51 lines
1.3 KiB
Rust
51 lines
1.3 KiB
Rust
use std::borrow::Cow;
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use std::convert::TryInto;
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use std::mem::size_of;
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use heed::{BoxedError, BytesDecode};
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use roaring::RoaringBitmap;
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use crate::heed_codec::BytesDecodeOwned;
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pub struct BoRoaringBitmapCodec;
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impl BoRoaringBitmapCodec {
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pub fn serialize_into(bitmap: &RoaringBitmap, out: &mut Vec<u8>) {
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out.reserve(bitmap.len() as usize * size_of::<u32>());
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bitmap.iter().map(u32::to_ne_bytes).for_each(|bytes| out.extend_from_slice(&bytes));
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}
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}
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impl BytesDecode<'_> for BoRoaringBitmapCodec {
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type DItem = RoaringBitmap;
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fn bytes_decode(bytes: &[u8]) -> Result<Self::DItem, BoxedError> {
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let mut bitmap = RoaringBitmap::new();
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for chunk in bytes.chunks(size_of::<u32>()) {
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let bytes = chunk.try_into()?;
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bitmap.push(u32::from_ne_bytes(bytes));
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}
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Ok(bitmap)
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}
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}
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impl BytesDecodeOwned for BoRoaringBitmapCodec {
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type DItem = RoaringBitmap;
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fn bytes_decode_owned(bytes: &[u8]) -> Result<Self::DItem, BoxedError> {
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Self::bytes_decode(bytes)
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}
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}
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impl heed::BytesEncode<'_> for BoRoaringBitmapCodec {
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type EItem = RoaringBitmap;
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fn bytes_encode(item: &Self::EItem) -> Result<Cow<[u8]>, BoxedError> {
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let mut out = Vec::new();
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BoRoaringBitmapCodec::serialize_into(item, &mut out);
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Ok(Cow::Owned(out))
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}
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}
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