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use crate::error::{ErrorType};
use crate::Deserializer;
use crate::Result;
use crate::stringparse::*;
use simd_lite::aarch64::*;
use crate::neon::stage1::*;
impl<'de> Deserializer<'de> {
#[cfg_attr(not(feature = "no-inline"), inline(always))]
pub fn parse_str_(&mut self) -> Result<&'de str> {
// Add 1 to skip the initial "
let idx = self.iidx + 1;
let mut padding = [0u8; 32];
//let mut read: usize = 0;
// we include the terminal '"' so we know where to end
// This is safe since we check sub's lenght in the range access above and only
// create sub sliced form sub to `sub.len()`.
let src: &[u8] = unsafe { &self.input.get_unchecked(idx..) };
let mut src_i: usize = 0;
let mut len = src_i;
loop {
// store to dest unconditionally - we can overwrite the bits we don't like
// later
let (v0, v1) = if src.len() >= src_i + 32 {
// This is safe since we ensure src is at least 16 wide
#[allow(clippy::cast_ptr_alignment)]
unsafe {
(
vld1q_u8(src.get_unchecked(src_i..src_i + 16).as_ptr()),
vld1q_u8(src.get_unchecked(src_i + 16..src_i + 32).as_ptr()),
)
}
} else {
unsafe {
padding
.get_unchecked_mut(..src.len() - src_i)
.clone_from_slice(src.get_unchecked(src_i..));
// This is safe since we ensure src is at least 32 wide
(
vld1q_u8(padding.get_unchecked(0..16).as_ptr()),
vld1q_u8(padding.get_unchecked(16..32).as_ptr()),
)
}
};
let ParseStringHelper { bs_bits, quote_bits } = find_bs_bits_and_quote_bits(v0, v1);
if (bs_bits.wrapping_sub(1) & quote_bits) != 0 {
// we encountered quotes first. Move dst to point to quotes and exit
// find out where the quote is...
let quote_dist: u32 = quote_bits.trailing_zeros();
///////////////////////
// Above, check for overflow in case someone has a crazy string (>=4GB?)
// But only add the overflow check when the document itself exceeds 4GB
// Currently unneeded because we refuse to parse docs larger or equal to 4GB.
////////////////////////
// we advance the point, accounting for the fact that we have a NULl termination
len += quote_dist as usize;
unsafe {
let v = self.input.get_unchecked(idx..idx + len) as *const [u8] as *const str;
return Ok(&*v);
}
// we compare the pointers since we care if they are 'at the same spot'
// not if they are the same value
}
if (quote_bits.wrapping_sub(1) & bs_bits) != 0 {
// Move to the 'bad' character
let bs_dist: u32 = bs_bits.trailing_zeros();
len += bs_dist as usize;
src_i += bs_dist as usize;
break;
} else {
// they are the same. Since they can't co-occur, it means we encountered
// neither.
src_i += 32;
len += 32;
}
}
let mut dst_i: usize = 0;
let dst: &mut [u8] = self.strings.as_mut_slice();
loop {
let (v0, v1) = if src.len() >= src_i + 32 {
// This is safe since we ensure src is at least 16 wide
#[allow(clippy::cast_ptr_alignment)]
unsafe {
(
vld1q_u8(src.get_unchecked(src_i..src_i + 16).as_ptr()),
vld1q_u8(src.get_unchecked(src_i + 16..src_i + 32).as_ptr()),
)
}
} else {
unsafe {
padding
.get_unchecked_mut(..src.len() - src_i)
.clone_from_slice(src.get_unchecked(src_i..));
// This is safe since we ensure src is at least 32 wide
(
vld1q_u8(padding.get_unchecked(0..16).as_ptr()),
vld1q_u8(padding.get_unchecked(16..32).as_ptr()),
)
}
};
unsafe {
dst.get_unchecked_mut(dst_i..dst_i + 32).copy_from_slice(src.get_unchecked(src_i..src_i + 32));
}
// store to dest unconditionally - we can overwrite the bits we don't like
// later
let ParseStringHelper { bs_bits, quote_bits } = find_bs_bits_and_quote_bits(v0, v1);
if (bs_bits.wrapping_sub(1) & quote_bits) != 0 {
// we encountered quotes first. Move dst to point to quotes and exit
// find out where the quote is...
let quote_dist: u32 = quote_bits.trailing_zeros();
///////////////////////
// Above, check for overflow in case someone has a crazy string (>=4GB?)
// But only add the overflow check when the document itself exceeds 4GB
// Currently unneeded because we refuse to parse docs larger or equal to 4GB.
////////////////////////
// we advance the point, accounting for the fact that we have a NULl termination
dst_i += quote_dist as usize;
unsafe {
self.input
.get_unchecked_mut(idx + len..idx + len + dst_i)
.clone_from_slice(&self.strings.get_unchecked(..dst_i));
let v = self.input.get_unchecked(idx..idx + len + dst_i) as *const [u8]
as *const str;
self.str_offset += dst_i as usize;
return Ok(&*v);
}
// we compare the pointers since we care if they are 'at the same spot'
// not if they are the same value
}
if (quote_bits.wrapping_sub(1) & bs_bits) != 0 {
// find out where the backspace is
let bs_dist: u32 = bs_bits.trailing_zeros();
let escape_char: u8 = unsafe { *src.get_unchecked(src_i + bs_dist as usize + 1) };
// we encountered backslash first. Handle backslash
if escape_char == b'u' {
// move src/dst up to the start; they will be further adjusted
// within the unicode codepoint handling code.
src_i += bs_dist as usize;
dst_i += bs_dist as usize;
let (o, s) = if let Ok(r) = handle_unicode_codepoint(
unsafe { src.get_unchecked(src_i..) },
unsafe { dst.get_unchecked_mut(dst_i..) }
)
{
r
} else {
return Err(self.error(ErrorType::InvlaidUnicodeCodepoint));
};
if o == 0 {
return Err(self.error(ErrorType::InvlaidUnicodeCodepoint));
};
// We moved o steps forword at the destiation and 6 on the source
src_i += s;
dst_i += o;
} else {
// simple 1:1 conversion. Will eat bs_dist+2 characters in input and
// write bs_dist+1 characters to output
// note this may reach beyond the part of the buffer we've actually
// seen. I think this is ok
let escape_result: u8 =
unsafe { *ESCAPE_MAP.get_unchecked(escape_char as usize) };
if escape_result == 0 {
return Err(self.error(ErrorType::InvalidEscape));
}
unsafe {
*dst.get_unchecked_mut(dst_i + bs_dist as usize) = escape_result;
}
src_i += bs_dist as usize + 2;
dst_i += bs_dist as usize + 1;
}
} else {
// they are the same. Since they can't co-occur, it means we encountered
// neither.
src_i += 32;
dst_i += 32;
}
}
}
}