vendor/url-2.1.0/src/form_urlencoded.rs - toolchain/rustc - Git at Google

 // Copyright 2013-2016 The rust-url developers.
 //
 // 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.

 //! Parser and serializer for the [`application/x-www-form-urlencoded` syntax](
 //! http://url.spec.whatwg.org/#application/x-www-form-urlencoded),
 //! as used by HTML forms.
 //!
 //! Converts between a string (such as an URL’s query string)
 //! and a sequence of (name, value) pairs.

 use percent_encoding::{percent_decode, percent_encode_byte};
 use query_encoding::{self, decode_utf8_lossy, EncodingOverride};
 use std::borrow::{Borrow, Cow};
 use std::str;

 /// Convert a byte string in the `application/x-www-form-urlencoded` syntax
 /// into a iterator of (name, value) pairs.
 ///
 /// Use `parse(input.as_bytes())` to parse a `&str` string.
 ///
 /// The names and values are percent-decoded. For instance, `%23first=%25try%25` will be
 /// converted to `[("#first", "%try%")]`.
 #[inline]
 pub fn parse(input: &[u8]) -> Parse {
     Parse { input }
 }
 /// The return type of `parse()`.
 #[derive(Copy, Clone)]
 pub struct Parse<'a> {
     input: &'a [u8],
 }

 impl<'a> Iterator for Parse<'a> {
     type Item = (Cow<'a, str>, Cow<'a, str>);

     fn next(&mut self) -> Option<Self::Item> {
         loop {
             if self.input.is_empty() {
                 return None;
             }
             let mut split2 = self.input.splitn(2, |&b| b == b'&');
             let sequence = split2.next().unwrap();
             self.input = split2.next().unwrap_or(&[][..]);
             if sequence.is_empty() {
                 continue;
             }
             let mut split2 = sequence.splitn(2, |&b| b == b'=');
             let name = split2.next().unwrap();
             let value = split2.next().unwrap_or(&[][..]);
             return Some((decode(name), decode(value)));
         }
     }
 }

 fn decode(input: &[u8]) -> Cow<str> {
     let replaced = replace_plus(input);
     decode_utf8_lossy(match percent_decode(&replaced).into() {
         Cow::Owned(vec) => Cow::Owned(vec),
         Cow::Borrowed(_) => replaced,
     })
 }

 /// Replace b'+' with b' '
 fn replace_plus(input: &[u8]) -> Cow<[u8]> {
     match input.iter().position(|&b| b == b'+') {
         None => Cow::Borrowed(input),
         Some(first_position) => {
             let mut replaced = input.to_owned();
             replaced[first_position] = b' ';
             for byte in &mut replaced[first_position + 1..] {
                 if *byte == b'+' {
                     *byte = b' ';
                 }
             }
             Cow::Owned(replaced)
         }
     }
 }

 impl<'a> Parse<'a> {
     /// Return a new iterator that yields pairs of `String` instead of pairs of `Cow<str>`.
     pub fn into_owned(self) -> ParseIntoOwned<'a> {
         ParseIntoOwned { inner: self }
     }
 }

 /// Like `Parse`, but yields pairs of `String` instead of pairs of `Cow<str>`.
 pub struct ParseIntoOwned<'a> {
     inner: Parse<'a>,
 }

 impl<'a> Iterator for ParseIntoOwned<'a> {
     type Item = (String, String);

     fn next(&mut self) -> Option<Self::Item> {
         self.inner
             .next()
             .map(|(k, v)| (k.into_owned(), v.into_owned()))
     }
 }

 /// The [`application/x-www-form-urlencoded` byte serializer](
 /// https://url.spec.whatwg.org/#concept-urlencoded-byte-serializer).
 ///
 /// Return an iterator of `&str` slices.
 pub fn byte_serialize(input: &[u8]) -> ByteSerialize {
     ByteSerialize { bytes: input }
 }

 /// Return value of `byte_serialize()`.
 #[derive(Debug)]
 pub struct ByteSerialize<'a> {
     bytes: &'a [u8],
 }

 fn byte_serialized_unchanged(byte: u8) -> bool {
     matches!(byte, b'*' | b'-' | b'.' | b'0' ..= b'9' | b'A' ..= b'Z' | b'_' | b'a' ..= b'z')
 }

 impl<'a> Iterator for ByteSerialize<'a> {
     type Item = &'a str;

     fn next(&mut self) -> Option<&'a str> {
         if let Some((&first, tail)) = self.bytes.split_first() {
             if !byte_serialized_unchanged(first) {
                 self.bytes = tail;
                 return Some(if first == b' ' {
                     "+"
                 } else {
                     percent_encode_byte(first)
                 });
             }
             let position = tail.iter().position(|&b| !byte_serialized_unchanged(b));
             let (unchanged_slice, remaining) = match position {
                 // 1 for first_byte + i unchanged in tail
                 Some(i) => self.bytes.split_at(1 + i),
                 None => (self.bytes, &[][..]),
             };
             self.bytes = remaining;
             Some(unsafe { str::from_utf8_unchecked(unchanged_slice) })
         } else {
             None
         }
     }

     fn size_hint(&self) -> (usize, Option<usize>) {
         if self.bytes.is_empty() {
             (0, Some(0))
         } else {
             (1, Some(self.bytes.len()))
         }
     }
 }

 /// The [`application/x-www-form-urlencoded` serializer](
 /// https://url.spec.whatwg.org/#concept-urlencoded-serializer).
 pub struct Serializer<'a, T: Target> {
     target: Option<T>,
     start_position: usize,
     encoding: EncodingOverride<'a>,
 }

 pub trait Target {
     fn as_mut_string(&mut self) -> &mut String;
     fn finish(self) -> Self::Finished;
     type Finished;
 }

 impl Target for String {
     fn as_mut_string(&mut self) -> &mut String {
         self
     }
     fn finish(self) -> Self {
         self
     }
     type Finished = Self;
 }

 impl<'a> Target for &'a mut String {
     fn as_mut_string(&mut self) -> &mut String {
         &mut **self
     }
     fn finish(self) -> Self {
         self
     }
     type Finished = Self;
 }

 // `as_mut_string` string here exposes the internal serialization of an `Url`,
 // which should not be exposed to users.
 // We achieve that by not giving users direct access to `UrlQuery`:
 // * Its fields are private
 //   (and so can not be constructed with struct literal syntax outside of this crate),
 // * It has no constructor
 // * It is only visible (on the type level) to users in the return type of
 //   `Url::query_pairs_mut` which is `Serializer<UrlQuery>`
 // * `Serializer` keeps its target in a private field
 // * Unlike in other `Target` impls, `UrlQuery::finished` does not return `Self`.
 impl<'a> Target for ::UrlQuery<'a> {
     fn as_mut_string(&mut self) -> &mut String {
         &mut self.url.as_mut().unwrap().serialization
     }

     fn finish(mut self) -> &'a mut ::Url {
         let url = self.url.take().unwrap();
         url.restore_already_parsed_fragment(self.fragment.take());
         url
     }

     type Finished = &'a mut ::Url;
 }

 impl<'a, T: Target> Serializer<'a, T> {
     /// Create a new `application/x-www-form-urlencoded` serializer for the given target.
     ///
     /// If the target is non-empty,
     /// its content is assumed to already be in `application/x-www-form-urlencoded` syntax.
     pub fn new(target: T) -> Self {
         Self::for_suffix(target, 0)
     }

     /// Create a new `application/x-www-form-urlencoded` serializer
     /// for a suffix of the given target.
     ///
     /// If that suffix is non-empty,
     /// its content is assumed to already be in `application/x-www-form-urlencoded` syntax.
     pub fn for_suffix(mut target: T, start_position: usize) -> Self {
         &target.as_mut_string()[start_position..]; // Panic if out of bounds
         Serializer {
             target: Some(target),
             start_position,
             encoding: None,
         }
     }

     /// Remove any existing name/value pair.
     ///
     /// Panics if called after `.finish()`.
     pub fn clear(&mut self) -> &mut Self {
         string(&mut self.target).truncate(self.start_position);
         self
     }

     /// Set the character encoding to be used for names and values before percent-encoding.
     pub fn encoding_override(&mut self, new: EncodingOverride<'a>) -> &mut Self {
         self.encoding = new;
         self
     }

     /// Serialize and append a name/value pair.
     ///
     /// Panics if called after `.finish()`.
     pub fn append_pair(&mut self, name: &str, value: &str) -> &mut Self {
         append_pair(
             string(&mut self.target),
             self.start_position,
             self.encoding,
             name,
             value,
         );
         self
     }

     /// Serialize and append a number of name/value pairs.
     ///
     /// This simply calls `append_pair` repeatedly.
     /// This can be more convenient, so the user doesn’t need to introduce a block
     /// to limit the scope of `Serializer`’s borrow of its string.
     ///
     /// Panics if called after `.finish()`.
     pub fn extend_pairs<I, K, V>(&mut self, iter: I) -> &mut Self
     where
         I: IntoIterator,
         I::Item: Borrow<(K, V)>,
         K: AsRef<str>,
         V: AsRef<str>,
     {
         {
             let string = string(&mut self.target);
             for pair in iter {
                 let &(ref k, ref v) = pair.borrow();
                 append_pair(
                     string,
                     self.start_position,
                     self.encoding,
                     k.as_ref(),
                     v.as_ref(),
                 );
             }
         }
         self
     }

     /// If this serializer was constructed with a string, take and return that string.
     ///
     /// ```rust
     /// use url::form_urlencoded;
     /// let encoded: String = form_urlencoded::Serializer::new(String::new())
     ///     .append_pair("foo", "bar & baz")
     ///     .append_pair("saison", "Été+hiver")
     ///     .finish();
     /// assert_eq!(encoded, "foo=bar+%26+baz&saison=%C3%89t%C3%A9%2Bhiver");
     /// ```
     ///
     /// Panics if called more than once.
     pub fn finish(&mut self) -> T::Finished {
         self.target
             .take()
             .expect("url::form_urlencoded::Serializer double finish")
             .finish()
     }
 }

 fn append_separator_if_needed(string: &mut String, start_position: usize) {
     if string.len() > start_position {
         string.push('&')
     }
 }

 fn string<T: Target>(target: &mut Option<T>) -> &mut String {
     target
         .as_mut()
         .expect("url::form_urlencoded::Serializer finished")
         .as_mut_string()
 }

 fn append_pair(
     string: &mut String,
     start_position: usize,
     encoding: EncodingOverride,
     name: &str,
     value: &str,
 ) {
     append_separator_if_needed(string, start_position);
     append_encoded(name, string, encoding);
     string.push('=');
     append_encoded(value, string, encoding);
 }

 fn append_encoded(s: &str, string: &mut String, encoding: EncodingOverride) {
     string.extend(byte_serialize(&query_encoding::encode(encoding, s.into())))
 }
	// Copyright 2013-2016 The rust-url developers.
	//
	// 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.

	//! Parser and serializer for the [`application/x-www-form-urlencoded` syntax](
	//! http://url.spec.whatwg.org/#application/x-www-form-urlencoded),
	//! as used by HTML forms.
	//!
	//! Converts between a string (such as an URL’s query string)
	//! and a sequence of (name, value) pairs.

	use percent_encoding::{percent_decode, percent_encode_byte};
	use query_encoding::{self, decode_utf8_lossy, EncodingOverride};
	use std::borrow::{Borrow, Cow};
	use std::str;

	/// Convert a byte string in the `application/x-www-form-urlencoded` syntax
	/// into a iterator of (name, value) pairs.
	///
	/// Use `parse(input.as_bytes())` to parse a `&str` string.
	///
	/// The names and values are percent-decoded. For instance, `%23first=%25try%25` will be
	/// converted to `[("#first", "%try%")]`.
	#[inline]
	pub fn parse(input: &[u8]) -> Parse {
	Parse { input }
	}
	/// The return type of `parse()`.
	#[derive(Copy, Clone)]
	pub struct Parse<'a> {
	input: &'a [u8],
	}

	impl<'a> Iterator for Parse<'a> {
	type Item = (Cow<'a, str>, Cow<'a, str>);

	fn next(&mut self) -> Option<Self::Item> {
	loop {
	if self.input.is_empty() {
	return None;
	}
	let mut split2 = self.input.splitn(2, \|&b\| b == b'&');
	let sequence = split2.next().unwrap();
	self.input = split2.next().unwrap_or(&[][..]);
	if sequence.is_empty() {
	continue;
	}
	let mut split2 = sequence.splitn(2, \|&b\| b == b'=');
	let name = split2.next().unwrap();
	let value = split2.next().unwrap_or(&[][..]);
	return Some((decode(name), decode(value)));
	}
	}
	}

	fn decode(input: &[u8]) -> Cow<str> {
	let replaced = replace_plus(input);
	decode_utf8_lossy(match percent_decode(&replaced).into() {
	Cow::Owned(vec) => Cow::Owned(vec),
	Cow::Borrowed(_) => replaced,
	})
	}

	/// Replace b'+' with b' '
	fn replace_plus(input: &[u8]) -> Cow<[u8]> {
	match input.iter().position(\|&b\| b == b'+') {
	None => Cow::Borrowed(input),
	Some(first_position) => {
	let mut replaced = input.to_owned();
	replaced[first_position] = b' ';
	for byte in &mut replaced[first_position + 1..] {
	if *byte == b'+' {
	*byte = b' ';
	}
	}
	Cow::Owned(replaced)
	}
	}
	}

	impl<'a> Parse<'a> {
	/// Return a new iterator that yields pairs of `String` instead of pairs of `Cow<str>`.
	pub fn into_owned(self) -> ParseIntoOwned<'a> {
	ParseIntoOwned { inner: self }
	}
	}

	/// Like `Parse`, but yields pairs of `String` instead of pairs of `Cow<str>`.
	pub struct ParseIntoOwned<'a> {
	inner: Parse<'a>,
	}

	impl<'a> Iterator for ParseIntoOwned<'a> {
	type Item = (String, String);

	fn next(&mut self) -> Option<Self::Item> {
	self.inner
	.next()
	.map(\|(k, v)\| (k.into_owned(), v.into_owned()))
	}
	}

	/// The [`application/x-www-form-urlencoded` byte serializer](
	/// https://url.spec.whatwg.org/#concept-urlencoded-byte-serializer).
	///
	/// Return an iterator of `&str` slices.
	pub fn byte_serialize(input: &[u8]) -> ByteSerialize {
	ByteSerialize { bytes: input }
	}

	/// Return value of `byte_serialize()`.
	#[derive(Debug)]
	pub struct ByteSerialize<'a> {
	bytes: &'a [u8],
	}

	fn byte_serialized_unchanged(byte: u8) -> bool {
	matches!(byte, b'*' \| b'-' \| b'.' \| b'0' ..= b'9' \| b'A' ..= b'Z' \| b'_' \| b'a' ..= b'z')
	}

	impl<'a> Iterator for ByteSerialize<'a> {
	type Item = &'a str;

	fn next(&mut self) -> Option<&'a str> {
	if let Some((&first, tail)) = self.bytes.split_first() {
	if !byte_serialized_unchanged(first) {
	self.bytes = tail;
	return Some(if first == b' ' {
	"+"
	} else {
	percent_encode_byte(first)
	});
	}
	let position = tail.iter().position(\|&b\| !byte_serialized_unchanged(b));
	let (unchanged_slice, remaining) = match position {
	// 1 for first_byte + i unchanged in tail
	Some(i) => self.bytes.split_at(1 + i),
	None => (self.bytes, &[][..]),
	};
	self.bytes = remaining;
	Some(unsafe { str::from_utf8_unchecked(unchanged_slice) })
	} else {
	None
	}
	}

	fn size_hint(&self) -> (usize, Option<usize>) {
	if self.bytes.is_empty() {
	(0, Some(0))
	} else {
	(1, Some(self.bytes.len()))
	}
	}
	}

	/// The [`application/x-www-form-urlencoded` serializer](
	/// https://url.spec.whatwg.org/#concept-urlencoded-serializer).
	pub struct Serializer<'a, T: Target> {
	target: Option<T>,
	start_position: usize,
	encoding: EncodingOverride<'a>,
	}

	pub trait Target {
	fn as_mut_string(&mut self) -> &mut String;
	fn finish(self) -> Self::Finished;
	type Finished;
	}

	impl Target for String {
	fn as_mut_string(&mut self) -> &mut String {
	self
	}
	fn finish(self) -> Self {
	self
	}
	type Finished = Self;
	}

	impl<'a> Target for &'a mut String {
	fn as_mut_string(&mut self) -> &mut String {
	&mut **self
	}
	fn finish(self) -> Self {
	self
	}
	type Finished = Self;
	}

	// `as_mut_string` string here exposes the internal serialization of an `Url`,
	// which should not be exposed to users.
	// We achieve that by not giving users direct access to `UrlQuery`:
	// * Its fields are private
	// (and so can not be constructed with struct literal syntax outside of this crate),
	// * It has no constructor
	// * It is only visible (on the type level) to users in the return type of
	// `Url::query_pairs_mut` which is `Serializer<UrlQuery>`
	// * `Serializer` keeps its target in a private field
	// * Unlike in other `Target` impls, `UrlQuery::finished` does not return `Self`.
	impl<'a> Target for ::UrlQuery<'a> {
	fn as_mut_string(&mut self) -> &mut String {
	&mut self.url.as_mut().unwrap().serialization
	}

	fn finish(mut self) -> &'a mut ::Url {
	let url = self.url.take().unwrap();
	url.restore_already_parsed_fragment(self.fragment.take());
	url
	}

	type Finished = &'a mut ::Url;
	}

	impl<'a, T: Target> Serializer<'a, T> {
	/// Create a new `application/x-www-form-urlencoded` serializer for the given target.
	///
	/// If the target is non-empty,
	/// its content is assumed to already be in `application/x-www-form-urlencoded` syntax.
	pub fn new(target: T) -> Self {
	Self::for_suffix(target, 0)
	}

	/// Create a new `application/x-www-form-urlencoded` serializer
	/// for a suffix of the given target.
	///
	/// If that suffix is non-empty,
	/// its content is assumed to already be in `application/x-www-form-urlencoded` syntax.
	pub fn for_suffix(mut target: T, start_position: usize) -> Self {
	&target.as_mut_string()[start_position..]; // Panic if out of bounds
	Serializer {
	target: Some(target),
	start_position,
	encoding: None,
	}
	}

	/// Remove any existing name/value pair.
	///
	/// Panics if called after `.finish()`.
	pub fn clear(&mut self) -> &mut Self {
	string(&mut self.target).truncate(self.start_position);
	self
	}

	/// Set the character encoding to be used for names and values before percent-encoding.
	pub fn encoding_override(&mut self, new: EncodingOverride<'a>) -> &mut Self {
	self.encoding = new;
	self
	}

	/// Serialize and append a name/value pair.
	///
	/// Panics if called after `.finish()`.
	pub fn append_pair(&mut self, name: &str, value: &str) -> &mut Self {
	append_pair(
	string(&mut self.target),
	self.start_position,
	self.encoding,
	name,
	value,
	);
	self
	}

	/// Serialize and append a number of name/value pairs.
	///
	/// This simply calls `append_pair` repeatedly.
	/// This can be more convenient, so the user doesn’t need to introduce a block
	/// to limit the scope of `Serializer`’s borrow of its string.
	///
	/// Panics if called after `.finish()`.
	pub fn extend_pairs<I, K, V>(&mut self, iter: I) -> &mut Self
	where
	I: IntoIterator,
	I::Item: Borrow<(K, V)>,
	K: AsRef<str>,
	V: AsRef<str>,
	{
	{
	let string = string(&mut self.target);
	for pair in iter {
	let &(ref k, ref v) = pair.borrow();
	append_pair(
	string,
	self.start_position,
	self.encoding,
	k.as_ref(),
	v.as_ref(),
	);
	}
	}
	self
	}

	/// If this serializer was constructed with a string, take and return that string.
	///
	/// ```rust
	/// use url::form_urlencoded;
	/// let encoded: String = form_urlencoded::Serializer::new(String::new())
	/// .append_pair("foo", "bar & baz")
	/// .append_pair("saison", "Été+hiver")
	/// .finish();
	/// assert_eq!(encoded, "foo=bar+%26+baz&saison=%C3%89t%C3%A9%2Bhiver");
	/// ```
	///
	/// Panics if called more than once.
	pub fn finish(&mut self) -> T::Finished {
	self.target
	.take()
	.expect("url::form_urlencoded::Serializer double finish")
	.finish()
	}
	}

	fn append_separator_if_needed(string: &mut String, start_position: usize) {
	if string.len() > start_position {
	string.push('&')
	}
	}

	fn string<T: Target>(target: &mut Option<T>) -> &mut String {
	target
	.as_mut()
	.expect("url::form_urlencoded::Serializer finished")
	.as_mut_string()
	}

	fn append_pair(
	string: &mut String,
	start_position: usize,
	encoding: EncodingOverride,
	name: &str,
	value: &str,
	) {
	append_separator_if_needed(string, start_position);
	append_encoded(name, string, encoding);
	string.push('=');
	append_encoded(value, string, encoding);
	}

	fn append_encoded(s: &str, string: &mut String, encoding: EncodingOverride) {
	string.extend(byte_serialize(&query_encoding::encode(encoding, s.into())))
	}