bytes-str 0.2.1

use std::{
    borrow::{Borrow, BorrowMut, Cow},
    cmp::Ordering,
    convert::Infallible,
    ffi::OsStr,
    fmt::{self, Debug, Display},
    hash::{Hash, Hasher},
    net::{SocketAddr, ToSocketAddrs},
    ops::{Add, AddAssign, Deref, DerefMut, Index, IndexMut},
    path::Path,
    slice::SliceIndex,
    str::{FromStr, Utf8Error},
};

use bytes::{Bytes, BytesMut};

/// [String] but backed by a [BytesMut]
///
/// # Features
///
/// ## `serde`
///
/// If the `serde` feature is enabled, the [BytesString] type will be
/// [serde::Serialize] and [serde::Deserialize].
///
/// The [BytesString] type will be serialized just like a [String] type.
#[derive(Clone, Default, PartialEq, Eq)]
pub struct BytesString {
    pub(crate) bytes: BytesMut,
}

impl BytesString {
    /// Returns a new, empty BytesString.
    ///
    /// # Examples
    ///
    /// ```
    /// use bytes_str::BytesString;
    ///
    /// let s = BytesString::new();
    ///
    /// assert!(s.is_empty());
    /// ```
    pub fn new() -> Self {
        Self {
            bytes: BytesMut::new(),
        }
    }

    /// Returns a new, empty BytesString with the specified capacity.
    ///
    /// The capacity is the size of the internal buffer in bytes.
    ///
    /// The actual capacity may be larger than the specified capacity.
    ///
    /// # Examples
    ///
    /// ```
    /// use bytes_str::BytesString;
    ///
    /// let s = BytesString::with_capacity(10);
    ///
    /// assert!(s.capacity() >= 10);
    /// ```
    pub fn with_capacity(capacity: usize) -> Self {
        Self {
            bytes: BytesMut::with_capacity(capacity),
        }
    }

    /// Returns the length of this String, in bytes.
    ///
    /// # Examples
    ///
    /// ```
    /// use bytes_str::BytesString;
    ///
    /// let s = BytesString::from("hello");
    ///
    /// assert_eq!(s.len(), 5);
    /// ```
    pub fn len(&self) -> usize {
        self.bytes.len()
    }

    /// Returns the capacity of this String, in bytes.
    ///
    /// # Examples
    ///
    /// ```
    /// use bytes_str::BytesString;
    ///
    /// let s = BytesString::from("hello");
    ///
    /// assert!(s.capacity() >= 5);
    /// ```
    pub fn capacity(&self) -> usize {
        self.bytes.capacity()
    }

    /// Reserves the minimum capacity for exactly `additional` more bytes to be
    /// stored without reallocating.
    ///
    /// # Panics
    ///
    /// Panics if the new capacity overflows usize.
    ///
    /// # Examples
    ///
    /// ```
    /// use bytes_str::BytesString;
    ///
    /// let mut s = BytesString::from("hello");
    ///
    /// s.reserve(10);
    ///
    /// assert!(s.capacity() >= 15);
    /// ```
    pub fn reserve(&mut self, additional: usize) {
        self.bytes.reserve(additional);
    }

    /// Splits the string into two at the given index.
    ///
    /// Returns a newly allocated String. `self` contains bytes at indices
    /// greater than `at`, and the returned string contains bytes at indices
    /// less than `at`.
    ///
    /// # Examples
    ///
    /// ```
    /// use bytes_str::BytesString;
    ///
    /// let mut s = BytesString::from("hello");
    ///
    /// let other = s.split_off(2);
    ///
    /// assert_eq!(s, "he");
    /// assert_eq!(other, "llo");
    /// ```
    pub fn split_off(&mut self, at: usize) -> Self {
        Self {
            bytes: self.bytes.split_off(at),
        }
    }

    /// Returns a byte slice of this String’s contents.
    ///
    /// # Examples
    ///
    /// ```
    /// use bytes_str::BytesString;
    ///
    /// let s = BytesString::from("hello");
    ///
    /// assert_eq!(s.as_bytes(), b"hello");
    /// ```
    pub fn as_bytes(&self) -> &[u8] {
        self.bytes.as_ref()
    }

    /// Returns true if the BytesString has a length of 0.
    ///
    /// # Examples
    ///
    /// ```
    /// use bytes_str::BytesString;
    ///
    /// let s = BytesString::new();
    ///
    /// assert!(s.is_empty());
    /// ```
    pub fn is_empty(&self) -> bool {
        self.bytes.is_empty()
    }

    /// Truncates the BytesString to the specified length.
    ///
    /// If new_len is greater than or equal to the string’s current length, this
    /// has no effect.
    ///
    /// Note that this method has no effect on the allocated capacity of the
    /// string
    ///
    /// # Arguments
    ///
    /// * `new_len` - The new length of the BytesString
    ///
    /// # Panics
    ///
    /// Panics if new_len does not lie on a char boundary.
    ///
    /// # Examples
    ///
    /// ```
    /// use bytes_str::BytesString;
    ///
    /// let mut s = BytesString::from("hello");
    ///
    /// s.truncate(3);
    ///
    /// assert_eq!(s, "hel");
    /// ```
    ///
    ///
    /// Shortens this String to the specified length.
    pub fn truncate(&mut self, new_len: usize) {
        if new_len <= self.len() {
            assert!(self.is_char_boundary(new_len));
            self.bytes.truncate(new_len);
        }
    }

    /// Clears the BytesString, removing all bytes.
    ///
    /// # Examples
    ///
    /// ```
    /// use bytes_str::BytesString;
    ///
    /// let mut s = BytesString::from("hello");
    ///
    /// s.clear();
    ///
    /// assert!(s.is_empty());
    /// ```
    pub fn clear(&mut self) {
        self.bytes.clear();
    }

    /// Appends a character to the end of this BytesString.
    ///
    /// # Examples
    ///
    /// ```
    /// use bytes_str::BytesString;
    ///
    /// let mut s = BytesString::from("hello");
    ///
    /// s.push(' ');
    ///
    /// assert_eq!(s, "hello ");
    /// ```
    pub fn push(&mut self, ch: char) {
        let mut buf = [0; 4];
        let bytes = ch.encode_utf8(&mut buf);
        self.bytes.extend_from_slice(bytes.as_bytes());
    }

    /// Appends a string slice to the end of this BytesString.
    ///
    /// # Examples
    ///
    /// ```
    /// use bytes_str::BytesString;
    ///
    /// let mut s = BytesString::from("hello");
    ///
    /// s.push_str(" world");
    ///
    /// assert_eq!(s, "hello world");
    /// ```
    pub fn push_str(&mut self, s: &str) {
        self.bytes.extend_from_slice(s.as_bytes());
    }

    /// Returns a string slice containing the entire BytesString.
    ///
    /// # Examples
    ///
    /// ```
    /// use bytes_str::BytesString;
    ///
    /// let s = BytesString::from("hello");
    ///
    /// assert_eq!(s.as_str(), "hello");
    /// ```
    pub fn as_str(&self) -> &str {
        unsafe { std::str::from_utf8_unchecked(&self.bytes) }
    }

    /// Returns a mutable string slice containing the entire BytesString.
    ///
    /// # Examples
    ///
    /// ```
    /// use bytes_str::BytesString;
    ///
    /// let mut s = BytesString::from("hello");
    ///
    /// s.as_mut_str().make_ascii_uppercase();
    ///
    /// assert_eq!(s, "HELLO");
    /// ```
    pub fn as_mut_str(&mut self) -> &mut str {
        unsafe { std::str::from_utf8_unchecked_mut(&mut self.bytes) }
    }

    /// Converts the BytesString into a [BytesMut].
    ///
    /// # Examples
    ///
    /// ```
    /// use bytes_str::BytesString;
    /// use bytes::BytesMut;
    ///
    /// let s = BytesString::from("hello");
    ///
    /// let bytes = s.into_bytes();
    ///
    /// assert_eq!(bytes, BytesMut::from(&b"hello"[..]));
    /// ```
    pub fn into_bytes(self) -> BytesMut {
        self.bytes
    }

    /// Converts a [BytesMut] into a [BytesString] without checking if the bytes
    /// are valid UTF-8.
    ///
    /// # Safety
    ///
    /// This function is unsafe because it does not check if the bytes are valid
    /// UTF-8.
    pub unsafe fn from_bytes_unchecked(bytes: BytesMut) -> Self {
        Self { bytes }
    }

    /// Converts a [BytesMut] into a [BytesString] if the bytes are valid UTF-8.
    ///
    /// # Errors
    ///
    /// Returns a [Utf8Error] if the bytes are not valid UTF-8.
    ///
    /// # Examples
    ///
    /// ```
    /// use bytes_str::BytesString;
    /// use bytes::BytesMut;
    ///
    /// let s = BytesString::from_utf8(BytesMut::from(&b"hello"[..]));
    /// ```
    pub fn from_utf8(bytes: BytesMut) -> Result<Self, Utf8Error> {
        std::str::from_utf8(bytes.as_ref())?;

        Ok(Self { bytes })
    }

    /// Converts a slice of bytes into a [BytesString] if the bytes are valid
    /// UTF-8.
    ///
    /// # Errors
    ///
    /// Returns a [Utf8Error] if the bytes are not valid UTF-8.
    ///
    /// # Examples
    ///
    /// ```
    /// use bytes_str::BytesString;
    ///
    /// let s = BytesString::from_utf8_slice(b"hello");
    /// ```
    pub fn from_utf8_slice(bytes: &[u8]) -> Result<Self, Utf8Error> {
        std::str::from_utf8(bytes)?;

        Ok(Self {
            bytes: BytesMut::from(bytes),
        })
    }
}

impl Deref for BytesString {
    type Target = str;

    fn deref(&self) -> &Self::Target {
        self.as_str()
    }
}

impl DerefMut for BytesString {
    fn deref_mut(&mut self) -> &mut Self::Target {
        self.as_mut_str()
    }
}

impl AsRef<str> for BytesString {
    fn as_ref(&self) -> &str {
        self.as_str()
    }
}

impl Borrow<str> for BytesString {
    fn borrow(&self) -> &str {
        self.as_str()
    }
}

impl From<String> for BytesString {
    fn from(s: String) -> Self {
        Self {
            bytes: Bytes::from(s.into_bytes()).into(),
        }
    }
}

impl From<&str> for BytesString {
    fn from(s: &str) -> Self {
        Self {
            bytes: BytesMut::from(s),
        }
    }
}

impl From<BytesString> for BytesMut {
    fn from(s: BytesString) -> Self {
        s.bytes
    }
}

impl From<BytesString> for Bytes {
    fn from(s: BytesString) -> Self {
        s.bytes.into()
    }
}

impl From<char> for BytesString {
    fn from(ch: char) -> Self {
        let mut bytes = BytesString::with_capacity(ch.len_utf8());
        bytes.push(ch);
        bytes
    }
}

impl PartialEq<str> for BytesString {
    fn eq(&self, other: &str) -> bool {
        self.as_str() == other
    }
}

impl PartialEq<&'_ str> for BytesString {
    fn eq(&self, other: &&str) -> bool {
        self.as_str() == *other
    }
}

impl PartialEq<Cow<'_, str>> for BytesString {
    fn eq(&self, other: &Cow<'_, str>) -> bool {
        self.as_str() == *other
    }
}

impl PartialEq<BytesString> for str {
    fn eq(&self, other: &BytesString) -> bool {
        self == other.as_str()
    }
}

impl PartialEq<BytesString> for &'_ str {
    fn eq(&self, other: &BytesString) -> bool {
        *self == other.as_str()
    }
}

impl PartialEq<BytesString> for Bytes {
    fn eq(&self, other: &BytesString) -> bool {
        self == other.as_bytes()
    }
}

impl PartialEq<String> for BytesString {
    fn eq(&self, other: &String) -> bool {
        self.as_str() == other
    }
}

impl PartialEq<BytesString> for String {
    fn eq(&self, other: &BytesString) -> bool {
        self == other.as_str()
    }
}

impl Add<&str> for BytesString {
    type Output = Self;

    fn add(mut self, other: &str) -> Self::Output {
        self += other;
        self
    }
}

impl AddAssign<&str> for BytesString {
    fn add_assign(&mut self, other: &str) {
        self.push_str(other);
    }
}

impl Add<BytesString> for BytesString {
    type Output = Self;

    fn add(mut self, other: BytesString) -> Self::Output {
        self += other;
        self
    }
}

impl AddAssign<BytesString> for BytesString {
    fn add_assign(&mut self, other: BytesString) {
        self.bytes.extend(other.bytes);
    }
}

impl AsMut<str> for BytesString {
    fn as_mut(&mut self) -> &mut str {
        self.as_mut_str()
    }
}

impl AsRef<[u8]> for BytesString {
    fn as_ref(&self) -> &[u8] {
        self.as_bytes()
    }
}

impl AsRef<OsStr> for BytesString {
    fn as_ref(&self) -> &OsStr {
        OsStr::new(self.as_str())
    }
}

impl AsRef<Path> for BytesString {
    fn as_ref(&self) -> &Path {
        Path::new(self.as_str())
    }
}

impl BorrowMut<str> for BytesString {
    fn borrow_mut(&mut self) -> &mut str {
        self.as_mut_str()
    }
}

impl Debug for BytesString {
    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
        Debug::fmt(self.as_str(), f)
    }
}

impl Display for BytesString {
    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
        Display::fmt(self.as_str(), f)
    }
}

impl PartialOrd for BytesString {
    fn partial_cmp(&self, other: &Self) -> Option<Ordering> {
        Some(self.cmp(other))
    }
}

impl Ord for BytesString {
    fn cmp(&self, other: &Self) -> Ordering {
        self.as_str().cmp(other.as_str())
    }
}

impl<'a> Extend<&'a char> for BytesString {
    fn extend<T: IntoIterator<Item = &'a char>>(&mut self, iter: T) {
        self.extend(iter.into_iter().copied());
    }
}
impl Extend<char> for BytesString {
    fn extend<T: IntoIterator<Item = char>>(&mut self, iter: T) {
        let mut buf = [0; 4];
        for ch in iter {
            let bytes = ch.encode_utf8(&mut buf);
            self.bytes.extend_from_slice(bytes.as_bytes());
        }
    }
}

impl<'a> Extend<&'a str> for BytesString {
    fn extend<T: IntoIterator<Item = &'a str>>(&mut self, iter: T) {
        for s in iter {
            self.push_str(s);
        }
    }
}

impl Extend<Box<str>> for BytesString {
    fn extend<T: IntoIterator<Item = Box<str>>>(&mut self, iter: T) {
        for s in iter {
            self.push_str(&s);
        }
    }
}

impl<'a> Extend<Cow<'a, str>> for BytesString {
    fn extend<T: IntoIterator<Item = Cow<'a, str>>>(&mut self, iter: T) {
        for s in iter {
            self.push_str(&s);
        }
    }
}

impl Extend<String> for BytesString {
    fn extend<T: IntoIterator<Item = String>>(&mut self, iter: T) {
        for s in iter {
            self.push_str(&s);
        }
    }
}

impl<'a> Extend<&'a String> for BytesString {
    fn extend<T: IntoIterator<Item = &'a String>>(&mut self, iter: T) {
        for s in iter {
            self.push_str(s);
        }
    }
}

impl Extend<BytesString> for BytesString {
    fn extend<T: IntoIterator<Item = BytesString>>(&mut self, iter: T) {
        for s in iter {
            self.bytes.extend(s.bytes);
        }
    }
}

impl FromIterator<char> for BytesString {
    fn from_iter<T: IntoIterator<Item = char>>(iter: T) -> Self {
        let mut bytes = BytesString::new();
        bytes.extend(iter);
        bytes
    }
}

impl<'a> FromIterator<&'a str> for BytesString {
    fn from_iter<T: IntoIterator<Item = &'a str>>(iter: T) -> Self {
        let mut bytes = BytesString::new();
        bytes.extend(iter);
        bytes
    }
}

impl FromIterator<Box<str>> for BytesString {
    fn from_iter<T: IntoIterator<Item = Box<str>>>(iter: T) -> Self {
        let mut bytes = BytesString::new();
        bytes.extend(iter);
        bytes
    }
}

impl<'a> FromIterator<Cow<'a, str>> for BytesString {
    fn from_iter<T: IntoIterator<Item = Cow<'a, str>>>(iter: T) -> Self {
        let mut bytes = BytesString::new();
        bytes.extend(iter);
        bytes
    }
}

impl FromIterator<String> for BytesString {
    fn from_iter<T: IntoIterator<Item = String>>(iter: T) -> Self {
        let mut bytes = BytesString::new();
        bytes.extend(iter);
        bytes
    }
}

impl FromIterator<BytesString> for BytesString {
    fn from_iter<T: IntoIterator<Item = BytesString>>(iter: T) -> Self {
        let mut bytes = BytesString::new();
        bytes.extend(iter);
        bytes
    }
}

impl FromStr for BytesString {
    type Err = Infallible;

    fn from_str(s: &str) -> Result<Self, Self::Err> {
        Ok(Self {
            bytes: BytesMut::from(s),
        })
    }
}

impl<I> Index<I> for BytesString
where
    I: SliceIndex<str>,
{
    type Output = I::Output;

    fn index(&self, index: I) -> &Self::Output {
        self.as_str().index(index)
    }
}

impl<I> IndexMut<I> for BytesString
where
    I: SliceIndex<str>,
{
    fn index_mut(&mut self, index: I) -> &mut Self::Output {
        self.as_mut_str().index_mut(index)
    }
}

impl ToSocketAddrs for BytesString {
    type Iter = std::vec::IntoIter<SocketAddr>;

    fn to_socket_addrs(&self) -> Result<Self::Iter, std::io::Error> {
        self.as_str().to_socket_addrs()
    }
}

/// This produces the same hash as [str]
impl Hash for BytesString {
    fn hash<H: Hasher>(&self, state: &mut H) {
        self.as_str().hash(state);
    }
}

#[cfg(feature = "serde")]
mod serde_impl {
    use serde::{Deserialize, Deserializer, Serialize, Serializer};

    use super::*;

    impl<'de> Deserialize<'de> for BytesString {
        fn deserialize<D>(deserializer: D) -> Result<Self, D::Error>
        where
            D: Deserializer<'de>,
        {
            let s = String::deserialize(deserializer)?;
            Ok(Self::from(s))
        }
    }

    impl Serialize for BytesString {
        fn serialize<S>(&self, serializer: S) -> Result<S::Ok, S::Error>
        where
            S: Serializer,
        {
            serializer.serialize_str(self.as_str())
        }
    }
}