Optimize some span operations

Decode span data only once
This commit is contained in:
Vadim Petrochenkov 2017-10-21 17:21:02 +03:00
parent 2e6a1a9fb4
commit 06f7f1f68b
2 changed files with 58 additions and 30 deletions

View File

@ -370,17 +370,18 @@ impl<'gcx> HashStable<StableHashingContext<'gcx>> for Span {
// If this is not an empty or invalid span, we want to hash the last
// position that belongs to it, as opposed to hashing the first
// position past it.
let span_hi = if self.hi() > self.lo() {
let span = self.data();
let span_hi = if span.hi > span.lo {
// We might end up in the middle of a multibyte character here,
// but that's OK, since we are not trying to decode anything at
// this position.
self.hi() - ::syntax_pos::BytePos(1)
span.hi - ::syntax_pos::BytePos(1)
} else {
self.hi()
span.hi
};
{
let loc1 = hcx.codemap().byte_pos_to_line_and_col(self.lo());
let loc1 = hcx.codemap().byte_pos_to_line_and_col(span.lo);
let loc1 = loc1.as_ref()
.map(|&(ref fm, line, col)| (&fm.name[..], line, col.to_usize()))
.unwrap_or(("???", 0, 0));
@ -413,7 +414,7 @@ impl<'gcx> HashStable<StableHashingContext<'gcx>> for Span {
}
}
if self.ctxt() == SyntaxContext::empty() {
if span.ctxt == SyntaxContext::empty() {
0u8.hash_stable(hcx, hasher);
} else {
1u8.hash_stable(hcx, hasher);

View File

@ -75,6 +75,21 @@ pub struct SpanData {
pub ctxt: SyntaxContext,
}
impl SpanData {
#[inline]
pub fn with_lo(&self, lo: BytePos) -> Span {
Span::new(lo, self.hi, self.ctxt)
}
#[inline]
pub fn with_hi(&self, hi: BytePos) -> Span {
Span::new(self.lo, hi, self.ctxt)
}
#[inline]
pub fn with_ctxt(&self, ctxt: SyntaxContext) -> Span {
Span::new(self.lo, self.hi, ctxt)
}
}
// The interner in thread-local, so `Span` shouldn't move between threads.
impl !Send for Span {}
impl !Sync for Span {}
@ -109,8 +124,7 @@ impl Span {
}
#[inline]
pub fn with_lo(self, lo: BytePos) -> Span {
let base = self.data();
Span::new(lo, base.hi, base.ctxt)
self.data().with_lo(lo)
}
#[inline]
pub fn hi(self) -> BytePos {
@ -118,8 +132,7 @@ impl Span {
}
#[inline]
pub fn with_hi(self, hi: BytePos) -> Span {
let base = self.data();
Span::new(base.lo, hi, base.ctxt)
self.data().with_hi(hi)
}
#[inline]
pub fn ctxt(self) -> SyntaxContext {
@ -127,20 +140,21 @@ impl Span {
}
#[inline]
pub fn with_ctxt(self, ctxt: SyntaxContext) -> Span {
let base = self.data();
Span::new(base.lo, base.hi, ctxt)
self.data().with_ctxt(ctxt)
}
/// Returns a new span representing just the end-point of this span
pub fn end_point(self) -> Span {
let lo = cmp::max(self.hi().0 - 1, self.lo().0);
self.with_lo(BytePos(lo))
let span = self.data();
let lo = cmp::max(span.hi.0 - 1, span.lo.0);
span.with_lo(BytePos(lo))
}
/// Returns a new span representing the next character after the end-point of this span
pub fn next_point(self) -> Span {
let lo = cmp::max(self.hi().0, self.lo().0 + 1);
Span::new(BytePos(lo), BytePos(lo), self.ctxt())
let span = self.data();
let lo = cmp::max(span.hi.0, span.lo.0 + 1);
Span::new(BytePos(lo), BytePos(lo), span.ctxt)
}
/// Returns `self` if `self` is not the dummy span, and `other` otherwise.
@ -150,7 +164,9 @@ impl Span {
/// Return true if `self` fully encloses `other`.
pub fn contains(self, other: Span) -> bool {
self.lo() <= other.lo() && other.hi() <= self.hi()
let span = self.data();
let other = other.data();
span.lo <= other.lo && other.hi <= span.hi
}
/// Return true if the spans are equal with regards to the source text.
@ -158,13 +174,17 @@ impl Span {
/// Use this instead of `==` when either span could be generated code,
/// and you only care that they point to the same bytes of source text.
pub fn source_equal(&self, other: &Span) -> bool {
self.lo() == other.lo() && self.hi() == other.hi()
let span = self.data();
let other = other.data();
span.lo == other.lo && span.hi == other.hi
}
/// Returns `Some(span)`, where the start is trimmed by the end of `other`
pub fn trim_start(self, other: Span) -> Option<Span> {
if self.hi() > other.hi() {
Some(self.with_lo(cmp::max(self.lo(), other.hi())))
let span = self.data();
let other = other.data();
if span.hi > other.hi {
Some(span.with_lo(cmp::max(span.lo, other.hi)))
} else {
None
}
@ -268,29 +288,35 @@ impl Span {
/// Return a `Span` that would enclose both `self` and `end`.
pub fn to(self, end: Span) -> Span {
let span = self.data();
let end = end.data();
Span::new(
cmp::min(self.lo(), end.lo()),
cmp::max(self.hi(), end.hi()),
cmp::min(span.lo, end.lo),
cmp::max(span.hi, end.hi),
// FIXME(jseyfried): self.ctxt should always equal end.ctxt here (c.f. issue #23480)
if self.ctxt() == SyntaxContext::empty() { end.ctxt() } else { self.ctxt() },
if span.ctxt == SyntaxContext::empty() { end.ctxt } else { span.ctxt },
)
}
/// Return a `Span` between the end of `self` to the beginning of `end`.
pub fn between(self, end: Span) -> Span {
let span = self.data();
let end = end.data();
Span::new(
self.hi(),
end.lo(),
if end.ctxt() == SyntaxContext::empty() { end.ctxt() } else { self.ctxt() },
span.hi,
end.lo,
if end.ctxt == SyntaxContext::empty() { end.ctxt } else { span.ctxt },
)
}
/// Return a `Span` between the beginning of `self` to the beginning of `end`.
pub fn until(self, end: Span) -> Span {
let span = self.data();
let end = end.data();
Span::new(
self.lo(),
end.lo(),
if end.ctxt() == SyntaxContext::empty() { end.ctxt() } else { self.ctxt() },
span.lo,
end.lo,
if end.ctxt == SyntaxContext::empty() { end.ctxt } else { span.ctxt },
)
}
}
@ -316,13 +342,14 @@ impl Default for Span {
impl serialize::UseSpecializedEncodable for Span {
fn default_encode<S: Encoder>(&self, s: &mut S) -> Result<(), S::Error> {
let span = self.data();
s.emit_struct("Span", 2, |s| {
s.emit_struct_field("lo", 0, |s| {
self.lo().encode(s)
span.lo.encode(s)
})?;
s.emit_struct_field("hi", 1, |s| {
self.hi().encode(s)
span.hi.encode(s)
})
})
}