add log file writing

src/engine/configEngine.cpp

@@ -23,6 +23,7 @@
 #ifdef _WIN32
 #include "winStuff.h"
 #define CONFIG_FILE "\\furnace.cfg"
+#define LOG_FILE "\\furnace.log"
 #else
 #ifdef __HAIKU__
 #include <support/SupportDefs.h>

src/engine/engine.cpp

@@ -4221,7 +4221,7 @@ bool DivEngine::deinitAudioBackend(bool dueToSwitchMaster) {
   return true;
 }
 
-bool DivEngine::init() {
+void DivEngine::preInit() {
   // register systems
   if (!systemsRegistered) registerSystems();
 
@@ -4229,8 +4229,13 @@ bool DivEngine::init() {
   initConfDir();
   logD("config path: %s",configPath.c_str());
 
+  String logPath=configPath+DIR_SEPARATOR_STR+"furnace.log";
+  startLogFile(logPath.c_str());
+  
   loadConf();
+}
 
+bool DivEngine::init() {
   loadSampleROMs();
 
   // set default system preset

src/engine/engine.h

@@ -1012,6 +1012,9 @@ class DivEngine {
     // quit dispatch
     void quitDispatch();
 
+    // pre-initialize the engine.
+    void preInit();
+
     // initialize the engine.
     bool init();
 

src/log.cpp

@@ -18,6 +18,8 @@
  */
 
 #include "ta-log.h"
+#include <thread>
+#include <condition_variable>
 
 #ifdef IS_MOBILE
 int logLevel=LOGLEVEL_TRACE;
@@ -25,11 +27,54 @@ int logLevel=LOGLEVEL_TRACE;
 int logLevel=LOGLEVEL_INFO;
 #endif
 
+FILE* logFile;
+char* logFileBuf;
+unsigned int logFilePosI=0;
+unsigned int logFilePosO=0;
+std::thread* logFileThread;
+std::mutex logFileLock;
+std::mutex logFileLockI;
+std::condition_variable logFileNotify;
+bool logFileAvail=false;
+
 std::atomic<unsigned short> logPosition;
 
 LogEntry logEntries[TA_LOG_SIZE];
 
 static constexpr unsigned int TA_LOG_MASK=TA_LOG_SIZE-1;
+static constexpr unsigned int TA_LOGFILE_BUF_MASK=TA_LOGFILE_BUF_SIZE-1;
+
+const char* logTypes[5]={
+  "ERROR",
+  "warning",
+  "info",
+  "debug",
+  "trace"
+};
+
+void appendLogBuf(const char* msg, size_t len) {
+  logFileLockI.lock();
+
+  int remaining=logFilePosO-logFilePosI;
+  if (remaining<=0) remaining+=TA_LOGFILE_BUF_SIZE;
+
+  if (len>=(unsigned int)remaining) {
+    printf("line too long to fit in log buffer!\n");
+    logFileLockI.unlock();
+    return;
+  }
+
+  if ((logFilePosI+len)>=TA_LOGFILE_BUF_SIZE) {
+    size_t firstWrite=TA_LOGFILE_BUF_SIZE-logFilePosI;
+    memcpy(logFileBuf+logFilePosI,msg,firstWrite);
+    memcpy(logFileBuf,msg+firstWrite,len-firstWrite);
+  } else {
+    memcpy(logFileBuf+logFilePosI,msg,len);
+  }
+
+  logFilePosI=(logFilePosI+len)&TA_LOGFILE_BUF_MASK;
+  logFileLockI.unlock();
+}
 
 int writeLog(int level, const char* msg, fmt::printf_args args) {
   time_t thisMakesNoSense=time(NULL);
@@ -54,6 +99,20 @@ int writeLog(int level, const char* msg, fmt::printf_args args) {
   logEntries[pos].loglevel=level;
   logEntries[pos].ready=true;
 
+  // write to log file
+  if (logFileAvail) {
+    std::string toWrite=fmt::sprintf(
+      "%02d:%02d:%02d [%s] %s\n",
+      logEntries[pos].time.tm_hour,
+      logEntries[pos].time.tm_min,
+      logEntries[pos].time.tm_sec,
+      logTypes[logEntries[pos].loglevel],
+      logEntries[pos].text
+    );
+    appendLogBuf(toWrite.c_str(),toWrite.size());
+    logFileNotify.notify_one();
+  }
+
   if (logLevel<level) return 0;
   switch (level) {
     case LOGLEVEL_ERROR:
@@ -71,8 +130,70 @@ int writeLog(int level, const char* msg, fmt::printf_args args) {
 }
 
 void initLog() {
+  // initalize log buffer
   logPosition=0;
   for (int i=0; i<TA_LOG_SIZE; i++) {
     logEntries[i].text.reserve(128);
   }
+
+  // initialize log to file thread
+  logFileAvail=false;
 }
+
+void _logFileThread() {
+  std::unique_lock<std::mutex> lock(logFileLock);
+  while (true) {
+    unsigned int logFilePosICopy=logFilePosI;
+    if (logFilePosICopy!=logFilePosO) {
+      // write
+      if (logFilePosO>logFilePosICopy) {
+        fwrite(logFileBuf+logFilePosO,1,TA_LOGFILE_BUF_SIZE-logFilePosO,logFile);
+        logFilePosO=0;
+      } else {
+        fwrite(logFileBuf+logFilePosO,1,logFilePosICopy-logFilePosO,logFile);
+        logFilePosO=logFilePosICopy;
+      }
+    } else {
+      // wait
+      if (!logFileAvail) break;
+      fflush(logFile);
+      logFileNotify.wait(lock);
+    }
+  }
+}
+
+bool startLogFile(const char* path) {
+  if (logFileAvail) return true;
+
+  // rotate log file if possible
+  
+  // open log file
+  if ((logFile=fopen(path,"w+"))==NULL) {
+    logFileAvail=false;
+    logW("could not open log file! (%s)",strerror(errno));
+    return false;
+  }
+
+  logFileBuf=new char[TA_LOGFILE_BUF_SIZE];
+  logFilePosI=0;
+  logFilePosO=0;
+  logFileAvail=true;
+
+  logFileThread=new std::thread(_logFileThread);
+  return true;
+}
+
+bool finishLogFile() {
+  if (!logFileAvail) return false;
+
+  logFileAvail=false;
+
+  // flush
+  logFileLockI.lock();
+  logFileNotify.notify_one();
+  logFileThread->join();
+  logFileLockI.unlock();
+
+  fclose(logFile);
+  return true;
+}

src/main.cpp

@@ -416,7 +416,11 @@ int main(int argc, char** argv) {
     logI("usage: %s file",argv[0]);
     return 1;
   }
+
   logI("Furnace version " DIV_VERSION ".");
+
+  e.preInit();
+
   if (!fileName.empty()) {
     logI("loading module...");
     FILE* f=ps_fopen(fileName.c_str(),"rb");
@@ -584,6 +588,8 @@ int main(int argc, char** argv) {
   logI("stopping engine.");
   e.quit();
 
+  finishLogFile();
+
 #ifdef _WIN32
   if (coResult==S_OK || coResult==S_FALSE) {
     CoUninitialize();

src/ta-log.h

@@ -35,6 +35,9 @@
 // this has to be a power of 2
 #define TA_LOG_SIZE 2048
 
+// this as well
+#define TA_LOGFILE_BUF_SIZE 65536
+
 extern int logLevel;
 
 extern std::atomic<unsigned short> logPosition;
@@ -76,4 +79,6 @@ template<typename... T> int logE(const char* msg, const T&... args) {
 }
 
 void initLog();
+bool startLogFile(const char* path);
+bool finishLogFile();
 #endif