Add a toJson method to database

- only tag information for tags with count>0 is written out

src/TagInfo.cpp

@@ -25,6 +25,7 @@
 ////////////////////////////////////////////////////////////////////////////////
 
 #include <TagInfo.h>
+#include <sstream>
 
 ////////////////////////////////////////////////////////////////////////////////
 TagInfo::TagInfo (unsigned int count)
@@ -43,3 +44,18 @@ unsigned int TagInfo::decrement ()
 {
   return --_count;
 }
+
+////////////////////////////////////////////////////////////////////////////////
+bool TagInfo::hasCount ()
+{
+  return _count > 0;
+}
+
+////////////////////////////////////////////////////////////////////////////////
+std::string TagInfo::toJson ()
+{
+  std::stringstream output;
+  output << "{\"count\":" << _count << "}";
+
+  return output.str ();
+}

src/TagInfo.h

@@ -27,6 +27,8 @@
 #ifndef INCLUDED_TAGINFO
 #define INCLUDED_TAGINFO
 
+#include <string>
+
 class TagInfo
 {
 public:
@@ -35,6 +37,9 @@ public:
   unsigned int increment ();
   unsigned int decrement ();
 
+  bool hasCount ();
+
+  std::string toJson ();
 
 private:
   unsigned int _count = 0;

src/TagInfoDatabase.cpp

@@ -73,3 +73,30 @@ void TagInfoDatabase::add (const std::string& tag, const TagInfo& tagInfo)
 {
   _tagInformation.emplace (tag, tagInfo);
 }
+
+///////////////////////////////////////////////////////////////////////////////
+std::string TagInfoDatabase::toJson ()
+{
+  std::stringstream json;
+  bool first = true;
+
+  json << "{";
+
+  for (auto& pair : _tagInformation)
+  {
+    auto tagInfo = pair.second;
+
+    if (tagInfo.hasCount ())
+    {
+      json << (first ? "" : ",")
+         << "\"" << escape(pair.first, '"') << "\":"
+         << tagInfo.toJson ();
+
+      first = (first ? false : first);
+    }
+  }
+
+  json << "}";
+
+  return json.str ();
+}

src/TagInfoDatabase.h

@@ -39,6 +39,8 @@ public:
 
   void add (const std::string&, const TagInfo&);
 
+  std::string toJson ();
+
 private:
   std::map <std::string, TagInfo> _tagInformation {};
 };