Method look_up_object

src/loose.rs:410–446

Look up `oid` in the map in order to convert it to `algo`. If this object is in the map, return the offset in the table for the main algorithm.

(&self, oid: &ObjectID)

    ///
    /// If this object is in the map, return the offset in the table for the main algorithm.
    fn look_up_object(&self, oid: &ObjectID) -> Option<usize> {
        let oid_algo = HashAlgorithm::from_u32(oid.algo)?;
        let params = self.obj_formats.get(&oid_algo)?;
        let short_table =
            &self.memory[params.data_off..params.data_off + (params.shortened_len * self.nitems)];
        let index = Self::binary_search_slice(
            short_table,
            &oid.as_slice().unwrap()[0..params.shortened_len],
        )?;
        match params.mapping_off {
            Some(from_off) => {
                // oid is in a compatibility algorithm.  Find the mapping index.
                let mapped = Self::u32_at_offset(self.memory, from_off + index * 4) as usize;
                if mapped >= self.nitems {
                    return None;
                }
                let oid_offset = params.full_off + mapped * oid_algo.raw_len();
                if self.memory[oid_offset..oid_offset + oid_algo.raw_len()]
                    != *oid.as_slice().unwrap()
                {
                    return None;
                }
                Some(mapped)
            }
            None => {
                // oid is in the main algorithm.  Find the object ID in the main map to confirm
                // it's correct.
                let oid_offset = params.full_off + index * oid_algo.raw_len();
                if self.memory[oid_offset..oid_offset + oid_algo.raw_len()]
                    != *oid.as_slice().unwrap()
                {
                    return None;
                }
                Some(index)
            }
        }
    }

    #[allow(dead_code)]
    fn map_object(&self, oid: &ObjectID, algo: HashAlgorithm) -> Option<MappedObject> {