def append_parray(self, parray, align=True, update_constants=False):
""" Add particles from a particle array
properties that are not there in self will be added
"""
if parray.gpu is None:
parray.set_device_helper(DeviceHelper(parray))
if parray.gpu.get_number_of_particles() == 0:
return
num_extra_particles = parray.gpu.get_number_of_particles()
old_num_particles = self.get_number_of_particles()
new_num_particles = num_extra_particles + old_num_particles
# extend current arrays by the required number of particles
self.extend(num_extra_particles)
my_stride = self._particle_array.stride
for prop_name in parray.gpu.properties:
stride = parray.stride.get(prop_name, 1)
if stride > 1 and prop_name not in my_stride:
my_stride[prop_name] = stride
if prop_name in self.properties:
arr = self._data[prop_name]
source = parray.gpu.get_device_array(prop_name)
arr.dev[old_num_particles * stride:] = source.dev
else:
# meaning this property is not there in self.
dtype = parray.gpu.get_device_array(prop_name).dtype
arr = Array(dtype, n=new_num_particles * stride,
backend=self.backend)
arr.fill(parray.default_values[prop_name])
self.update_prop(prop_name, arr)
# now add the values to the end of the created array
dest = self._data[prop_name]
source = parray.gpu.get_device_array(prop_name)
dest.dev[old_num_particles * stride:] = source.dev
if update_constants:
for const in parray.gpu.constants:
if const not in self.constants:
arr = parray.gpu.get_device_array(const)
self.update_const(const, arr.copy())
if num_extra_particles > 0 and align:
self.align_particles()
def remove_particles(self, indices):
""" Remove particles whose indices are given in index_list.
We repeatedly interchange the values of the last element and
values from the index_list and reduce the size of the array
by one. This is done for every property that is being maintained.
Parameters
----------
indices : array
an array of indices, this array can be a list, numpy array
or a LongArray.
Notes
-----
Pseudo-code for the implementation::
if index_list.length > number of particles
raise ValueError
sorted_indices <- index_list sorted in ascending order.
for every every array in property_array
array.remove(sorted_indices)
"""
if len(indices) > self.get_number_of_particles():
msg = 'Number of particles to be removed is greater than'
msg += 'number of particles in array'
raise ValueError(msg)
num_particles = self.get_number_of_particles()
if_remove = Array(np.int32, n=num_particles, backend=self.backend)
if_remove.fill(0)
fill_if_remove_knl = self._get_remove_particles_kernel()
fill_if_remove_knl(indices, if_remove, num_particles)
self._remove_particles_bool(if_remove)
def remove_particles(self, indices, align=True):
""" Remove particles whose indices are given in index_list.
Parameters
----------
indices : array
an array of indices, this array can be a list, numpy array
or a LongArray.
"""
if len(indices) > self.get_number_of_particles():
msg = 'Number of particles to be removed is greater than'
msg += 'number of particles in array'
raise ValueError(msg)
num_particles = self.get_number_of_particles()
if_remove = Array(np.int32, n=num_particles, backend=self.backend)
if_remove.fill(0)
fill_if_remove_knl = self._get_remove_particles_kernel()
fill_if_remove_knl(indices, if_remove, num_particles)
self._remove_particles_bool(if_remove, align=align)
def _build_tree(self, fixed_depth=None):
# We build the tree one layer at a time. We stop building new
# layers after either all the
# nodes are leaves or after reaching the target depth (fixed_depth).
# At this point, the information for each layer is segmented / not
# contiguous in memory, and so we run a merge_layers procedure to
# move the data for all layers into a single array.
#
# The procedure for building each layer can be split up as follows
# 1) Determine which child each particle is going to belong to in the
# next layer
# 2) Perform a kind of segmented scan over this. This gives us the
# new order of the particles so that consecutive particles lie in
# the same child
# 3) Reorder the particles based on this order
# 4) Create a new layer and set the node data for the new layer. We
# get to know which particles belong to each node directly from the
# results of step 2
# 5) Set the predicted offsets of the children of the nodes in the
# new layer. If a node has fewer than leaf_size particles, it's a
# leaf. A kind of prefix sum over this directly let's us know the
# predicted offsets.
# Rinse and repeat for building more layers.
#
# Note that after building the last layer, the predicted offsets for
# the children might not be correctly since we're not going to build
# more layers. The _merge_layers procedure sets the offsets in the
# last layer to -1 to correct this.
num_leaves_here = 0
n = self.n
temp_vars = {}
self.depth = 0
self.num_nodes = [1]
# Cumulative sum of nodes in the previous layers
csum_nodes_prev = 0
csum_nodes = 1
# Initialize temporary data (but persistent across layers)
self._create_temp_vars(temp_vars)
child_count_prefix_sum = Array(get_vector_dtype('uint', self.k),
n=n,
backend='opencl')
seg_flag = Array(cl.cltypes.char, n=n, backend='opencl')
seg_flag.fill(0)
seg_flag.dev[0] = 1
offsets_temp = [Array(np.int32, n=1, backend='opencl')]
offsets_temp[-1].fill(1)
pbounds_temp = [Array(cl.cltypes.uint2, n=1, backend='opencl')]
pbounds_temp[-1].dev[0].set(cl.cltypes.make_uint2(0, n))
# FIXME: Depths above 20 possible and feasible for binary / quad trees
loop_lim = min(fixed_depth, 20)
for depth in range(1, loop_lim):
num_nodes = self.k * (self.num_nodes[-1] - num_leaves_here)
if num_nodes == 0:
break
else:
self.depth += 1
self.num_nodes.append(num_nodes)
# Allocate new layer
offsets_temp.append(
Array(np.int32, n=self.num_nodes[-1], backend='opencl'))
pbounds_temp.append(
Array(cl.cltypes.uint2, n=self.num_nodes[-1],
backend='opencl'))
# Generate particle index and reorder the particles
self._reorder_particles(depth, child_count_prefix_sum,
offsets_temp[-2], pbounds_temp[-2],
seg_flag, csum_nodes_prev, temp_vars)
num_leaves_here = self._update_node_data(
offsets_temp[-2], pbounds_temp[-2], offsets_temp[-1],
pbounds_temp[-1], seg_flag, child_count_prefix_sum, csum_nodes,
csum_nodes + self.num_nodes[-1], n)
csum_nodes_prev = csum_nodes
csum_nodes += self.num_nodes[-1]
self._merge_layers(offsets_temp, pbounds_temp)
self._clean_temp_vars(temp_vars)
class Tree(object):
"""k-ary Tree
"""
def __init__(self, n, k=8, leaf_size=32):
self.ctx = get_context()
self.queue = get_queue()
self.sorted = False
self.main_helper = get_helper(os.path.join('tree', 'tree.mako'))
self.initialized = False
self.preamble = ""
self.leaf_size = leaf_size
self.k = k
self.n = n
self.sorted = False
self.depth = 0
self.index_function_args = []
self.index_function_arg_ctypes = []
self.index_function_arg_dtypes = []
self.index_function_consts = []
self.index_function_const_ctypes = []
self.index_code = ""
self.set_index_function_info()
def set_index_function_info(self):
raise NotImplementedError
def get_data_args(self):
return [getattr(self, v) for v in self.index_function_args]
def get_index_constants(self, depth):
raise NotImplementedError
def _initialize_data(self):
self.sorted = False
num_particles = self.n
self.pids = Array(np.uint32, n=num_particles, backend='opencl')
self.cids = Array(np.uint32, n=num_particles, backend='opencl')
self.cids.fill(0)
for var, dtype in zip(self.index_function_args,
self.index_function_arg_dtypes):
setattr(self, var, Array(dtype, n=num_particles, backend='opencl'))
# Filled after tree built
self.pbounds = None
self.offsets = None
self.initialized = True
def _reinitialize_data(self):
self.sorted = False
num_particles = self.n
self.pids.resize(num_particles)
self.cids.resize(num_particles)
self.cids.fill(0)
for var in self.index_function_args:
getattr(self, var).resize(num_particles)
# Filled after tree built
self.pbounds = None
self.offsets = None
def _setup_build(self):
if not self.initialized:
self._initialize_data()
else:
self._reinitialize_data()
def _build(self, fixed_depth=None):
self._build_tree(fixed_depth)
###########################################################################
# Core construction algorithm and helper functions
###########################################################################
# A little bit of manual book-keeping for temporary variables.
# More specifically, these temporary variables would otherwise be thrown
# away after building each layer of the tree.
# We could instead just allocate new arrays after building each layer and
# and let the GC take care of stuff but I'm guessing this is a
# a better approach to save on memory
def _create_temp_vars(self, temp_vars):
n = self.n
temp_vars['pids'] = Array(np.uint32, n=n, backend='opencl')
for var, dtype in zip(self.index_function_args,
self.index_function_arg_dtypes):
temp_vars[var] = Array(dtype, n=n, backend='opencl')
temp_vars['cids'] = Array(np.uint32, n=n, backend='opencl')
def _exchange_temp_vars(self, temp_vars):
for k in temp_vars.keys():
t = temp_vars[k]
temp_vars[k] = getattr(self, k)
setattr(self, k, t)
def _clean_temp_vars(self, temp_vars):
for k in list(temp_vars.keys()):
del temp_vars[k]
def _get_temp_data_args(self, temp_vars):
result = [temp_vars[v] for v in self.index_function_args]
return result
def _reorder_particles(self, depth, child_count_prefix_sum, offsets_parent,
pbounds_parent, seg_flag, csum_nodes_prev,
temp_vars):
# Scan
args = [('__global ' + ctype + ' *' + v) for v, ctype in zip(
self.index_function_args, self.index_function_arg_ctypes)]
args += [(ctype + ' ' + v) for v, ctype in zip(
self.index_function_consts, self.index_function_const_ctypes)]
args = ', '.join(args)
particle_kernel = _get_particle_kernel(self.ctx, self.k, args,
self.index_code)
args = [seg_flag.dev, child_count_prefix_sum.dev]
args += [x.dev for x in self.get_data_args()]
args += self.get_index_constants(depth)
particle_kernel(*args)
# Reorder particles
reorder_particles = self.main_helper.get_kernel(
'reorder_particles',
k=self.k,
data_vars=tuple(self.index_function_args),
data_var_ctypes=tuple(self.index_function_arg_ctypes),
const_vars=tuple(self.index_function_consts),
const_var_ctypes=tuple(self.index_function_const_ctypes),
index_code=self.index_code)
args = [
self.pids.dev, self.cids.dev, seg_flag.dev, pbounds_parent.dev,
offsets_parent.dev, child_count_prefix_sum.dev,
temp_vars['pids'].dev, temp_vars['cids'].dev
]
args += [x.dev for x in self.get_data_args()]
args += [x.dev for x in self._get_temp_data_args(temp_vars)]
args += self.get_index_constants(depth)
args += [np.uint32(csum_nodes_prev)]
reorder_particles(*args)
self._exchange_temp_vars(temp_vars)
def _merge_layers(self, offsets_temp, pbounds_temp):
curr_offset = 0
total_nodes = 0
for i in range(self.depth + 1):
total_nodes += self.num_nodes[i]
self.offsets = Array(np.int32, n=total_nodes, backend='opencl')
self.pbounds = Array(cl.cltypes.uint2, n=total_nodes, backend='opencl')
append_layer = self.main_helper.get_kernel('append_layer')
self.total_nodes = total_nodes
for i in range(self.depth + 1):
append_layer(offsets_temp[i].dev, pbounds_temp[i].dev,
self.offsets.dev, self.pbounds.dev,
np.int32(curr_offset), np.uint8(i == self.depth))
curr_offset += self.num_nodes[i]
def _update_node_data(self, offsets_prev, pbounds_prev, offsets, pbounds,
seg_flag, child_count_prefix_sum, csum_nodes,
csum_nodes_next, n):
"""Update node data and return number of children which are leaves."""
# Update particle-related data of children
set_node_data = self.main_helper.get_kernel("set_node_data", k=self.k)
set_node_data(offsets_prev.dev, pbounds_prev.dev, offsets.dev,
pbounds.dev, seg_flag.dev, child_count_prefix_sum.dev,
np.uint32(csum_nodes), np.uint32(n))
# Set children offsets
leaf_count = Array(np.uint32, n=1, backend='opencl')
set_offsets = _get_set_offset_kernel(self.ctx, self.k, self.leaf_size)
set_offsets(pbounds.dev, offsets.dev, leaf_count.dev,
np.uint32(csum_nodes_next))
return leaf_count.dev[0].get()
def _build_tree(self, fixed_depth=None):
# We build the tree one layer at a time. We stop building new
# layers after either all the
# nodes are leaves or after reaching the target depth (fixed_depth).
# At this point, the information for each layer is segmented / not
# contiguous in memory, and so we run a merge_layers procedure to
# move the data for all layers into a single array.
#
# The procedure for building each layer can be split up as follows
# 1) Determine which child each particle is going to belong to in the
# next layer
# 2) Perform a kind of segmented scan over this. This gives us the
# new order of the particles so that consecutive particles lie in
# the same child
# 3) Reorder the particles based on this order
# 4) Create a new layer and set the node data for the new layer. We
# get to know which particles belong to each node directly from the
# results of step 2
# 5) Set the predicted offsets of the children of the nodes in the
# new layer. If a node has fewer than leaf_size particles, it's a
# leaf. A kind of prefix sum over this directly let's us know the
# predicted offsets.
# Rinse and repeat for building more layers.
#
# Note that after building the last layer, the predicted offsets for
# the children might not be correctly since we're not going to build
# more layers. The _merge_layers procedure sets the offsets in the
# last layer to -1 to correct this.
num_leaves_here = 0
n = self.n
temp_vars = {}
self.depth = 0
self.num_nodes = [1]
# Cumulative sum of nodes in the previous layers
csum_nodes_prev = 0
csum_nodes = 1
# Initialize temporary data (but persistent across layers)
self._create_temp_vars(temp_vars)
child_count_prefix_sum = Array(get_vector_dtype('uint', self.k),
n=n,
backend='opencl')
seg_flag = Array(cl.cltypes.char, n=n, backend='opencl')
seg_flag.fill(0)
seg_flag.dev[0] = 1
offsets_temp = [Array(np.int32, n=1, backend='opencl')]
offsets_temp[-1].fill(1)
pbounds_temp = [Array(cl.cltypes.uint2, n=1, backend='opencl')]
pbounds_temp[-1].dev[0].set(cl.cltypes.make_uint2(0, n))
# FIXME: Depths above 20 possible and feasible for binary / quad trees
loop_lim = min(fixed_depth, 20)
for depth in range(1, loop_lim):
num_nodes = self.k * (self.num_nodes[-1] - num_leaves_here)
if num_nodes == 0:
break
else:
self.depth += 1
self.num_nodes.append(num_nodes)
# Allocate new layer
offsets_temp.append(
Array(np.int32, n=self.num_nodes[-1], backend='opencl'))
pbounds_temp.append(
Array(cl.cltypes.uint2, n=self.num_nodes[-1],
backend='opencl'))
# Generate particle index and reorder the particles
self._reorder_particles(depth, child_count_prefix_sum,
offsets_temp[-2], pbounds_temp[-2],
seg_flag, csum_nodes_prev, temp_vars)
num_leaves_here = self._update_node_data(
offsets_temp[-2], pbounds_temp[-2], offsets_temp[-1],
pbounds_temp[-1], seg_flag, child_count_prefix_sum, csum_nodes,
csum_nodes + self.num_nodes[-1], n)
csum_nodes_prev = csum_nodes
csum_nodes += self.num_nodes[-1]
self._merge_layers(offsets_temp, pbounds_temp)
self._clean_temp_vars(temp_vars)
###########################################################################
# Misc
###########################################################################
def _get_unique_cids_and_count(self):
n = self.n
self.unique_cids = Array(np.uint32, n=n, backend='opencl')
self.unique_cids_map = Array(np.uint32, n=n, backend='opencl')
uniq_count = Array(np.uint32, n=1, backend='opencl')
unique_cids_kernel = _get_unique_cids_kernel(self.ctx)
unique_cids_kernel(self.cids.dev, self.unique_cids_map.dev,
self.unique_cids.dev, uniq_count.dev)
self.unique_cid_count = uniq_count.dev[0].get()
def get_leaves(self):
leaves = Array(np.uint32,
n=self.offsets.dev.shape[0],
backend='opencl')
num_leaves = Array(np.uint32, n=1, backend='opencl')
leaves_kernel = _get_leaves_kernel(self.ctx, self.leaf_size)
leaves_kernel(self.offsets.dev, self.pbounds.dev, leaves.dev,
num_leaves.dev)
num_leaves = num_leaves.dev[0].get()
return leaves.dev[:num_leaves], num_leaves
def _sort(self):
"""Set tree as being sorted
The particle array needs to be aligned by the caller!
"""
if not self.sorted:
self.sorted = 1
###########################################################################
# Tree API
###########################################################################
def allocate_node_prop(self, dtype):
return Array(dtype, n=self.total_nodes, backend='opencl')
def allocate_leaf_prop(self, dtype):
return Array(dtype, n=int(self.unique_cid_count), backend='opencl')
def get_preamble(self):
if self.sorted:
return "#define PID(idx) (idx)"
else:
return "#define PID(idx) (pids[idx])"
def get_leaf_size_partitions(self, group_min, group_max):
"""Partition leaves based on leaf size
Parameters
----------
group_min
Minimum leaf size
group_max
Maximum leaf size
Returns
-------
groups : Array
An array which contains the cell ids of leaves
with leaf size > group_min and leaf size <= group_max
group_count : int
The number of leaves which satisfy the given condition
on the leaf size
"""
groups = Array(np.uint32,
n=int(self.unique_cid_count),
backend='opencl')
group_count = Array(np.uint32, n=1, backend='opencl')
get_cid_groups = _get_cid_groups_kernel(self.ctx)
get_cid_groups(self.unique_cids.dev[:self.unique_cid_count],
self.pbounds.dev, groups.dev, group_count.dev,
np.int32(group_min), np.int32(group_max))
result = groups, int(group_count.dev[0].get())
return result
def tree_bottom_up(self,
args,
setup,
leaf_operation,
node_operation,
output_expr,
preamble=""):
return tree_bottom_up(self.ctx, args, setup, leaf_operation,
node_operation, output_expr, preamble)
def leaf_tree_traverse(self,
args,
setup,
node_operation,
leaf_operation,
output_expr,
common_operation="",
preamble=""):
"""
Traverse this (source) tree. One thread for each leaf of
destination tree.
"""
return leaf_tree_traverse(self.ctx, self.k, args, setup,
node_operation, leaf_operation, output_expr,
common_operation, preamble)
def point_tree_traverse(self,
args,
setup,
node_operation,
leaf_operation,
output_expr,
common_operation="",
preamble=""):
"""
Traverse this (source) tree. One thread for each particle of
destination tree.
"""
return point_tree_traverse(self.ctx, self.k, args, setup,
node_operation, leaf_operation, output_expr,
common_operation, preamble)
