Method l2_table

block/src/qcow/mod.rs:818–846

Returns an L2_table of cluster addresses, only used for debugging.

(&mut self, l1_index: usize)

    /// Returns an L2_table of cluster addresses, only used for debugging.
    pub fn l2_table(&mut self, l1_index: usize) -> BlockResult<Option<&[u64]>> {
        let l2_addr_disk = *self
            .l1_table
            .get(l1_index)
            .ok_or_else(|| BlockError::new(BlockErrorKind::OutOfBounds, Error::InvalidIndex))?;

        if l2_addr_disk == 0 {
            // Reading from an unallocated cluster will return zeros.
            return Ok(None);
        }

        if !self.l2_cache.contains_key(l1_index) {
            // Not in the cache.
            let table = VecCache::from_vec(
                Self::read_l2_cluster(&mut self.raw_file, l2_addr_disk)
                    .map_err(|e| BlockError::new(BlockErrorKind::Io, Error::ReadingPointers(e)))?,
            );
            let l1_table = &self.l1_table;
            let raw_file = &mut self.raw_file;
            self.l2_cache
                .insert(l1_index, table, |index, evicted| {
                    raw_file.write_pointer_table_direct(l1_table[index], evicted.iter())
                })
                .map_err(|e| BlockError::new(BlockErrorKind::Io, Error::EvictingCache(e)))?;
        }

        // The index must exist as it was just inserted if it didn't already.
        Ok(Some(self.l2_cache.get(l1_index).unwrap().get_values()))
    }

    /// Returns the refcount table for this file. This is only useful for debugging.
    pub fn ref_table(&self) -> &[u64] {