diff options
Diffstat (limited to 'src/lib.rs')
-rw-r--r-- | src/lib.rs | 620 |
1 files changed, 620 insertions, 0 deletions
diff --git a/src/lib.rs b/src/lib.rs new file mode 100644 index 0000000..c754182 --- /dev/null +++ b/src/lib.rs @@ -0,0 +1,620 @@ +// DOCS + +use std::collections::HashMap; +use std::borrow::ToOwned; +use std::str::FromStr; +use std::fmt; +use std::error::Error; + + +#[derive(Clone, Debug)] +pub struct Property { + /// Key in component. + pub name: String, + + /// Parameters. + pub params: HashMap<String, String>, + + /// Value as unparsed string. + pub raw_value: String, + + /// Property group. E.g. a contentline like `foo.FN:Markus` would result in the group being + /// `"foo"`. + pub prop_group: Option<String> +} + +impl Property { + /// Create property from unescaped string. + pub fn new<N, V>(name: N, value: V) -> Property + where N: Into<String>, + V: AsRef<str> + { + Property { + name: name.into(), + params: HashMap::new(), + raw_value: escape_chars(value.as_ref()), + prop_group: None + } + } + + /// Get value as unescaped string. + pub fn value_as_string(&self) -> String { + unescape_chars(&self.raw_value) + } +} + +#[derive(Clone, Debug)] +pub struct Component { + /// The name of the component, such as `VCARD` or `VEVENT`. + pub name: String, + + /// The component's properties. + pub props: HashMap<String, Vec<Property>>, + + /// The component's child- or sub-components. + pub subcomponents: Vec<Component> +} + +impl Component { + pub fn new<N: Into<String>>(name: N) -> Component { + Component { + name: name.into(), + props: HashMap::new(), + subcomponents: vec![] + } + } + + /// Append the given property, preserve other same-named properties. + pub fn push(&mut self, prop: Property) { + self.props.entry(prop.name.clone()).or_insert_with(Vec::new).push(prop); + } + + /// Set the given property, remove other same-named properties. + pub fn set(&mut self, prop: Property) { + self.props.insert(prop.name.clone(), vec![prop]); + } + + /// Retrieve one property by key. Returns `None` if not exactly one property was found. + pub fn get_only<P: AsRef<str>>(&self, name: P) -> Option<&Property> { + match self.props.get(name.as_ref()) { + Some(x) if x.len() == 1 => Some(&x[0]), + _ => None + } + } + + /// Retrieve properties by key. Returns an empty slice if key doesn't exist. + pub fn get_all<P: AsRef<str>>(&self, name: P) -> &[Property] { + static EMPTY: &'static [Property] = &[]; + match self.props.get(name.as_ref()) { + Some(values) => &values[..], + None => EMPTY + } + } + + /// Remove a single property. + pub fn pop<P: AsRef<str>>(&mut self, name: P) -> Option<Property> { + match self.props.get_mut(name.as_ref()) { + Some(values) => values.pop(), + None => None + } + } + + /// Remove all properties + pub fn remove<P: AsRef<str>>(&mut self, name: P) -> Option<Vec<Property>> { + self.props.remove(name.as_ref()) + } +} + +impl FromStr for Component { + type Err = ParseError; + + /// Same as `vobject::parse_component` + fn from_str(s: &str) -> ParseResult<Component> { + parse_component(s) + } +} + + + +struct Parser<'s> { + pub input: &'s str, + pub pos: usize, +} + +impl<'s> Parser<'s> { + pub fn new(input: &'s str) -> Self { + Parser { + input: input, + pos: 0, + } + } + + /// look-ahead for next char at given offset from current position + /// (self.pos), taking [line unfolding] + /// (https://tools.ietf.org/html/rfc5545#section-3.1) into account, + /// without actually + /// consuming it (immutable self). + /// + /// Return an option for next char, and needed increment to consume it + /// from current position. + /// CR characters get always skipped, resulting in CRLF to be simplified as + /// LF, which seems to be acceptable because + /// - the remainders of the lib do accept a lone LF as a line termination + /// (a bit laxer than RFC 5545) + /// - CR alone [is not acceptable content] + /// (https://tools.ietf.org/html/rfc5545#section-3.1) + fn peek_at(&self, at: usize) -> Option<(char, usize)> { + match self.input[self.pos+at..].chars().next() { + None => None, + Some('\r') => self.peek_at(at + 1), + Some('\n') => { + match self.peek_at(at + 1) { + Some((' ', offset)) | + Some(('\t', offset)) => self.peek_at(offset), + _ => Some(('\n', at + 1)), + } + } + Some(x) => Some((x, at + x.len_utf8())) + } + } + + #[inline] + fn peek(&self) -> Option<(char, usize)> { + self.peek_at(0) + } + + pub fn eof(&self) -> bool { + self.pos >= self.input.len() + } + + fn assert_char(&self, c: char) -> ParseResult<()> { + let real_c = match self.peek() { + Some((x, _)) => x, + None => return Err(ParseError::new(format!("Expected {}, found EOL", c))), + }; + + if real_c != c { + return Err(ParseError::new(format!("Expected {}, found {}", c, real_c))) + }; + + Ok(()) + } + + fn consume_char(&mut self) -> Option<char> { + match self.peek() { + Some((c, offset)) => { self.pos += offset; Some(c) }, + None => None + } + } + + /// If next peeked char is the given `c`, consume it and return `true`, + /// otherwise return `false`. + fn consume_only_char(&mut self, c: char) -> bool { + match self.peek() { + Some((d, offset)) if d == c => { self.pos += offset; true }, + _ => false + } + } + + fn consume_eol(&mut self) -> ParseResult<()> { + let start_pos = self.pos; + + let consumed = match self.consume_char() { + Some('\n') => true, + Some('\r') => match self.consume_char() { + Some('\n') => true, + _ => false, + }, + _ => false, + }; + + if consumed { + Ok(()) + } else { + self.pos = start_pos; + Err(ParseError::new("Expected EOL.")) + } + } + + fn sloppy_terminate_line(&mut self) -> ParseResult<()> { + if !self.eof() { + try!(self.consume_eol()); + while let Ok(_) = self.consume_eol() {} + }; + + Ok(()) + } + + // GR this used to return just a slice from input, but line unfolding + // makes it contradictory, unless one'd want to rescan everything. + // Since actually useful calls used to_owned() on the result, which + // does copy into a String's buffer, let's create a String right away + // implementation detail : instead of pushing char after char, we + // do it by the biggest contiguous slices possible, because I believe it + // to be more efficient (less checks for reallocation etc). + fn consume_while<F: Fn(char) -> bool>(&mut self, test: F) -> String { + let mut sl_start_pos = self.pos; + let mut res = String::new(); + while !self.eof() { + match self.peek() { + Some((c, offset)) => { + if !test(c) { + break + } else { + if offset > c.len_utf8() { + // we have some skipping and therefore need to flush + res.push_str(&self.input[sl_start_pos..self.pos]); + res.push(c); + sl_start_pos = self.pos + offset; + } + self.pos += offset; + } + }, + _ => break + } + } + // Final flush + if sl_start_pos < self.pos { + res.push_str(&self.input[sl_start_pos..self.pos]) + } + res + } + + pub fn consume_property(&mut self) -> ParseResult<Property> { + let group = self.consume_property_group().ok(); + let name = try!(self.consume_property_name()); + let params = self.consume_params(); + + try!(self.assert_char(':')); + self.consume_char(); + + let value = try!(self.consume_property_value()); + + Ok(Property { + name: name, + params: params, + raw_value: value, + prop_group: group, + }) + } + + fn consume_property_name(&mut self) -> ParseResult<String> { + let rv = self.consume_while(|x| x == '-' || x.is_alphanumeric()); + if rv.is_empty() { + Err(ParseError::new("No property name found.")) + } else { + Ok(rv) + } + } + + fn consume_property_group(&mut self) -> ParseResult<String> { + let start_pos = self.pos; + let name = self.consume_property_name(); + + let e = match name { + Ok(name) => match self.assert_char('.') { + Ok(_) => { + self.consume_char(); + return Ok(name); + }, + Err(e) => Err(e), + }, + Err(e) => Err(e), + }; + + self.pos = start_pos; + e + } + + fn consume_property_value(&mut self) -> ParseResult<String> { + let rv = self.consume_while(|x| x != '\r' && x != '\n'); + try!(self.sloppy_terminate_line()); + Ok(rv) + } + + fn consume_param_name(&mut self) -> ParseResult<String> { + match self.consume_property_name() { + Ok(x) => Ok(x), + Err(e) => Err(ParseError::new(format!("No param name found: {}", e))), + } + } + + fn consume_param_value(&mut self) -> ParseResult<String> { + let qsafe = |x| { + x != '"' && + x != '\r' && + x != '\n' && + x != '\u{7F}' && + x > '\u{1F}' + }; + + if self.consume_only_char('"') { + let rv = self.consume_while(qsafe); + try!(self.assert_char('"')); + self.consume_char(); + Ok(rv) + } else { + Ok(self.consume_while(|x| qsafe(x) && x != ';' && x != ':')) + } + } + + fn consume_param(&mut self) -> ParseResult<(String, String)> { + let name = try!(self.consume_param_name()); + let start_pos = self.pos; + let value = if self.consume_only_char('=') { + match self.consume_param_value() { + Ok(x) => x, + Err(e) => { self.pos = start_pos; return Err(e); } + } + } else { + String::new() + }; + + Ok((name, value)) + } + + fn consume_params(&mut self) -> HashMap<String, String> { + let mut rv: HashMap<String, String> = HashMap::new(); + while self.consume_only_char(';') { + match self.consume_param() { + Ok((name, value)) => { rv.insert(name.to_owned(), value.to_owned()); }, + Err(_) => break, + } + } + rv + } + + fn consume_component(&mut self) -> ParseResult<Component> { + let start_pos = self.pos; + let mut property = try!(self.consume_property()); + if property.name != "BEGIN" { + self.pos = start_pos; + return Err(ParseError::new("Expected BEGIN tag.")); + }; + + // Create a component with the name of the BEGIN tag's value + let mut component = Component::new(property.raw_value); + + loop { + let previous_pos = self.pos; + property = try!(self.consume_property()); + if property.name == "BEGIN" { + self.pos = previous_pos; + component.subcomponents.push(try!(self.consume_component())); + } else if property.name == "END" { + if property.raw_value != component.name { + return Err(ParseError::new(format!( + "Mismatched tags: BEGIN:{} vs END:{}", + component.name, property.raw_value + ))) + } + + break; + } else { + component.push(property); + } + } + + Ok(component) + } +} + +/// Parse exactly one component. Trailing data generates errors. +pub fn parse_component(s: &str) -> ParseResult<Component> { + let mut parser = Parser::new(s); + let rv = try!(parser.consume_component()); + if !parser.eof() { + Err(ParseError::new(format!("Trailing data: `{}`", &parser.input[parser.pos..]))) + } else { + Ok(rv) + } +} + +/// Write a component to a String. +pub fn write_component(c: &Component) -> String { + fn inner(buf: &mut String, c: &Component) { + buf.push_str("BEGIN:"); + buf.push_str(&c.name); + buf.push_str("\r\n"); + + for (prop_name, props) in &c.props { + for prop in props.iter() { + if let Some(ref x) = prop.prop_group { + buf.push_str(&x); + buf.push('.'); + }; + buf.push_str(&prop_name); + for (param_key, param_value) in &prop.params { + buf.push(';'); + buf.push_str(¶m_key); + buf.push('='); + buf.push_str(¶m_value); + } + buf.push(':'); + buf.push_str(&fold_line(&prop.raw_value)); + buf.push_str("\r\n"); + } + } + + for subcomponent in &c.subcomponents { + inner(buf, subcomponent); + } + + buf.push_str("END:"); + buf.push_str(&c.name); + buf.push_str("\r\n"); + } + + let mut buf = String::new(); + inner(&mut buf, c); + buf +} + +/// Escape text for a VObject property value. +pub fn escape_chars(s: &str) -> String { + // Order matters! Lifted from icalendar.parser + // https://github.com/collective/icalendar/ + s + .replace("\\N", "\n") + .replace("\\", "\\\\") + .replace(";", "\\;") + .replace(",", "\\,") + .replace("\r\n", "\\n") + .replace("\n", "\\n") +} + +/// Unescape text from a VObject property value. +pub fn unescape_chars(s: &str) -> String { + // Order matters! Lifted from icalendar.parser + // https://github.com/collective/icalendar/ + s + .replace("\\N", "\\n") + .replace("\r\n", "\n") + .replace("\\n", "\n") + .replace("\\,", ",") + .replace("\\;", ";") + .replace("\\\\", "\\") +} + +/// Fold contentline to 75 bytes or less. This function assumes the input +/// to be unfolded, which means no '\n' or '\r' in it. +pub fn fold_line(line: &str) -> String { + let limit = 75; + let len = line.len(); + let mut bytes_remaining = len; + let mut ret = String::with_capacity(len + (len / limit * 3)); + + let mut pos = 0; + let mut next_pos = limit; + while bytes_remaining > limit { + while line.is_char_boundary(next_pos) == false { + next_pos -= 1; + } + ret.push_str(&line[pos..next_pos]); + ret.push_str("\r\n "); + + bytes_remaining -= next_pos - pos; + pos = next_pos; + next_pos += limit; + } + + ret.push_str(&line[len - bytes_remaining..]); + ret +} + +#[derive(PartialEq, Eq, Debug)] +pub struct ParseError { + desc: String +} + +pub type ParseResult<T> = Result<T, ParseError>; + +impl Error for ParseError { + fn description(&self) -> &str { + &self.desc[..] + } + + fn cause(&self) -> Option<&Error> { + None + } +} + +impl fmt::Display for ParseError { + fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result { + self.description().fmt(f) + } +} + +impl ParseError { + pub fn new<T: Into<String>>(desc: T) -> Self { + ParseError { + desc: desc.into(), + } + } + + pub fn into_string(self) -> String { + self.desc + } +} + +#[cfg(test)] +mod tests { + use super::{Parser, ParseError, fold_line}; + + #[test] + fn test_unfold1() { + let mut p = Parser{input: "ab\r\n c", pos: 2}; + assert_eq!(p.consume_char(), Some('c')); + assert_eq!(p.pos, 6); + } + + #[test] + fn test_unfold2() { + let mut p = Parser{input: "ab\n\tc\nx", pos: 2}; + assert_eq!(p.consume_char(), Some('c')); + assert_eq!(p.consume_char(), Some('\n')); + assert_eq!(p.consume_char(), Some('x')); + } + + #[test] + fn test_fold() { + let line = "This should be multiple lines and fold on char boundaries. 毎害止\ + 加食下組多地将写館来局必第。東証細再記得玲祉込吉宣会法授"; + let expected = "This should be multiple lines and fold on char boundaries. 毎害止\ + 加食\r\n 下組多地将写館来局必第。東証細再記得玲祉込吉宣会法\r\n 授"; + assert_eq!(expected, fold_line(line)); + assert_eq!("ab", fold_line("ab")); + } + + #[test] + fn test_consume_while() { + let mut p = Parser{input:"af\n oo:bar", pos: 1}; + assert_eq!(p.consume_while(|x| x != ':'), "foo"); + assert_eq!(p.consume_char(), Some(':')); + assert_eq!(p.consume_while(|x| x != '\n'), "bar"); + } + + #[test] + fn test_consume_while2() { + let mut p = Parser{input:"af\n oo\n\t:bar", pos: 1}; + assert_eq!(p.consume_while(|x| x != ':'), "foo"); + assert_eq!(p.consume_char(), Some(':')); + assert_eq!(p.consume_while(|x| x != '\n'), "bar"); + } + + #[test] + fn test_consume_while3() { + let mut p = Parser{input:"af\n oo:\n bar", pos: 1}; + assert_eq!(p.consume_while(|x| x != ':'), "foo"); + assert_eq!(p.consume_char(), Some(':')); + assert_eq!(p.consume_while(|x| x != '\n'), "bar"); + } + + #[test] + fn test_consume_only_char() { + let mut p = Parser{input:"\n \"bar", pos: 0}; + assert!(p.consume_only_char('"')); + assert_eq!(p.pos, 3); + assert!(!p.consume_only_char('"')); + assert_eq!(p.pos, 3); + assert!(p.consume_only_char('b')); + assert_eq!(p.pos, 4); + } + + #[test] + fn mismatched_begin_end_tags_returns_error() { + // Test for infinite loops as well + use std::sync::mpsc::{channel, RecvTimeoutError}; + use std::time::Duration; + let mut p = Parser {input: "BEGIN:a\nBEGIN:b\nEND:a", pos: 0}; + + let (tx, rx) = channel(); + ::std::thread::spawn(move|| { tx.send(p.consume_component()) }); + + match rx.recv_timeout(Duration::from_millis(50)) { + Err(RecvTimeoutError::Timeout) => assert!(false), + Ok(Err(ParseError {desc: _} )) => assert!(true), + _ => assert!(false), + } + } +} |