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// Copyright (c) 2009 The Chromium OS Authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.
#include "update_engine/payload_generator/graph_utils.h"
#include <string>
#include <utility>
#include <vector>
#include <base/basictypes.h>
#include <base/logging.h>
#include "update_engine/payload_constants.h"
using std::make_pair;
using std::pair;
using std::string;
using std::vector;
namespace chromeos_update_engine {
namespace graph_utils {
uint64_t EdgeWeight(const Graph& graph, const Edge& edge) {
uint64_t weight = 0;
const vector<Extent>& extents =
graph[edge.first].out_edges.find(edge.second)->second.extents;
for (vector<Extent>::const_iterator it = extents.begin();
it != extents.end(); ++it) {
if (it->start_block() != kSparseHole)
weight += it->num_blocks();
}
return weight;
}
void AppendBlockToExtents(vector<Extent>* extents, uint64_t block) {
// First try to extend the last extent in |extents|, if any.
if (!extents->empty()) {
Extent& extent = extents->back();
uint64_t next_block = extent.start_block() == kSparseHole ?
kSparseHole : extent.start_block() + extent.num_blocks();
if (next_block == block) {
extent.set_num_blocks(extent.num_blocks() + 1);
return;
}
}
// If unable to extend the last extent, append a new single-block extent.
Extent new_extent;
new_extent.set_start_block(block);
new_extent.set_num_blocks(1);
extents->push_back(new_extent);
}
void AddReadBeforeDep(Vertex* src,
Vertex::Index dst,
uint64_t block) {
Vertex::EdgeMap::iterator edge_it = src->out_edges.find(dst);
if (edge_it == src->out_edges.end()) {
// Must create new edge
pair<Vertex::EdgeMap::iterator, bool> result =
src->out_edges.insert(make_pair(dst, EdgeProperties()));
CHECK(result.second);
edge_it = result.first;
}
AppendBlockToExtents(&edge_it->second.extents, block);
}
void AddReadBeforeDepExtents(Vertex* src,
Vertex::Index dst,
const vector<Extent>& extents) {
// TODO(adlr): Be more efficient than adding each block individually.
for (vector<Extent>::const_iterator it = extents.begin(), e = extents.end();
it != e; ++it) {
const Extent& extent = *it;
for (uint64_t block = extent.start_block(),
block_end = extent.start_block() + extent.num_blocks();
block != block_end; ++block) {
AddReadBeforeDep(src, dst, block);
}
}
}
void DropWriteBeforeDeps(Vertex::EdgeMap* edge_map) {
// Specially crafted for-loop for the map-iterate-delete dance.
for (Vertex::EdgeMap::iterator it = edge_map->begin();
it != edge_map->end(); ) {
if (!it->second.write_extents.empty())
it->second.write_extents.clear();
if (it->second.extents.empty()) {
// Erase *it, as it contains no blocks
edge_map->erase(it++);
} else {
++it;
}
}
}
// For each node N in graph, drop all edges N->|index|.
void DropIncomingEdgesTo(Graph* graph, Vertex::Index index) {
// This would be much more efficient if we had doubly-linked
// edges in the graph.
for (Graph::iterator it = graph->begin(), e = graph->end(); it != e; ++it) {
it->out_edges.erase(index);
}
}
Extent GetElement(const std::vector<Extent>& collection, size_t index) {
return collection[index];
}
Extent GetElement(
const google::protobuf::RepeatedPtrField<Extent>& collection,
size_t index) {
return collection.Get(index);
}
namespace {
template<typename T>
void DumpExtents(const T& field, int prepend_space_count) {
string header(prepend_space_count, ' ');
for (int i = 0, e = field.size(); i != e; ++i) {
LOG(INFO) << header << "(" << GetElement(field, i).start_block() << ", "
<< GetElement(field, i).num_blocks() << ")";
}
}
void DumpOutEdges(const Vertex::EdgeMap& out_edges) {
for (Vertex::EdgeMap::const_iterator it = out_edges.begin(),
e = out_edges.end(); it != e; ++it) {
LOG(INFO) << " " << it->first << " read-before:";
DumpExtents(it->second.extents, 6);
LOG(INFO) << " write-before:";
DumpExtents(it->second.write_extents, 6);
}
}
} // namespace
void DumpGraph(const Graph& graph) {
LOG(INFO) << "Graph length: " << graph.size();
for (Graph::size_type i = 0, e = graph.size(); i != e; ++i) {
string type_str = "UNK";
switch(graph[i].op.type()) {
case DeltaArchiveManifest_InstallOperation_Type_BSDIFF:
type_str = "BSDIFF";
break;
case DeltaArchiveManifest_InstallOperation_Type_MOVE:
type_str = "MOVE";
break;
case DeltaArchiveManifest_InstallOperation_Type_REPLACE:
type_str = "REPLACE";
break;
case DeltaArchiveManifest_InstallOperation_Type_REPLACE_BZ:
type_str = "REPLACE_BZ";
break;
}
LOG(INFO) << i
<< (graph[i].valid ? "" : "-INV")
<< ": " << graph[i].file_name
<< " " << graph[i].chunk_size << "@" << graph[i].chunk_offset
<< ": " << type_str;
LOG(INFO) << " src_extents:";
DumpExtents(graph[i].op.src_extents(), 4);
LOG(INFO) << " dst_extents:";
DumpExtents(graph[i].op.dst_extents(), 4);
LOG(INFO) << " out edges:";
DumpOutEdges(graph[i].out_edges);
}
}
} // namespace graph_utils
bool operator==(const Extent& a, const Extent& b) {
return a.start_block() == b.start_block() && a.num_blocks() == b.num_blocks();
}
} // namespace chromeos_update_engine
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