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utf8 validation: Cleanup code by renaming index variable

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This commit is contained in:
Ulrik Sverdrup 2016-11-22 13:47:45 +01:00
parent 4a8b04eda0
commit 0dffc1e193
1 changed files with 15 additions and 15 deletions
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30
src/libcore/str/mod.rs
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@ -1215,15 +1215,15 @@ fn contains_nonascii(x: usize) -> bool {
/// invalid sequence.
#[inline(always)]
fn run_utf8_validation(v: &[u8]) -> Result<(), Utf8Error> {
let mut offset = 0;
let mut index = 0;
let len = v.len();
let usize_bytes = mem::size_of::<usize>();
let ascii_block_size = 2 * usize_bytes;
let blocks_end = if len >= ascii_block_size { len - ascii_block_size + 1 } else { 0 };
while offset < len {
let old_offset = offset;
while index < len {
let old_offset = index;
macro_rules! err { () => {{
return Err(Utf8Error {
valid_up_to: old_offset
@ -1231,15 +1231,15 @@ fn run_utf8_validation(v: &[u8]) -> Result<(), Utf8Error> {
}}}
macro_rules! next { () => {{
offset += 1;
index += 1;
// we needed data, but there was none: error!
if offset >= len {
if index >= len {
err!()
}
v[offset]
v[index]
}}}
let first = v[offset];
let first = v[index];
if first >= 128 {
let w = UTF8_CHAR_WIDTH[first as usize];
let second = next!();
@ -1282,17 +1282,17 @@ fn run_utf8_validation(v: &[u8]) -> Result<(), Utf8Error> {
}
_ => err!()
}
offset += 1;
index += 1;
} else {
// Ascii case, try to skip forward quickly.
// When the pointer is aligned, read 2 words of data per iteration
// until we find a word containing a non-ascii byte.
let ptr = v.as_ptr();
let align = (ptr as usize + offset) & (usize_bytes - 1);
let align = (ptr as usize + index) & (usize_bytes - 1);
if align == 0 {
while offset < blocks_end {
while index < blocks_end {
unsafe {
let block = ptr.offset(offset as isize) as *const usize;
let block = ptr.offset(index as isize) as *const usize;
// break if there is a nonascii byte
let zu = contains_nonascii(*block);
let zv = contains_nonascii(*block.offset(1));
@ -1300,14 +1300,14 @@ fn run_utf8_validation(v: &[u8]) -> Result<(), Utf8Error> {
break;
}
}
offset += ascii_block_size;
index += ascii_block_size;
}
// step from the point where the wordwise loop stopped
while offset < len && v[offset] < 128 {
offset += 1;
while index < len && v[index] < 128 {
index += 1;
}
} else {
offset += 1;
index += 1;
}
}
}