use std::borrow::Cow; use std::str; pub struct StrBytesCodec; impl<'a> heed::BytesDecode<'a> for StrBytesCodec { type DItem = (&'a str, &'a [u8]); fn bytes_decode(bytes: &'a [u8]) -> Option { let s1_end = bytes.iter().position(|b| *b == 0)?; let (s1_bytes, s2_bytes) = bytes.split_at(s1_end); let s1 = str::from_utf8(s1_bytes).ok()?; let s2 = &s2_bytes[1..]; Some((s1, s2)) } } impl<'a> heed::BytesEncode<'a> for StrBytesCodec { type EItem = (&'a str, &'a [u8]); fn bytes_encode((s1, s2): &Self::EItem) -> Option> { let mut bytes = Vec::with_capacity(s1.len() + s2.len() + 1); bytes.extend_from_slice(s1.as_bytes()); bytes.push(0); bytes.extend_from_slice(s2); Some(Cow::Owned(bytes)) } }