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use base64;
use line_wrap;
use std::{borrow::Cow, io::Write};
use xml_rs::{
name::Name,
namespace::Namespace,
writer::{EmitterConfig, Error as XmlWriterError, EventWriter, XmlEvent},
};
use crate::{
error::{self, Error, ErrorKind, EventKind},
stream::{Writer, XmlWriteOptions},
Date, Integer, Uid,
};
static XML_PROLOGUE: &str = r#"<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE plist PUBLIC "-//Apple//DTD PLIST 1.0//EN" "http://www.apple.com/DTDs/PropertyList-1.0.dtd">
<plist version="1.0">
"#;
#[derive(PartialEq)]
enum Element {
Dictionary,
Array,
}
pub struct XmlWriter<W: Write> {
xml_writer: EventWriter<W>,
stack: Vec<Element>,
expecting_key: bool,
written_prologue: bool,
// Not very nice
empty_namespace: Namespace,
}
impl<W: Write> XmlWriter<W> {
pub fn new(writer: W) -> XmlWriter<W> {
let opts = XmlWriteOptions::default();
XmlWriter::new_with_options(writer, &opts)
}
pub fn new_with_options(writer: W, opts: &XmlWriteOptions) -> XmlWriter<W> {
let config = EmitterConfig::new()
.line_separator("\n")
.indent_string(opts.indent_str.clone())
.perform_indent(true)
.write_document_declaration(false)
.normalize_empty_elements(true)
.cdata_to_characters(true)
.keep_element_names_stack(false)
.autopad_comments(true)
.pad_self_closing(false);
XmlWriter {
xml_writer: EventWriter::new_with_config(writer, config),
stack: Vec::new(),
expecting_key: false,
written_prologue: false,
empty_namespace: Namespace::empty(),
}
}
fn write_element_and_value(&mut self, name: &str, value: &str) -> Result<(), Error> {
self.start_element(name)?;
self.write_value(value)?;
self.end_element(name)?;
Ok(())
}
fn start_element(&mut self, name: &str) -> Result<(), Error> {
self.xml_writer
.write(XmlEvent::StartElement {
name: Name::local(name),
attributes: Cow::Borrowed(&[]),
namespace: Cow::Borrowed(&self.empty_namespace),
})
.map_err(from_xml_error)?;
Ok(())
}
fn end_element(&mut self, name: &str) -> Result<(), Error> {
self.xml_writer
.write(XmlEvent::EndElement {
name: Some(Name::local(name)),
})
.map_err(from_xml_error)?;
Ok(())
}
fn write_value(&mut self, value: &str) -> Result<(), Error> {
self.xml_writer
.write(XmlEvent::Characters(value))
.map_err(from_xml_error)?;
Ok(())
}
pub fn into_inner(self) -> W {
self.xml_writer.into_inner()
}
fn write_event<F: FnOnce(&mut Self) -> Result<(), Error>>(
&mut self,
f: F,
) -> Result<(), Error> {
if !self.written_prologue {
self.xml_writer
.inner_mut()
.write_all(XML_PROLOGUE.as_bytes())
.map_err(error::from_io_without_position)?;
self.written_prologue = true;
}
f(self)?;
// If there are no more open tags then write the </plist> element
if self.stack.is_empty() {
// We didn't tell the xml_writer about the <plist> tag so we'll skip telling it
// about the </plist> tag as well.
self.xml_writer
.inner_mut()
.write_all(b"\n</plist>")
.map_err(error::from_io_without_position)?;
self.xml_writer
.inner_mut()
.flush()
.map_err(error::from_io_without_position)?;
}
Ok(())
}
fn write_value_event<F: FnOnce(&mut Self) -> Result<(), Error>>(
&mut self,
event_kind: EventKind,
f: F,
) -> Result<(), Error> {
self.write_event(|this| {
if this.expecting_key {
return Err(ErrorKind::UnexpectedEventType {
expected: EventKind::DictionaryKeyOrEndCollection,
found: event_kind,
}
.without_position());
}
f(this)?;
this.expecting_key = this.stack.last() == Some(&Element::Dictionary);
Ok(())
})
}
}
impl<W: Write> Writer for XmlWriter<W> {
fn write_start_array(&mut self, _len: Option<u64>) -> Result<(), Error> {
self.write_value_event(EventKind::StartArray, |this| {
this.start_element("array")?;
this.stack.push(Element::Array);
Ok(())
})
}
fn write_start_dictionary(&mut self, _len: Option<u64>) -> Result<(), Error> {
self.write_value_event(EventKind::StartDictionary, |this| {
this.start_element("dict")?;
this.stack.push(Element::Dictionary);
Ok(())
})
}
fn write_end_collection(&mut self) -> Result<(), Error> {
self.write_event(|this| {
match (this.stack.pop(), this.expecting_key) {
(Some(Element::Dictionary), true) => {
this.end_element("dict")?;
}
(Some(Element::Array), _) => {
this.end_element("array")?;
}
(Some(Element::Dictionary), false) | (None, _) => {
return Err(ErrorKind::UnexpectedEventType {
expected: EventKind::ValueOrStartCollection,
found: EventKind::EndCollection,
}
.without_position());
}
}
this.expecting_key = this.stack.last() == Some(&Element::Dictionary);
Ok(())
})
}
fn write_boolean(&mut self, value: bool) -> Result<(), Error> {
self.write_value_event(EventKind::Boolean, |this| {
let value_str = if value { "true" } else { "false" };
this.start_element(value_str)?;
this.end_element(value_str)
})
}
fn write_data(&mut self, value: &[u8]) -> Result<(), Error> {
self.write_value_event(EventKind::Data, |this| {
let base64_data = base64_encode_plist(&value, this.stack.len());
this.write_element_and_value("data", &base64_data)
})
}
fn write_date(&mut self, value: Date) -> Result<(), Error> {
self.write_value_event(EventKind::Date, |this| {
this.write_element_and_value("date", &value.to_rfc3339())
})
}
fn write_integer(&mut self, value: Integer) -> Result<(), Error> {
self.write_value_event(EventKind::Integer, |this| {
this.write_element_and_value("integer", &value.to_string())
})
}
fn write_real(&mut self, value: f64) -> Result<(), Error> {
self.write_value_event(EventKind::Real, |this| {
this.write_element_and_value("real", &value.to_string())
})
}
fn write_string(&mut self, value: &str) -> Result<(), Error> {
self.write_event(|this| {
if this.expecting_key {
this.write_element_and_value("key", &*value)?;
this.expecting_key = false;
} else {
this.write_element_and_value("string", &*value)?;
this.expecting_key = this.stack.last() == Some(&Element::Dictionary);
}
Ok(())
})
}
fn write_uid(&mut self, _value: Uid) -> Result<(), Error> {
Err(ErrorKind::UidNotSupportedInXmlPlist.without_position())
}
}
pub(crate) fn from_xml_error(err: XmlWriterError) -> Error {
match err {
XmlWriterError::Io(err) => ErrorKind::Io(err).without_position(),
XmlWriterError::DocumentStartAlreadyEmitted
| XmlWriterError::LastElementNameNotAvailable
| XmlWriterError::EndElementNameIsNotEqualToLastStartElementName
| XmlWriterError::EndElementNameIsNotSpecified => unreachable!(),
}
}
fn base64_encode_plist(data: &[u8], indent: usize) -> String {
// XML plist data elements are always formatted by apple tools as
// <data>
// AAAA..AA (68 characters per line)
// </data>
// Allocate space for base 64 string and line endings up front
const LINE_LEN: usize = 68;
let mut line_ending = Vec::with_capacity(1 + indent);
line_ending.push(b'\n');
(0..indent).for_each(|_| line_ending.push(b'\t'));
// Find the max length of `data` encoded as a base 64 string with padding
let base64_max_string_len = data.len() * 4 / 3 + 4;
// Find the max length of the formatted base 64 string as: max length of the base 64 string
// + line endings and indents at the start of the string and after every line
let base64_max_string_len_with_formatting =
base64_max_string_len + (2 + base64_max_string_len / LINE_LEN) * line_ending.len();
let mut output = vec![0; base64_max_string_len_with_formatting];
// Start output with a line ending and indent
output[..line_ending.len()].copy_from_slice(&line_ending);
// Encode `data` as a base 64 string
let base64_string_len =
base64::encode_config_slice(data, base64::STANDARD, &mut output[line_ending.len()..]);
// Line wrap the base 64 encoded string
let line_wrap_len = line_wrap::line_wrap(
&mut output[line_ending.len()..],
base64_string_len,
LINE_LEN,
&line_wrap::SliceLineEnding::new(&line_ending),
);
// Add the final line ending and indent
output[line_ending.len() + base64_string_len + line_wrap_len..][..line_ending.len()]
.copy_from_slice(&line_ending);
// Ensure output is the correct length
output.truncate(base64_string_len + line_wrap_len + 2 * line_ending.len());
String::from_utf8(output).expect("base 64 string must be valid utf8")
}
#[cfg(test)]
mod tests {
use std::io::Cursor;
use super::*;
use crate::stream::Event;
#[test]
fn streaming_parser() {
let plist = &[
Event::StartDictionary(None),
Event::String("Author".into()),
Event::String("William Shakespeare".into()),
Event::String("Lines".into()),
Event::StartArray(None),
Event::String("It is a tale told by an idiot,".into()),
Event::String("Full of sound and fury, signifying nothing.".into()),
Event::Data((0..128).collect::<Vec<_>>().into()),
Event::EndCollection,
Event::String("Death".into()),
Event::Integer(1564.into()),
Event::String("Height".into()),
Event::Real(1.60),
Event::String("Data".into()),
Event::Data(vec![0, 0, 0, 190, 0, 0, 0, 3, 0, 0, 0, 30, 0, 0, 0].into()),
Event::String("Birthdate".into()),
Event::Date(super::Date::from_rfc3339("1981-05-16T11:32:06Z").unwrap()),
Event::String("Comment".into()),
Event::String("2 < 3".into()), // make sure characters are escaped
Event::String("BiggestNumber".into()),
Event::Integer(18446744073709551615u64.into()),
Event::String("SmallestNumber".into()),
Event::Integer((-9223372036854775808i64).into()),
Event::String("IsTrue".into()),
Event::Boolean(true),
Event::String("IsNotFalse".into()),
Event::Boolean(false),
Event::EndCollection,
];
let mut cursor = Cursor::new(Vec::new());
{
let mut plist_w = XmlWriter::new(&mut cursor);
for item in plist {
plist_w.write(item).unwrap();
}
}
let comparison = "<?xml version=\"1.0\" encoding=\"UTF-8\"?>
<!DOCTYPE plist PUBLIC \"-//Apple//DTD PLIST 1.0//EN\" \"http://www.apple.com/DTDs/PropertyList-1.0.dtd\">
<plist version=\"1.0\">
<dict>
\t<key>Author</key>
\t<string>William Shakespeare</string>
\t<key>Lines</key>
\t<array>
\t\t<string>It is a tale told by an idiot,</string>
\t\t<string>Full of sound and fury, signifying nothing.</string>
\t\t<data>
\t\tAAECAwQFBgcICQoLDA0ODxAREhMUFRYXGBkaGxwdHh8gISIjJCUmJygpKissLS4vMDEy
\t\tMzQ1Njc4OTo7PD0+P0BBQkNERUZHSElKS0xNTk9QUVJTVFVWV1hZWltcXV5fYGFiY2Rl
\t\tZmdoaWprbG1ub3BxcnN0dXZ3eHl6e3x9fn8=
\t\t</data>
\t</array>
\t<key>Death</key>
\t<integer>1564</integer>
\t<key>Height</key>
\t<real>1.6</real>
\t<key>Data</key>
\t<data>
\tAAAAvgAAAAMAAAAeAAAA
\t</data>
\t<key>Birthdate</key>
\t<date>1981-05-16T11:32:06Z</date>
\t<key>Comment</key>
\t<string>2 < 3</string>
\t<key>BiggestNumber</key>
\t<integer>18446744073709551615</integer>
\t<key>SmallestNumber</key>
\t<integer>-9223372036854775808</integer>
\t<key>IsTrue</key>
\t<true/>
\t<key>IsNotFalse</key>
\t<false/>
</dict>
</plist>";
let s = String::from_utf8(cursor.into_inner()).unwrap();
assert_eq!(s, comparison);
}
}