Replace regex matching of description.xml with string find.

C++ regex library is slow and not fully supported for earlier gcc versions.

Replace regex matching of description.xml with string find.
C++ regex library is slow and not fully supported for earlier gcc versions.
Jojo-1000 · Jan
1 parent 6914599f
Showing 2 changed files with 39 additions and 21 deletions
hueplusplus/Hue.cpp
hueplusplus/include/Hue.h
@@ -19,9 +19,11 @@
 #include "include/Hue.h"
+#include <algorithm>
+#include <cctype>
 #include <chrono>
 #include <iostream>
-#include <regex>
+#include <locale>
 #include <stdexcept>
 #include <thread>
@@ -39,15 +41,8 @@ HueFinder::HueFinder(std::shared_ptr&lt;const IHttpHandler&gt; handler)
 std::vector<HueFinder::HueIdentification> HueFinder::FindBridges() const {
   UPnP uplug;
   std::vector<std::pair<std::string, std::string>> foundDevices =
-      uplug.getDevices(http_handler);
+    uplug.getDevices(http_handler);
-  // Does not work
-  std::regex manufRegex(
-      "<manufacturer>Royal Philips Electronics</manufacturer>");
-  std::regex manURLRegex(
-      "<manufacturerURL>http://www\\.philips\\.com</manufacturerURL>");
-  std::regex modelRegex("<modelName>Philips hue bridge[^<]*</modelName>");
-  std::regex serialRegex("<serialNumber>(\\w+)</serialNumber>");
   std::vector<HueIdentification> foundBridges;
   for (const std::pair<std::string, std::string> &p : foundDevices) {
     size_t found = p.second.find("IpBridge");
@@ -57,18 +52,12 @@ std::vector&lt;HueFinder::HueIdentification&gt; HueFinder::FindBridges() const {
       size_t length = p.first.find(":", start) - start;
       bridge.ip = p.first.substr(start, length);
       std::string desc = http_handler->GETString(
-          "/description.xml", "application/xml", "", bridge.ip);
-      std::smatch matchResult;
-      if (std::regex_search(desc, manufRegex) &&
-          std::regex_search(desc, manURLRegex) &&
-          std::regex_search(desc, modelRegex) &&
-          std::regex_search(desc, matchResult, serialRegex)) {
-        // The string matches
-        // Get 1st submatch (0 is whole match)
-        bridge.mac = matchResult[1].str();
+        "/description.xml", "application/xml", "", bridge.ip);
+      std::string mac = ParseDescription(desc);
+      if (!mac.empty()) {
+        bridge.mac = NormalizeMac(mac);
         foundBridges.push_back(std::move(bridge));
       }
-      // break;
     }
   }
   return foundBridges;
@@ -113,6 +102,28 @@ std::string HueFinder::NormalizeMac(std::string input) {
   return input;
 }
+std::string HueFinder::ParseDescription(const std::string & description)
+{
+  const char* manufacturer = "<manufacturer>Royal Philips Electronics</manufacturer>";
+  const char* manURL = "<manufacturerURL>http://www.philips.com</manufacturerURL>";
+  const char* model = "<modelName>Philips hue bridge";
+  const char* serialBegin = "<serialNumber>";
+  const char* serialEnd = "</serialNumber>";
+  if (description.find(manufacturer) != std::string::npos && description.find(manURL) != std::string::npos
+    && description.find(model) != std::string::npos) {
+    std::size_t begin = description.find(serialBegin);
+    std::size_t end = description.find(serialEnd, begin);
+    if (begin != std::string::npos && end != std::string::npos) {
+      begin += std::strlen(serialBegin);
+      if (begin < description.size()) {
+        std::string result = description.substr(begin, end);
+        return result;
+      }
+    }
+  }
+  return std::string();
+}
+
 Hue::Hue(const std::string &ip, const std::string &username,
          std::shared_ptr<const IHttpHandler> handler)
     : ip(ip), username(username), http_handler(std::move(handler)),
@@ -86,9 +86,16 @@ private:
   //! \returns \p input without separators and whitespace, in upper case.
   static std::string NormalizeMac(std::string input);
+  //! \brief Parses mac address from description.xml
+  //!
+  //! \param description Content of description.xml file as returned by GET request.
+  //! \returns Content of xml element \c serialNumber if description matches a Hue bridge,
+  //! otherwise an empty string.
+  static std::string ParseDescription(const std::string& description);
+
   std::map<std::string, std::string>
-      usernames; //!< Maps all macs to usernames added by \ref
-                 //!< HueFinder::AddUsername
+    usernames; //!< Maps all macs to usernames added by \ref
+               //!< HueFinder::AddUsername
   std::shared_ptr<const IHttpHandler> http_handler;
 };