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//! This is an implementation of [`Reader`] for reading from a [`BufRead`] as↩
//! underlying byte stream.↩
↩
use std::fs::File;↩
use std::io::{self, BufRead, BufReader};↩
use std::path::Path;↩
↩
use crate::errors::{Error, Result};↩
use crate::events::Event;↩
use crate::name::QName;↩
use crate::parser::Parser;↩
use crate::reader::{BangType, ReadTextResult, Reader, Span, XmlSource};↩
use crate::utils::is_whitespace;↩
↩
macro_rules! impl_buffered_source {↩
($($lf:lifetime, $reader:tt, $async:ident, $await:ident)?) => {↩
#[cfg(not(feature = "encoding"))]↩
#[inline]↩
$($async)? fn remove_utf8_bom(&mut self) -> io::Result<()> {↩
use crate::encoding::UTF8_BOM;↩
↩
loop {↩
break match self $(.$reader)? .fill_buf() $(.$await)? {↩
Ok(n) => {↩
if n.starts_with(UTF8_BOM) {↩
self $(.$reader)? .consume(UTF8_BOM.len());↩
}↩
Ok(())↩
},↩
Err(ref e) if e.kind() == io::ErrorKind::Interrupted => continue,↩
Err(e) => Err(e),↩
};↩
}↩
}↩
↩
#[cfg(feature = "encoding")]↩
#[inline]↩
$($async)? fn detect_encoding(&mut self) -> io::Result<Option<&'static encoding_rs::Encoding>> {↩
loop {↩
break match self $(.$reader)? .fill_buf() $(.$await)? {↩
Ok(n) => if let Some((enc, bom_len)) = crate::encoding::detect_encoding(n) {↩
self $(.$reader)? .consume(bom_len);↩
Ok(Some(enc))↩
} else {↩
Ok(None)↩
},↩
Err(ref e) if e.kind() == io::ErrorKind::Interrupted => continue,↩
Err(e) => Err(e),↩
};↩
}↩
}↩
↩
#[inline]↩
$($async)? fn read_text $(<$lf>)? (↩
&mut self,↩
buf: &'b mut Vec<u8>,↩
position: &mut u64,↩
) -> ReadTextResult<'b, &'b mut Vec<u8>> {↩
let mut read = 0;↩
let start = buf.len();↩
loop {↩
let available = match self $(.$reader)? .fill_buf() $(.$await)? {↩
Ok(n) if n.is_empty() => break,↩
Ok(n) => n,↩
Err(ref e) if e.kind() == io::ErrorKind::Interrupted => continue,↩
Err(e) => {↩
*position += read;↩
return ReadTextResult::Err(e);↩
}↩
};↩
↩
match memchr::memchr(b'<', available) {↩
// Special handling is needed only on the first iteration.↩
// On next iterations we already read something and should emit Text event↩
Some(0) if read == 0 => {↩
self $(.$reader)? .consume(1);↩
*position += 1;↩
return ReadTextResult::Markup(buf);↩
}↩
Some(i) => {↩
buf.extend_from_slice(&available[..i]);↩
↩
let used = i + 1;↩
self $(.$reader)? .consume(used);↩
read += used as u64;↩
↩
*position += read;↩
return ReadTextResult::UpToMarkup(&buf[start..]);↩
}↩
None => {↩
buf.extend_from_slice(available);↩
↩
let used = available.len();↩
self $(.$reader)? .consume(used);↩
read += used as u64;↩
}↩
}↩
}↩
↩
*position += read;↩
ReadTextResult::UpToEof(&buf[start..])↩
}↩
↩
#[inline]↩
$($async)? fn read_with<$($lf,)? P: Parser>(↩
&mut self,↩
mut parser: P,↩
buf: &'b mut Vec<u8>,↩
position: &mut u64,↩
) -> Result<&'b [u8]> {↩
let mut read = 0;↩
let start = buf.len();↩
loop {↩
let available = match self $(.$reader)? .fill_buf() $(.$await)? {↩
Ok(n) if n.is_empty() => break,↩
Ok(n) => n,↩
Err(ref e) if e.kind() == io::ErrorKind::Interrupted => continue,↩
Err(e) => {↩
*position += read;↩
return Err(Error::Io(e.into()));↩
}↩
};↩
↩
if let Some(i) = parser.feed(available) {↩
buf.extend_from_slice(&available[..i]);↩
↩
// +1 for `>` which we do not include↩
self $(.$reader)? .consume(i + 1);↩
read += i as u64 + 1;↩
↩
*position += read;↩
return Ok(&buf[start..]);↩
}↩
↩
// The `>` symbol not yet found, continue reading↩
buf.extend_from_slice(available);↩
↩
let used = available.len();↩
self $(.$reader)? .consume(used);↩
read += used as u64;↩
}↩
↩
*position += read;↩
Err(Error::Syntax(P::eof_error()))↩
}↩
↩
#[inline]↩
$($async)? fn read_bang_element $(<$lf>)? (↩
&mut self,↩
buf: &'b mut Vec<u8>,↩
position: &mut u64,↩
) -> Result<(BangType, &'b [u8])> {↩
// Peeked one bang ('!') before being called, so it's guaranteed to↩
// start with it.↩
let start = buf.len();↩
let mut read = 1;↩
buf.push(b'!');↩
self $(.$reader)? .consume(1);↩
↩
let mut bang_type = BangType::new(self.peek_one() $(.$await)? ?)?;↩
↩
loop {↩
match self $(.$reader)? .fill_buf() $(.$await)? {↩
// Note: Do not update position, so the error points to↩
// somewhere sane rather than at the EOF↩
Ok(n) if n.is_empty() => break,↩
Ok(available) => {↩
// We only parse from start because we don't want to consider↩
// whatever is in the buffer before the bang element↩
if let Some((consumed, used)) = bang_type.parse(&buf[start..], available) {↩
buf.extend_from_slice(consumed);↩
↩
self $(.$reader)? .consume(used);↩
read += used as u64;↩
↩
*position += read;↩
return Ok((bang_type, &buf[start..]));↩
} else {↩
buf.extend_from_slice(available);↩
↩
let used = available.len();↩
self $(.$reader)? .consume(used);↩
read += used as u64;↩
}↩
}↩
Err(ref e) if e.kind() == io::ErrorKind::Interrupted => continue,↩
Err(e) => {↩
*position += read;↩
return Err(Error::Io(e.into()));↩
}↩
}↩
}↩
↩
*position += read;↩
Err(bang_type.to_err().into())↩
}↩
↩
#[inline]↩
$($async)? fn skip_whitespace(&mut self, position: &mut u64) -> io::Result<()> {↩
loop {↩
break match self $(.$reader)? .fill_buf() $(.$await)? {↩
Ok(n) => {↩
let count = n.iter().position(|b| !is_whitespace(*b)).unwrap_or(n.len());↩
if count > 0 {↩
self $(.$reader)? .consume(count);↩
*position += count as u64;↩
continue;↩
} else {↩
Ok(())↩
}↩
}↩
Err(ref e) if e.kind() == io::ErrorKind::Interrupted => continue,↩
Err(e) => Err(e),↩
};↩
}↩
}↩
↩
#[inline]↩
$($async)? fn peek_one(&mut self) -> io::Result<Option<u8>> {↩
loop {↩
break match self $(.$reader)? .fill_buf() $(.$await)? {↩
Ok(n) => Ok(n.first().cloned()),↩
Err(ref e) if e.kind() == io::ErrorKind::Interrupted => continue,↩
Err(e) => Err(e),↩
};↩
}↩
}↩
};↩
}↩
↩
// Make it public for use in async implementations.↩
// New rustc reports↩
// > warning: the item `impl_buffered_source` is imported redundantly↩
// so make it public only when async feature is enabled↩
#[cfg(feature = "async-tokio")]↩
pub(super) use impl_buffered_source;↩
↩
/// Implementation of `XmlSource` for any `BufRead` reader using a user-given↩
/// `Vec<u8>` as buffer that will be borrowed by events.↩
impl<'b, R: BufRead> XmlSource<'b, &'b mut Vec<u8>> for R {↩
impl_buffered_source!();↩
}↩
↩
////////////////////////////////////////////////////////////////////////////////////////////////////↩
↩
/// This is an implementation for reading from a [`BufRead`] as underlying byte stream.↩
impl<R: BufRead> Reader<R> {↩
/// Reads the next `Event`.↩
///↩
/// This is the main entry point for reading XML `Event`s.↩
///↩
/// `Event`s borrow `buf` and can be converted to own their data if needed (uses `Cow`↩
/// internally).↩
///↩
/// Having the possibility to control the internal buffers gives you some additional benefits↩
/// such as:↩
///↩
/// - Reduce the number of allocations by reusing the same buffer. For constrained systems,↩
/// you can call `buf.clear()` once you are done with processing the event (typically at the↩
/// end of your loop).↩
/// - Reserve the buffer length if you know the file size (using `Vec::with_capacity`).↩
///↩
/// # Examples↩
///↩
/// ```↩
/// # use pretty_assertions::assert_eq;↩
/// use quick_xml::events::Event;↩
/// use quick_xml::reader::Reader;↩
///↩
/// let xml = r#"<tag1 att1 = "test">↩
/// <tag2><!--Test comment-->Test</tag2>↩
/// <tag2>Test 2</tag2>↩
/// </tag1>"#;↩
/// let mut reader = Reader::from_str(xml);↩
/// reader.config_mut().trim_text(true);↩
/// let mut count = 0;↩
/// let mut buf = Vec::new();↩
/// let mut txt = Vec::new();↩
/// loop {↩
/// match reader.read_event_into(&mut buf) {↩
/// Ok(Event::Start(_)) => count += 1,↩
/// Ok(Event::Text(e)) => txt.push(e.unescape().unwrap().into_owned()),↩
/// Err(e) => panic!("Error at position {}: {:?}", reader.error_position(), e),↩
/// Ok(Event::Eof) => break,↩
/// _ => (),↩
/// }↩
/// buf.clear();↩
/// }↩
/// assert_eq!(count, 3);↩
/// assert_eq!(txt, vec!["Test".to_string(), "Test 2".to_string()]);↩
/// ```↩
#[inline]↩
pub fn read_event_into<'b>(&mut self, buf: &'b mut Vec<u8>) -> Result<Event<'b>> {↩
self.read_event_impl(buf)↩
}↩
↩
/// Reads until end element is found using provided buffer as intermediate↩
/// storage for events content. This function is supposed to be called after↩
/// you already read a [`Start`] event.↩
///↩
/// Returns a span that cover content between `>` of an opening tag and `<` of↩
/// a closing tag or an empty slice, if [`expand_empty_elements`] is set and↩
/// this method was called after reading expanded [`Start`] event.↩
///↩
/// Manages nested cases where parent and child elements have the _literally_↩
/// same name.↩
///↩
/// If a corresponding [`End`] event is not found, an error of type [`Error::IllFormed`]↩
/// will be returned. In particularly, that error will be returned if you call↩
/// this method without consuming the corresponding [`Start`] event first.↩
///↩
/// If your reader created from a string slice or byte array slice, it is↩
/// better to use [`read_to_end()`] method, because it will not copy bytes↩
/// into intermediate buffer.↩
///↩
/// The provided `buf` buffer will be filled only by one event content at time.↩
/// Before reading of each event the buffer will be cleared. If you know an↩
/// appropriate size of each event, you can preallocate the buffer to reduce↩
/// number of reallocations.↩
///↩
/// The `end` parameter should contain name of the end element _in the reader↩
/// encoding_. It is good practice to always get that parameter using↩
/// [`BytesStart::to_end()`] method.↩
///↩
/// The correctness of the skipped events does not checked, if you disabled↩
/// the [`check_end_names`] option.↩
///↩
/// # Namespaces↩
///↩
/// While the `Reader` does not support namespace resolution, namespaces↩
/// does not change the algorithm for comparing names. Although the names↩
/// `a:name` and `b:name` where both prefixes `a` and `b` resolves to the↩
/// same namespace, are semantically equivalent, `</b:name>` cannot close↩
/// `<a:name>`, because according to [the specification]↩
///↩
/// > The end of every element that begins with a **start-tag** MUST be marked↩
/// > by an **end-tag** containing a name that echoes the element's type as↩
/// > given in the **start-tag**↩
///↩
/// # Examples↩
///↩
/// This example shows, how you can skip XML content after you read the↩
/// start event.↩
///↩
/// ```↩
/// # use pretty_assertions::assert_eq;↩
/// use quick_xml::events::{BytesStart, Event};↩
/// use quick_xml::reader::Reader;↩
///↩
/// let mut reader = Reader::from_str(r#"↩
/// <outer>↩
/// <inner>↩
/// <inner></inner>↩
/// <inner/>↩
/// <outer></outer>↩
/// <outer/>↩
/// </inner>↩
/// </outer>↩
/// "#);↩
/// reader.config_mut().trim_text(true);↩
/// let mut buf = Vec::new();↩
///↩
/// let start = BytesStart::new("outer");↩
/// let end = start.to_end().into_owned();↩
///↩
/// // First, we read a start event...↩
/// assert_eq!(reader.read_event_into(&mut buf).unwrap(), Event::Start(start));↩
///↩
/// // ...then, we could skip all events to the corresponding end event.↩
/// // This call will correctly handle nested <outer> elements.↩
/// // Note, however, that this method does not handle namespaces.↩
/// reader.read_to_end_into(end.name(), &mut buf).unwrap();↩
///↩
/// // At the end we should get an Eof event, because we ate the whole XML↩
/// assert_eq!(reader.read_event_into(&mut buf).unwrap(), Event::Eof);↩
/// ```↩
///↩
/// [`Start`]: Event::Start↩
/// [`End`]: Event::End↩
/// [`BytesStart::to_end()`]: crate::events::BytesStart::to_end↩
/// [`read_to_end()`]: Self::read_to_end↩
/// [`expand_empty_elements`]: crate::reader::Config::expand_empty_elements↩
/// [`check_end_names`]: crate::reader::Config::check_end_names↩
pub fn read_to_end_into(&mut self, end: QName, buf: &mut Vec<u8>) -> Result<Span> {↩
Ok(read_to_end!(self, end, buf, read_event_impl, {↩
buf.clear();↩
}))↩
}↩
}↩
↩
impl Reader<BufReader<File>> {↩
/// Creates an XML reader from a file path.↩
pub fn from_file<P: AsRef<Path>>(path: P) -> Result<Self> {↩
let file = File::open(path)?;↩
let reader = BufReader::new(file);↩
Ok(Self::from_reader(reader))↩
}↩
}↩
↩
#[cfg(test)]↩
mod test {↩
use crate::reader::test::check;↩
use crate::reader::XmlSource;↩
↩
/// Default buffer constructor just pass the byte array from the test↩
fn identity<T>(input: T) -> T {↩
input↩
}↩
↩
check!(↩
#[test]↩
read_event_impl,↩
read_until_close,↩
identity,↩
&mut Vec::new()↩
);↩
}↩