266 lines
7.4 KiB
Rust
266 lines
7.4 KiB
Rust
//! String type used by SWF files.
|
|
|
|
pub use encoding_rs::{Encoding, SHIFT_JIS, UTF_8, WINDOWS_1252};
|
|
use std::{borrow::Cow, fmt};
|
|
|
|
/// A bstr-like string type analogous to [`str`] that's returned by SWF parsing functions:
|
|
///
|
|
/// * The encoding depends on the SWF version (UTF-8 for SWF6 and higher).
|
|
/// Use `Reader::encoding` or [`SwfStr::encoding_for_version`] to get the
|
|
/// proper encoding.
|
|
/// * Invalid data for any particular encoding is allowed;
|
|
/// any conversions to std::String will be lossy for invalid data.
|
|
///
|
|
/// To convert this to a standard Rust string, use [`SwfStr::to_str_lossy`].
|
|
#[derive(Eq, PartialEq)]
|
|
#[repr(transparent)]
|
|
pub struct SwfStr {
|
|
/// The string bytes.
|
|
string: [u8],
|
|
}
|
|
|
|
impl SwfStr {
|
|
/// Creates a new `SwfStr` from a byte slice.
|
|
/// The data is not required to be valid for the given encoding.
|
|
///
|
|
/// # Examples
|
|
///
|
|
/// ```rust
|
|
/// use swf::SwfStr;
|
|
///
|
|
/// let s = SwfStr::from_bytes(b"Hello, World!");
|
|
/// ```
|
|
#[inline]
|
|
pub fn from_bytes(string: &[u8]) -> &Self {
|
|
// SAFETY: Casting is safe because internal representations are
|
|
// the same, see repr(transparent).
|
|
unsafe { &*(string as *const [u8] as *const Self) }
|
|
}
|
|
|
|
/// Creates a `SwfStr` from a byte slice by reading until a NULL byte (`0`) is encountered.
|
|
/// Returns `None` if no NULL byte was found.
|
|
///
|
|
/// # Examples
|
|
///
|
|
/// ```rust
|
|
/// use swf::SwfStr;
|
|
///
|
|
/// let s = SwfStr::from_bytes_null_terminated(b"I'm null-terminated!\0");
|
|
/// assert!(s.is_some());
|
|
///
|
|
/// let s = SwfStr::from_bytes_null_terminated(b"I'm not terminated...");
|
|
/// assert!(s.is_none());
|
|
/// ```
|
|
#[inline]
|
|
pub fn from_bytes_null_terminated(string: &[u8]) -> Option<&Self> {
|
|
// If investigations show that the bounds check is not elided,
|
|
// it should be safe to use `get_unchecked` here instead.
|
|
// Initial Godbolt research shows it doesn't make a difference.
|
|
string
|
|
.iter()
|
|
.position(|&c| c == 0)
|
|
.map(|i| Self::from_bytes(&string[..i]))
|
|
}
|
|
|
|
/// Creates a new UTF-8 `SwfStr` from a Rust [`str`].
|
|
///
|
|
/// # Examples
|
|
///
|
|
/// ```rust
|
|
/// use swf::SwfStr;
|
|
///
|
|
/// let s = SwfStr::from_utf8_str("Hello, 🌏!");
|
|
/// ```
|
|
#[inline]
|
|
pub fn from_utf8_str(string: &str) -> &Self {
|
|
Self::from_bytes(string.as_bytes())
|
|
}
|
|
|
|
/// Creates a new UTF-8 `SwfStr` from a Rust [`str`].
|
|
///
|
|
/// # Examples
|
|
///
|
|
/// ```rust
|
|
/// use swf::SwfStr;
|
|
///
|
|
/// let s = SwfStr::from_utf8_str_null_terminated("I'm null-terminated!\0");
|
|
/// assert!(s.is_some());
|
|
///
|
|
/// let s = SwfStr::from_utf8_str_null_terminated("I'm not terminated...");
|
|
/// assert!(s.is_none());
|
|
/// ```
|
|
#[inline]
|
|
pub fn from_utf8_str_null_terminated(string: &str) -> Option<&Self> {
|
|
Self::from_bytes_null_terminated(string.as_bytes())
|
|
}
|
|
|
|
/// Creates a new `SwfStr` with the given encoding from a Rust [`str`].
|
|
/// Returns `None` if the encoding is not lossless.
|
|
///
|
|
/// The string will be re-encoded with the given encoding.
|
|
/// The string will be truncated if a NULL byte (`0`) is encountered.
|
|
///
|
|
/// Intended for tests.
|
|
///
|
|
/// # Examples
|
|
///
|
|
/// ```rust
|
|
/// use swf::SwfStr;
|
|
/// use encoding_rs::WINDOWS_1252;
|
|
///
|
|
/// let s = SwfStr::from_str_with_encoding("Hello, World!", WINDOWS_1252);
|
|
/// assert!(s.is_some());
|
|
/// ```
|
|
pub fn from_str_with_encoding<'a>(
|
|
string: &'a str,
|
|
encoding: &'static Encoding,
|
|
) -> Option<&'a Self> {
|
|
if let (Cow::Borrowed(s), _, false) = encoding.encode(&string) {
|
|
Some(Self::from_bytes(s))
|
|
} else {
|
|
None
|
|
}
|
|
}
|
|
|
|
/// Returns the suggested string encoding for the given SWF version.
|
|
///
|
|
/// For SWF version 6 and higher, this is always UTF-8.
|
|
/// For SWF version 5 and lower, this is locale-dependent,
|
|
/// and we default to WINDOWS-1252.
|
|
///
|
|
/// # Examples
|
|
///
|
|
/// ```rust
|
|
/// use swf::SwfStr;
|
|
/// use encoding_rs::{UTF_8, WINDOWS_1252};
|
|
///
|
|
/// assert_eq!(SwfStr::encoding_for_version(9), UTF_8);
|
|
/// assert_eq!(SwfStr::encoding_for_version(3), WINDOWS_1252);
|
|
/// ```
|
|
#[inline]
|
|
pub fn encoding_for_version(swf_version: u8) -> &'static Encoding {
|
|
if swf_version >= 6 {
|
|
UTF_8
|
|
} else {
|
|
WINDOWS_1252
|
|
}
|
|
}
|
|
|
|
/// Returns the byte slice of this string.
|
|
///
|
|
/// # Examples
|
|
///
|
|
/// ```rust
|
|
/// use swf::SwfStr;
|
|
///
|
|
/// let s = SwfStr::from_utf8_str("💖");
|
|
/// assert_eq!(s.as_bytes(), [0xF0, 0x9F, 0x92, 0x96]);
|
|
/// ```
|
|
#[inline]
|
|
pub const fn as_bytes(&self) -> &[u8] {
|
|
&self.string
|
|
}
|
|
|
|
/// Returns `true` if the string has a length of zero, and `false` otherwise.
|
|
///
|
|
/// # Examples
|
|
///
|
|
/// ```rust
|
|
/// use swf::SwfStr;
|
|
///
|
|
/// let s = SwfStr::from_bytes(&[]);
|
|
/// assert!(s.is_empty());
|
|
///
|
|
/// let s = SwfStr::from_utf8_str("💖");
|
|
/// assert!(!s.is_empty());
|
|
#[inline]
|
|
pub const fn is_empty(&self) -> bool {
|
|
self.string.is_empty()
|
|
}
|
|
|
|
/// Returns the length of the string in bytes.
|
|
///
|
|
/// # Examples
|
|
///
|
|
/// ```rust
|
|
/// use swf::SwfStr;
|
|
///
|
|
/// let s = SwfStr::from_utf8_str("");
|
|
/// assert_eq!(s.len(), 0);
|
|
///
|
|
/// let s = SwfStr::from_utf8_str("Hi!");
|
|
/// assert_eq!(s.len(), 3);
|
|
///
|
|
/// let s = SwfStr::from_utf8_str("💖");
|
|
/// assert_eq!(s.len(), 4);
|
|
/// ```
|
|
#[inline]
|
|
pub const fn len(&self) -> usize {
|
|
self.string.len()
|
|
}
|
|
|
|
/// Decodes the string into a Rust UTF-8 [`str`].
|
|
///
|
|
/// The UTF-8 replacement character will be used for any invalid data.
|
|
///
|
|
/// # Examples
|
|
///
|
|
/// ```rust
|
|
/// use swf::SwfStr;
|
|
/// use encoding_rs::UTF_8;
|
|
///
|
|
/// let s = SwfStr::from_bytes(&[0xF0, 0x9F, 0x92, 0x96]);
|
|
/// assert_eq!(s.to_str_lossy(UTF_8), "💖");
|
|
/// ```
|
|
#[inline]
|
|
pub fn to_str_lossy(&self, encoding: &'static Encoding) -> Cow<'_, str> {
|
|
encoding.decode_without_bom_handling(&self.string).0
|
|
}
|
|
|
|
/// Decodes the string into a Rust UTF-8 [`String`].
|
|
///
|
|
/// The UTF-8 replacement character will be used for any invalid data.
|
|
///
|
|
/// # Examples
|
|
///
|
|
/// ```rust
|
|
/// use swf::SwfStr;
|
|
/// use encoding_rs::UTF_8;
|
|
///
|
|
/// let s = SwfStr::from_bytes(&[0xF0, 0x9F, 0x92, 0x96]);
|
|
/// assert_eq!(s.to_string_lossy(UTF_8), "💖");
|
|
/// ```
|
|
#[inline]
|
|
pub fn to_string_lossy(&self, encoding: &'static Encoding) -> String {
|
|
self.to_str_lossy(encoding).into_owned()
|
|
}
|
|
}
|
|
|
|
impl<'a> Default for &'a SwfStr {
|
|
fn default() -> &'a SwfStr {
|
|
SwfStr::from_bytes(&[])
|
|
}
|
|
}
|
|
|
|
impl<'a> From<&'a str> for &'a SwfStr {
|
|
fn from(s: &'a str) -> &'a SwfStr {
|
|
SwfStr::from_utf8_str(s)
|
|
}
|
|
}
|
|
|
|
impl<'a, T: ?Sized + AsRef<str>> PartialEq<T> for SwfStr {
|
|
fn eq(&self, other: &T) -> bool {
|
|
&self.string == other.as_ref().as_bytes()
|
|
}
|
|
}
|
|
|
|
impl fmt::Debug for SwfStr {
|
|
/// Formats the `SwfStr` using the given formatter.
|
|
///
|
|
/// Note: this method assumes UTF-8 encoding;
|
|
/// other encodings like Shift-JIS will output gibberish.
|
|
fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
|
|
f.write_str(&self.to_str_lossy(UTF_8))
|
|
}
|
|
}
|