Ejemplo n.º 1
0
def test_subs_no_key_data_eq():
    # Numpy throws a deprecation warning on bool(array == scalar), which
    # pollutes the terminal. This test checks that `subs` never tries to
    # compare keys (scalars) with values (which could be arrays)`subs` never
    # tries to compare keys (scalars) with values (which could be arrays).
    a = MutateOnEq()
    subs(a, 'x', 1)
    assert a.hit_eq == 0
    subs((add, a, 'x'), 'x', 1)
    assert a.hit_eq == 0
Ejemplo n.º 2
0
def test_subs_no_key_data_eq():
    # Numpy throws a deprecation warning on bool(array == scalar), which
    # pollutes the terminal. This test checks that `subs` never tries to
    # compare keys (scalars) with values (which could be arrays)`subs` never
    # tries to compare keys (scalars) with values (which could be arrays).
    a = MutateOnEq()
    subs(a, "x", 1)
    assert a.hit_eq == 0
    subs((add, a, "x"), "x", 1)
    assert a.hit_eq == 0
Ejemplo n.º 3
0
def test_subs_with_unfriendly_eq():
    try:
        import numpy as np
    except:
        return
    else:
        task = (np.sum, np.array([1, 2]))
        assert (subs(task, (4, 5), 1) == task) is True
Ejemplo n.º 4
0
def test_subs_with_unfriendly_eq():
    try:
        import numpy as np
    except:
        return
    else:
        task = (np.sum, np.array([1, 2]))
        assert (subs(task, (4, 5), 1) == task) is True
Ejemplo n.º 5
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def test_subs_with_surprisingly_friendly_eq():
    try:
        import pandas as pd
    except:
        return
    else:
        df = pd.DataFrame()
        assert subs(df, 'x', 1) is df
Ejemplo n.º 6
0
def test_subs_with_surprisingly_friendly_eq():
    try:
        import pandas as pd
    except:
        return
    else:
        df = pd.DataFrame()
        assert subs(df, 'x', 1) is df
Ejemplo n.º 7
0
def test_subs_with_unfriendly_eq():
    try:
        import numpy as np
    except:
        return
    else:
        task = (np.sum, np.array([1, 2]))
        assert (subs(task, (4, 5), 1) == task) is True

    class MyException(Exception):
        pass

    class F():
        def __eq__(self, other):
            raise MyException()

    task = F()
    assert subs(task, 1, 2) is task
Ejemplo n.º 8
0
def test_subs_with_unfriendly_eq():
    try:
        import numpy as np
    except ImportError:
        return
    else:
        task = (np.sum, np.array([1, 2]))
        assert (subs(task, (4, 5), 1) == task) is True

    class MyException(Exception):
        pass

    class F():
        def __eq__(self, other):
            raise MyException()

    task = F()
    assert subs(task, 1, 2) is task
Ejemplo n.º 9
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def test_subs_unexpected_hashable_key():
    class UnexpectedButHashable:
        def __init__(self):
            self.name = "a"

        def __hash__(self):
            return hash(self.name)

        def __eq__(self, other):
            return isinstance(other, UnexpectedButHashable)

    assert subs((id, UnexpectedButHashable()), UnexpectedButHashable(), 1) == (id, 1)
Ejemplo n.º 10
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def test_subs_unexpected_hashable_key():
    class UnexpectedButHashable:
        def __init__(self):
            self.name = "a"

        def __hash__(self):
            return hash(self.name)

        def __eq__(self, other):
            return isinstance(other, UnexpectedButHashable)

    assert subs((id, UnexpectedButHashable()), UnexpectedButHashable(), 1) == (id, 1)
Ejemplo n.º 11
0
 def _apply(self, sub_dict):
     term = self.rhs
     for key, val in sub_dict.items():
         term = subs(term, key, val)
     return term
Ejemplo n.º 12
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def test_subs():
    assert subs((sum, [1, 'x']), 'x', 2) == (sum, [1, 2])
    assert subs((sum, [1, ['x']]), 'x', 2) == (sum, [1, [2]])
Ejemplo n.º 13
0
def fuse_linear(dsk, keys=None, dependencies=None, rename_keys=True):
    """Return new dask graph with linear sequence of tasks fused together.

    If specified, the keys in ``keys`` keyword argument are *not* fused.
    Supply ``dependencies`` from output of ``cull`` if available to avoid
    recomputing dependencies.

    **This function is mostly superseded by ``fuse``**

    Parameters
    ----------
    dsk: dict
    keys: list
    dependencies: dict, optional
        {key: [list-of-keys]}.  Must be a list to provide count of each key
        This optional input often comes from ``cull``
    rename_keys: bool or func, optional
        Whether to rename fused keys with ``default_fused_linear_keys_renamer``
        or not.  Renaming fused keys can keep the graph more understandable
        and comprehensive, but it comes at the cost of additional processing.
        If False, then the top-most key will be used.  For advanced usage, a
        func is also accepted, ``new_key = rename_keys(fused_key_list)``.

    Examples
    --------
    >>> def inc(x):
    ...     return x + 1

    >>> def add(x, y):
    ...     return x + y

    >>> d = {'a': 1, 'b': (inc, 'a'), 'c': (inc, 'b')}
    >>> dsk, dependencies = fuse(d)
    >>> dsk # doctest: +SKIP
    {'a-b-c': (inc, (inc, 1)), 'c': 'a-b-c'}
    >>> dsk, dependencies = fuse(d, rename_keys=False)
    >>> dsk # doctest: +ELLIPSIS
    {'c': (<function inc at ...>, (<function inc at ...>, 1))}
    >>> dsk, dependencies = fuse(d, keys=['b'], rename_keys=False)
    >>> dsk  # doctest: +ELLIPSIS
    {'b': (<function inc at ...>, 1), 'c': (<function inc at ...>, 'b')}

    Returns
    -------
    dsk: output graph with keys fused
    dependencies: dict mapping dependencies after fusion.  Useful side effect
        to accelerate other downstream optimizations.
    """
    if keys is not None and not isinstance(keys, set):
        if not isinstance(keys, list):
            keys = [keys]
        keys = set(flatten(keys))

    if dependencies is None:
        dependencies = {k: get_dependencies(dsk, k, as_list=True) for k in dsk}

    # locate all members of linear chains
    child2parent = {}
    unfusible = set()
    for parent in dsk:
        deps = dependencies[parent]
        has_many_children = len(deps) > 1
        for child in deps:
            if keys is not None and child in keys:
                unfusible.add(child)
            elif child in child2parent:
                del child2parent[child]
                unfusible.add(child)
            elif has_many_children:
                unfusible.add(child)
            elif child not in unfusible:
                child2parent[child] = parent

    # construct the chains from ancestor to descendant
    chains = []
    parent2child = dict(map(reversed, child2parent.items()))
    while child2parent:
        child, parent = child2parent.popitem()
        chain = [child, parent]
        while parent in child2parent:
            parent = child2parent.pop(parent)
            del parent2child[parent]
            chain.append(parent)
        chain.reverse()
        while child in parent2child:
            child = parent2child.pop(child)
            del child2parent[child]
            chain.append(child)
        chains.append(chain)

    dependencies = {k: set(v) for k, v in dependencies.items()}

    if rename_keys is True:
        key_renamer = default_fused_linear_keys_renamer
    elif rename_keys is False:
        key_renamer = None
    else:
        key_renamer = rename_keys

    # create a new dask with fused chains
    rv = {}
    fused = set()
    aliases = set()
    is_renamed = False
    for chain in chains:
        if key_renamer is not None:
            new_key = key_renamer(chain)
            is_renamed = (
                new_key is not None and new_key not in dsk and new_key not in rv
            )
        child = chain.pop()
        val = dsk[child]
        while chain:
            parent = chain.pop()
            dependencies[parent].update(dependencies.pop(child))
            dependencies[parent].remove(child)
            val = subs(dsk[parent], child, val)
            fused.add(child)
            child = parent
        fused.add(child)
        if is_renamed:
            rv[new_key] = val
            rv[child] = new_key
            dependencies[new_key] = dependencies[child]
            dependencies[child] = {new_key}
            aliases.add(child)
        else:
            rv[child] = val
    for key, val in dsk.items():
        if key not in fused:
            rv[key] = val
    if aliases:
        for key, deps in dependencies.items():
            for old_key in deps & aliases:
                new_key = rv[old_key]
                deps.remove(old_key)
                deps.add(new_key)
                rv[key] = subs(rv[key], old_key, new_key)
        if keys is not None:
            for key in aliases - keys:
                del rv[key]
                del dependencies[key]
    return rv, dependencies
Ejemplo n.º 14
0
def fuse(
    dsk,
    keys=None,
    dependencies=None,
    ave_width=_default,
    max_width=_default,
    max_height=_default,
    max_depth_new_edges=_default,
    rename_keys=_default,
    fuse_subgraphs=_default,
):
    """Fuse tasks that form reductions; more advanced than ``fuse_linear``

    This trades parallelism opportunities for faster scheduling by making tasks
    less granular.  It can replace ``fuse_linear`` in optimization passes.

    This optimization applies to all reductions--tasks that have at most one
    dependent--so it may be viewed as fusing "multiple input, single output"
    groups of tasks into a single task.  There are many parameters to fine
    tune the behavior, which are described below.  ``ave_width`` is the
    natural parameter with which to compare parallelism to granularity, so
    it should always be specified.  Reasonable values for other parameters
    will be determined using ``ave_width`` if necessary.

    Parameters
    ----------
    dsk: dict
        dask graph
    keys: list or set, optional
        Keys that must remain in the returned dask graph
    dependencies: dict, optional
        {key: [list-of-keys]}.  Must be a list to provide count of each key
        This optional input often comes from ``cull``
    ave_width: float (default 1)
        Upper limit for ``width = num_nodes / height``, a good measure of
        parallelizability.
        dask.config key: ``optimization.fuse.ave-width``
    max_width: int (default infinite)
        Don't fuse if total width is greater than this.
        dask.config key: ``optimization.fuse.max-width``
    max_height: int or None (default None)
        Don't fuse more than this many levels. Set to None to dynamically
        adjust to ``1.5 + ave_width * log(ave_width + 1)``.
        dask.config key: ``optimization.fuse.max-height``
    max_depth_new_edges: int or None (default None)
        Don't fuse if new dependencies are added after this many levels.
        Set to None to dynamically adjust to ave_width * 1.5.
        dask.config key: ``optimization.fuse.max-depth-new-edges``
    rename_keys: bool or func, optional (default True)
        Whether to rename the fused keys with ``default_fused_keys_renamer``
        or not.  Renaming fused keys can keep the graph more understandable
        and comprehensive, but it comes at the cost of additional processing.
        If False, then the top-most key will be used.  For advanced usage, a
        function to create the new name is also accepted.
        dask.config key: ``optimization.fuse.rename-keys``
    fuse_subgraphs : bool or None, optional (default None)
        Whether to fuse multiple tasks into ``SubgraphCallable`` objects.
        Set to None to let the default optimizer of individual dask collections decide.
        If no collection-specific default exists, None defaults to False.
        dask.config key: ``optimization.fuse.subgraphs``

    Returns
    -------
    dsk
        output graph with keys fused
    dependencies
        dict mapping dependencies after fusion.  Useful side effect to accelerate other
        downstream optimizations.
    """

    # Perform low-level fusion unless the user has
    # specified False explicitly.
    if config.get("optimization.fuse.active") is False:
        return dsk, dependencies

    if keys is not None and not isinstance(keys, set):
        if not isinstance(keys, list):
            keys = [keys]
        keys = set(flatten(keys))

    # Read defaults from dask.yaml and/or user-defined config file
    if ave_width is _default:
        ave_width = config.get("optimization.fuse.ave-width")
        assert ave_width is not _default
    if max_height is _default:
        max_height = config.get("optimization.fuse.max-height")
        assert max_height is not _default
    if max_depth_new_edges is _default:
        max_depth_new_edges = config.get("optimization.fuse.max-depth-new-edges")
        assert max_depth_new_edges is not _default
    if max_depth_new_edges is None:
        max_depth_new_edges = ave_width * 1.5
    if max_width is _default:
        max_width = config.get("optimization.fuse.max-width")
        assert max_width is not _default
    if max_width is None:
        max_width = 1.5 + ave_width * math.log(ave_width + 1)
    if fuse_subgraphs is _default:
        fuse_subgraphs = config.get("optimization.fuse.subgraphs")
        assert fuse_subgraphs is not _default
    if fuse_subgraphs is None:
        fuse_subgraphs = False

    if not ave_width or not max_height:
        return dsk, dependencies

    if rename_keys is _default:
        rename_keys = config.get("optimization.fuse.rename-keys")
        assert rename_keys is not _default
    if rename_keys is True:
        key_renamer = default_fused_keys_renamer
    elif rename_keys is False:
        key_renamer = None
    elif not callable(rename_keys):
        raise TypeError("rename_keys must be a boolean or callable")
    else:
        key_renamer = rename_keys
    rename_keys = key_renamer is not None

    if dependencies is None:
        deps = {k: get_dependencies(dsk, k, as_list=True) for k in dsk}
    else:
        deps = dict(dependencies)

    rdeps = {}
    for k, vals in deps.items():
        for v in vals:
            if v not in rdeps:
                rdeps[v] = [k]
            else:
                rdeps[v].append(k)
        deps[k] = set(vals)

    reducible = {k for k, vals in rdeps.items() if len(vals) == 1}
    if keys:
        reducible -= keys

    for k, v in dsk.items():
        if type(v) is not tuple and not isinstance(v, (numbers.Number, str)):
            reducible.discard(k)

    if not reducible and (
        not fuse_subgraphs or all(len(set(v)) != 1 for v in rdeps.values())
    ):
        # Quick return if there's nothing to do. Only progress if there's tasks
        # fusible by the main `fuse`, or by `fuse_subgraphs` if enabled.
        return dsk, deps

    rv = dsk.copy()
    fused_trees = {}
    # These are the stacks we use to store data as we traverse the graph
    info_stack = []
    children_stack = []
    # For speed
    deps_pop = deps.pop
    reducible_add = reducible.add
    reducible_pop = reducible.pop
    reducible_remove = reducible.remove
    fused_trees_pop = fused_trees.pop
    info_stack_append = info_stack.append
    info_stack_pop = info_stack.pop
    children_stack_append = children_stack.append
    children_stack_extend = children_stack.extend
    children_stack_pop = children_stack.pop
    while reducible:
        parent = reducible_pop()
        reducible_add(parent)
        while parent in reducible:
            # Go to the top
            parent = rdeps[parent][0]
        children_stack_append(parent)
        children_stack_extend(reducible & deps[parent])
        while True:
            child = children_stack[-1]
            if child != parent:
                children = reducible & deps[child]
                while children:
                    # Depth-first search
                    children_stack_extend(children)
                    parent = child
                    child = children_stack[-1]
                    children = reducible & deps[child]
                children_stack_pop()
                # This is a leaf node in the reduction region
                # key, task, fused_keys, height, width, number of nodes, fudge, set of edges
                info_stack_append(
                    (
                        child,
                        rv[child],
                        [child] if rename_keys else None,
                        1,
                        1,
                        1,
                        0,
                        deps[child] - reducible,
                    )
                )
            else:
                children_stack_pop()
                # Calculate metrics and fuse as appropriate
                deps_parent = deps[parent]
                edges = deps_parent - reducible
                children = deps_parent - edges
                num_children = len(children)

                if num_children == 1:
                    (
                        child_key,
                        child_task,
                        child_keys,
                        height,
                        width,
                        num_nodes,
                        fudge,
                        children_edges,
                    ) = info_stack_pop()
                    num_children_edges = len(children_edges)

                    if fudge > num_children_edges - 1 >= 0:
                        fudge = num_children_edges - 1
                    edges |= children_edges
                    no_new_edges = len(edges) == num_children_edges
                    if not no_new_edges:
                        fudge += 1
                    if (
                        (num_nodes + fudge) / height <= ave_width
                        and
                        # Sanity check; don't go too deep if new levels introduce new edge dependencies
                        (no_new_edges or height < max_depth_new_edges)
                    ):
                        # Perform substitutions as we go
                        val = subs(dsk[parent], child_key, child_task)
                        deps_parent.remove(child_key)
                        deps_parent |= deps_pop(child_key)
                        del rv[child_key]
                        reducible_remove(child_key)
                        if rename_keys:
                            child_keys.append(parent)
                            fused_trees[parent] = child_keys
                            fused_trees_pop(child_key, None)

                        if children_stack:
                            if no_new_edges:
                                # Linear fuse
                                info_stack_append(
                                    (
                                        parent,
                                        val,
                                        child_keys,
                                        height,
                                        width,
                                        num_nodes,
                                        fudge,
                                        edges,
                                    )
                                )
                            else:
                                info_stack_append(
                                    (
                                        parent,
                                        val,
                                        child_keys,
                                        height + 1,
                                        width,
                                        num_nodes + 1,
                                        fudge,
                                        edges,
                                    )
                                )
                        else:
                            rv[parent] = val
                            break
                    else:
                        rv[child_key] = child_task
                        reducible_remove(child_key)
                        if children_stack:
                            # Allow the parent to be fused, but only under strict circumstances.
                            # Ensure that linear chains may still be fused.
                            if fudge > int(ave_width - 1):
                                fudge = int(ave_width - 1)
                            # This task *implicitly* depends on `edges`
                            info_stack_append(
                                (
                                    parent,
                                    rv[parent],
                                    [parent] if rename_keys else None,
                                    1,
                                    width,
                                    1,
                                    fudge,
                                    edges,
                                )
                            )
                        else:
                            break
                else:
                    child_keys = []
                    height = 1
                    width = 0
                    num_single_nodes = 0
                    num_nodes = 0
                    fudge = 0
                    children_edges = set()
                    max_num_edges = 0
                    children_info = info_stack[-num_children:]
                    del info_stack[-num_children:]
                    for (
                        cur_key,
                        cur_task,
                        cur_keys,
                        cur_height,
                        cur_width,
                        cur_num_nodes,
                        cur_fudge,
                        cur_edges,
                    ) in children_info:
                        if cur_height == 1:
                            num_single_nodes += 1
                        elif cur_height > height:
                            height = cur_height
                        width += cur_width
                        num_nodes += cur_num_nodes
                        fudge += cur_fudge
                        if len(cur_edges) > max_num_edges:
                            max_num_edges = len(cur_edges)
                        children_edges |= cur_edges
                    # Fudge factor to account for possible parallelism with the boundaries
                    num_children_edges = len(children_edges)
                    fudge += min(
                        num_children - 1, max(0, num_children_edges - max_num_edges)
                    )

                    if fudge > num_children_edges - 1 >= 0:
                        fudge = num_children_edges - 1
                    edges |= children_edges
                    no_new_edges = len(edges) == num_children_edges
                    if not no_new_edges:
                        fudge += 1
                    if (
                        (num_nodes + fudge) / height <= ave_width
                        and num_single_nodes <= ave_width
                        and width <= max_width
                        and height <= max_height
                        and
                        # Sanity check; don't go too deep if new levels introduce new edge dependencies
                        (no_new_edges or height < max_depth_new_edges)
                    ):
                        # Perform substitutions as we go
                        val = dsk[parent]
                        children_deps = set()
                        for child_info in children_info:
                            cur_child = child_info[0]
                            val = subs(val, cur_child, child_info[1])
                            del rv[cur_child]
                            children_deps |= deps_pop(cur_child)
                            reducible_remove(cur_child)
                            if rename_keys:
                                fused_trees_pop(cur_child, None)
                                child_keys.extend(child_info[2])
                        deps_parent -= children
                        deps_parent |= children_deps

                        if rename_keys:
                            child_keys.append(parent)
                            fused_trees[parent] = child_keys

                        if children_stack:
                            info_stack_append(
                                (
                                    parent,
                                    val,
                                    child_keys,
                                    height + 1,
                                    width,
                                    num_nodes + 1,
                                    fudge,
                                    edges,
                                )
                            )
                        else:
                            rv[parent] = val
                            break
                    else:
                        for child_info in children_info:
                            rv[child_info[0]] = child_info[1]
                            reducible_remove(child_info[0])
                        if children_stack:
                            # Allow the parent to be fused, but only under strict circumstances.
                            # Ensure that linear chains may still be fused.
                            if width > max_width:
                                width = max_width
                            if fudge > int(ave_width - 1):
                                fudge = int(ave_width - 1)
                            # key, task, height, width, number of nodes, fudge, set of edges
                            # This task *implicitly* depends on `edges`
                            info_stack_append(
                                (
                                    parent,
                                    rv[parent],
                                    [parent] if rename_keys else None,
                                    1,
                                    width,
                                    1,
                                    fudge,
                                    edges,
                                )
                            )
                        else:
                            break
                # Traverse upwards
                parent = rdeps[parent][0]

    if fuse_subgraphs:
        _inplace_fuse_subgraphs(rv, keys, deps, fused_trees, rename_keys)

    if key_renamer:
        for root_key, fused_keys in fused_trees.items():
            alias = key_renamer(fused_keys)
            if alias is not None and alias not in rv:
                rv[alias] = rv[root_key]
                rv[root_key] = alias
                deps[alias] = deps[root_key]
                deps[root_key] = {alias}

    return rv, deps
Ejemplo n.º 15
0
def inline(dsk, keys=None, inline_constants=True, dependencies=None):
    """Return new dask with the given keys inlined with their values.

    Inlines all constants if ``inline_constants`` keyword is True. Note that
    the constant keys will remain in the graph, to remove them follow
    ``inline`` with ``cull``.

    Examples
    --------
    >>> def inc(x):
    ...     return x + 1

    >>> def add(x, y):
    ...     return x + y

    >>> d = {'x': 1, 'y': (inc, 'x'), 'z': (add, 'x', 'y')}
    >>> inline(d)       # doctest: +ELLIPSIS
    {'x': 1, 'y': (<function inc at ...>, 1), 'z': (<function add at ...>, 1, 'y')}

    >>> inline(d, keys='y') # doctest: +ELLIPSIS
    {'x': 1, 'y': (<function inc at ...>, 1), 'z': (<function add at ...>, 1, (<function inc at ...>, 1))}

    >>> inline(d, keys='y', inline_constants=False) # doctest: +ELLIPSIS
    {'x': 1, 'y': (<function inc at ...>, 'x'), 'z': (<function add at ...>, 'x', (<function inc at ...>, 'x'))}
    """
    if dependencies and isinstance(next(iter(dependencies.values())), list):
        dependencies = {k: set(v) for k, v in dependencies.items()}

    keys = _flat_set(keys)

    if dependencies is None:
        dependencies = {k: get_dependencies(dsk, k) for k in dsk}

    if inline_constants:
        keys.update(
            k
            for k, v in dsk.items()
            if (ishashable(v) and v in dsk) or (not dependencies[k] and not istask(v))
        )

    # Keys may depend on other keys, so determine replace order with toposort.
    # The values stored in `keysubs` do not include other keys.
    replaceorder = toposort(
        {k: dsk[k] for k in keys if k in dsk}, dependencies=dependencies
    )
    keysubs = {}
    for key in replaceorder:
        val = dsk[key]
        for dep in keys & dependencies[key]:
            if dep in keysubs:
                replace = keysubs[dep]
            else:
                replace = dsk[dep]
            val = subs(val, dep, replace)
        keysubs[key] = val

    # Make new dask with substitutions
    dsk2 = keysubs.copy()
    for key, val in dsk.items():
        if key not in dsk2:
            for item in keys & dependencies[key]:
                val = subs(val, item, keysubs[item])
            dsk2[key] = val
    return dsk2
Ejemplo n.º 16
0
 def _apply(self, sub_dict):
     term = self.rhs
     for key, val in sub_dict.items():
         term = subs(term, key, val)
     return term
Ejemplo n.º 17
0
def test_subs():
    assert subs((sum, [1, "x"]), "x", 2) == (sum, [1, 2])
    assert subs((sum, [1, ["x"]]), "x", 2) == (sum, [1, [2]])
Ejemplo n.º 18
0
def test_subs():
    assert subs((sum, [1, 'x']), 'x', 2) == (sum, [1, 2])
    assert subs((sum, [1, ['x']]), 'x', 2) == (sum, [1, [2]])