Update event and attribute related structs to str

Author: dralley

Changelog.md

@@ -238,7 +238,6 @@
 - [#416]: `BytesStart::to_borrowed` renamed to `BytesStart::borrow`, the same method
   added to all events
 
-- [#421]: `decode_and_unescape*` methods now does one less allocation if unescaping is not required
 - [#421]: Removed ability to deserialize byte arrays from serde deserializer.
   XML is not able to store binary data directly, you should always use some encoding
   scheme, for example, HEX or Base64

benches/macrobenches.rs

@@ -50,7 +50,7 @@ fn parse_document_from_str(doc: &str) -> XmlResult<()> {
         match criterion::black_box(r.read_event()?) {
             Event::Start(e) | Event::Empty(e) => {
                 for attr in e.attributes() {
-                    criterion::black_box(attr?.decode_and_unescape_value(&r)?);
+                    criterion::black_box(attr?.unescape_value()?);
                 }
             }
             Event::Text(e) => {
@@ -75,7 +75,7 @@ fn parse_document_from_bytes(doc: &[u8]) -> XmlResult<()> {
         match criterion::black_box(r.read_event_into(&mut buf)?) {
             Event::Start(e) | Event::Empty(e) => {
                 for attr in e.attributes() {
-                    criterion::black_box(attr?.decode_and_unescape_value(&r)?);
+                    criterion::black_box(attr?.unescape_value()?);
                 }
             }
             Event::Text(e) => {
@@ -101,7 +101,7 @@ fn parse_document_from_str_with_namespaces(doc: &str) -> XmlResult<()> {
             (resolved_ns, Event::Start(e) | Event::Empty(e)) => {
                 criterion::black_box(resolved_ns);
                 for attr in e.attributes() {
-                    criterion::black_box(attr?.decode_and_unescape_value(&r)?);
+                    criterion::black_box(attr?.unescape_value()?);
                 }
             }
             (resolved_ns, Event::Text(e)) => {
@@ -129,7 +129,7 @@ fn parse_document_from_bytes_with_namespaces(doc: &[u8]) -> XmlResult<()> {
             (resolved_ns, Event::Start(e) | Event::Empty(e)) => {
                 criterion::black_box(resolved_ns);
                 for attr in e.attributes() {
-                    criterion::black_box(attr?.decode_and_unescape_value(&r)?);
+                    criterion::black_box(attr?.unescape_value()?);
                 }
             }
             (resolved_ns, Event::Text(e)) => {

examples/custom_entities.rs

@@ -33,7 +33,7 @@ fn main() -> Result<(), Box<dyn std::error::Error>> {
     loop {
         match reader.read_event() {
             Ok(Event::DocType(ref e)) => {
-                for cap in entity_re.captures_iter(e) {
+                for cap in entity_re.captures_iter(e.as_bytes()) {
                     custom_entities.insert(
                         String::from_utf8(cap[1].to_owned())?,
                         String::from_utf8(cap[2].to_owned())?,
@@ -46,7 +46,7 @@ fn main() -> Result<(), Box<dyn std::error::Error>> {
                         .attributes()
                         .map(|a| {
                             a.unwrap()
-                                .decode_and_unescape_value_with(&reader, |ent| {
+                                .unescape_value_with(|ent| {
                                     custom_entities.get(ent).map(|s| s.as_str())
                                 })
                                 .unwrap()

src/escapei.rs

@@ -131,8 +131,9 @@ pub(crate) fn _escape<F: Fn(u8) -> bool>(raw: &str, escape_chars: F) -> Cow<str>
         if let Some(raw) = bytes.get(pos..) {
             escaped.extend_from_slice(raw);
         }
-        // SAFETY: we operate on UTF-8 input and search for an one byte chars only,
-        // so all slices that was put to the `escaped` is a valid UTF-8 encoded strings
+        // SAFETY: we operate on UTF-8 input and search for only one-byte chars, so
+        // the end point will always be at a character boundary, and we can yield a
+        // valid UTF-8 slice always.
         // TODO: Can be replaced with `unsafe { String::from_utf8_unchecked() }`
         // if unsafe code will be allowed
         Cow::Owned(String::from_utf8(escaped).unwrap())