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Diffstat (limited to 'examples/cpp/route_guide/helper.cc')
| -rw-r--r-- | examples/cpp/route_guide/helper.cc | 178 |
1 files changed, 178 insertions, 0 deletions
diff --git a/examples/cpp/route_guide/helper.cc b/examples/cpp/route_guide/helper.cc new file mode 100644 index 0000000000..c2415afdf7 --- /dev/null +++ b/examples/cpp/route_guide/helper.cc @@ -0,0 +1,178 @@ +/* + * + * Copyright 2015, Google Inc. + * All rights reserved. + * + * 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. + * + */ + +#include <algorithm> +#include <cctype> +#include <fstream> +#include <iostream> +#include <sstream> +#include <string> +#include <vector> +#include "route_guide.grpc.pb.h" + +namespace examples { + +std::string GetDbFileContent(int argc, char** argv) { + std::string db_path; + std::string arg_str("--db_path"); + if (argc > 1) { + std::string argv_1 = argv[1]; + size_t start_position = argv_1.find(arg_str); + if (start_position != std::string::npos) { + start_position += arg_str.size(); + if (argv_1[start_position] == ' ' || + argv_1[start_position] == '=') { + db_path = argv_1.substr(start_position + 1); + } + } + } else { + db_path = "route_guide_db.json"; + } + std::ifstream db_file(db_path); + if (!db_file.is_open()) { + std::cout << "Failed to open " << db_path << std::endl; + return ""; + } + std::stringstream db; + db << db_file.rdbuf(); + return db.str(); +} + +// A simple parser for the json db file. It requires the db file to have the +// exact form of [{"location": { "latitude": 123, "longitude": 456}, "name": +// "the name can be empty" }, { ... } ... The spaces will be stripped. +class Parser { + public: + explicit Parser(const std::string& db) : db_(db) { + // Remove all spaces. + db_.erase( + std::remove_if(db_.begin(), db_.end(), isspace), + db_.end()); + if (!Match("[")) { + SetFailedAndReturnFalse(); + } + } + + bool Finished() { + return current_ >= db_.size(); + } + + bool TryParseOne(Feature* feature) { + if (failed_ || Finished() || !Match("{")) { + return SetFailedAndReturnFalse(); + } + if (!Match(location_) || !Match("{") || !Match(latitude_)) { + return SetFailedAndReturnFalse(); + } + long temp = 0; + ReadLong(&temp); + feature->mutable_location()->set_latitude(temp); + if (!Match(",") || !Match(longitude_)) { + return SetFailedAndReturnFalse(); + } + ReadLong(&temp); + feature->mutable_location()->set_longitude(temp); + if (!Match("},") || !Match(name_) || !Match("\"")) { + return SetFailedAndReturnFalse(); + } + size_t name_start = current_; + while (current_ != db_.size() && db_[current_++] != '"') { + } + if (current_ == db_.size()) { + return SetFailedAndReturnFalse(); + } + feature->set_name(db_.substr(name_start, current_-name_start-1)); + if (!Match("},")) { + if (db_[current_ - 1] == ']' && current_ == db_.size()) { + return true; + } + return SetFailedAndReturnFalse(); + } + return true; + } + + private: + + bool SetFailedAndReturnFalse() { + failed_ = true; + return false; + } + + bool Match(const std::string& prefix) { + bool eq = db_.substr(current_, prefix.size()) == prefix; + current_ += prefix.size(); + return eq; + } + + void ReadLong(long* l) { + size_t start = current_; + while (current_ != db_.size() && db_[current_] != ',' && db_[current_] != '}') { + current_++; + } + // It will throw an exception if fails. + *l = std::stol(db_.substr(start, current_ - start)); + } + + bool failed_ = false; + std::string db_; + size_t current_ = 0; + const std::string location_ = "\"location\":"; + const std::string latitude_ = "\"latitude\":"; + const std::string longitude_ = "\"longitude\":"; + const std::string name_ = "\"name\":"; +}; + +void ParseDb(const std::string& db, std::vector<Feature>* feature_list) { + feature_list->clear(); + std::string db_content(db); + db_content.erase( + std::remove_if(db_content.begin(), db_content.end(), isspace), + db_content.end()); + + Parser parser(db_content); + Feature feature; + while (!parser.Finished()) { + feature_list->push_back(Feature()); + if (!parser.TryParseOne(&feature_list->back())) { + std::cout << "Error parsing the db file"; + feature_list->clear(); + break; + } + } + std::cout << "DB parsed, loaded " << feature_list->size() + << " features." << std::endl; +} + + +} // namespace examples + |