31 lines
941 B
Rust
31 lines
941 B
Rust
use std::borrow::Cow;
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use std::str;
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pub struct StrStrU8Codec;
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impl<'a> heed::BytesDecode<'a> for StrStrU8Codec {
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type DItem = (&'a str, &'a str, u8);
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fn bytes_decode(bytes: &'a [u8]) -> Option<Self::DItem> {
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let (n, bytes) = bytes.split_last()?;
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let s1_end = bytes.iter().position(|b| *b == 0)?;
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let (s1_bytes, s2_bytes) = bytes.split_at(s1_end);
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let s1 = str::from_utf8(s1_bytes).ok()?;
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let s2 = str::from_utf8(&s2_bytes[1..]).ok()?;
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Some((s1, s2, *n))
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}
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}
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impl<'a> heed::BytesEncode<'a> for StrStrU8Codec {
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type EItem = (&'a str, &'a str, u8);
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fn bytes_encode((s1, s2, n): &Self::EItem) -> Option<Cow<[u8]>> {
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let mut bytes = Vec::with_capacity(s1.len() + s2.len() + 1 + 1);
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bytes.extend_from_slice(s1.as_bytes());
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bytes.push(0);
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bytes.extend_from_slice(s2.as_bytes());
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bytes.push(*n);
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Some(Cow::Owned(bytes))
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}
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}
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