protecting log rotation with a mutex

[yaz-moved-to-github.git] / src / log.c

diff --git a/src/log.c b/src/log.c
index 134ce98..8c750a6 100644 (file)
--- a/src/log.c
+++ b/src/log.c
@@ -2,7 +2,7 @@
  * Copyright (c) 1995-2004, Index Data
  * See the file LICENSE for details.
  *
- * $Id: log.c,v 1.3 2004-11-02 11:37:21 heikki Exp $
+ * $Id: log.c,v 1.8 2004-11-02 15:47:31 heikki Exp $
  */
 
 /**
@@ -18,6 +18,14 @@
 #include <windows.h>
 #endif
 
+#if YAZ_POSIX_THREADS
+#include <pthread.h>
+#endif
+
+#if YAZ_GNU_THREADS
+#include <pth.h>
+#endif
+
 #include <stdio.h>
 #include <stdlib.h>
 #include <ctype.h>
@@ -27,6 +35,10 @@
 #include <time.h>
 #include <yaz/nmem.h>
 #include <yaz/log.h>
+#include <yaz/nmem.h>
+
+static NMEM_MUTEX log_mutex=0;
+static mutex_init_flag=0; /* not yet initialized */
 
 #define HAS_STRERROR 1
 
@@ -42,17 +54,23 @@ char *strerror(int n)
 #endif
 
 
+
 static int l_level = LOG_DEFAULT_LEVEL;
 static FILE *l_file = NULL;
 static char l_prefix[512] = "";
 static char l_prefix2[512] = "";
 static char l_fname[512] = "";
+
 static char l_old_default_format[]="%H:%M:%S-%d/%m";
 static char l_new_default_format[]="%Y%m%d-%H%M%S";
 #define TIMEFORMAT_LEN 50
 static char l_custom_format[TIMEFORMAT_LEN]="";
 static char *l_actual_format=l_old_default_format;
 
+/** l_max_size tells when to rotate the log. Default to 1 GB */
+/*static int l_max_size=1024*1024*1024;*/
+static int l_max_size=1024;   /* while testing */
+
 static struct {
     int mask;
     char *name;
@@ -69,10 +87,20 @@ static struct {
     { LOG_APP2  , "app2" },
     { LOG_APP3  , "app3" },
     { LOG_ALL,   "all"  },
+    { LOG_FLUSH, "flush" },
     { 0,         "none" },
     { 0, NULL }
 };  
 
+static void init_mutex()
+{
+    if (mutex_init_flag)
+        return;
+    nmem_mutex_create (&log_mutex);
+    mutex_init_flag=1;
+}
+
+
 FILE *yaz_log_file(void)
 {
     if (!l_file)
@@ -82,6 +110,8 @@ FILE *yaz_log_file(void)
 
 void yaz_log_init_file (const char *fname)
 {
+    if (!mutex_init_flag)
+        init_mutex();
     if (fname)
     {
        strncpy(l_fname, fname, sizeof(l_fname)-1);
@@ -95,9 +125,10 @@ void yaz_log_init_file (const char *fname)
 void yaz_log_reopen(void)
 {
     FILE *new_file;
+    if (!mutex_init_flag)
+        init_mutex();
     if (!l_file)
         l_file = stderr;
-
     if (!*l_fname)
        new_file=stderr;
     else if (!(new_file = fopen(l_fname, "a")))
@@ -106,13 +137,38 @@ void yaz_log_reopen(void)
     {
         fclose (l_file);
     }
-    setvbuf(new_file, 0, _IONBF, 0);
+    if (l_level & LOG_FLUSH)
+        setvbuf(new_file, 0, _IONBF, 0);
     l_file = new_file;
 }
 
+static void rotate_log()
+{
+    char newname[512];
+    if (l_file==stderr)
+        return; /* can't rotate that */
+    if (!*l_fname)
+        return; /* hmm, no name, can't rotate */
+    strncpy(newname, l_fname, 510);
+    newname[510]='\0'; /* make sure it is terminated */
+    strcat(newname,".1");
+#ifdef WIN32
+    fclose(l_file);
+    l_file=stderr;
+#endif
+    rename(l_fname, newname);
+    yaz_log_reopen();
+}
+
+
 void yaz_log_init_level (int level)
 {
-    l_level = level;
+    if ( (l_level & LOG_FLUSH) != (level & LOG_FLUSH) )
+    {
+        l_level = level;
+        yaz_log_reopen(); /* make sure we set buffering right */
+    } else
+        l_level = level;
 }
 
 void yaz_log_init_prefix (const char *prefix)
@@ -133,6 +189,8 @@ void yaz_log_init_prefix2 (const char *prefix)
 
 void yaz_log_init(int level, const char *prefix, const char *fname)
 {
+    if (!mutex_init_flag)
+        init_mutex();
     yaz_log_init_level (level);
     yaz_log_init_prefix (prefix);
     if (fname && *fname)
@@ -165,11 +223,24 @@ void yaz_log(int level, const char *fmt, ...)
     struct tm *tim;
     char tbuf[TIMEFORMAT_LEN]="";
     int o_level = level;
+    int flen; 
 
     if (!(level & l_level))
        return;
+    if (!mutex_init_flag)
+        init_mutex();
     if (!l_file)
         l_file = stderr;
+    
+    if (l_file != stderr)
+    {
+        nmem_mutex_enter (log_mutex);
+        flen=ftell(l_file);
+        if (flen>l_max_size) 
+            rotate_log();
+        nmem_mutex_leave (log_mutex);
+    }
+
     *flags = '\0';
     for (i = 0; level && mask_names[i].name; i++)
        if (mask_names[i].mask & level)
@@ -208,7 +279,8 @@ void yaz_log(int level, const char *fmt, ...)
     tbuf[TIMEFORMAT_LEN-1]='\0';
     fprintf(l_file, "%s %s%s %s%s\n", tbuf, l_prefix, flags,
             l_prefix2, buf);
-    fflush(l_file);
+    if (l_level & (LOG_FLUSH|LOG_DEBUG) )
+        fflush(l_file);
     if (end_hook_func)
        (*end_hook_func)(o_level, buf, end_hook_info);
 }