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use super::*;
pub type ListIndex = i128;
pub const INDEX_BYTES: usize = 16;
#[derive(Eq, PartialEq, Hash, Clone, Copy)]
#[repr(u8)]
enum Tag {
Blob = 0,
List = 1,
Table = 2,
}
pub fn encode_list_index(i: ListIndex) -> [u8; INDEX_BYTES] {
(i ^ ListIndex::min_value()).to_be_bytes()
}
pub fn decode_list_index(inp: &[u8]) -> Option<ListIndex> {
if inp.len() != INDEX_BYTES {
return None;
}
let mut buf = [0u8; INDEX_BYTES];
buf.copy_from_slice(inp);
Some(ListIndex::min_value() ^ ListIndex::from_be_bytes(buf))
}
pub fn blob(name: &[u8]) -> Vec<u8> {
let mut out = Vec::with_capacity(1 + name.len() + 2);
out.push(Tag::Blob as u8);
out.extend_from_slice(escape(name).as_ref());
out
}
#[inline(always)]
fn list_inner(name: &[u8], ix: Option<ListIndex>) -> Vec<u8> {
let escaped_name = escape(name);
let mut out = Vec::with_capacity(
1
+ escaped_name.len() + 2
+ 1
+ ix.map_or_else(|| 0, |_| INDEX_BYTES),
);
out.push(Tag::List as u8);
out.extend_from_slice(&escaped_name);
out.extend_from_slice(&TERMINATOR);
match ix {
Some(ix) => {
out.push(1);
let ix_bytes = encode_list_index(ix);
out.extend_from_slice(&ix_bytes);
}
None => {
out.push(0);
}
}
out
}
pub fn list(name: &[u8], ix: ListIndex) -> Vec<u8> {
list_inner(name, Some(ix))
}
pub fn list_meta(name: &[u8]) -> Vec<u8> {
list_inner(name, None)
}
#[inline(always)]
fn table_inner(name: &[u8], key: Option<&[u8]>) -> Vec<u8> {
let escaped_name = escape(name);
let escaped_key = key.map(escape);
let mut out = Vec::with_capacity(
1
+ escaped_name.len() + 2
+ 1
+ escaped_key.as_ref().map_or_else(|| 0, |k| k.len()),
);
out.push(Tag::Table as u8);
out.extend_from_slice(&escaped_name);
out.extend_from_slice(&TERMINATOR);
match escaped_key {
None => {
out.push(0);
}
Some(key) => {
out.push(1);
out.extend_from_slice(&key);
}
}
out
}
pub fn table(name: &[u8], key: &[u8]) -> Vec<u8> {
table_inner(name, Some(key))
}
pub fn table_meta(name: &[u8]) -> Vec<u8> {
table_inner(name, None)
}