implement mobject_store_create

MOBJECT_CLUSTER_FILE env variable must be set to point to a
valid file generated by the mobject server.

src/libmobject-store.c

@@ -7,6 +7,7 @@
 #include "mobject-store-config.h"
 
 #include <stdio.h>
+#include <stdlib.h>
 #include <assert.h>
 
 #include <margo.h>
@@ -14,47 +15,68 @@
 
 #include "libmobject-store.h"
 
-struct mobject_store_handle
+#define MOBJECT_CLUSTER_FILE_ENV "MOBJECT_CLUSTER_FILE"
+
+typedef struct mobject_store_handle
 {
-    int test;
-};
+    ssg_group_id_t gid;
+} mobject_store_handle_t;
+
 
 int mobject_store_create(mobject_store_t *cluster, const char * const id)
 {
-    struct mobject_store_handle *cluster_handle;
+    mobject_store_handle_t *cluster_handle;
+    char *cluster_file;
+    int ret;
+
     (void)id; /* XXX: id unused in mobject */
 
     /* allocate a new cluster handle and set some fields */
     cluster_handle = malloc(sizeof(*cluster_handle));
     if (!cluster_handle)
-        return(-1); /* TODO: error codes */
-    cluster_handle->test = 123;
-
-    /* TODO find the SSG group ID for the mobject cluster group */
+        return -1;
+    memset(cluster_handle, 0, sizeof(cluster_handle));
+
+    /* use env variable to determine how to connect to the cluster */
+    /* NOTE: this is the _only_ method for specifying a cluster for now... */
+    cluster_file = getenv(MOBJECT_CLUSTER_FILE_ENV);
+    if (!cluster_file)
+    {
+        fprintf(stderr, "Error: %s env variable must point to mobject cluster file\n",
+            MOBJECT_CLUSTER_FILE_ENV);
+        return -1;
+    }
+
+    ret = ssg_group_id_load(cluster_file, &cluster_handle->gid);
+    if (ret != 0)
+    {
+        fprintf(stderr, "Error: Unable to load mobject cluster info from file %s\n",
+            cluster_file);
+        return -1;
+    }
 
     /* set the returned cluster handle */
     *cluster = cluster_handle;
 
-    return(0);
+    return 0;
 }
 
-#if 0
 int mobject_store_connect(mobject_store_t cluster)
 {
     /* TODO ssg attach to mobject cluster group id */
+
+    return 0;
 }
-#endif
 
 void mobject_store_shutdown(mobject_store_t cluster)
 {
-    struct mobject_store_handle *cluster_handle =
-        (struct mobject_store_handle *)cluster;
+    mobject_store_handle_t *cluster_handle =
+        (mobject_store_handle_t *)cluster;
     assert(cluster_handle != NULL);
 
-    /* TODO ssg detatch from mobject cluster group id */
+    /* TODO ssg detatch from mobject cluster group id. free gid? */
 
     free(cluster_handle);
 
     return;
 }
-