Example #1
0
// Returns the slice to which any down-resolution data should be written for the given higher-res block coord.
func (d *Data) getLoresCache(v dvid.VersionID, block dvid.IZYXString) ([]byte, error) {
	// Setup the octant buffer and block cache.
	downresBlock, err := block.Downres()
	if err != nil {
		return nil, fmt.Errorf("unable to downres labelblk %q block: %v\n", d.DataName(), err)
	}

	var chunkPt dvid.ChunkPoint3d
	chunkPt, err = block.ToChunkPoint3d()
	if err != nil {
		return nil, err
	}

	// determine which down-res sector (0-7 where it's x, then y, then z ordering) in 2x2x2 block
	// the given block will sit.
	nx := chunkPt[0] % 2
	ny := chunkPt[1] % 2
	nz := chunkPt[2] % 2
	sector := (nz * 4) + (ny * 2) + nx

	// Get the sector slice from the octant corresponding to the downres block coord.
	// Initialize blockCache if necessary.
	d.vcache_mu.Lock()
	defer d.vcache_mu.Unlock()

	var bc blockCache
	if d.vcache == nil {
		d.vcache = make(map[dvid.VersionID]blockCache)
	} else {
		var found bool
		bc, found = d.vcache[v]
		if !found {
			bc = nil
		}
	}
	if bc == nil {
		bc = make(blockCache)
		d.vcache[v] = bc
	}

	// Get the relevant slice.
	oct := bc[downresBlock]
	if oct[sector] == nil {
		nbytes := d.BlockSize().Prod() // actually / 8 (downres 2^3) then * 8 bytes for label
		oct[sector] = make([]byte, nbytes)
	}
	d.vcache[v][downresBlock] = oct
	return oct[sector], nil
}
Example #2
0
// Store a label into a block using RLEs.
func (d *Data) storeRLEs(data []byte, toLabel uint64, zyxStr dvid.IZYXString, rles dvid.RLEs) error {
	// Get the block coordinate
	bcoord, err := zyxStr.ToChunkPoint3d()
	if err != nil {
		return err
	}

	// Get the first voxel offset
	blockSize := d.BlockSize()
	offset := bcoord.MinPoint(blockSize)

	// Iterate through rles, getting span for this block of bytes.
	nx := blockSize.Value(0) * 8
	nxy := nx * blockSize.Value(1)
	for _, rle := range rles {
		p := rle.StartPt().Sub(offset)
		i := p.Value(2)*nxy + p.Value(1)*nx + p.Value(0)*8
		for n := int32(0); n < rle.Length(); n++ {
			binary.LittleEndian.PutUint64(data[i:i+8], toLabel)
			i += 8
		}
	}
	return nil
}