Added functions to ease support of multiple version of traces

[lttv.git] / ltt / tracefile.c

diff --git a/ltt/tracefile.c b/ltt/tracefile.c
index efb2ca93f36b7c5d0c4ac23b2a8a5af257d6f51b..3d69ddf76e26a51ccad3e779e3226aa9781ba491 100644 (file)
--- a/ltt/tracefile.c
+++ b/ltt/tracefile.c
@@ -1729,3 +1729,147 @@ static __attribute__((constructor)) void init(void)
 {
   LTT_TRACEFILE_NAME_METADATA = g_quark_from_string("metadata");
 }
+
+/*****************************************************************************
+ *Function name
+ *    ltt_tracefile_open_header    : based on ltt_tracefile_open but it stops
+ *                                  when it gets the header                                    
+ *Input params 
+ *    fileName       : path to the tracefile
+ *    tf             : the tracefile (metadata_0) where the header will be read
+ *Return value
+ *    ltt_subbuffer_header_t         : the header containing the version number
+ ****************************************************************************/
+static ltt_subbuffer_header_t * ltt_tracefile_open_header(gchar * fileName, LttTracefile *tf)
+{
+  struct stat    lTDFStat;    /* Trace data file status */
+  ltt_subbuffer_header_t *header;
+  int page_size = getpagesize();
+
+  //open the file
+  tf->long_name = g_quark_from_string(fileName);
+  tf->fd = open(fileName, O_RDONLY);
+  if(tf->fd < 0){
+    g_warning("Unable to open input data file %s\n", fileName);
+    goto end;
+  }
+ 
+  // Get the file's status 
+  if(fstat(tf->fd, &lTDFStat) < 0){
+    g_warning("Unable to get the status of the input data file %s\n", fileName);
+    goto close_file;
+  }
+
+  // Is the file large enough to contain a trace 
+  if(lTDFStat.st_size <
+      (off_t)(ltt_subbuffer_header_size())){
+    g_print("The input data file %s does not contain a trace\n", fileName);
+    goto close_file;
+  }
+  
+  /* Temporarily map the buffer start header to get trace information */
+  /* Multiple of pages aligned head */
+  tf->buffer.head = mmap(0,
+      PAGE_ALIGN(ltt_subbuffer_header_size()), PROT_READ, 
+      MAP_PRIVATE, tf->fd, 0);
+  if(tf->buffer.head == MAP_FAILED) {
+    perror("Error in allocating memory for buffer of tracefile");
+    goto close_file;
+  }
+  g_assert( ( (gulong)tf->buffer.head&(8-1) ) == 0); // make sure it's aligned.
+  
+  header = (ltt_subbuffer_header_t *)tf->buffer.head;
+  
+  
+  return header;
+
+  /* Error */
+
+close_file:
+  close(tf->fd);
+end:
+  return 0;
+}
+
+
+/*****************************************************************************
+ *Function name
+ *    get_version    : get the trace version from a metadata_0 trace file
+ *Input params 
+ *    pathname       : path to the trace
+ *    version_number  : the struct that will get the version number
+ *Return value
+ *    int         : 1 if succeed, -1 if error
+ ****************************************************************************/
+
+int get_version(const gchar *pathname, struct LttTraceVersion * version_number) 
+{
+       gchar abs_path[PATH_MAX];
+       int ret = 0;
+       DIR *dir;
+       struct dirent *entry;
+       struct stat stat_buf;
+       gchar path[PATH_MAX];
+       
+       LttTracefile tmp_tf;
+       LttTrace  * t;
+       ltt_subbuffer_header_t *header;
+       
+       t = g_new(LttTrace, 1);
+         
+       get_absolute_pathname(pathname, abs_path);
+
+       /* Test to see if it looks like a trace */
+       dir = opendir(abs_path);
+       
+       if(dir == NULL) {
+               perror(abs_path);
+               goto open_error;
+       }
+       
+       while((entry = readdir(dir)) != NULL) {
+               strcpy(path, abs_path);
+               strcat(path, "/");
+               strcat(path, entry->d_name);
+               ret = stat(path, &stat_buf);
+               if(ret == -1) {
+                       perror(path);
+                       continue;
+               }
+       }
+       
+       closedir(dir);  
+       dir = opendir(abs_path);
+
+       while((entry = readdir(dir)) != NULL) {
+
+               if(entry->d_name[0] == '.') continue;
+               if(g_strcmp0(entry->d_name, "metadata_0") != 0) continue;
+               
+               strcpy(path, abs_path);
+               strcat(path, "/");
+               strcat(path, entry->d_name);
+               if(ret == -1) {
+                       perror(path);
+                       continue;
+               }
+               
+               header = ltt_tracefile_open_header(path, &tmp_tf);
+               
+               if(header == NULL) {
+                       g_info("Error getting the header %s", path);
+
+                       continue; /* error opening the tracefile : bad magic number ? */
+               }
+                               
+               version_number->ltt_major_version = header->major_version;
+               version_number->ltt_minor_version = header->minor_version;
+               
+       }
+       
+       return 0;
+       
+       open_error:
+       g_free(t);
+       return -1;
+}