76 lines
2.4 KiB
Rust
76 lines
2.4 KiB
Rust
use std::borrow::Cow;
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use heed::{BytesDecode, BytesEncode};
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use sdset::Set;
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use crate::DocumentId;
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use super::cow_set::CowSet;
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pub struct DocumentsIds;
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impl BytesEncode<'_> for DocumentsIds {
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type EItem = Set<DocumentId>;
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fn bytes_encode(item: &Self::EItem) -> Option<Cow<[u8]>> {
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CowSet::bytes_encode(item)
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}
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}
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impl<'a> BytesDecode<'a> for DocumentsIds {
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type DItem = Cow<'a, Set<DocumentId>>;
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fn bytes_decode(bytes: &'a [u8]) -> Option<Self::DItem> {
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CowSet::bytes_decode(bytes)
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}
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}
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pub struct DiscoverIds<'a> {
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ids_iter: std::slice::Iter<'a, DocumentId>,
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left_id: Option<u32>,
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right_id: Option<u32>,
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available_range: std::ops::Range<u32>,
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}
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impl DiscoverIds<'_> {
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pub fn new(ids: &Set<DocumentId>) -> DiscoverIds {
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let mut ids_iter = ids.iter();
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let right_id = ids_iter.next().map(|id| id.0);
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let available_range = 0..right_id.unwrap_or(u32::max_value());
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DiscoverIds { ids_iter, left_id: None, right_id, available_range }
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}
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}
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impl Iterator for DiscoverIds<'_> {
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type Item = DocumentId;
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fn next(&mut self) -> Option<Self::Item> {
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loop {
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match self.available_range.next() {
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// The available range gives us a new id, we return it.
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Some(id) => return Some(DocumentId(id)),
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// The available range is exhausted, we need to find the next one.
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None if self.available_range.end == u32::max_value() => return None,
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None => loop {
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self.left_id = self.right_id.take();
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self.right_id = self.ids_iter.next().map(|id| id.0);
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match (self.left_id, self.right_id) {
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// We found a gap in the used ids, we can yield all ids
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// until the end of the gap
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(Some(l), Some(r)) => if l.saturating_add(1) != r {
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self.available_range = (l + 1)..r;
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break;
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},
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// The last used id has been reached, we can use all ids
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// until u32 MAX
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(Some(l), None) => {
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self.available_range = l.saturating_add(1)..u32::max_value();
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break;
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},
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_ => (),
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}
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},
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}
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}
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}
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}
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