Merge branch 'master' of github.com:ogre/pizero_tracker

tracker/code/main/async_log_t.h

@@ -0,0 +1,99 @@
+#pragma once
+
+#include <string>
+#include <vector>
+#include <map>
+#include <mutex>
+#include <tuple>
+#include <utility>
+#include <iostream>
+#include <fstream>
+
+class async_log_t
+{
+private:
+    using logs_t = std::map< std::string, std::vector<std::string> >;
+    logs_t      logs_;
+    std::mutex  mtx_;
+    std::string base_dir_{"./"};
+
+public:
+    bool log(const std::string& fname, const std::string& msg)
+    {
+        std::lock_guard<std::mutex> _lock(mtx_);
+        auto log_stream = logs_.find(fname);
+        if(log_stream == logs_.end()) {
+            bool insert_ok = false;
+            std::tie(log_stream, insert_ok) = logs_.emplace( std::make_pair(fname, std::vector<std::string>()) );
+            if(!insert_ok)
+                return false;
+        }
+        log_stream->second.push_back(msg);
+        return true;
+    }
+
+    void save(void)
+    {
+        logs_t logs_to_save;
+
+        {
+            std::lock_guard<std::mutex> _lock(mtx_);
+            logs_to_save.swap(logs_);
+        }
+
+        for(const auto& log_file_iter : logs_to_save) {
+            std::ofstream of;
+            of.open( base_dir_ + "/" + log_file_iter.first, std::ofstream::app );
+            if(of) {
+                for(const auto& msg : log_file_iter.second)
+                    of<<msg<<std::endl;
+            }
+            of.close();
+        }
+    }
+};
+
+/*
+
+int main(int argc, char** argv)
+{
+    using namespace std;
+
+    signal(SIGINT,  CTRL_C);
+	signal(SIGTERM, CTRL_C);
+
+    async_log_t logs;
+
+    // log something 3 times per second
+    auto log_producer = [&logs](std::string logfile){
+        while(G_RUN) {
+            cout<<"Log to "<<logfile<<endl;
+            logs.log(logfile, "some message");
+            this_thread::sleep_for( chrono::milliseconds(300) );
+        }
+    };
+
+    // save logs every 3 seconds
+    auto log_saver = [&logs]() {
+        while(G_RUN) {
+            this_thread::sleep_for(chrono::seconds(3));
+            logs.save();
+        }
+    };
+
+
+    std::vector<std::thread>     threads;
+
+    threads.emplace_back( std::thread( [&log_producer](){log_producer("fileA.log");} ) );
+    threads.emplace_back( std::thread( [&log_producer](){log_producer("fileB.log");} ) );
+    threads.emplace_back( std::thread( [&log_producer](){log_producer("fileC.log");} ) );
+    threads.emplace_back( std::thread(log_saver) );
+
+    for(auto& t : threads)
+        if( t.joinable() )
+            t.join();
+
+    logs.save(); // last save
+
+}
+*/