# Copyright (C) 2009, 2010 Canonical Ltd # # This program is free software; you can redistribute it and/or modify # it under the terms of the GNU General Public License as published by # the Free Software Foundation; either version 2 of the License, or # (at your option) any later version. # # This program is distributed in the hope that it will be useful, # but WITHOUT ANY WARRANTY; without even the implied warranty of # MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the # GNU General Public License for more details. # # You should have received a copy of the GNU General Public License # along with this program; if not, write to the Free Software # Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA # # cython: language_level=3 """Implementation of Graph algorithms when we have already loaded everything. """ cdef extern from "python-compat.h": pass from cpython.bytes cimport ( PyBytes_CheckExact, ) from cpython.dict cimport ( PyDict_CheckExact, PyDict_DelItem, PyDict_GetItem, PyDict_Next, PyDict_SetItem, PyDict_Size, ) from cpython.list cimport ( PyList_Append, PyList_CheckExact, PyList_GET_SIZE, PyList_GET_ITEM, PyList_SetItem, ) from cpython.object cimport ( Py_LT, PyObject, PyObject_RichCompareBool, ) from cpython.ref cimport ( Py_INCREF, ) from cpython.tuple cimport ( PyTuple_CheckExact, PyTuple_GET_SIZE, PyTuple_GET_ITEM, PyTuple_New, PyTuple_SET_ITEM, ) import collections import gc from . import errors, revision cdef object NULL_REVISION NULL_REVISION = revision.NULL_REVISION cdef class _KnownGraphNode: """Represents a single object in the known graph.""" cdef object key cdef object parents cdef object children cdef public long gdfo cdef int seen cdef object extra def __init__(self, key): self.key = key self.parents = None self.children = [] # Greatest distance from origin self.gdfo = -1 self.seen = 0 self.extra = None property child_keys: def __get__(self): cdef _KnownGraphNode child keys = [] for child in self.children: PyList_Append(keys, child.key) return keys property parent_keys: def __get__(self): if self.parents is None: return None cdef _KnownGraphNode parent keys = [] for parent in self.parents: PyList_Append(keys, parent.key) return keys cdef clear_references(self): self.parents = None self.children = None def __repr__(self): cdef _KnownGraphNode node parent_keys = [] if self.parents is not None: for node in self.parents: parent_keys.append(node.key) child_keys = [] if self.children is not None: for node in self.children: child_keys.append(node.key) return '%s(%s gdfo:%s par:%s child:%s)' % ( self.__class__.__name__, self.key, self.gdfo, parent_keys, child_keys) cdef _KnownGraphNode _get_list_node(lst, Py_ssize_t pos): cdef PyObject *temp_node temp_node = PyList_GET_ITEM(lst, pos) return <_KnownGraphNode>temp_node cdef _KnownGraphNode _get_tuple_node(tpl, Py_ssize_t pos): cdef PyObject *temp_node temp_node = PyTuple_GET_ITEM(tpl, pos) return <_KnownGraphNode>temp_node def get_key(node): cdef _KnownGraphNode real_node real_node = node return real_node.key cdef object _sort_list_nodes(object lst_or_tpl, int reverse): """Sort a list of _KnownGraphNode objects. If lst_or_tpl is a list, it is allowed to mutate in place. It may also just return the input list if everything is already sorted. """ cdef _KnownGraphNode node1, node2 cdef int do_swap, is_tuple cdef Py_ssize_t length is_tuple = PyTuple_CheckExact(lst_or_tpl) if not (is_tuple or PyList_CheckExact(lst_or_tpl)): raise TypeError('lst_or_tpl must be a list or tuple.') length = len(lst_or_tpl) if length == 0 or length == 1: return lst_or_tpl if length == 2: if is_tuple: node1 = _get_tuple_node(lst_or_tpl, 0) node2 = _get_tuple_node(lst_or_tpl, 1) else: node1 = _get_list_node(lst_or_tpl, 0) node2 = _get_list_node(lst_or_tpl, 1) if reverse: do_swap = PyObject_RichCompareBool(node1.key, node2.key, Py_LT) else: do_swap = PyObject_RichCompareBool(node2.key, node1.key, Py_LT) if not do_swap: return lst_or_tpl if is_tuple: return (node2, node1) else: # Swap 'in-place', since lists are mutable Py_INCREF(node1) PyList_SetItem(lst_or_tpl, 1, node1) Py_INCREF(node2) PyList_SetItem(lst_or_tpl, 0, node2) return lst_or_tpl # For all other sizes, we just use 'sorted()' if is_tuple: # Note that sorted() is just list(iterable).sort() lst_or_tpl = list(lst_or_tpl) lst_or_tpl.sort(key=get_key, reverse=reverse) return lst_or_tpl cdef class _MergeSorter cdef class KnownGraph: """This is a class which assumes we already know the full graph.""" cdef public object _nodes cdef public object _known_heads cdef public int do_cache def __init__(self, parent_map, do_cache=True): """Create a new KnownGraph instance. :param parent_map: A dictionary mapping key => parent_keys """ # tests at pre-allocating the node dict actually slowed things down self._nodes = {} # Maps {sorted(revision_id, revision_id): heads} self._known_heads = {} self.do_cache = int(do_cache) # TODO: consider disabling gc since we are allocating a lot of nodes # that won't be collectable anyway. real world testing has not # shown a specific impact, yet. self._initialize_nodes(parent_map) self._find_gdfo() def __dealloc__(self): cdef _KnownGraphNode child cdef Py_ssize_t pos cdef PyObject *temp_node while PyDict_Next(self._nodes, &pos, NULL, &temp_node): child = <_KnownGraphNode>temp_node child.clear_references() cdef _KnownGraphNode _get_or_create_node(self, key): cdef PyObject *temp_node cdef _KnownGraphNode node temp_node = PyDict_GetItem(self._nodes, key) if temp_node == NULL: node = _KnownGraphNode(key) PyDict_SetItem(self._nodes, key, node) else: node = <_KnownGraphNode>temp_node return node cdef _populate_parents(self, _KnownGraphNode node, parent_keys): cdef Py_ssize_t num_parent_keys, pos cdef _KnownGraphNode parent_node num_parent_keys = len(parent_keys) # We know how many parents, so we pre allocate the tuple parent_nodes = PyTuple_New(num_parent_keys) for pos from 0 <= pos < num_parent_keys: # Note: it costs us 10ms out of 40ms to lookup all of these # parents, it doesn't seem to be an allocation overhead, # but rather a lookup overhead. There doesn't seem to be # a way around it, and that is one reason why # KnownGraphNode maintains a direct pointer to the parent # node. # We use [] because parent_keys may be a tuple or list parent_node = self._get_or_create_node(parent_keys[pos]) # PyTuple_SET_ITEM will steal a reference, so INCREF first Py_INCREF(parent_node) PyTuple_SET_ITEM(parent_nodes, pos, parent_node) PyList_Append(parent_node.children, node) node.parents = parent_nodes def _initialize_nodes(self, parent_map): """Populate self._nodes. After this has finished: - self._nodes will have an entry for every entry in parent_map. - ghosts will have a parent_keys = None, - all nodes found will also have child_keys populated with all known child keys, """ cdef PyObject *temp_key cdef PyObject *temp_parent_keys cdef PyObject *temp_node cdef Py_ssize_t pos cdef _KnownGraphNode node cdef _KnownGraphNode parent_node if not PyDict_CheckExact(parent_map): raise TypeError('parent_map should be a dict of {key:parent_keys}') # for key, parent_keys in parent_map.iteritems(): pos = 0 while PyDict_Next(parent_map, &pos, &temp_key, &temp_parent_keys): key = temp_key parent_keys = temp_parent_keys node = self._get_or_create_node(key) self._populate_parents(node, parent_keys) def _find_tails(self): cdef PyObject *temp_node cdef _KnownGraphNode node cdef Py_ssize_t pos tails = [] pos = 0 while PyDict_Next(self._nodes, &pos, NULL, &temp_node): node = <_KnownGraphNode>temp_node if node.parents is None or PyTuple_GET_SIZE(node.parents) == 0: node.gdfo = 1 PyList_Append(tails, node) return tails def _find_tips(self): cdef PyObject *temp_node cdef _KnownGraphNode node cdef Py_ssize_t pos tips = [] pos = 0 while PyDict_Next(self._nodes, &pos, NULL, &temp_node): node = <_KnownGraphNode>temp_node if PyList_GET_SIZE(node.children) == 0: PyList_Append(tips, node) return tips def _find_gdfo(self): cdef _KnownGraphNode node cdef _KnownGraphNode child cdef PyObject *temp cdef Py_ssize_t pos cdef int replace cdef Py_ssize_t last_item cdef long next_gdfo pending = self._find_tails() last_item = PyList_GET_SIZE(pending) - 1 while last_item >= 0: # Avoid pop followed by push, instead, peek, and replace # timing shows this is 930ms => 770ms for OOo node = _get_list_node(pending, last_item) last_item = last_item - 1 next_gdfo = node.gdfo + 1 for pos from 0 <= pos < PyList_GET_SIZE(node.children): child = _get_list_node(node.children, pos) if next_gdfo > child.gdfo: child.gdfo = next_gdfo child.seen = child.seen + 1 if child.seen == PyTuple_GET_SIZE(child.parents): # This child is populated, queue it to be walked last_item = last_item + 1 if last_item < PyList_GET_SIZE(pending): Py_INCREF(child) # SetItem steals a ref PyList_SetItem(pending, last_item, child) else: PyList_Append(pending, child) # We have queued this node, we don't need to track it # anymore child.seen = 0 def add_node(self, key, parent_keys): """Add a new node to the graph. If this fills in a ghost, then the gdfos of all children will be updated accordingly. :param key: The node being added. If this is a duplicate, this is a no-op. :param parent_keys: The parents of the given node. :return: None (should we return if this was a ghost, etc?) """ cdef PyObject *maybe_node cdef _KnownGraphNode node, parent_node, child_node cdef long parent_gdfo, next_gdfo maybe_node = PyDict_GetItem(self._nodes, key) if maybe_node != NULL: node = <_KnownGraphNode>maybe_node if node.parents is None: # We are filling in a ghost self._populate_parents(node, parent_keys) # We can't trust cached heads anymore self._known_heads.clear() else: # Ensure that the parent_key list matches existing_parent_keys = [] for parent_node in node.parents: existing_parent_keys.append(parent_node.key) # Make sure we use a list for the comparison, in case it was a # tuple, etc parent_keys = list(parent_keys) if existing_parent_keys == parent_keys: # Exact match, nothing more to do return else: raise ValueError('Parent key mismatch, existing node %s' ' has parents of %s not %s' % (key, existing_parent_keys, parent_keys)) else: node = _KnownGraphNode(key) PyDict_SetItem(self._nodes, key, node) self._populate_parents(node, parent_keys) parent_gdfo = 0 for parent_node in node.parents: if parent_node.gdfo == -1: # This is a newly introduced ghost, so it gets gdfo of 1 parent_node.gdfo = 1 if parent_gdfo < parent_node.gdfo: parent_gdfo = parent_node.gdfo node.gdfo = parent_gdfo + 1 # Now fill the gdfo to all children # Note that this loop is slightly inefficient, in that we may visit the # same child (and its decendents) more than once, however, it is # 'efficient' in that we only walk to nodes that would be updated, # rather than all nodes # We use a deque rather than a simple list stack, to go for BFD rather # than DFD. So that if a longer path is possible, we walk it before we # get to the final child pending = collections.deque([node]) pending_popleft = pending.popleft pending_append = pending.append while pending: node = pending_popleft() next_gdfo = node.gdfo + 1 for child_node in node.children: if child_node.gdfo < next_gdfo: # This child is being updated, we need to check its # children child_node.gdfo = next_gdfo pending_append(child_node) def heads(self, keys): """Return the heads from amongst keys. This is done by searching the ancestries of each key. Any key that is reachable from another key is not returned; all the others are. This operation scales with the relative depth between any two keys. It uses gdfo to avoid walking all ancestry. :param keys: An iterable of keys. :return: A set of the heads. Note that as a set there is no ordering information. Callers will need to filter their input to create order if they need it. """ cdef PyObject *maybe_node cdef PyObject *maybe_heads cdef PyObject *temp_node cdef _KnownGraphNode node cdef Py_ssize_t pos, last_item cdef long min_gdfo heads_key = frozenset(keys) maybe_heads = PyDict_GetItem(self._known_heads, heads_key) if maybe_heads != NULL: return maybe_heads # Not cached, compute it ourselves candidate_nodes = {} for key in keys: maybe_node = PyDict_GetItem(self._nodes, key) if maybe_node == NULL: raise KeyError('key %s not in nodes' % (key,)) PyDict_SetItem(candidate_nodes, key, maybe_node) maybe_node = PyDict_GetItem(candidate_nodes, NULL_REVISION) if maybe_node != NULL: # NULL_REVISION is only a head if it is the only entry candidate_nodes.pop(NULL_REVISION) if not candidate_nodes: return frozenset([NULL_REVISION]) # The keys changed, so recalculate heads_key heads_key = frozenset(candidate_nodes) if PyDict_Size(candidate_nodes) < 2: return heads_key cleanup = [] pending = [] # we know a gdfo cannot be longer than a linear chain of all nodes min_gdfo = PyDict_Size(self._nodes) + 1 # Build up nodes that need to be walked, note that starting nodes are # not added to seen() pos = 0 while PyDict_Next(candidate_nodes, &pos, NULL, &temp_node): node = <_KnownGraphNode>temp_node if node.parents is not None: pending.extend(node.parents) if node.gdfo < min_gdfo: min_gdfo = node.gdfo # Now do all the real work last_item = PyList_GET_SIZE(pending) - 1 while last_item >= 0: node = _get_list_node(pending, last_item) last_item = last_item - 1 if node.seen: # node already appears in some ancestry continue PyList_Append(cleanup, node) node.seen = 1 if node.gdfo <= min_gdfo: continue if node.parents is not None and PyTuple_GET_SIZE(node.parents) > 0: for pos from 0 <= pos < PyTuple_GET_SIZE(node.parents): parent_node = _get_tuple_node(node.parents, pos) last_item = last_item + 1 if last_item < PyList_GET_SIZE(pending): Py_INCREF(parent_node) # SetItem steals a ref PyList_SetItem(pending, last_item, parent_node) else: PyList_Append(pending, parent_node) heads = [] pos = 0 while PyDict_Next(candidate_nodes, &pos, NULL, &temp_node): node = <_KnownGraphNode>temp_node if not node.seen: PyList_Append(heads, node.key) heads = frozenset(heads) for pos from 0 <= pos < PyList_GET_SIZE(cleanup): node = _get_list_node(cleanup, pos) node.seen = 0 if self.do_cache: PyDict_SetItem(self._known_heads, heads_key, heads) return heads def topo_sort(self): """Return the nodes in topological order. All parents must occur before all children. """ # This is, for the most part, the same iteration order that we used for # _find_gdfo, consider finding a way to remove the duplication # In general, we find the 'tails' (nodes with no parents), and then # walk to the children. For children that have all of their parents # yielded, we queue up the child to be yielded as well. cdef _KnownGraphNode node cdef _KnownGraphNode child cdef PyObject *temp cdef Py_ssize_t pos cdef int replace cdef Py_ssize_t last_item pending = self._find_tails() if PyList_GET_SIZE(pending) == 0 and len(self._nodes) > 0: raise errors.GraphCycleError(self._nodes) topo_order = [] last_item = PyList_GET_SIZE(pending) - 1 while last_item >= 0: # Avoid pop followed by push, instead, peek, and replace # timing shows this is 930ms => 770ms for OOo node = _get_list_node(pending, last_item) last_item = last_item - 1 if node.parents is not None: # We don't include ghost parents PyList_Append(topo_order, node.key) for pos from 0 <= pos < PyList_GET_SIZE(node.children): child = _get_list_node(node.children, pos) if child.gdfo == -1: # We know we have a graph cycle because a node has a parent # which we couldn't find raise errors.GraphCycleError(self._nodes) child.seen = child.seen + 1 if child.seen == PyTuple_GET_SIZE(child.parents): # All parents of this child have been yielded, queue this # one to be yielded as well last_item = last_item + 1 if last_item < PyList_GET_SIZE(pending): Py_INCREF(child) # SetItem steals a ref PyList_SetItem(pending, last_item, child) else: PyList_Append(pending, child) # We have queued this node, we don't need to track it # anymore child.seen = 0 # We started from the parents, so we don't need to do anymore work return topo_order def gc_sort(self): """Return a reverse topological ordering which is 'stable'. There are a few constraints: 1) Reverse topological (all children before all parents) 2) Grouped by prefix 3) 'stable' sorting, so that we get the same result, independent of machine, or extra data. To do this, we use the same basic algorithm as topo_sort, but when we aren't sure what node to access next, we sort them lexicographically. """ cdef PyObject *temp cdef Py_ssize_t pos, last_item cdef _KnownGraphNode node, node2, parent_node tips = self._find_tips() # Split the tips based on prefix prefix_tips = {} for pos from 0 <= pos < PyList_GET_SIZE(tips): node = _get_list_node(tips, pos) if PyBytes_CheckExact(node.key) or len(node.key) == 1: prefix = '' else: prefix = node.key[0] temp = PyDict_GetItem(prefix_tips, prefix) if temp == NULL: prefix_tips[prefix] = [node] else: tip_nodes = temp PyList_Append(tip_nodes, node) result = [] for prefix in sorted(prefix_tips): temp = PyDict_GetItem(prefix_tips, prefix) assert temp != NULL tip_nodes = temp pending = _sort_list_nodes(tip_nodes, 1) last_item = PyList_GET_SIZE(pending) - 1 while last_item >= 0: node = _get_list_node(pending, last_item) last_item = last_item - 1 if node.parents is None: # Ghost continue PyList_Append(result, node.key) # Sorting the parent keys isn't strictly necessary for stable # sorting of a given graph. But it does help minimize the # differences between graphs # For bzr.dev ancestry: # 4.73ms no sort # 7.73ms RichCompareBool sort parents = _sort_list_nodes(node.parents, 1) for pos from 0 <= pos < len(parents): if PyTuple_CheckExact(parents): parent_node = _get_tuple_node(parents, pos) else: parent_node = _get_list_node(parents, pos) # TODO: GraphCycle detection parent_node.seen = parent_node.seen + 1 if (parent_node.seen == PyList_GET_SIZE(parent_node.children)): # All children have been processed, queue up this # parent last_item = last_item + 1 if last_item < PyList_GET_SIZE(pending): Py_INCREF(parent_node) # SetItem steals a ref PyList_SetItem(pending, last_item, parent_node) else: PyList_Append(pending, parent_node) parent_node.seen = 0 return result def merge_sort(self, tip_key): """Compute the merge sorted graph output.""" cdef _MergeSorter sorter # TODO: consider disabling gc since we are allocating a lot of nodes # that won't be collectable anyway. real world testing has not # shown a specific impact, yet. sorter = _MergeSorter(self, tip_key) return sorter.topo_order() def get_parent_keys(self, key): """Get the parents for a key Returns a list containing the parents keys. If the key is a ghost, None is returned. A KeyError will be raised if the key is not in the graph. :param keys: Key to check (eg revision_id) :return: A list of parents """ return self._nodes[key].parent_keys def get_child_keys(self, key): """Get the children for a key Returns a list containing the children keys. A KeyError will be raised if the key is not in the graph. :param keys: Key to check (eg revision_id) :return: A list of children """ return self._nodes[key].child_keys cdef class _MergeSortNode: """Tracks information about a node during the merge_sort operation.""" # Public api cdef public object key cdef public long merge_depth cdef public object end_of_merge # True/False Is this the end of the current merge # Private api, used while computing the information cdef _KnownGraphNode left_parent cdef _KnownGraphNode left_pending_parent cdef object pending_parents # list of _KnownGraphNode for non-left parents cdef long _revno_first cdef long _revno_second cdef long _revno_last # TODO: turn these into flag/bit fields rather than individual members cdef int is_first_child # Is this the first child? cdef int seen_by_child # A child node has seen this parent cdef int completed # Fully Processed def __init__(self, key): self.key = key self.merge_depth = -1 self.left_parent = None self.left_pending_parent = None self.pending_parents = None self._revno_first = -1 self._revno_second = -1 self._revno_last = -1 self.is_first_child = 0 self.seen_by_child = 0 self.completed = 0 def __repr__(self): return '%s(%s depth:%s rev:%s,%s,%s first:%s seen:%s)' % ( self.__class__.__name__, self.key, self.merge_depth, self._revno_first, self._revno_second, self._revno_last, self.is_first_child, self.seen_by_child) cdef int has_pending_parents(self): # cannot_raise if self.left_pending_parent is not None or self.pending_parents: return 1 return 0 cdef object _revno(self): if self._revno_first == -1: if self._revno_second != -1: raise RuntimeError('Something wrong with: %s' % (self,)) return (self._revno_last,) else: return (self._revno_first, self._revno_second, self._revno_last) property revno: def __get__(self): return self._revno() cdef class _MergeSorter: """This class does the work of computing the merge_sort ordering. We have some small advantages, in that we get all the extra information that KnownGraph knows, like knowing the child lists, etc. """ # Current performance numbers for merge_sort(bzr_dev_parent_map): # 302ms tsort.merge_sort() # 91ms graph.KnownGraph().merge_sort() # 40ms kg.merge_sort() cdef KnownGraph graph cdef object _depth_first_stack # list cdef Py_ssize_t _last_stack_item # offset to last item on stack # cdef object _ms_nodes # dict of key => _MergeSortNode cdef object _revno_to_branch_count # {revno => num child branches} cdef object _scheduled_nodes # List of nodes ready to be yielded def __init__(self, known_graph, tip_key): cdef _KnownGraphNode node self.graph = known_graph # self._ms_nodes = {} self._revno_to_branch_count = {} self._depth_first_stack = [] self._last_stack_item = -1 self._scheduled_nodes = [] if (tip_key is not None and tip_key != NULL_REVISION and tip_key != (NULL_REVISION,)): node = self.graph._nodes[tip_key] self._push_node(node, 0) cdef _MergeSortNode _get_ms_node(self, _KnownGraphNode node): cdef PyObject *temp_node cdef _MergeSortNode ms_node if node.extra is None: ms_node = _MergeSortNode(node.key) node.extra = ms_node else: ms_node = <_MergeSortNode>node.extra return ms_node cdef _push_node(self, _KnownGraphNode node, long merge_depth): cdef _KnownGraphNode parent_node cdef _MergeSortNode ms_node, ms_parent_node cdef Py_ssize_t pos ms_node = self._get_ms_node(node) ms_node.merge_depth = merge_depth if node.parents is None: raise RuntimeError('ghost nodes should not be pushed' ' onto the stack: %s' % (node,)) if PyTuple_GET_SIZE(node.parents) > 0: parent_node = _get_tuple_node(node.parents, 0) ms_node.left_parent = parent_node if parent_node.parents is None: # left-hand ghost ms_node.left_pending_parent = None ms_node.left_parent = None else: ms_node.left_pending_parent = parent_node if PyTuple_GET_SIZE(node.parents) > 1: ms_node.pending_parents = [] for pos from 1 <= pos < PyTuple_GET_SIZE(node.parents): parent_node = _get_tuple_node(node.parents, pos) if parent_node.parents is None: # ghost continue PyList_Append(ms_node.pending_parents, parent_node) ms_node.is_first_child = 1 if ms_node.left_parent is not None: ms_parent_node = self._get_ms_node(ms_node.left_parent) if ms_parent_node.seen_by_child: ms_node.is_first_child = 0 ms_parent_node.seen_by_child = 1 self._last_stack_item = self._last_stack_item + 1 if self._last_stack_item < PyList_GET_SIZE(self._depth_first_stack): Py_INCREF(node) # SetItem steals a ref PyList_SetItem(self._depth_first_stack, self._last_stack_item, node) else: PyList_Append(self._depth_first_stack, node) cdef _pop_node(self): cdef PyObject *temp cdef _MergeSortNode ms_node, ms_parent_node, ms_prev_node cdef _KnownGraphNode node, parent_node, prev_node node = _get_list_node(self._depth_first_stack, self._last_stack_item) ms_node = <_MergeSortNode>node.extra self._last_stack_item = self._last_stack_item - 1 if ms_node.left_parent is not None: # Assign the revision number from the left-hand parent ms_parent_node = <_MergeSortNode>ms_node.left_parent.extra if ms_node.is_first_child: # First child just increments the final digit ms_node._revno_first = ms_parent_node._revno_first ms_node._revno_second = ms_parent_node._revno_second ms_node._revno_last = ms_parent_node._revno_last + 1 else: # Not the first child, make a new branch # (mainline_revno, branch_count, 1) if ms_parent_node._revno_first == -1: # Mainline ancestor, the increment is on the last digit base_revno = ms_parent_node._revno_last else: base_revno = ms_parent_node._revno_first temp = PyDict_GetItem(self._revno_to_branch_count, base_revno) if temp == NULL: branch_count = 1 else: branch_count = (temp) + 1 PyDict_SetItem(self._revno_to_branch_count, base_revno, branch_count) ms_node._revno_first = base_revno ms_node._revno_second = branch_count ms_node._revno_last = 1 else: temp = PyDict_GetItem(self._revno_to_branch_count, 0) if temp == NULL: # The first root node doesn't have a 3-digit revno root_count = 0 ms_node._revno_first = -1 ms_node._revno_second = -1 ms_node._revno_last = 1 else: root_count = (temp) + 1 ms_node._revno_first = 0 ms_node._revno_second = root_count ms_node._revno_last = 1 PyDict_SetItem(self._revno_to_branch_count, 0, root_count) ms_node.completed = 1 if PyList_GET_SIZE(self._scheduled_nodes) == 0: # The first scheduled node is always the end of merge ms_node.end_of_merge = True else: prev_node = _get_list_node(self._scheduled_nodes, PyList_GET_SIZE(self._scheduled_nodes) - 1) ms_prev_node = <_MergeSortNode>prev_node.extra if ms_prev_node.merge_depth < ms_node.merge_depth: # The previously pushed node is to our left, so this is the end # of this right-hand chain ms_node.end_of_merge = True elif (ms_prev_node.merge_depth == ms_node.merge_depth and prev_node not in node.parents): # The next node is not a direct parent of this node ms_node.end_of_merge = True else: ms_node.end_of_merge = False PyList_Append(self._scheduled_nodes, node) cdef _schedule_stack(self): cdef _KnownGraphNode last_node, next_node cdef _MergeSortNode ms_node, ms_last_node, ms_next_node cdef long next_merge_depth ordered = [] while self._last_stack_item >= 0: # Peek at the last item on the stack last_node = _get_list_node(self._depth_first_stack, self._last_stack_item) if last_node.gdfo == -1: # if _find_gdfo skipped a node, that means there is a graph # cycle, error out now raise errors.GraphCycleError(self.graph._nodes) ms_last_node = <_MergeSortNode>last_node.extra if not ms_last_node.has_pending_parents(): # Processed all parents, pop this node self._pop_node() continue while ms_last_node.has_pending_parents(): if ms_last_node.left_pending_parent is not None: # recurse depth first into the primary parent next_node = ms_last_node.left_pending_parent ms_last_node.left_pending_parent = None else: # place any merges in right-to-left order for scheduling # which gives us left-to-right order after we reverse # the scheduled queue. # Note: This has the effect of allocating common-new # revisions to the right-most subtree rather than the # left most, which will display nicely (you get # smaller trees at the top of the combined merge). next_node = ms_last_node.pending_parents.pop() ms_next_node = self._get_ms_node(next_node) if ms_next_node.completed: # this parent was completed by a child on the # call stack. skip it. continue # otherwise transfer it from the source graph into the # top of the current depth first search stack. if next_node is ms_last_node.left_parent: next_merge_depth = ms_last_node.merge_depth else: next_merge_depth = ms_last_node.merge_depth + 1 self._push_node(next_node, next_merge_depth) # and do not continue processing parents until this 'call' # has recursed. break cdef topo_order(self): cdef _MergeSortNode ms_node cdef _KnownGraphNode node cdef Py_ssize_t pos cdef PyObject *temp_key cdef PyObject *temp_node # Note: allocating a _MergeSortNode and deallocating it for all nodes # costs approx 8.52ms (21%) of the total runtime # We might consider moving the attributes into the base # KnownGraph object. self._schedule_stack() # We've set up the basic schedule, now we can continue processing the # output. # Note: This final loop costs us 40.0ms => 28.8ms (11ms, 25%) on # bzr.dev, to convert the internal Object representation into a # Tuple representation... # 2ms is walking the data and computing revno tuples # 7ms is computing the return tuple # 4ms is PyList_Append() ordered = [] # output the result in reverse order, and separate the generated info for pos from PyList_GET_SIZE(self._scheduled_nodes) > pos >= 0: node = _get_list_node(self._scheduled_nodes, pos) ms_node = <_MergeSortNode>node.extra PyList_Append(ordered, ms_node) node.extra = None # Clear out the scheduled nodes now that we're done self._scheduled_nodes = [] return ordered