Method get_or_create_version

src/models/prob_node.rs:47–92

(
        this: *mut Self,
        version: VersionNumber,
        synchronization_map: &TSHashTable<SharedLatestNode, ()>,
        cache: &HNSWIndexCache,
        file_id: IndexFileId,
        offset

    #[allow(invalid_reference_casting)]
    #[allow(clippy::not_unsafe_ptr_arg_deref)]
    pub fn get_or_create_version(
        this: *mut Self,
        version: VersionNumber,
        synchronization_map: &TSHashTable<SharedLatestNode, ()>,
        cache: &HNSWIndexCache,
        file_id: IndexFileId,
        offset_counter: &HNSWIndexFileOffsetCounter,
    ) -> Result<(SharedNode, bool), BufIoError> {
        let self_ = unsafe { &*this };
        let latest = unsafe { &*self_.latest };
        let node = latest.try_get_data(cache)?;
        if node.version.load(Ordering::Relaxed) == *version {
            return Ok((self_.latest, false));
        }
        synchronization_map.lock_key_and_try(this, || {
            if node.version.load(Ordering::Relaxed) == *version {
                return Ok((self_.latest, false));
            }

            let offset = if node.hnsw_level.0 == 0 {
                offset_counter.next_level_0_offset()
            } else {
                offset_counter.next_offset()
            };

            unsafe {
                *(&latest.file_index as *const _ as *mut _) = FileIndex { file_id, offset };
            }

            node.version.store(*version, Ordering::Release);

            let cursor = cache.latest_version_links_bufman.open_cursor()?;
            cache
                .latest_version_links_bufman
                .seek_with_cursor(cursor, self_.file_offset.0 as u64)?;
            cache
                .latest_version_links_bufman
                .update_u32_with_cursor(cursor, offset.0)?;
            cache
                .latest_version_links_bufman
                .update_u32_with_cursor(cursor, *file_id)?;
            cache.latest_version_links_bufman.close_cursor(cursor)?;

            Ok((self_.latest, true))
        })
    }
}

pub type SharedLatestNode = *mut LatestNode;