1 // Protocol Buffers - Google's data interchange format 2 // Copyright 2008 Google Inc. All rights reserved. 3 // https://developers.google.com/protocol-buffers/ 4 // 5 // Redistribution and use in source and binary forms, with or without 6 // modification, are permitted provided that the following conditions are 7 // met: 8 // 9 // * Redistributions of source code must retain the above copyright 10 // notice, this list of conditions and the following disclaimer. 11 // * Redistributions in binary form must reproduce the above 12 // copyright notice, this list of conditions and the following disclaimer 13 // in the documentation and/or other materials provided with the 14 // distribution. 15 // * Neither the name of Google Inc. nor the names of its 16 // contributors may be used to endorse or promote products derived from 17 // this software without specific prior written permission. 18 // 19 // THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS 20 // "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT 21 // LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR 22 // A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT 23 // OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, 24 // SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT 25 // LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, 26 // DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY 27 // THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT 28 // (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE 29 // OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 30 31 // Author: seongkim@google.com (Seong Beom Kim) 32 // Based on original Protocol Buffers design by 33 // Sanjay Ghemawat, Jeff Dean, and others. 34 35 #ifndef GOOGLE_PROTOBUF_COMPILER_CPP_PADDING_OPTIMIZER_H__ 36 #define GOOGLE_PROTOBUF_COMPILER_CPP_PADDING_OPTIMIZER_H__ 37 38 #include <google/protobuf/compiler/cpp/cpp_message_layout_helper.h> 39 40 namespace google { 41 namespace protobuf { 42 namespace compiler { 43 namespace cpp { 44 45 // Rearranges the fields of a message to minimize padding. 46 // Fields are grouped by the type and the size. 47 // For example, grouping four boolean fields and one int32 48 // field results in zero padding overhead. See OptimizeLayout's 49 // comment for details. 50 class PaddingOptimizer : public MessageLayoutHelper { 51 public: PaddingOptimizer()52 PaddingOptimizer() {} ~PaddingOptimizer()53 ~PaddingOptimizer() override {} 54 55 void OptimizeLayout(std::vector<const FieldDescriptor*>* fields, 56 const Options& options, 57 MessageSCCAnalyzer* scc_analyzer) override; 58 }; 59 60 } // namespace cpp 61 } // namespace compiler 62 } // namespace protobuf 63 } // namespace google 64 65 #endif // GOOGLE_PROTOBUF_COMPILER_CPP_PADDING_OPTIMIZER_H__ 66