summaryrefslogtreecommitdiffstats
path: root/third_party/rust/bumpalo/src/collections/str/lossy.rs
diff options
context:
space:
mode:
authorDaniel Baumann <daniel.baumann@progress-linux.org>2024-04-07 19:33:14 +0000
committerDaniel Baumann <daniel.baumann@progress-linux.org>2024-04-07 19:33:14 +0000
commit36d22d82aa202bb199967e9512281e9a53db42c9 (patch)
tree105e8c98ddea1c1e4784a60a5a6410fa416be2de /third_party/rust/bumpalo/src/collections/str/lossy.rs
parentInitial commit. (diff)
downloadfirefox-esr-36d22d82aa202bb199967e9512281e9a53db42c9.tar.xz
firefox-esr-36d22d82aa202bb199967e9512281e9a53db42c9.zip
Adding upstream version 115.7.0esr.upstream/115.7.0esr
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to 'third_party/rust/bumpalo/src/collections/str/lossy.rs')
-rw-r--r--third_party/rust/bumpalo/src/collections/str/lossy.rs209
1 files changed, 209 insertions, 0 deletions
diff --git a/third_party/rust/bumpalo/src/collections/str/lossy.rs b/third_party/rust/bumpalo/src/collections/str/lossy.rs
new file mode 100644
index 0000000000..b1012a4129
--- /dev/null
+++ b/third_party/rust/bumpalo/src/collections/str/lossy.rs
@@ -0,0 +1,209 @@
+// Copyright 2012-2017 The Rust Project Developers. See the COPYRIGHT
+// file at the top-level directory of this distribution and at
+// http://rust-lang.org/COPYRIGHT.
+//
+// Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
+// http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
+// <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
+// option. This file may not be copied, modified, or distributed
+// except according to those terms.
+
+use crate::collections::str as core_str;
+use core::char;
+use core::fmt;
+use core::fmt::Write;
+use core::str;
+
+/// Lossy UTF-8 string.
+pub struct Utf8Lossy<'a> {
+ bytes: &'a [u8],
+}
+
+impl<'a> Utf8Lossy<'a> {
+ pub fn from_bytes(bytes: &'a [u8]) -> Utf8Lossy<'a> {
+ Utf8Lossy { bytes }
+ }
+
+ pub fn chunks(&self) -> Utf8LossyChunksIter<'a> {
+ Utf8LossyChunksIter {
+ source: &self.bytes,
+ }
+ }
+}
+
+/// Iterator over lossy UTF-8 string
+#[allow(missing_debug_implementations)]
+pub struct Utf8LossyChunksIter<'a> {
+ source: &'a [u8],
+}
+
+#[derive(PartialEq, Eq, Debug)]
+pub struct Utf8LossyChunk<'a> {
+ /// Sequence of valid chars.
+ /// Can be empty between broken UTF-8 chars.
+ pub valid: &'a str,
+ /// Single broken char, empty if none.
+ /// Empty iff iterator item is last.
+ pub broken: &'a [u8],
+}
+
+impl<'a> Iterator for Utf8LossyChunksIter<'a> {
+ type Item = Utf8LossyChunk<'a>;
+
+ fn next(&mut self) -> Option<Utf8LossyChunk<'a>> {
+ if self.source.is_empty() {
+ return None;
+ }
+
+ const TAG_CONT_U8: u8 = 128;
+ fn unsafe_get(xs: &[u8], i: usize) -> u8 {
+ unsafe { *xs.get_unchecked(i) }
+ }
+ fn safe_get(xs: &[u8], i: usize) -> u8 {
+ if i >= xs.len() {
+ 0
+ } else {
+ unsafe_get(xs, i)
+ }
+ }
+
+ let mut i = 0;
+ while i < self.source.len() {
+ let i_ = i;
+
+ let byte = unsafe_get(self.source, i);
+ i += 1;
+
+ if byte < 128 {
+ } else {
+ let w = core_str::utf8_char_width(byte);
+
+ macro_rules! error {
+ () => {{
+ unsafe {
+ let r = Utf8LossyChunk {
+ valid: str::from_utf8_unchecked(&self.source[0..i_]),
+ broken: &self.source[i_..i],
+ };
+ self.source = &self.source[i..];
+ return Some(r);
+ }
+ }};
+ }
+
+ match w {
+ 2 => {
+ if safe_get(self.source, i) & 192 != TAG_CONT_U8 {
+ error!();
+ }
+ i += 1;
+ }
+ 3 => {
+ match (byte, safe_get(self.source, i)) {
+ (0xE0, 0xA0..=0xBF) => (),
+ (0xE1..=0xEC, 0x80..=0xBF) => (),
+ (0xED, 0x80..=0x9F) => (),
+ (0xEE..=0xEF, 0x80..=0xBF) => (),
+ _ => {
+ error!();
+ }
+ }
+ i += 1;
+ if safe_get(self.source, i) & 192 != TAG_CONT_U8 {
+ error!();
+ }
+ i += 1;
+ }
+ 4 => {
+ match (byte, safe_get(self.source, i)) {
+ (0xF0, 0x90..=0xBF) => (),
+ (0xF1..=0xF3, 0x80..=0xBF) => (),
+ (0xF4, 0x80..=0x8F) => (),
+ _ => {
+ error!();
+ }
+ }
+ i += 1;
+ if safe_get(self.source, i) & 192 != TAG_CONT_U8 {
+ error!();
+ }
+ i += 1;
+ if safe_get(self.source, i) & 192 != TAG_CONT_U8 {
+ error!();
+ }
+ i += 1;
+ }
+ _ => {
+ error!();
+ }
+ }
+ }
+ }
+
+ let r = Utf8LossyChunk {
+ valid: unsafe { str::from_utf8_unchecked(self.source) },
+ broken: &[],
+ };
+ self.source = &[];
+ Some(r)
+ }
+}
+
+impl<'a> fmt::Display for Utf8Lossy<'a> {
+ fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
+ // If we're the empty string then our iterator won't actually yield
+ // anything, so perform the formatting manually
+ if self.bytes.is_empty() {
+ return "".fmt(f);
+ }
+
+ for Utf8LossyChunk { valid, broken } in self.chunks() {
+ // If we successfully decoded the whole chunk as a valid string then
+ // we can return a direct formatting of the string which will also
+ // respect various formatting flags if possible.
+ if valid.len() == self.bytes.len() {
+ assert!(broken.is_empty());
+ return valid.fmt(f);
+ }
+
+ f.write_str(valid)?;
+ if !broken.is_empty() {
+ f.write_char(char::REPLACEMENT_CHARACTER)?;
+ }
+ }
+ Ok(())
+ }
+}
+
+impl<'a> fmt::Debug for Utf8Lossy<'a> {
+ fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
+ f.write_char('"')?;
+
+ for Utf8LossyChunk { valid, broken } in self.chunks() {
+ // Valid part.
+ // Here we partially parse UTF-8 again which is suboptimal.
+ {
+ let mut from = 0;
+ for (i, c) in valid.char_indices() {
+ let esc = c.escape_debug();
+ // If char needs escaping, flush backlog so far and write, else skip
+ if esc.len() != 1 {
+ f.write_str(&valid[from..i])?;
+ for c in esc {
+ f.write_char(c)?;
+ }
+ from = i + c.len_utf8();
+ }
+ }
+ f.write_str(&valid[from..])?;
+ }
+
+ // Broken parts of string as hex escape.
+ for &b in broken {
+ write!(f, "\\x{:02x}", b)?;
+ }
+ }
+
+ f.write_char('"')
+ }
+}