//
// Copyright (C) 2010 The Android Open Source Project
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
// http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.
//
#include "update_engine/payload_generator/cycle_breaker.h"
#include <set>
#include <string>
#include <utility>
#include <vector>
#include <base/logging.h>
#include <gtest/gtest.h>
#include "update_engine/common/utils.h"
#include "update_engine/payload_generator/graph_types.h"
using std::make_pair;
using std::pair;
using std::set;
using std::string;
using std::vector;
namespace chromeos_update_engine {
namespace {
void SetOpForNodes(Graph* graph) {
for (Vertex& vertex : *graph) {
vertex.aop.op.set_type(InstallOperation::MOVE);
}
}
} // namespace
class CycleBreakerTest : public ::testing::Test {};
TEST(CycleBreakerTest, SimpleTest) {
int counter = 0;
const Vertex::Index n_a = counter++;
const Vertex::Index n_b = counter++;
const Vertex::Index n_c = counter++;
const Vertex::Index n_d = counter++;
const Vertex::Index n_e = counter++;
const Vertex::Index n_f = counter++;
const Vertex::Index n_g = counter++;
const Vertex::Index n_h = counter++;
const Graph::size_type kNodeCount = counter++;
Graph graph(kNodeCount);
SetOpForNodes(&graph);
graph[n_a].out_edges.insert(make_pair(n_e, EdgeProperties()));
graph[n_a].out_edges.insert(make_pair(n_f, EdgeProperties()));
graph[n_b].out_edges.insert(make_pair(n_a, EdgeProperties()));
graph[n_c].out_edges.insert(make_pair(n_d, EdgeProperties()));
graph[n_d].out_edges.insert(make_pair(n_e, EdgeProperties()));
graph[n_d].out_edges.insert(make_pair(n_f, EdgeProperties()));
graph[n_e].out_edges.insert(make_pair(n_b, EdgeProperties()));
graph[n_e].out_edges.insert(make_pair(n_c, EdgeProperties()));
graph[n_e].out_edges.insert(make_pair(n_f, EdgeProperties()));
graph[n_f].out_edges.insert(make_pair(n_g, EdgeProperties()));
graph[n_g].out_edges.insert(make_pair(n_h, EdgeProperties()));
graph[n_h].out_edges.insert(make_pair(n_g, EdgeProperties()));
CycleBreaker breaker;
set<Edge> broken_edges;
breaker.BreakCycles(graph, &broken_edges);
// The following cycles must be cut:
// A->E->B
// C->D->E
// G->H
EXPECT_TRUE(utils::SetContainsKey(broken_edges, make_pair(n_a, n_e)) ||
utils::SetContainsKey(broken_edges, make_pair(n_e, n_b)) ||
utils::SetContainsKey(broken_edges, make_pair(n_b, n_a)));
EXPECT_TRUE(utils::SetContainsKey(broken_edges, make_pair(n_c, n_d)) ||
utils::SetContainsKey(broken_edges, make_pair(n_d, n_e)) ||
utils::SetContainsKey(broken_edges, make_pair(n_e, n_c)));
EXPECT_TRUE(utils::SetContainsKey(broken_edges, make_pair(n_g, n_h)) ||
utils::SetContainsKey(broken_edges, make_pair(n_h, n_g)));
EXPECT_EQ(3U, broken_edges.size());
}
namespace {
pair<Vertex::Index, EdgeProperties> EdgeWithWeight(Vertex::Index dest,
uint64_t weight) {
EdgeProperties props;
props.extents.resize(1);
props.extents[0].set_num_blocks(weight);
return make_pair(dest, props);
}
} // namespace
// This creates a bunch of cycles like this:
//
// root <------.
// (t)-> / | \ |
// V V V |
// N N N |
// \ | / |
// VVV |
// N |
// / | \ |
// V V V |
// N N N |
// ... |
// (s)-> \ | / |
// VVV |
// N |
// \_________/
//
// such that the original cutting algo would cut edges (s). We changed
// the algorithm to cut cycles (t) instead, since they are closer to the
// root, and that can massively speed up cycle cutting.
TEST(CycleBreakerTest, AggressiveCutTest) {
size_t counter = 0;
const int kNodesPerGroup = 4;
const int kGroups = 33;
Graph graph(kGroups * kNodesPerGroup + 1); // + 1 for the root node
SetOpForNodes(&graph);
const Vertex::Index n_root = counter++;
Vertex::Index last_hub = n_root;
for (int i = 0; i < kGroups; i++) {
uint64_t weight = 5;
if (i == 0)
weight = 2;
else if (i == (kGroups - 1))
weight = 1;
const Vertex::Index next_hub = counter++;
for (int j = 0; j < (kNodesPerGroup - 1); j++) {
const Vertex::Index node = counter++;
graph[last_hub].out_edges.insert(EdgeWithWeight(node, weight));
graph[node].out_edges.insert(EdgeWithWeight(next_hub, weight));
}
last_hub = next_hub;
}
graph[last_hub].out_edges.insert(EdgeWithWeight(n_root, 5));
EXPECT_EQ(counter, graph.size());
CycleBreaker breaker;
set<Edge> broken_edges;
LOG(INFO) << "If this hangs for more than 1 second, the test has failed.";
breaker.BreakCycles(graph, &broken_edges);
set<Edge> expected_cuts;
for (Vertex::EdgeMap::const_iterator it = graph[n_root].out_edges.begin(),
e = graph[n_root].out_edges.end(); it != e; ++it) {
expected_cuts.insert(make_pair(n_root, it->first));
}
EXPECT_TRUE(broken_edges == expected_cuts);
}
TEST(CycleBreakerTest, WeightTest) {
size_t counter = 0;
const Vertex::Index n_a = counter++;
const Vertex::Index n_b = counter++;
const Vertex::Index n_c = counter++;
const Vertex::Index n_d = counter++;
const Vertex::Index n_e = counter++;
const Vertex::Index n_f = counter++;
const Vertex::Index n_g = counter++;
const Vertex::Index n_h = counter++;
const Vertex::Index n_i = counter++;
const Vertex::Index n_j = counter++;
const Graph::size_type kNodeCount = counter++;
Graph graph(kNodeCount);
SetOpForNodes(&graph);
graph[n_a].out_edges.insert(EdgeWithWeight(n_b, 4));
graph[n_a].out_edges.insert(EdgeWithWeight(n_f, 3));
graph[n_a].out_edges.insert(EdgeWithWeight(n_h, 2));
graph[n_b].out_edges.insert(EdgeWithWeight(n_a, 3));
graph[n_b].out_edges.insert(EdgeWithWeight(n_c, 4));
graph[n_c].out_edges.insert(EdgeWithWeight(n_b, 5));
graph[n_c].out_edges.insert(EdgeWithWeight(n_d, 3));
graph[n_d].out_edges.insert(EdgeWithWeight(n_a, 6));
graph[n_d].out_edges.insert(EdgeWithWeight(n_e, 3));
graph[n_e].out_edges.insert(EdgeWithWeight(n_d, 4));
graph[n_e].out_edges.insert(EdgeWithWeight(n_g, 5));
graph[n_f].out_edges.insert(EdgeWithWeight(n_g, 2));
graph[n_g].out_edges.insert(EdgeWithWeight(n_f, 3));
graph[n_g].out_edges.insert(EdgeWithWeight(n_d, 5));
graph[n_h].out_edges.insert(EdgeWithWeight(n_i, 8));
graph[n_i].out_edges.insert(EdgeWithWeight(n_e, 4));
graph[n_i].out_edges.insert(EdgeWithWeight(n_h, 9));
graph[n_i].out_edges.insert(EdgeWithWeight(n_j, 6));
CycleBreaker breaker;
set<Edge> broken_edges;
breaker.BreakCycles(graph, &broken_edges);
// These are required to be broken:
EXPECT_TRUE(utils::SetContainsKey(broken_edges, make_pair(n_b, n_a)));
EXPECT_TRUE(utils::SetContainsKey(broken_edges, make_pair(n_b, n_c)));
EXPECT_TRUE(utils::SetContainsKey(broken_edges, make_pair(n_d, n_e)));
EXPECT_TRUE(utils::SetContainsKey(broken_edges, make_pair(n_f, n_g)));
EXPECT_TRUE(utils::SetContainsKey(broken_edges, make_pair(n_h, n_i)));
}
TEST(CycleBreakerTest, UnblockGraphTest) {
size_t counter = 0;
const Vertex::Index n_a = counter++;
const Vertex::Index n_b = counter++;
const Vertex::Index n_c = counter++;
const Vertex::Index n_d = counter++;
const Graph::size_type kNodeCount = counter++;
Graph graph(kNodeCount);
SetOpForNodes(&graph);
graph[n_a].out_edges.insert(EdgeWithWeight(n_b, 1));
graph[n_a].out_edges.insert(EdgeWithWeight(n_c, 1));
graph[n_b].out_edges.insert(EdgeWithWeight(n_c, 2));
graph[n_c].out_edges.insert(EdgeWithWeight(n_b, 2));
graph[n_b].out_edges.insert(EdgeWithWeight(n_d, 2));
graph[n_d].out_edges.insert(EdgeWithWeight(n_a, 2));
CycleBreaker breaker;
set<Edge> broken_edges;
breaker.BreakCycles(graph, &broken_edges);
// These are required to be broken:
EXPECT_TRUE(utils::SetContainsKey(broken_edges, make_pair(n_a, n_b)));
EXPECT_TRUE(utils::SetContainsKey(broken_edges, make_pair(n_a, n_c)));
}
TEST(CycleBreakerTest, SkipOpsTest) {
size_t counter = 0;
const Vertex::Index n_a = counter++;
const Vertex::Index n_b = counter++;
const Vertex::Index n_c = counter++;
const Graph::size_type kNodeCount = counter++;
Graph graph(kNodeCount);
SetOpForNodes(&graph);
graph[n_a].aop.op.set_type(InstallOperation::REPLACE_BZ);
graph[n_c].aop.op.set_type(InstallOperation::REPLACE);
graph[n_a].out_edges.insert(EdgeWithWeight(n_b, 1));
graph[n_c].out_edges.insert(EdgeWithWeight(n_b, 1));
CycleBreaker breaker;
set<Edge> broken_edges;
breaker.BreakCycles(graph, &broken_edges);
EXPECT_EQ(2U, breaker.skipped_ops());
}
} // namespace chromeos_update_engine