From 373f8e33be5e98e29bb795bfe1aeceacaa6c7424 Mon Sep 17 00:00:00 2001
From: Edouard DUPIN <yui.heero@gmail.com>
Date: Wed, 4 Jan 2017 22:31:03 +0100
Subject: [PATCH] [DEV] add basic of maximum number line in a log file

---
 elog/elog.cpp |  7 ++++++-
 elog/log.cpp  | 55 +++++++++++++++++++++++++++++++++++++++++++++++++--
 elog/log.hpp  |  9 +++++++++
 3 files changed, 68 insertions(+), 3 deletions(-)

diff --git a/elog/elog.cpp b/elog/elog.cpp
index 3de48f1..6ab8e76 100644
--- a/elog/elog.cpp
+++ b/elog/elog.cpp
@@ -75,6 +75,11 @@ void elog::init(int _argc, const char** _argv) {
 		if (startWith(data, "--elog-level=")) {
 			ELOG_INFO("Change global level at " << getLogLevel(std::string(data.begin()+13, data.end())));
 			elog::setLevel(getLogLevel(std::string(data.begin()+13, data.end())));
+		} else if (startWith(data, "--elog-max-line=")) {
+			std::string dataToParse = &data[16];
+			int value = 0;
+			sscanf(dataToParse.c_str(), "%d", &value);
+			elog::setMaxLineNumberInFile(value);
 		} else if (data == "--elog-color") {
 			elog::setColor(true);
 		} else if (data == "--elog-no-color") {
@@ -146,6 +151,7 @@ void elog::init(int _argc, const char** _argv) {
 			ELOG_PRINT("            X     Log level to set [0..6]");
 			ELOG_PRINT("            note: ':' can be replace with '/' or '+'");
 			ELOG_PRINT("        --elog-file=pathToFile   File to store the logs: (disable console logs)");
+			ELOG_PRINT("        --elog-max-line=XXX      Number of line in the log file");
 			ELOG_PRINT("        --elog-color             Enable color in log (default in Linux/debug)");
 			ELOG_PRINT("        --elog-no-color          Disable color in log (default in Linux/release and Other)");
 			ELOG_PRINT("        --elog-back-trace        Enable back-trace when an error log level is generated (to get a fast debug)");
@@ -185,4 +191,3 @@ void elog::init(int _argc, const char** _argv) {
 	ELOG_INFO("E-LOG system init (END)");
 }
 
-
diff --git a/elog/log.cpp b/elog/log.cpp
index 4ed2fcd..b1bb643 100644
--- a/elog/log.cpp
+++ b/elog/log.cpp
@@ -116,6 +116,7 @@ size_t& getNameSizeLog() {
 	static size_t g_val = 5;
 	return g_val;
 }
+
 static std::vector<std::pair<std::string, enum elog::level> >& getList() {
 	static std::vector<std::pair<std::string, enum elog::level> > g_val;
 	return g_val;
@@ -277,9 +278,27 @@ static void getDisplayTime(char* data) {
 static std::mutex g_lock;
 static elog::callbackLog callbackUserLog(nullptr);
 
+static std::string& getLogFileName() {
+	static std::string g_val="";
+	return g_val;
+}
 static FILE*& getLogFile() {
-	static FILE* file=nullptr;
-	return file;
+	static FILE* g_val=nullptr;
+	return g_val;
+}
+
+static size_t& getLogFileCount() {
+	static size_t g_val = 0;
+	return g_val;
+}
+
+static size_t& getLogFileMaxCount() {
+	static size_t g_val = 0;
+	return g_val;
+}
+
+void elog::setMaxLineNumberInFile(size_t _status) {
+	getLogFileMaxCount() = _status;
 }
 
 
@@ -352,6 +371,7 @@ static bool FSNODE_LOCAL_exist(const std::string& _path) {
 void elog::setLogInFile(const std::string& _filename) {
 	elog::unsetLogInFile();
 	ELOG_PRINT("Log in file: '" << _filename << "'");
+	getLogFileName() = _filename;
 	FILE*& file = getLogFile();
 	// create path of the file:
 	size_t found=_filename.find_last_of("/\\");
@@ -368,6 +388,7 @@ void elog::setLogInFile(const std::string& _filename) {
 }
 
 void elog::unsetLogInFile() {
+	getLogFileName() = "";
 	g_lock.lock();
 	FILE*& file = getLogFile();
 	// close file only if needed ...
@@ -618,6 +639,8 @@ void elog::logChar(int32_t _id, int32_t _level, int32_t _ligne, const char* _fun
 	g_lock.lock();
 	{
 		FILE*& file = getLogFile();
+		size_t& fileCurrentCount = getLogFileCount();
+		size_t& fileMaxCount = getLogFileMaxCount();
 		// close file only if needed ...
 		if (file != nullptr) {
 			*pointer++ = '\n';
@@ -631,6 +654,24 @@ void elog::logChar(int32_t _id, int32_t _level, int32_t _ligne, const char* _fun
 					fflush(file);
 					break;
 			}
+			// Increment the line counter in file
+			fileCurrentCount++;
+			if (fileMaxCount != 0) {
+				// the user request a maximum line number in the file:
+				if (fileCurrentCount > fileMaxCount) {
+					fileCurrentCount = 0;
+					fflush(file);
+					fclose(file);
+					std::string tmpFileName = getLogFileName();
+					if (    tmpFileName.size() > 0
+					     && tmpFileName[tmpFileName.size()-1] == '2') {
+						getLogFileName().pop_back();
+					} else {
+						getLogFileName() += "2";
+					}
+					file = fopen(getLogFileName().c_str(), "w");
+				}
+			}
 			// if we log in file, we have no need to log otherwise ... just "tail -f log.txt"
 			g_lock.unlock();
 			return;
@@ -681,3 +722,13 @@ void elog::logChar(int32_t _id, int32_t _level, int32_t _ligne, const char* _fun
 }
 
 
+void elog::flush() {
+	g_lock.lock();
+	FILE*& file = getLogFile();
+	if (file != nullptr) {
+		fflush(file);
+	}
+	fflush(stdout);
+	g_lock.unlock();
+	return;
+}
\ No newline at end of file
diff --git a/elog/log.hpp b/elog/log.hpp
index 319fea2..a71437e 100644
--- a/elog/log.hpp
+++ b/elog/log.hpp
@@ -107,6 +107,11 @@ namespace elog {
 	 * @param[in] _status New value.
 	 */
 	void setBackTrace(bool _status);
+	/**
+	 * @brief Set back-trace display on Error log enable or disable.
+	 * @param[in] _status New number of lines.
+	 */
+	void setMaxLineNumberInFile(size_t _status);
 	/**
 	 * @brief Call log to display
 	 * @param[in] _id Id of the instance type
@@ -169,6 +174,10 @@ namespace elog {
 	 * @brief Disable log in a file
 	 */
 	void unsetLogInFile();
+	/**
+	 * @brief When loggin in file, the flush is not done automaticaly ==> need to do it manualy
+	 */
+	void flush();
 };
 
 /**