From 82b2786d6bb521af4cff634031f8409f3e330ef0 Mon Sep 17 00:00:00 2001 From: Rob Ede Date: Thu, 6 Feb 2020 23:51:02 +0000 Subject: [PATCH] replace unsafe content length implementation --- actix-http/src/helpers.rs | 95 +++++++++++++++++++-------------------- 1 file changed, 47 insertions(+), 48 deletions(-) diff --git a/actix-http/src/helpers.rs b/actix-http/src/helpers.rs index 58ebff61f..9868e3f5b 100644 --- a/actix-http/src/helpers.rs +++ b/actix-http/src/helpers.rs @@ -1,4 +1,4 @@ -use std::{io, mem, ptr, slice}; +use std::{io, ptr, slice}; use bytes::{BufMut, BytesMut}; use http::Version; @@ -14,9 +14,7 @@ const DEC_DIGITS_LUT: &[u8] = b"0001020304050607080910111213141516171819\ 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' ', - ]; + let mut buf: [u8; STATUS_LINE_BUF_SIZE] = *b"HTTP/1.1 "; match version { Version::HTTP_2 => buf[5] = b'2', Version::HTTP_10 => buf[7] = b'0', @@ -64,60 +62,55 @@ pub(crate) fn write_status_line(version: Version, mut n: u16, bytes: &mut BytesM } } +const DIGITS_START: u8 = b'0'; + /// NOTE: bytes object has to contain enough space -pub fn write_content_length(mut n: usize, bytes: &mut BytesMut) { +pub fn write_content_length(n: usize, bytes: &mut BytesMut) { + bytes.put_slice(b"\r\ncontent-length: "); + 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); + bytes.put_u8(DIGITS_START + (n as u8)); } 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); + let n = n as u8; + + let d10 = n / 10; + let d1 = n % 10; + + bytes.put_u8(DIGITS_START + d10); + bytes.put_u8(DIGITS_START + d1); } 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, - ) - }; + let n = n as u16; - // decode last 1 - buf[18] = (n as u8) + b'0'; + let d100 = (n / 100) as u8; + let d10 = ((n / 10) % 10) as u8; + let d1 = (n % 10) as u8; - bytes.put_slice(&buf); + bytes.put_u8(DIGITS_START + d100); + bytes.put_u8(DIGITS_START + d10); + bytes.put_u8(DIGITS_START + d1); + } else if n < 10000 { + let n = n as u16; + + let d1000 = (n / 1000) as u8; + let d100 = ((n / 100) % 10) as u8; + let d10 = ((n / 10) % 10) as u8; + let d1 = (n % 10) as u8; + + bytes.put_u8(DIGITS_START + d1000); + bytes.put_u8(DIGITS_START + d100); + bytes.put_u8(DIGITS_START + d10); + bytes.put_u8(DIGITS_START + d1); } else { - bytes.put_slice(b"\r\ncontent-length: "); - convert_usize(n, bytes); + write_usize(n, bytes); } + + bytes.put_slice(b"\r\n"); } -pub(crate) fn convert_usize(mut n: usize, bytes: &mut BytesMut) { +pub(crate) fn write_usize(mut n: usize, bytes: &mut BytesMut) { let mut curr: isize = 39; - let mut buf: [u8; 41] = unsafe { mem::MaybeUninit::uninit().assume_init() }; - buf[39] = b'\r'; - buf[40] = b'\n'; + let mut buf = [0u8; 39]; + let buf_ptr = buf.as_mut_ptr(); let lut_ptr = DEC_DIGITS_LUT.as_ptr(); @@ -165,7 +158,7 @@ pub(crate) fn convert_usize(mut n: usize, bytes: &mut BytesMut) { unsafe { bytes.extend_from_slice(slice::from_raw_parts( buf_ptr.offset(curr), - 41 - curr as usize, + 39 - curr as usize, )); } } @@ -231,5 +224,11 @@ mod tests { bytes.reserve(50); write_content_length(5909, &mut bytes); assert_eq!(bytes.split().freeze(), b"\r\ncontent-length: 5909\r\n"[..]); + bytes.reserve(50); + write_content_length(10001, &mut bytes); + assert_eq!(bytes.split().freeze(), b"\r\ncontent-length: 10001\r\n"[..]); + bytes.reserve(50); + write_content_length(59094, &mut bytes); + assert_eq!(bytes.split().freeze(), b"\r\ncontent-length: 59094\r\n"[..]); } }