Rocket/core/http/src/raw_str.rs
2021-06-01 11:16:40 -07:00

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Rust
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use std::borrow::{Borrow, Cow};
use std::convert::AsRef;
use std::cmp::Ordering;
use std::str::Utf8Error;
use std::fmt;
use ref_cast::RefCast;
use stable_pattern::{Pattern, Searcher, ReverseSearcher, Split, SplitInternal};
use crate::uri::fmt::{percent_encode, DEFAULT_ENCODE_SET};
use crate::uncased::UncasedStr;
/// A reference to a string inside of a raw HTTP message.
///
/// A `RawStr` is an unsanitzed, unvalidated, and undecoded raw string from an
/// HTTP message. It exists to separate validated string inputs, represented by
/// the `String`, `&str`, and `Cow<str>` types, from unvalidated inputs,
/// represented by `&RawStr`.
///
/// # Validation
///
/// An `&RawStr` should be converted into one of the validated string input
/// types through methods on `RawStr`. These methods are summarized below:
///
/// * **[`url_decode()`]** - used to decode a raw string in a form value
/// context
/// * **[`percent_decode()`], [`percent_decode_lossy()`]** - used to
/// percent-decode a raw string, typically in a URL context
/// * **[`html_escape()`]** - used to decode a string for use in HTML
/// templates
/// * **[`as_str()`]** - used when the `RawStr` is known to be safe in the
/// context of its intended use. Use sparingly and with care!
/// * **[`as_uncased_str()`]** - used when the `RawStr` is known to be safe in
/// the context of its intended, uncased use
///
/// **Note:** Template engines like Tera and Handlebars all functions like
/// [`html_escape()`] on all rendered template outputs by default.
///
/// [`as_str()`]: RawStr::as_str()
/// [`as_uncased_str()`]: RawStr::as_uncased_str()
/// [`url_decode()`]: RawStr::url_decode()
/// [`html_escape()`]: RawStr::html_escape()
/// [`percent_decode()`]: RawStr::percent_decode()
/// [`percent_decode_lossy()`]: RawStr::percent_decode_lossy()
///
/// # Usage
///
/// A `RawStr` is a dynamically sized type (just like `str`). It is always used
/// through a reference an as `&RawStr` (just like &str).
#[repr(transparent)]
#[derive(RefCast, PartialEq, Eq, PartialOrd, Ord, Hash)]
pub struct RawStr(str);
impl ToOwned for RawStr {
type Owned = RawStrBuf;
fn to_owned(&self) -> Self::Owned {
RawStrBuf(self.to_string())
}
}
/// An owned version of [`RawStr`].
#[repr(transparent)]
#[derive(RefCast, PartialEq, Eq, PartialOrd, Ord, Hash)]
pub struct RawStrBuf(String);
impl RawStrBuf {
/// Cost-free conversion from `self` into a `String`.
///
/// # Example
///
/// ```rust
/// # extern crate rocket;
/// use rocket::http::RawStrBuf;
///
/// let raw = RawStrBuf::from(format!("hello {}", "world"));
/// let string = raw.into_string();
/// ```
pub fn into_string(self) -> String {
self.0
}
}
impl RawStr {
/// Constructs an `&RawStr` from a string-like type at no cost.
///
/// # Example
///
/// ```rust
/// # extern crate rocket;
/// use rocket::http::RawStr;
///
/// let raw_str = RawStr::new("Hello, world!");
///
/// // `into` can also be used; note that the type must be specified
/// let raw_str: &RawStr = "Hello, world!".into();
/// ```
pub fn new<S: AsRef<str> + ?Sized>(string: &S) -> &RawStr {
RawStr::ref_cast(string.as_ref())
}
/// Construct a `Cow<RawStr>` from a `Cow<Str>`. Does not allocate.
///
/// See [`RawStr::into_cow_str()`] for the inverse operation.
///
/// # Example
///
/// ```rust
/// # extern crate rocket;
/// use std::borrow::Cow;
/// use rocket::http::RawStr;
///
/// let cow_str = Cow::from("hello!");
/// let cow_raw = RawStr::from_cow_str(cow_str);
/// assert_eq!(cow_raw.as_str(), "hello!");
/// ```
pub fn from_cow_str<'a>(cow: Cow<'a, str>) -> Cow<'a, RawStr> {
match cow {
Cow::Borrowed(b) => Cow::Borrowed(b.into()),
Cow::Owned(b) => Cow::Owned(b.into()),
}
}
/// Construct a `Cow<str>` from a `Cow<RawStr>`. Does not allocate.
///
/// See [`RawStr::from_cow_str()`] for the inverse operation.
///
/// # Example
///
/// ```rust
/// # extern crate rocket;
/// use std::borrow::Cow;
/// use rocket::http::RawStr;
///
/// let cow_raw = Cow::from(RawStr::new("hello!"));
/// let cow_str = RawStr::into_cow_str(cow_raw);
/// assert_eq!(&*cow_str, "hello!");
/// ```
pub fn into_cow_str<'a>(cow: Cow<'a, RawStr>) -> Cow<'a, str> {
match cow {
Cow::Borrowed(b) => Cow::Borrowed(b.as_str()),
Cow::Owned(b) => Cow::Owned(b.into_string()),
}
}
/// Percent-decodes `self`.
fn _percent_decode(&self) -> percent_encoding::PercentDecode<'_> {
percent_encoding::percent_decode(self.as_bytes())
}
/// Returns a percent-decoded version of the string.
///
/// # Errors
///
/// Returns an `Err` if the percent encoded values are not valid UTF-8.
///
/// # Example
///
/// With a valid string:
///
/// ```rust
/// # extern crate rocket;
/// use rocket::http::RawStr;
///
/// let raw_str = RawStr::new("Hello%21");
/// let decoded = raw_str.percent_decode();
/// assert_eq!(decoded, Ok("Hello!".into()));
/// ```
///
/// With an invalid string:
///
/// ```rust
/// # extern crate rocket;
/// use rocket::http::RawStr;
///
/// // Note: Rocket should never hand you a bad `&RawStr`.
/// let bad_str = unsafe { std::str::from_utf8_unchecked(b"a=\xff") };
/// let bad_raw_str = RawStr::new(bad_str);
/// assert!(bad_raw_str.percent_decode().is_err());
/// ```
#[inline(always)]
pub fn percent_decode(&self) -> Result<Cow<'_, str>, Utf8Error> {
self._percent_decode().decode_utf8()
}
/// Returns a percent-decoded version of the string. Any invalid UTF-8
/// percent-encoded byte sequences will be replaced <20> U+FFFD, the
/// replacement character.
///
/// # Example
///
/// With a valid string:
///
/// ```rust
/// # extern crate rocket;
/// use rocket::http::RawStr;
///
/// let raw_str = RawStr::new("Hello%21");
/// let decoded = raw_str.percent_decode_lossy();
/// assert_eq!(decoded, "Hello!");
/// ```
///
/// With an invalid string:
///
/// ```rust
/// # extern crate rocket;
/// use rocket::http::RawStr;
///
/// // Note: Rocket should never hand you a bad `&RawStr`.
/// let bad_str = unsafe { std::str::from_utf8_unchecked(b"a=\xff") };
/// let bad_raw_str = RawStr::new(bad_str);
/// assert_eq!(bad_raw_str.percent_decode_lossy(), "a=<3D>");
/// ```
#[inline(always)]
pub fn percent_decode_lossy(&self) -> Cow<'_, str> {
self._percent_decode().decode_utf8_lossy()
}
/// Replaces '+' with ' ' in `self`, allocating only when necessary.
fn _replace_plus(&self) -> Cow<'_, str> {
let string = self.as_str();
let mut allocated = String::new(); // this is allocation free
for i in memchr::memchr_iter(b'+', string.as_bytes()) {
if allocated.is_empty() {
allocated = string.into();
}
unsafe { allocated.as_bytes_mut()[i] = b' '; }
}
match allocated.is_empty() {
true => Cow::Borrowed(string),
false => Cow::Owned(allocated)
}
}
/// Returns a percent-encoded version of the string.
///
/// # Example
///
/// With a valid string:
///
/// ```rust
/// # extern crate rocket;
/// use rocket::http::RawStr;
///
/// let raw_str = RawStr::new("Hello%21");
/// let decoded = raw_str.percent_decode();
/// assert_eq!(decoded, Ok("Hello!".into()));
/// ```
///
/// With an invalid string:
///
/// ```rust
/// # extern crate rocket;
/// use rocket::http::RawStr;
///
/// // Note: Rocket should never hand you a bad `&RawStr`.
/// let bad_str = unsafe { std::str::from_utf8_unchecked(b"a=\xff") };
/// let bad_raw_str = RawStr::new(bad_str);
/// assert!(bad_raw_str.percent_decode().is_err());
/// ```
#[inline(always)]
pub fn percent_encode(&self) -> Cow<'_, RawStr> {
Self::from_cow_str(percent_encode::<DEFAULT_ENCODE_SET>(self))
}
/// Returns a URL-decoded version of the string. This is identical to
/// percent decoding except that `+` characters are converted into spaces.
/// This is the encoding used by form values.
///
/// # Errors
///
/// Returns an `Err` if the percent encoded values are not valid UTF-8.
///
/// # Example
///
/// ```rust
/// # extern crate rocket;
/// use rocket::http::RawStr;
///
/// let raw_str = RawStr::new("Hello%2C+world%21");
/// let decoded = raw_str.url_decode();
/// assert_eq!(decoded.unwrap(), "Hello, world!");
/// ```
pub fn url_decode(&self) -> Result<Cow<'_, str>, Utf8Error> {
let string = self._replace_plus();
match percent_encoding::percent_decode(string.as_bytes()).decode_utf8()? {
Cow::Owned(s) => Ok(Cow::Owned(s)),
Cow::Borrowed(_) => Ok(string)
}
}
/// Returns a URL-decoded version of the string.
///
/// Any invalid UTF-8 percent-encoded byte sequences will be replaced <20>
/// U+FFFD, the replacement character. This is identical to lossy percent
/// decoding except that `+` characters are converted into spaces. This is
/// the encoding used by form values.
///
/// # Example
///
/// With a valid string:
///
/// ```rust
/// # extern crate rocket;
/// use rocket::http::RawStr;
///
/// let raw_str: &RawStr = "Hello%2C+world%21".into();
/// let decoded = raw_str.url_decode_lossy();
/// assert_eq!(decoded, "Hello, world!");
/// ```
///
/// With an invalid string:
///
/// ```rust
/// # extern crate rocket;
/// use rocket::http::RawStr;
///
/// // Note: Rocket should never hand you a bad `&RawStr`.
/// let bad_str = unsafe { std::str::from_utf8_unchecked(b"a+b=\xff") };
/// let bad_raw_str = RawStr::new(bad_str);
/// assert_eq!(bad_raw_str.url_decode_lossy(), "a b=<3D>");
/// ```
pub fn url_decode_lossy(&self) -> Cow<'_, str> {
let string = self._replace_plus();
match percent_encoding::percent_decode(string.as_bytes()).decode_utf8_lossy() {
Cow::Owned(s) => Cow::Owned(s),
Cow::Borrowed(_) => string
}
}
/// Returns an HTML escaped version of `self`. Allocates only when
/// characters need to be escaped.
///
/// The following characters are escaped: `&`, `<`, `>`, `"`, `'`, `/`,
/// <code>`</code>. **This suffices as long as the escaped string is not
/// used in an execution context such as inside of &lt;script> or &lt;style>
/// tags!** See the [OWASP XSS Prevention Rules] for more information.
///
/// [OWASP XSS Prevention Rules]: https://www.owasp.org/index.php/XSS_%28Cross_Site_Scripting%29_Prevention_Cheat_Sheet#XSS_Prevention_Rules
///
/// # Example
///
/// Strings with HTML sequences are escaped:
///
/// ```rust
/// # extern crate rocket;
/// use rocket::http::RawStr;
///
/// let raw_str: &RawStr = "<b>Hi!</b>".into();
/// let escaped = raw_str.html_escape();
/// assert_eq!(escaped, "&lt;b&gt;Hi!&lt;&#x2F;b&gt;");
///
/// let raw_str: &RawStr = "Hello, <i>world!</i>".into();
/// let escaped = raw_str.html_escape();
/// assert_eq!(escaped, "Hello, &lt;i&gt;world!&lt;&#x2F;i&gt;");
/// ```
///
/// Strings without HTML sequences remain untouched:
///
/// ```rust
/// # extern crate rocket;
/// use rocket::http::RawStr;
///
/// let raw_str: &RawStr = "Hello!".into();
/// let escaped = raw_str.html_escape();
/// assert_eq!(escaped, "Hello!");
///
/// let raw_str: &RawStr = "大阪".into();
/// let escaped = raw_str.html_escape();
/// assert_eq!(escaped, "大阪");
/// ```
// NOTE: This is the ~fastest (a table-based implementation is slightly
// faster) implementation benchmarked for dense-ish escaping. For sparser
// texts, a regex-based-find solution is much faster.
pub fn html_escape(&self) -> Cow<'_, str> {
let mut escaped = false;
let mut allocated = Vec::new(); // this is allocation free
for c in self.as_bytes() {
match *c {
b'&' | b'<' | b'>' | b'"' | b'\'' | b'/' | b'`' => {
if !escaped {
let i = (c as *const u8 as usize) - (self.as_ptr() as usize);
allocated = Vec::with_capacity(self.len() * 2);
allocated.extend_from_slice(&self.as_bytes()[..i]);
}
match *c {
b'&' => allocated.extend_from_slice(b"&amp;"),
b'<' => allocated.extend_from_slice(b"&lt;"),
b'>' => allocated.extend_from_slice(b"&gt;"),
b'"' => allocated.extend_from_slice(b"&quot;"),
b'\'' => allocated.extend_from_slice(b"&#x27;"),
b'/' => allocated.extend_from_slice(b"&#x2F;"),
// Old versions of IE treat a ` as a '.
b'`' => allocated.extend_from_slice(b"&#96;"),
_ => unreachable!()
}
escaped = true;
}
_ if escaped => allocated.push(*c),
_ => { }
}
}
if escaped {
// This use of `unsafe` is only correct if the bytes in `allocated`
// form a valid UTF-8 string. We prove this by cases:
//
// 1. In the `!escaped` branch, capacity for the vector is first
// allocated. No characters are pushed to `allocated` prior to
// this branch running since the `escaped` flag isn't set. To
// enter this branch, the current byte must be a valid ASCII
// character. This implies that every byte preceding forms a
// valid UTF-8 string since ASCII characters in UTF-8 are never
// part of a multi-byte sequence. Thus, extending the `allocated`
// vector with these bytes results in a valid UTF-8 string in
// `allocated`.
//
// 2. After the `!escaped` branch, `allocated` is extended with a
// byte string of valid ASCII characters. Thus, `allocated` is
// still a valid UTF-8 string.
//
// 3. In the `_ if escaped` branch, the byte is simply pushed into
// the `allocated` vector. At this point, `allocated` may contain
// an invalid UTF-8 string as we are not a known boundary.
// However, note that this byte is part of a known valid string
// (`self`). If the byte is not part of a multi-byte sequence, it
// is ASCII, and no further justification is needed. If the byte
// _is_ part of a multi-byte sequence, it is _not_ ASCII, and
// thus will not fall into the escaped character set and it will
// be pushed into `allocated` subsequently, resulting in a valid
// UTF-8 string in `allocated`.
unsafe { Cow::Owned(String::from_utf8_unchecked(allocated)) }
} else {
Cow::Borrowed(self.as_str())
}
}
/// Returns the length of `self`.
///
/// This length is in bytes, not [`char`]s or graphemes. In other words,
/// it may not be what a human considers the length of the string.
///
/// # Example
///
/// ```rust
/// # extern crate rocket;
/// use rocket::http::RawStr;
///
/// let raw_str = RawStr::new("Hello, world!");
/// assert_eq!(raw_str.len(), 13);
/// ```
#[inline]
pub const fn len(&self) -> usize {
self.0.len()
}
/// Returns `true` if `self` has a length of zero bytes.
///
/// # Example
///
/// ```rust
/// # extern crate rocket;
/// use rocket::http::RawStr;
///
/// let raw_str = RawStr::new("Hello, world!");
/// assert!(!raw_str.is_empty());
///
/// let raw_str = RawStr::new("");
/// assert!(raw_str.is_empty());
/// ```
#[inline]
pub const fn is_empty(&self) -> bool {
self.len() == 0
}
/// Converts `self` into an `&str`.
///
/// This method should be used sparingly. **Only use this method when you
/// are absolutely certain that doing so is safe.**
///
/// # Example
///
/// ```rust
/// # extern crate rocket;
/// use rocket::http::RawStr;
///
/// let raw_str = RawStr::new("Hello, world!");
/// assert_eq!(raw_str.as_str(), "Hello, world!");
/// ```
#[inline(always)]
pub const fn as_str(&self) -> &str {
&self.0
}
/// Converts `self` into an `&[u8]`.
///
/// # Example
///
/// ```rust
/// # extern crate rocket;
/// use rocket::http::RawStr;
///
/// let raw_str = RawStr::new("hi");
/// assert_eq!(raw_str.as_bytes(), &[0x68, 0x69]);
/// ```
#[inline(always)]
pub const fn as_bytes(&self) -> &[u8] {
self.0.as_bytes()
}
/// Converts a string slice to a raw pointer.
///
/// As string slices are a slice of bytes, the raw pointer points to a
/// [`u8`]. This pointer will be pointing to the first byte of the string
/// slice.
///
/// The caller must ensure that the returned pointer is never written to.
/// If you need to mutate the contents of the string slice, use [`as_mut_ptr`].
///
/// [`as_mut_ptr`]: str::as_mut_ptr
///
/// # Examples
///
/// Basic usage:
///
/// ```
/// # extern crate rocket;
/// use rocket::http::RawStr;
///
/// let raw_str = RawStr::new("hi");
/// let ptr = raw_str.as_ptr();
/// ```
pub const fn as_ptr(&self) -> *const u8 {
self.as_str().as_ptr()
}
/// Converts `self` into an `&UncasedStr`.
///
/// This method should be used sparingly. **Only use this method when you
/// are absolutely certain that doing so is safe.**
///
/// # Example
///
/// ```rust
/// # extern crate rocket;
/// use rocket::http::RawStr;
///
/// let raw_str = RawStr::new("Content-Type");
/// assert!(raw_str.as_uncased_str() == "content-TYPE");
/// ```
#[inline(always)]
pub fn as_uncased_str(&self) -> &UncasedStr {
self.as_str().into()
}
/// Returns `true` if the given pattern matches a sub-slice of
/// this string slice.
///
/// Returns `false` if it does not.
///
/// The pattern can be a `&str`, [`char`], a slice of [`char`]s, or a
/// function or closure that determines if a character matches.
///
/// [`char`]: prim@char
///
/// # Examples
///
/// Basic usage:
///
/// ```
/// # extern crate rocket;
/// use rocket::http::RawStr;
///
/// let bananas = RawStr::new("bananas");
///
/// assert!(bananas.contains("nana"));
/// assert!(!bananas.contains("apples"));
/// ```
#[inline]
pub fn contains<'a, P: Pattern<'a>>(&'a self, pat: P) -> bool {
pat.is_contained_in(self.as_str())
}
/// Returns `true` if the given pattern matches a prefix of this
/// string slice.
///
/// Returns `false` if it does not.
///
/// The pattern can be a `&str`, [`char`], a slice of [`char`]s, or a
/// function or closure that determines if a character matches.
///
/// [`char`]: prim@char
///
/// # Examples
///
/// Basic usage:
///
/// ```
/// # extern crate rocket;
/// use rocket::http::RawStr;
///
/// let bananas = RawStr::new("bananas");
///
/// assert!(bananas.starts_with("bana"));
/// assert!(!bananas.starts_with("nana"));
/// ```
pub fn starts_with<'a, P: Pattern<'a>>(&'a self, pat: P) -> bool {
pat.is_prefix_of(self.as_str())
}
/// Returns `true` if the given pattern matches a suffix of this
/// string slice.
///
/// Returns `false` if it does not.
///
/// The pattern can be a `&str`, [`char`], a slice of [`char`]s, or a
/// function or closure that determines if a character matches.
///
/// [`char`]: prim@char
///
/// # Examples
///
/// Basic usage:
///
/// ```
/// # extern crate rocket;
/// use rocket::http::RawStr;
///
/// let bananas = RawStr::new("bananas");
///
/// assert!(bananas.ends_with("anas"));
/// assert!(!bananas.ends_with("nana"));
/// ```
pub fn ends_with<'a, P>(&'a self, pat: P) -> bool
where P: Pattern<'a>, <P as Pattern<'a>>::Searcher: ReverseSearcher<'a>
{
pat.is_suffix_of(self.as_str())
}
/// Returns the byte index of the first character of this string slice that
/// matches the pattern.
///
/// Returns [`None`] if the pattern doesn't match.
///
/// The pattern can be a `&str`, [`char`], a slice of [`char`]s, or a
/// function or closure that determines if a character matches.
///
/// [`char`]: prim@char
///
/// # Example
///
/// ```
/// # extern crate rocket;
/// use rocket::http::RawStr;
///
/// let s = RawStr::new("Löwe 老虎 Léopard Gepardi");
///
/// assert_eq!(s.find('L'), Some(0));
/// assert_eq!(s.find('é'), Some(14));
/// assert_eq!(s.find("pard"), Some(17));
/// ```
#[inline]
pub fn find<'a, P: Pattern<'a>>(&'a self, pat: P) -> Option<usize> {
pat.into_searcher(self.as_str()).next_match().map(|(i, _)| i)
}
/// An iterator over substrings of this string slice, separated by
/// characters matched by a pattern.
///
/// The pattern can be a `&str`, [`char`], a slice of [`char`]s, or a
/// function or closure that determines if a character matches.
///
/// [`char`]: prim@char
///
/// # Examples
///
/// Simple patterns:
///
/// ```
/// # extern crate rocket;
/// use rocket::http::RawStr;
///
/// let v: Vec<_> = RawStr::new("Mary had a little lamb")
/// .split(' ')
/// .map(|r| r.as_str())
/// .collect();
///
/// assert_eq!(v, ["Mary", "had", "a", "little", "lamb"]);
/// ```
#[inline]
pub fn split<'a, P>(&'a self, pat: P) -> impl Iterator<Item = &'a RawStr>
where P: Pattern<'a>
{
let split: Split<'_, P> = Split(SplitInternal {
start: 0,
end: self.len(),
matcher: pat.into_searcher(self.as_str()),
allow_trailing_empty: true,
finished: false,
});
split.map(|s| s.into())
}
/// Splits `self` into two pieces: the piece _before_ the first byte `b` and
/// the piece _after_ (not including `b`). Returns the tuple (`before`,
/// `after`). If `b` is not in `self`, or `b` is not an ASCII characters,
/// returns the entire string `self` as `before` and the empty string as
/// `after`.
///
/// # Example
///
/// ```rust
/// # extern crate rocket;
/// use rocket::http::RawStr;
///
/// let haystack = RawStr::new("a good boy!");
///
/// let (before, after) = haystack.split_at_byte(b'a');
/// assert_eq!(before, "");
/// assert_eq!(after, " good boy!");
///
/// let (before, after) = haystack.split_at_byte(b' ');
/// assert_eq!(before, "a");
/// assert_eq!(after, "good boy!");
///
/// let (before, after) = haystack.split_at_byte(b'o');
/// assert_eq!(before, "a g");
/// assert_eq!(after, "od boy!");
///
/// let (before, after) = haystack.split_at_byte(b'!');
/// assert_eq!(before, "a good boy");
/// assert_eq!(after, "");
///
/// let (before, after) = haystack.split_at_byte(b'?');
/// assert_eq!(before, "a good boy!");
/// assert_eq!(after, "");
///
/// let haystack = RawStr::new("");
/// let (before, after) = haystack.split_at_byte(b' ');
/// assert_eq!(before, "");
/// assert_eq!(after, "");
/// ```
#[inline]
pub fn split_at_byte(&self, b: u8) -> (&RawStr, &RawStr) {
if !b.is_ascii() {
return (self, &self[0..0]);
}
match memchr::memchr(b, self.as_bytes()) {
// SAFETY: `b` is a character boundary since it's ASCII, `i` is in
// bounds in `self` (or else None), and i is at most len - 1, so i +
// 1 is at most len.
Some(i) => unsafe {
let s = self.as_str();
let start = s.get_unchecked(0..i);
let end = s.get_unchecked((i + 1)..self.len());
(start.into(), end.into())
},
None => (self, &self[0..0])
}
}
/// Returns a string slice with the prefix removed.
///
/// If the string starts with the pattern `prefix`, returns substring after
/// the prefix, wrapped in `Some`. This method removes the prefix exactly
/// once.
///
/// If the string does not start with `prefix`, returns `None`.
///
/// The pattern can be a `&str`, `char`, a slice of `char`s, or a function
/// or closure that determines if a character matches.
///
/// # Examples
///
/// ```
/// # extern crate rocket;
/// use rocket::http::RawStr;
///
/// assert_eq!(RawStr::new("foo:bar").strip_prefix("foo:").unwrap(), "bar");
/// assert_eq!(RawStr::new("foofoo").strip_prefix("foo").unwrap(), "foo");
/// assert!(RawStr::new("foo:bar").strip_prefix("bar").is_none());
/// ```
#[inline]
pub fn strip_prefix<'a, P: Pattern<'a>>(&'a self, prefix: P) -> Option<&'a RawStr> {
prefix.strip_prefix_of(self.as_str()).map(RawStr::new)
}
/// Returns a string slice with the suffix removed.
///
/// If the string ends with the pattern `suffix`, returns the substring
/// before the suffix, wrapped in `Some`. Unlike `trim_end_matches`, this
/// method removes the suffix exactly once.
///
/// If the string does not end with `suffix`, returns `None`.
///
/// The pattern can be a `&str`, `char`, a slice of `char`s, or a function
/// or closure that determines if a character matches.
///
/// # Examples
///
/// ```
/// # extern crate rocket;
/// use rocket::http::RawStr;
///
/// assert_eq!(RawStr::new("bar:foo").strip_suffix(":foo").unwrap(), "bar");
/// assert_eq!(RawStr::new("foofoo").strip_suffix("foo").unwrap(), "foo");
/// assert!(RawStr::new("bar:foo").strip_suffix("bar").is_none());
/// ```
#[inline]
pub fn strip_suffix<'a, P>(&'a self, suffix: P) -> Option<&'a RawStr>
where P: Pattern<'a>,<P as Pattern<'a>>::Searcher: ReverseSearcher<'a>,
{
suffix.strip_suffix_of(self.as_str()).map(RawStr::new)
}
/// Parses this string slice into another type.
///
/// Because `parse` is so general, it can cause problems with type
/// inference. As such, `parse` is one of the few times you'll see
/// the syntax affectionately known as the 'turbofish': `::<>`. This
/// helps the inference algorithm understand specifically which type
/// you're trying to parse into.
///
/// # Errors
///
/// Will return `Err` if it's not possible to parse this string slice into
/// the desired type.
///
/// # Examples
///
/// Basic usage
///
/// ```
/// # extern crate rocket;
/// use rocket::http::RawStr;
///
/// let four: u32 = RawStr::new("4").parse().unwrap();
///
/// assert_eq!(4, four);
/// ```
#[inline]
pub fn parse<F: std::str::FromStr>(&self) -> Result<F, F::Err> {
std::str::FromStr::from_str(self.as_str())
}
}
#[cfg(feature = "serde")]
mod serde {
use _serde::{ser, de, Serialize, Deserialize};
use super::*;
impl Serialize for RawStr {
fn serialize<S>(&self, ser: S) -> Result<S::Ok, S::Error>
where S: ser::Serializer
{
self.as_str().serialize(ser)
}
}
impl<'de: 'a, 'a> Deserialize<'de> for &'a RawStr {
fn deserialize<D>(de: D) -> Result<Self, D::Error>
where D: de::Deserializer<'de>
{
<&'a str as Deserialize<'de>>::deserialize(de).map(RawStr::new)
}
}
}
impl fmt::Debug for RawStr {
#[inline(always)]
fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
self.0.fmt(f)
}
}
impl<'a> From<&'a str> for &'a RawStr {
#[inline(always)]
fn from(string: &'a str) -> &'a RawStr {
RawStr::new(string)
}
}
impl<'a> From<&'a RawStr> for Cow<'a, RawStr> {
fn from(raw: &'a RawStr) -> Self {
Cow::Borrowed(raw)
}
}
impl From<RawStrBuf> for Cow<'_, RawStr> {
fn from(raw: RawStrBuf) -> Self {
Cow::Owned(raw)
}
}
macro_rules! impl_partial {
($A:ty : $B:ty as $T:ty) => (
impl PartialEq<$A> for $B {
#[inline(always)]
fn eq(&self, other: &$A) -> bool {
let left: $T = self.as_ref();
let right: $T = other.as_ref();
left == right
}
}
impl PartialOrd<$A> for $B {
#[inline(always)]
fn partial_cmp(&self, other: &$A) -> Option<Ordering> {
let left: $T = self.as_ref();
let right: $T = other.as_ref();
left.partial_cmp(right)
}
}
);
($A:ty : $B:ty) => (impl_partial!($A : $B as &str);)
}
impl_partial!(RawStr : &RawStr);
impl_partial!(&RawStr : RawStr);
impl_partial!(str : RawStr);
impl_partial!(str : &RawStr);
impl_partial!(&str : RawStr);
impl_partial!(&&str : RawStr);
impl_partial!(Cow<'_, str> : RawStr);
impl_partial!(Cow<'_, str> : &RawStr);
impl_partial!(Cow<'_, RawStr> : RawStr as &RawStr);
impl_partial!(Cow<'_, RawStr> : &RawStr as &RawStr);
impl_partial!(RawStr : Cow<'_, str>);
impl_partial!(&RawStr : Cow<'_, str>);
impl_partial!(RawStr : Cow<'_, RawStr> as &RawStr);
impl_partial!(&RawStr : Cow<'_, RawStr> as &RawStr);
impl_partial!(String : RawStr);
impl_partial!(String : &RawStr);
impl_partial!(RawStr : String);
impl_partial!(&RawStr : String);
impl_partial!(RawStr : str);
impl_partial!(RawStr : &str);
impl_partial!(RawStr : &&str);
impl_partial!(&RawStr : str);
impl AsRef<str> for RawStr {
#[inline(always)]
fn as_ref(&self) -> &str {
self.as_str()
}
}
impl AsRef<RawStr> for str {
#[inline(always)]
fn as_ref(&self) -> &RawStr {
RawStr::new(self)
}
}
impl AsRef<RawStr> for RawStr {
#[inline(always)]
fn as_ref(&self) -> &RawStr {
self
}
}
impl AsRef<[u8]> for RawStr {
#[inline(always)]
fn as_ref(&self) -> &[u8] {
self.as_bytes()
}
}
impl<I: core::slice::SliceIndex<str, Output=str>> core::ops::Index<I> for RawStr {
type Output = RawStr;
#[inline]
fn index(&self, index: I) -> &Self::Output {
self.as_str()[index].into()
}
}
impl std::borrow::Borrow<str> for RawStr {
#[inline(always)]
fn borrow(&self) -> &str {
self.as_str()
}
}
impl std::borrow::Borrow<RawStr> for &str {
#[inline(always)]
fn borrow(&self) -> &RawStr {
(*self).into()
}
}
impl fmt::Display for RawStr {
#[inline(always)]
fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
self.0.fmt(f)
}
}
impl AsRef<RawStr> for RawStrBuf {
#[inline(always)]
fn as_ref(&self) -> &RawStr {
RawStr::new(self.0.as_str())
}
}
impl Borrow<RawStr> for RawStrBuf {
#[inline(always)]
fn borrow(&self) -> &RawStr {
self.as_ref()
}
}
impl std::ops::Deref for RawStrBuf {
type Target = RawStr;
#[inline(always)]
fn deref(&self) -> &Self::Target {
self.as_ref()
}
}
impl fmt::Display for RawStrBuf {
#[inline(always)]
fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
self.0.fmt(f)
}
}
impl fmt::Debug for RawStrBuf {
#[inline(always)]
fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
self.0.fmt(f)
}
}
impl From<String> for RawStrBuf {
#[inline(always)]
fn from(string: String) -> Self {
RawStrBuf(string)
}
}
impl From<&str> for RawStrBuf {
#[inline(always)]
fn from(string: &str) -> Self {
string.to_string().into()
}
}
impl From<&RawStr> for RawStrBuf {
#[inline(always)]
fn from(raw: &RawStr) -> Self {
raw.to_string().into()
}
}
#[cfg(test)]
mod tests {
use super::RawStr;
#[test]
fn can_compare() {
let raw_str = RawStr::new("abc");
assert_eq!(raw_str, "abc");
assert_eq!("abc", raw_str.as_str());
assert_eq!(raw_str, RawStr::new("abc"));
assert_eq!(raw_str, "abc".to_string());
assert_eq!("abc".to_string(), raw_str.as_str());
}
}