1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
|
// Protocol Buffers - Google's data interchange format
// Copyright 2008 Google Inc. All rights reserved.
// https://developers.google.com/protocol-buffers/
//
// Redistribution and use in source and binary forms, with or without
// modification, are permitted provided that the following conditions are
// met:
//
// * Redistributions of source code must retain the above copyright
// notice, this list of conditions and the following disclaimer.
// * Redistributions in binary form must reproduce the above
// copyright notice, this list of conditions and the following disclaimer
// in the documentation and/or other materials provided with the
// distribution.
// * Neither the name of Google Inc. nor the names of its
// contributors may be used to endorse or promote products derived from
// this software without specific prior written permission.
//
// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
// A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
// OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
// LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
// DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
// THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
#ifndef GOOGLE_PROTOBUF_COMPILER_SCC_H__
#define GOOGLE_PROTOBUF_COMPILER_SCC_H__
#include <map>
#include <google/protobuf/descriptor.h>
#include <google/protobuf/port_def.inc>
namespace google {
namespace protobuf {
namespace compiler {
// Description of each strongly connected component. Note that the order
// of both the descriptors in this SCC and the order of children is
// deterministic.
struct SCC {
std::vector<const Descriptor*> descriptors;
std::vector<const SCC*> children;
const Descriptor* GetRepresentative() const { return descriptors[0]; }
};
// This class is used for analyzing the SCC for each message, to ensure linear
// instead of quadratic performance, if we do this per message we would get
// O(V*(V+E)).
class PROTOC_EXPORT SCCAnalyzer {
public:
explicit SCCAnalyzer() : index_(0) {}
const SCC* GetSCC(const Descriptor* descriptor) {
if (cache_.count(descriptor)) return cache_[descriptor].scc;
return DFS(descriptor).scc;
}
private:
struct NodeData {
const SCC* scc; // if null it means its still on the stack
int index;
int lowlink;
};
std::map<const Descriptor*, NodeData> cache_;
std::vector<const Descriptor*> stack_;
int index_;
std::vector<std::unique_ptr<SCC>> garbage_bin_;
SCC* CreateSCC() {
garbage_bin_.emplace_back(new SCC());
return garbage_bin_.back().get();
}
// Tarjan's Strongly Connected Components algo
NodeData DFS(const Descriptor* descriptor);
// Add the SCC's that are children of this SCC to its children.
void AddChildren(SCC* scc);
// This is necessary for compiler bug in msvc2015.
GOOGLE_DISALLOW_EVIL_CONSTRUCTORS(SCCAnalyzer);
};
} // namespace compiler
} // namespace protobuf
} // namespace google
#include <google/protobuf/port_undef.inc>
#endif // GOOGLE_PROTOBUF_COMPILER_SCC_H__
|
