diff options
| -rw-r--r-- | pkgs/build-support/references-by-popularity/closure-graph.py | 53 |
1 files changed, 50 insertions, 3 deletions
diff --git a/pkgs/build-support/references-by-popularity/closure-graph.py b/pkgs/build-support/references-by-popularity/closure-graph.py index d67a5dfcf14..579f3b041fa 100644 --- a/pkgs/build-support/references-by-popularity/closure-graph.py +++ b/pkgs/build-support/references-by-popularity/closure-graph.py @@ -117,6 +117,17 @@ import unittest from pprint import pprint from collections import defaultdict + +def debug(msg, *args, **kwargs): + if False: + print( + "DEBUG: {}".format( + msg.format(*args, **kwargs) + ), + file=sys.stderr + ) + + # Find paths in the original dataset which are never referenced by # any other paths def find_roots(closures): @@ -327,10 +338,23 @@ class TestMakeLookup(unittest.TestCase): # /nix/store/tux: {} # } # } +subgraphs_cache = {} def make_graph_segment_from_root(root, lookup): + global subgraphs_cache children = {} for ref in lookup[root]: - children[ref] = make_graph_segment_from_root(ref, lookup) + # make_graph_segment_from_root is a pure function, and will + # always return the same result based on a given input. Thus, + # cache computation. + # + # Python's assignment will use a pointer, preventing memory + # bloat for large graphs. + if ref not in subgraphs_cache: + debug("Subgraph Cache miss on {}".format(ref)) + subgraphs_cache[ref] = make_graph_segment_from_root(ref, lookup) + else: + debug("Subgraph Cache hit on {}".format(ref)) + children[ref] = subgraphs_cache[ref] return children class TestMakeGraphSegmentFromRoot(unittest.TestCase): @@ -381,12 +405,27 @@ class TestMakeGraphSegmentFromRoot(unittest.TestCase): # /nix/store/baz: 4 # /nix/store/tux: 6 # ] +popularity_cache = {} def graph_popularity_contest(full_graph): + global popularity_cache popularity = defaultdict(int) for path, subgraph in full_graph.items(): popularity[path] += 1 - subcontest = graph_popularity_contest(subgraph) + # graph_popularity_contest is a pure function, and will + # always return the same result based on a given input. Thus, + # cache computation. + # + # Python's assignment will use a pointer, preventing memory + # bloat for large graphs. + if path not in popularity_cache: + debug("Popularity Cache miss on {}", path) + popularity_cache[path] = graph_popularity_contest(subgraph) + else: + debug("Popularity Cache hit on {}", path) + + subcontest = popularity_cache[path] for subpath, subpopularity in subcontest.items(): + debug("Calculating popularity for {}", subpath) popularity[subpath] += subpopularity + 1 return popularity @@ -474,6 +513,7 @@ def main(): filename = sys.argv[1] key = sys.argv[2] + debug("Loading from {}", filename) with open(filename) as f: data = json.load(f) @@ -497,14 +537,21 @@ def main(): # ] graph = data[key] + debug("Finding roots from {}", key) roots = find_roots(graph); + debug("Making lookup for {}", key) lookup = make_lookup(graph) full_graph = {} for root in roots: + debug("Making full graph for {}", root) full_graph[root] = make_graph_segment_from_root(root, lookup) - ordered = order_by_popularity(graph_popularity_contest(full_graph)) + debug("Running contest") + contest = graph_popularity_contest(full_graph) + debug("Ordering by popularity") + ordered = order_by_popularity(contest) + debug("Checking for missing paths") missing = [] for path in all_paths(graph): if path not in ordered: |