_slice(buf);
Ok(buf.len())
}
fn flush(&mut self) -> io::Result<()> {
Ok(())
}
}
pub(crate) trait DataFactory {
fn set(&self, ext: &mut Extensions);
}
pub(crate) struct Data<T>(pub(crate) T);
impl<T: Clone + 'static> DataFactory for Data<T> {
fn set(&self, ext: &mut Extensions) {
ext.insert(self.0.clone())
}
}
#[cfg(test)]
mod tests {
use super::*;
#[test]
fn test_write_content_length() {
let mut bytes = BytesMut::new();
bytes.reserve(50);
write_content_length(0, &mut bytes);
assert_eq!(bytes.take().freeze(), b"\r\ncontent-length: 0\r\n"[..]);
bytes.reserve(50);
write_content_length(9, &mut bytes);
assert_eq!(bytes.take().freeze(), b"\r\ncontent-length: 9\r\n"[..]);
bytes.reserve(50);
write_content_length(10, &mut bytes);
assert_eq!(bytes.take().freeze(), b"\r\ncontent-length: 10\r\n"[..]);
bytes.reserve(50);
write_content_length(99, &mut bytes);
assert_eq!(bytes.take().freeze(), b"\r\ncontent-length: 99\r\n"[..]);
bytes.reserve(50);
write_content_length(100, &mut bytes);
assert_eq!(bytes.take().freeze(), b"\r\ncontent-length: 100\r\n"[..]);
bytes.reserve(50);
write_content_length(101, &mut bytes);
assert_eq!(bytes.take().freeze(), b"\r\ncontent-length: 101\r\n"[..]);
bytes.reserve(50);
write_content_length(998, &mut bytes);
assert_eq!(bytes.take().freeze(), b"\r\ncontent-length: 998\r\n"[..]);
bytes.reserve(50);
write_content_length(1000, &mut bytes);
assert_eq!(bytes.take().freeze(), b"\r\ncontent-length: 1000\r\n"[..]);
bytes.reserve(50);
write_content_length(1001, &mut bytes);
assert_eq!(bytes.take().freeze(), b"\r\ncontent-length: 1001\r\n"[..]);
bytes.reserve(50);
write_content_length(5909, &mut bytes);
assert_eq!(bytes.take().freeze(), b"\r\ncontent-length: 5909\r\n"[..]);
}
}