add magic number, hack up the logutils to handle 2.00 file format

git-svn-id: https://svn.mcs.anl.gov/repos/darshan/trunk@244 3b7491f3-a168-0410-bf4b-c445ed680a29

darshan-log-format.h

@@ -14,6 +14,9 @@
 /* update this on file format changes */
 #define CP_VERSION "2.00"
 
+/* magic number for validating output files and checking byte order */
+#define CP_MAGIC_NR 6567223
+
 /* size (in bytes) of job record */
 #define CP_JOB_RECORD_SIZE 1024
 
@@ -217,6 +220,7 @@ struct darshan_file
 struct darshan_job
 {
     char version_string[8];
+    int64_t magic_nr;
     int64_t uid;
     int64_t start_time;
     int64_t end_time;

darshan-logutils.c

@@ -254,6 +254,16 @@ int darshan_log_getjob(darshan_fd file, struct darshan_job *job)
         perror("darshan_job_init");
         return(-1);
     }
+    /* TODO: error out on anything except 2.00 in trunk for now, build
+     * backwards compatibility later
+     */ 
+    if(strcmp(job->version_string, "2.00") == 0)
+        return(0);
+    fprintf(stderr, "Error: incompatible darshan file.\n");
+    fprintf(stderr, "Error: expected version %s, but got %s\n", 
+            CP_VERSION, job->version_string);
+
+    return(-1);
     if(strcmp(job->version_string, "1.21") == 0)
         return(0);
     if(strcmp(job->version_string, "1.22") == 0)
@@ -337,9 +347,18 @@ int darshan_log_getfile(darshan_fd fd, struct darshan_job *job, struct darshan_f
         }
     }
     else if(strcmp(job->version_string, "1.24") == 0)
+    {
+        ret = gzread(fd, file, sizeof(*file));
+        if(ret == sizeof(*file))
+        {
+            /* got exactly one, correct size record */
+            return(1);
+        }
+    }
+    else if(strcmp(job->version_string, "2.00") == 0)
     {
         /* make sure this is the current version */
-        assert(strcmp("1.24", CP_VERSION) == 0);
+        assert(strcmp("2.00", CP_VERSION) == 0);
 
         ret = gzread(fd, file, sizeof(*file));
         if(ret == sizeof(*file))
@@ -490,9 +509,14 @@ void darshan_log_close(darshan_fd file)
  */
 void darshan_log_print_version_warnings(struct darshan_job *job)
 {
+    if(strcmp(job->version_string, "2.00") == 0)
+    {
+        /* current version */
+        return;
+    }
+ 
     if(strcmp(job->version_string, "1.24") == 0)
     {
-        /* nothing to do, this is the current version */
         return;
     }
     

lib/darshan-posix.c

@@ -1028,6 +1028,7 @@ void darshan_initialize(int argc, char** argv,  int nprocs, int rank)
     }
 
     strcpy(darshan_global_job->log_job.version_string, CP_VERSION);
+    darshan_global_job->log_job.magic_nr = CP_MAGIC_NR;
     darshan_global_job->log_job.uid = getuid();
     darshan_global_job->log_job.start_time = time(NULL);
     darshan_global_job->log_job.nprocs = nprocs;