Initial checkin of gRPC to third_party/

third_party/grpc/examples/cpp/route_guide/helper.cc

+/*
+ *
+ * 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 routeguide {
+
+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 routeguide
+