use core::ops::Index;
use core::slice;
use core::str;
use core::fmt;
use scroll::{self, ctx, Pread};
#[cfg(feature = "std")]
use error;
pub struct Strtab<'a> {
bytes: &'a[u8],
delim: ctx::StrCtx,
}
#[inline(always)]
fn get_str(offset: usize, bytes: &[u8], delim: ctx::StrCtx) -> scroll::Result<&str> {
bytes.pread_with::<&str>(offset, delim)
}
impl<'a> Strtab<'a> {
pub fn new (bytes: &'a [u8], delim: u8) -> Self {
Strtab { delim: ctx::StrCtx::Delimiter(delim), bytes: bytes }
}
pub unsafe fn from_raw(ptr: *const u8, size: usize, delim: u8) -> Strtab<'a> {
Strtab { delim: ctx::StrCtx::Delimiter(delim), bytes: slice::from_raw_parts(ptr, size) }
}
#[cfg(feature = "std")]
pub fn parse(bytes: &'a [u8], offset: usize, len: usize, delim: u8) -> error::Result<Strtab<'a>> {
let (end, overflow) = offset.overflowing_add(len);
if overflow || end > bytes.len () {
return Err(error::Error::Malformed(format!("Strtable size ({}) + offset ({}) is out of bounds for {} #bytes. Overflowed: {}", len, offset, bytes.len(), overflow)));
}
Ok(Strtab { bytes: &bytes[offset..end], delim: ctx::StrCtx::Delimiter(delim) })
}
#[cfg(feature = "std")]
pub fn to_vec(self) -> error::Result<Vec<&'a str>> {
let len = self.bytes.len();
let mut strings = Vec::with_capacity(len);
let mut i = 0;
while i < len {
let string = self.get(i).unwrap()?;
i = i + string.len() + 1;
strings.push(string);
}
Ok(strings)
}
#[cfg(feature = "std")]
pub fn get(&self, offset: usize) -> Option<error::Result<&'a str>> {
if offset >= self.bytes.len() {
None
} else {
Some(get_str(offset, self.bytes, self.delim).map_err(|e| e.into()))
}
}
pub fn get_unsafe(&self, offset: usize) -> Option<&'a str> {
if offset >= self.bytes.len() {
None
} else {
Some(get_str(offset, self.bytes, self.delim).unwrap())
}
}
}
impl<'a> fmt::Debug for Strtab<'a> {
fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
write!(f, "delim: {:?} {:?}", self.delim, str::from_utf8(self.bytes))
}
}
impl<'a> Default for Strtab<'a> {
fn default() -> Strtab<'a> {
Strtab { bytes: &[], delim: ctx::StrCtx::default() }
}
}
impl<'a> Index<usize> for Strtab<'a> {
type Output = str;
#[inline(always)]
fn index(&self, offset: usize) -> &Self::Output {
get_str(offset, self.bytes, self.delim).unwrap()
}
}
#[test]
fn as_vec_no_final_null() {
let bytes = b"\0printf\0memmove\0busta";
let strtab = unsafe { Strtab::from_raw(bytes.as_ptr(), bytes.len(), 0x0) };
let vec = strtab.to_vec().unwrap();
assert_eq!(vec.len(), 4);
assert_eq!(vec, vec!["", "printf", "memmove", "busta"]);
}
#[test]
fn as_vec_no_first_null_no_final_null() {
let bytes = b"printf\0memmove\0busta";
let strtab = unsafe { Strtab::from_raw(bytes.as_ptr(), bytes.len(), 0x0) };
let vec = strtab.to_vec().unwrap();
assert_eq!(vec.len(), 3);
assert_eq!(vec, vec!["printf", "memmove", "busta"]);
}
#[test]
fn to_vec_final_null() {
let bytes = b"\0printf\0memmove\0busta\0";
let strtab = unsafe { Strtab::from_raw(bytes.as_ptr(), bytes.len(), 0x0) };
let vec = strtab.to_vec().unwrap();
assert_eq!(vec.len(), 4);
assert_eq!(vec, vec!["", "printf", "memmove", "busta"]);
}
#[test]
fn to_vec_newline_delim() {
let bytes = b"\nprintf\nmemmove\nbusta\n";
let strtab = unsafe { Strtab::from_raw(bytes.as_ptr(), bytes.len(), '\n' as u8) };
let vec = strtab.to_vec().unwrap();
assert_eq!(vec.len(), 4);
assert_eq!(vec, vec!["", "printf", "memmove", "busta"]);
}