use crate::follow::Follow;
use crate::primitives::*;
use crate::vtable::VTable;
#[derive(Clone, Copy, Debug, PartialEq, Eq)]
pub struct Table<'a> {
buf: &'a [u8],
loc: usize,
}
impl<'a> Table<'a> {
#[inline]
pub fn buf(&self) -> &'a [u8] {
self.buf
}
#[inline]
pub fn loc(&self) -> usize {
self.loc
}
#[inline]
pub unsafe fn new(buf: &'a [u8], loc: usize) -> Self {
Table { buf, loc }
}
#[inline]
pub fn vtable(&self) -> VTable<'a> {
unsafe { <BackwardsSOffset<VTable<'a>>>::follow(self.buf, self.loc) }
}
#[inline]
pub unsafe fn get<T: Follow<'a> + 'a>(
&self,
slot_byte_loc: VOffsetT,
default: Option<T::Inner>,
) -> Option<T::Inner> {
let o = self.vtable().get(slot_byte_loc) as usize;
if o == 0 {
return default;
}
Some(<T>::follow(self.buf, self.loc + o))
}
}
impl<'a> Follow<'a> for Table<'a> {
type Inner = Table<'a>;
#[inline]
unsafe fn follow(buf: &'a [u8], loc: usize) -> Self::Inner {
Table { buf, loc }
}
}
#[inline]
pub fn buffer_has_identifier(data: &[u8], ident: &str, size_prefixed: bool) -> bool {
assert_eq!(ident.len(), FILE_IDENTIFIER_LENGTH);
let got = if size_prefixed {
assert!(data.len() >= SIZE_SIZEPREFIX + SIZE_UOFFSET + FILE_IDENTIFIER_LENGTH);
unsafe { <SkipSizePrefix<SkipRootOffset<FileIdentifier>>>::follow(data, 0) }
} else {
assert!(data.len() >= SIZE_UOFFSET + FILE_IDENTIFIER_LENGTH);
unsafe { <SkipRootOffset<FileIdentifier>>::follow(data, 0) }
};
ident.as_bytes() == got
}