From daf1e229f7a5b5210651d5beddaec6ef1ed125bf Mon Sep 17 00:00:00 2001 From: Todd Gamblin Date: Mon, 29 Dec 2014 14:28:24 -0800 Subject: More compact graphs: do back edges before forward expansion. --- lib/spack/spack/spec.py | 126 ++++++++++++++++++++++++++++++------------------ 1 file changed, 80 insertions(+), 46 deletions(-) (limited to 'lib') diff --git a/lib/spack/spack/spec.py b/lib/spack/spack/spec.py index 0720fe6212..2cd7bfb6be 100644 --- a/lib/spack/spack/spec.py +++ b/lib/spack/spack/spec.py @@ -1330,105 +1330,140 @@ class Spec(object): N = kwargs.get('node', 'o') # Node character color = kwargs.get('color', True) out = kwargs.get('out', ColorStream(sys.stdout, color=color)) + debug = kwargs.get('debug', False) indent = kwargs.get('indent', 0) indent *= ' ' topo_order = self.topological_sort(reverse=True) + + # Work on a clone so the spec is self contained (no incoming + # parent edges), and so we don't destroy this spec. clone = self.copy() + + # Fast access to nodes in the spec. nodes = clone.index() + frontier = [] def ordered_deps(node): deps = node.dependencies return sorted((d for d in deps), reverse=True) - frontier = [] - - debug = False - def back_edge(end, start): + def back_edge(end, start, **kwargs): assert(end < start) + collapse = kwargs.get('collapse', True) + label = kwargs.get('label', '') # debug label - if (start - end) > 1: - if debug: - out.write(" " * 80) + if (start - end) > 1: + # This part draws a long back edge. out.write(indent) out.write("| " * (end + 1)) out.write("|_" * (start - end - 2)) - out.write("|/ ") - out.write("/ " * (len(frontier) - start)) - out.write("\n") + out.write("|/") + if collapse: + out.write(" ") + out.write("/ " * (len(frontier) - start)) + else: + out.write("| " * (len(frontier) - start)) - if debug: - out.write(" " * 80) + if debug: + out.write(" " * 20) + out.write("%s %s" % (frontier, label)) + out.write("\n") + + # This part draws the final collapsing line out.write(indent) out.write("| " * end) out.write("|/") out.write("| " * (start - end - 1)) - if (start - end) > 1: + if (start - end) > 1 or not collapse: out.write("| " * (len(frontier) - start)) else: out.write(" /" * (len(frontier) - start)) + + if debug: + out.write(" " * 20) + out.write("%s %s" % (frontier, label)) + out.write("\n") - def connect_deps(i, deps): + def connect_deps(i, deps, **kwargs): if len(deps) == 1 and deps in frontier: j = frontier.index(deps) if j < i: - back_edge(j, i) + back_edge(j, i, **kwargs) else: if i < j: frontier.pop(j) frontier.insert(i, deps) - back_edge(i, j+1) + back_edge(i, j+1, **kwargs) + return True elif deps: frontier.insert(i, deps) + return False def add_deps_to_frontier(node, i): deps = ordered_deps(node) - connect_deps(i, deps) + connect_deps(i, deps, label="add_deps") for d in deps: del nodes[d].dependents[node.name] - name = topo_order.pop() - add_deps_to_frontier(nodes[name], 0) + def find(seq, predicate): + for i, elt in enumerate(seq): + if predicate(elt): + return i + return -1 - if debug: - out.write("%-80s" % frontier) + add_deps_to_frontier(self, 0) out.write(indent) - out.write('%s %s\n' % (N, name)) - - while topo_order: - if debug: - out.write("%-80s" % frontier) + out.write('%s %s\n' % (N, self.name)) + topo_order.pop() - # Find last i, len(frontier[i]) > 1 - i = len(frontier) - 1 - for f in frontier[-1::-1]: - if len(f) > 1: break - i -= 1 + while frontier: + # Find an unexpanded part of frontier + i = find(frontier, lambda f: len(f) > 1) # Expand frontier until there are enough columns for all children. if i >= 0: - out.write(indent) - out.write("| " * i) - out.write("|\ ") - out.write("\ " * (len(frontier) - i - 1)) - out.write("\n") + # Do all back connections possible from this element + # before expanding. + back_connect = [d for d in frontier[i] if [d] in frontier[:i]] + for d in back_connect: + j = frontier.index([d]) + frontier[i].remove(d) + connect_deps(i, [d], collapse=False, label="back_connect") + + if not frontier[i]: + frontier.pop(i) + + elif len(frontier[i]) > 1: + name = frontier[i].pop(0) + deps = [name] + + out.write(indent) + out.write("| " * i) + out.write("|\ ") + out.write("\ " * (len(frontier) - i - 1)) + out.write("\n") - name = frontier[i].pop(0) - deps = [name] + connect_deps(i, deps, label="expansion") - connect_deps(i, deps) - if i+1 < len(frontier) and len(frontier[i+1]) == 1: - deps = frontier.pop(i+1) - connect_deps(i+1, deps) + # Handle any back edges to the right + j = i+1 + while j < len(frontier): + deps = frontier.pop(j) + # TODO: semantics of connect_deps are weird. + # TODO: false return means the popped item was put + # TODO: back & not connected. + if not connect_deps(j, deps, label="ending"): + j += 1 else: name = topo_order.pop() @@ -1438,9 +1473,10 @@ class Spec(object): # the frontier. Since specs are single-rooted DAGs, # the node is always there. If the graph had multiple # roots, we'd need to handle that case case of a new root. - i, elt = next(f for f in enumerate(frontier) if name in f[1]) + i = find(frontier, lambda f: name in f) frontier.pop(i) + out.write(indent) out.write("| " * i) out.write("%s " % N) out.write("| " * (len(frontier) - i)) @@ -1449,9 +1485,7 @@ class Spec(object): if node.dependencies: add_deps_to_frontier(node, i) elif frontier: - if debug: - out.write(" " * 80) - + out.write(indent) out.write("| " * i) out.write(" /" * (len(frontier) - i)) out.write("\n") -- cgit v1.2.3-60-g2f50