modify the log rotation method when program start (alibaba#932)

Co-authored-by: yyaoling <lihj00@163.com>

Author: photonlibos

common/alog.cpp

@@ -508,14 +508,21 @@ class AsyncLogOutput final : public BaseLogOutput {
 };
 
 ILogOutput* new_log_output_file(const char* fn, uint64_t rotate_limit,
-                                int max_log_files, uint64_t throttle) {
+                                int max_log_files, uint64_t throttle, bool rotate_on_start) {
     auto ret = new LogOutputFile();
     if (ret->log_output_file_setting(fn, rotate_limit, max_log_files) < 0) {
         delete ret;
         LOG_ERROR_RETURN(0, nullptr, "Failed to open log file ", fn);
         return nullptr;
     }
     ret->set_throttle(throttle);
+
+    // when init the new log output file, rotate the log files that last program created
+    if (rotate_on_start && ret->log_file_size != 0) {
+        ret->log_file_rotate();
+        ret->reopen_log_output_file();
+    }
+
     return ret;
 }
 

common/alog.h

@@ -73,7 +73,8 @@ extern ILogOutput * const log_output_null;
 extern ILogOutput * const log_output_stderr;
 extern ILogOutput * const log_output_stdout;
 
-ILogOutput* new_log_output_file(const char* fn, uint64_t rotate_limit = UINT64_MAX, int max_log_files = 10, uint64_t throttle = -1UL);
+ILogOutput* new_log_output_file(const char* fn, uint64_t rotate_limit = UINT64_MAX, int max_log_files = 10,
+                                uint64_t throttle = -1UL, bool rotate_on_start = false);
 ILogOutput* new_log_output_file(int fd, uint64_t throttle = -1UL);
 ILogOutput* new_async_log_output(ILogOutput* output, int queue_num = 1);