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Diffstat (limited to 'NorthstarDedicatedTest/include/protobuf/compiler/scc.h')
| -rw-r--r-- | NorthstarDedicatedTest/include/protobuf/compiler/scc.h | 164 |
1 files changed, 164 insertions, 0 deletions
diff --git a/NorthstarDedicatedTest/include/protobuf/compiler/scc.h b/NorthstarDedicatedTest/include/protobuf/compiler/scc.h new file mode 100644 index 00000000..93088bf9 --- /dev/null +++ b/NorthstarDedicatedTest/include/protobuf/compiler/scc.h @@ -0,0 +1,164 @@ +// 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 <stubs/logging.h> +#include <stubs/common.h> +#include <descriptor.h> + +#include <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]; } + + // All messages must necessarily be in the same file. + const FileDescriptor* GetFile() const { return descriptors[0]->file(); } +}; + +// 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)). +template <class DepsGenerator> +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) { + // Must not have visited already. + GOOGLE_DCHECK_EQ(cache_.count(descriptor), 0); + + // Mark visited by inserting in map. + NodeData& result = cache_[descriptor]; + // Initialize data structures. + result.index = result.lowlink = index_++; + stack_.push_back(descriptor); + + // Recurse the fields / nodes in graph + for (auto dep : DepsGenerator()(descriptor)) { + GOOGLE_CHECK(dep); + if (cache_.count(dep) == 0) { + // unexplored node + NodeData child_data = DFS(dep); + result.lowlink = std::min(result.lowlink, child_data.lowlink); + } else { + NodeData child_data = cache_[dep]; + if (child_data.scc == nullptr) { + // Still in the stack_ so we found a back edge + result.lowlink = std::min(result.lowlink, child_data.index); + } + } + } + if (result.index == result.lowlink) { + // This is the root of a strongly connected component + SCC* scc = CreateSCC(); + while (true) { + const Descriptor* scc_desc = stack_.back(); + scc->descriptors.push_back(scc_desc); + // Remove from stack + stack_.pop_back(); + cache_[scc_desc].scc = scc; + + if (scc_desc == descriptor) break; + } + + // The order of descriptors is random and depends how this SCC was + // discovered. In-order to ensure maximum stability we sort it by name. + std::sort(scc->descriptors.begin(), scc->descriptors.end(), + [](const Descriptor* a, const Descriptor* b) { + return a->full_name() < b->full_name(); + }); + AddChildren(scc); + } + return result; + } + + // Add the SCC's that are children of this SCC to its children. + void AddChildren(SCC* scc) { + std::set<const SCC*> seen; + for (auto descriptor : scc->descriptors) { + for (auto child_msg : DepsGenerator()(descriptor)) { + GOOGLE_CHECK(child_msg); + const SCC* child = GetSCC(child_msg); + if (child == scc) continue; + if (seen.insert(child).second) { + scc->children.push_back(child); + } + } + } + } + + // This is necessary for compiler bug in msvc2015. + GOOGLE_DISALLOW_EVIL_CONSTRUCTORS(SCCAnalyzer); +}; + +} // namespace compiler +} // namespace protobuf +} // namespace google + +#include <port_undef.inc> + +#endif // GOOGLE_PROTOBUF_COMPILER_SCC_H__ |