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scalar/escape: move exported fns to top, document tag_uri_unescape

This commit is contained in:
Paul Stemmet 2021-06-26 07:50:44 +00:00
parent c7a2b028f0
commit 20760ba9cd
Signed by: Paul Stemmet
GPG Key ID: EDEA539F594E7E75
1 changed files with 60 additions and 54 deletions
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114
src/scanner/scalar/escape.rs
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@ -67,60 +67,13 @@ pub(super) fn flow_unescape(base: &str, scratch: &mut Vec<u8>) -> Result<usize>
Ok(base.len() - buffer.len())
}
/// Writes a UTF8 codepoint to the scratch space
fn write_unicode_point(base: &str, scratch: &mut Vec<u8>, codepoint_len: u8) -> Result<usize>
{
let mut buffer = base;
let mut i = 0;
let mut value: u32 = 0;
if codepoint_len < 1
{
return Ok(0);
}
while i < codepoint_len
{
match buffer.as_bytes().first()
{
None => return Err(ScanError::UnexpectedEOF),
Some(c) if !c.is_ascii_hexdigit() => return Err(ScanError::UnknownEscape),
Some(b) => value = (value << 4) + as_hex(*b) as u32,
}
advance!(buffer, 1, i);
}
// Bit shift the value into the correct byte configuration
// for UTF8
match value
{
// v <= 127 (ASCII)
v if v <= 0x7F => scratch.push(v as u8),
// v <= 2047
v if v <= 0x7FF =>
{
scratch.extend_from_slice(&[0xC0 | (v >> 6) as u8, 0x80 | (v & 0x3F) as u8])
},
// v <= 65535
v if v <= 0xFFFF => scratch.extend_from_slice(&[
0xE0 | (v >> 12) as u8,
0x80 | ((v >> 6) & 0x3F) as u8,
0x80 | (v & 0x3F) as u8,
]),
// Otherwise it must be a full 4 byte code point
v => scratch.extend_from_slice(&[
0xF0 | (v >> 18) as u8,
0x80 | ((v >> 12) & 0x3F) as u8,
0x80 | ((v >> 6) & 0x3F) as u8,
0x80 | (v & 0x3F) as u8,
]),
}
Ok(codepoint_len as usize)
}
fn tag_uri_unescape(base: &str, scratch: &mut Vec<u8>, _directive: bool) -> Result<usize>
/// Unescape a percent encoded UTF8 tag escape sequence as
/// defined in [Section 5.6][Link], writing the code point
/// to the scratch, returning the length of .base consumed.
///
/// [Link]: https://yaml.org/spec/1.2/spec.html#ns-uri-char
pub(super) fn tag_uri_unescape(base: &str, scratch: &mut Vec<u8>, _directive: bool)
-> Result<usize>
{
let mut buffer = base;
let mut codepoint_len: i8 = 0;
@ -175,6 +128,59 @@ fn tag_uri_unescape(base: &str, scratch: &mut Vec<u8>, _directive: bool) -> Resu
Ok(base.len() - buffer.len())
}
/// Writes a UTF8 codepoint to the scratch space
fn write_unicode_point(base: &str, scratch: &mut Vec<u8>, codepoint_len: u8) -> Result<usize>
{
let mut buffer = base;
let mut i = 0;
let mut value: u32 = 0;
if codepoint_len < 1
{
return Ok(0);
}
while i < codepoint_len
{
match buffer.as_bytes().first()
{
None => return Err(ScanError::UnexpectedEOF),
Some(c) if !c.is_ascii_hexdigit() => return Err(ScanError::UnknownEscape),
Some(b) => value = (value << 4) + as_hex(*b) as u32,
}
advance!(buffer, 1, i);
}
// Bit shift the value into the correct byte configuration
// for UTF8
match value
{
// v <= 127 (ASCII)
v if v <= 0x7F => scratch.push(v as u8),
// v <= 2047
v if v <= 0x7FF =>
{
scratch.extend_from_slice(&[0xC0 | (v >> 6) as u8, 0x80 | (v & 0x3F) as u8])
},
// v <= 65535
v if v <= 0xFFFF => scratch.extend_from_slice(&[
0xE0 | (v >> 12) as u8,
0x80 | ((v >> 6) & 0x3F) as u8,
0x80 | (v & 0x3F) as u8,
]),
// Otherwise it must be a full 4 byte code point
v => scratch.extend_from_slice(&[
0xF0 | (v >> 18) as u8,
0x80 | ((v >> 12) & 0x3F) as u8,
0x80 | ((v >> 6) & 0x3F) as u8,
0x80 | (v & 0x3F) as u8,
]),
}
Ok(codepoint_len as usize)
}
/*
* Inclusive range suggested by clippy here is 5-10%
* slower than doing it by hand, see