break up logging logic, bugfixes

src/util.c

@@ -225,33 +225,47 @@ UIntArray* wm_nonempty_workspaces_to_strptrarray(Wm *wm)
     return ret;
 }
 
-void wm_log_state(Wm *wm, const char *prefixstr, const char* logfile)
+json_object* wm_state_to_json_object(Wm *wm, const char *prefixstr)
 {
-    RETURN_IF_NULL(prefixstr);
+    assert(prefixstr);
-    RETURN_IF_NULL(logfile);
+
+    json_object *ret = json_object_new_object();
 
     UIntArray *ws_str = wm_nonempty_workspaces_to_strptrarray(wm);
-
     char str[128] = {0};
-    char prefix[WM_PREFIX_LEN + 32] = {0};
-    snprintf(prefix, sizeof(prefix), "%lu:%s", time(NULL), prefixstr);
-
-    json_object *log_entry_obj = json_object_new_object();
 
     for (size_t i = 0; i < ws_str->size; i++) {
         WmWorkspaceToStrRet *ws_with_index = (WmWorkspaceToStrRet*)
             wm_uintarray_at(ws_str, i);
 
         snprintf(str, sizeof(str), "%ld", ws_with_index->ws_index);
-        json_object_object_add(log_entry_obj, str, json_tokener_parse(ws_with_index->str));
+        json_object_object_add(ret, str, json_tokener_parse(ws_with_index->str));
 
         free(ws_with_index->str);
         free(ws_with_index);
     }
 
+    return ret;
+}
+
+void wm_log_state(Wm *wm, const char *prefixstr, const char* logfile)
+{
+    RETURN_IF_NULL(prefixstr);
+    RETURN_IF_NULL(logfile);
+
+    DEBUG_PRINT("saving state to file: %s\n", logfile);
+
+    char prefix[WM_PREFIX_LEN + 32] = {0};
+    snprintf(prefix, sizeof(prefix), "%lu:%s", time(NULL), prefixstr);
+
+    json_object *log_entry_obj = wm_state_to_json_object(wm, prefixstr);
+
     int fd = -1;
     struct json_object *jobj = NULL;
-    if (access(logfile, F_OK) != 0) {
+
+    int access_ret = access(logfile, F_OK);
+    if (access_ret != 0) {
+        DEBUG_PRINT("logfile does not exist\n");
         fd = creat(logfile, 0644);
 
         if (fd < 0) {
@@ -261,19 +275,32 @@ void wm_log_state(Wm *wm, const char *prefixstr, const char* logfile)
 
         jobj = json_object_new_object();
     } else {
-        fd = open(logfile, O_RDWR);
+        DEBUG_PRINT("logfile exists\n");
 
+        struct stat st;
+        if (stat(logfile, &st) < 0) {
+            perror("stat");
+            goto ret;
+        }
+
+        fd = open(logfile, O_RDWR);
         if (fd < 0) {
             perror("open");
             goto ret;
         }
 
-        jobj = json_object_from_fd(fd);
+        if (st.st_size == 0) {
-        if (!jobj) {
+            DEBUG_PRINT("logfile is empty");
-            const char *err = json_util_get_last_err();
+            jobj = json_object_new_object();
-            fprintf(stderr, "wm: could not read json: %s\n", err);
+        } else {
-            // TODO maybe free
+            jobj = json_object_from_fd(fd);
-            goto ret;
+            if (!jobj) {
+                const char *err = json_util_get_last_err();
+                fprintf(stderr, "wm: could not read json: %s\n", err);
+                DEBUG_PRINT("wm: could not read json: %s\n", err);
+                // TODO maybe free
+                goto ret;
+            }
         }
     }
 
@@ -285,7 +312,7 @@ void wm_log_state(Wm *wm, const char *prefixstr, const char* logfile)
         goto ret;
     }
 
-    ret = open(logfile, O_TRUNC | O_WRONLY);
+    fd = open(logfile, O_TRUNC | O_WRONLY);
 
     if (ret < 0) {
         perror("open");
@@ -306,7 +333,6 @@ void wm_log_state(Wm *wm, const char *prefixstr, const char* logfile)
 
 ret:
     json_object_put(jobj);
-    wm_uintarray_free(ws_str);
 }
 
 TreeNode* wm_treenode_lmd(TreeNode *node)

src/util.h

@@ -121,6 +121,7 @@ TreeNode* wm_treenode_ptr_find_client_node(TreeNode *root, Client *client);
 NodeArray* wm_treenode_find_client_nodes(TreeNode *root);
 TreeNode* wm_treenode_split_get_sibling(TreeNode *node);
 NodeArray* wm_all_nodes_to_array(TreeNode *root);
+json_object* wm_state_to_json_object(Wm *wm, const char *prefixstr);
 void wm_log_state(Wm *wm, const char *prefixstr, const char* logfile);
 
 TreeNode* wm_treenode_lmd(TreeNode *node);