scenario: Add a TMPDIR global variables in scenarios

This also adds the notion of global variables which will be useable
in config files too.

And add some documentation about default variables in scenarios

docs/gst-validate-scenarios.md

@@ -93,3 +93,16 @@ action types in the [`GstValidateScenario` section].
   [`GST_STATE_NULL`]: GST_STATE_NULL
   [`GstValidateScenario` section]: GstValidateScenario
 
+## Default variables
+
+Any action can use the default variables:
+
+- `$(position)`: The current position in the pipeline as reported by
+  [gst_element_query_position()](gst_element_query_position)
+- `$(duration)`: The current duration of the pipeline as reported by
+  [gst_element_query_duration()](gst_element_query_duration)
+- `$(TMPDIR)`: The default temporary directory as returned by
+  [g_get_tmp_dir()](g_get_tmp_dir).
+
+
+It is also possible to set variables in scenario with the `set-vars` action.

validate/gst/validate/gst-validate-scenario.c

@@ -505,61 +505,6 @@ _update_well_known_vars (GstValidateScenario * scenario)
   }
 }
 
-static gchar *
-_replace_variables_in_string (GstValidateScenario * scenario,
-    GstValidateAction * action, const gchar * in_string)
-{
-  GRegex *regex;
-  gint varname_len;
-  GMatchInfo *match_info;
-  const gchar *var_value;
-  gchar *tmpstring, *string = g_strdup (in_string);
-
-  _update_well_known_vars (scenario);
-  regex = g_regex_new ("\\$\\((\\w+)\\)", 0, 0, NULL);
-  g_regex_match (regex, string, 0, &match_info);
-  while (g_match_info_matches (match_info)) {
-    GRegex *replace_regex;
-    gchar *tmp, *varname, *pvarname = g_match_info_fetch (match_info, 0);
-
-    varname_len = strlen (pvarname);
-    varname = g_malloc (sizeof (gchar) * (varname_len - 2));
-    strncpy (varname, &pvarname[2], varname_len - 3);
-    varname[varname_len - 3] = '\0';
-
-    if (gst_structure_has_field_typed (scenario->priv->vars, varname,
-            G_TYPE_DOUBLE)) {
-      var_value = varname;
-    } else {
-      var_value = gst_structure_get_string (scenario->priv->vars, varname);
-      if (!var_value) {
-        g_error ("Trying to use undefined variable : %s (%s)", varname,
-            gst_structure_to_string (scenario->priv->vars));
-
-        return NULL;
-      }
-    }
-
-    tmp = g_strdup_printf ("\\$\\(%s\\)", varname);
-    replace_regex = g_regex_new (tmp, 0, 0, NULL);
-    g_free (tmp);
-    tmpstring = string;
-    string = g_regex_replace (replace_regex, string, -1, 0, var_value, 0, NULL);
-
-    GST_INFO_OBJECT (action, "Setting variable %s to %s", varname, var_value);
-    g_free (tmpstring);
-    g_regex_unref (replace_regex);
-    g_free (pvarname);
-    g_free (varname);
-
-    g_match_info_next (match_info, NULL);
-  }
-  g_match_info_free (match_info);
-  g_regex_unref (regex);
-
-  return string;
-}
-
 static gboolean
 _set_variable_func (const gchar * name, double *value, gpointer user_data)
 {
@@ -635,7 +580,10 @@ gst_validate_action_get_clocktime (GstValidateScenario * scenario,
       return -1;
     }
 
-    strval = _replace_variables_in_string (scenario, action, tmpvalue);
+    _update_well_known_vars (scenario);
+    strval =
+        gst_validate_replace_variables_in_string (scenario->priv->vars,
+        tmpvalue);
     if (!strval)
       return FALSE;
 
@@ -2974,8 +2922,7 @@ _structure_set_variables (GQuark field_id, GValue * value,
   if (!scenario)
     return TRUE;
 
-  str =
-      _replace_variables_in_string (scenario, action,
+  str = gst_validate_replace_variables_in_string (scenario->priv->vars,
       g_value_get_string (value));
   if (str) {
     g_value_set_string (value, str);

validate/gst/validate/gst-validate-utils.c

@@ -46,6 +46,8 @@
 #define PARSER_MAX_ARGUMENT_COUNT 10
 
 static GRegex *_clean_structs_lines = NULL;
+static GRegex *_variables_regex = NULL;
+static GstStructure *global_vars = NULL;
 
 typedef struct
 {
@@ -939,3 +941,70 @@ gst_validate_element_matches_target (GstElement * element, GstStructure * s)
 
   return FALSE;
 }
+
+gchar *
+gst_validate_replace_variables_in_string (GstStructure * local_vars,
+    const gchar * in_string)
+{
+  gint varname_len;
+  GMatchInfo *match_info;
+  const gchar *var_value = NULL;
+  gchar *tmpstring, *string = g_strdup (in_string);
+
+  if (!_variables_regex)
+    _variables_regex = g_regex_new ("\\$\\((\\w+)\\)", 0, 0, NULL);
+
+  if (!global_vars) {
+    global_vars =
+        gst_structure_new ("vars", "TMPDIR", G_TYPE_STRING, g_get_tmp_dir (),
+        NULL);
+  }
+
+  g_regex_match (_variables_regex, string, 0, &match_info);
+  while (g_match_info_matches (match_info)) {
+    GRegex *replace_regex;
+    gchar *tmp, *varname, *pvarname = g_match_info_fetch (match_info, 0);
+
+    varname_len = strlen (pvarname);
+    varname = g_malloc (sizeof (gchar) * (varname_len - 2));
+    strncpy (varname, &pvarname[2], varname_len - 3);
+    varname[varname_len - 3] = '\0';
+
+    if (local_vars && gst_structure_has_field_typed (local_vars, varname,
+            G_TYPE_DOUBLE)) {
+      var_value = varname;
+    } else {
+      if (local_vars)
+        var_value = gst_structure_get_string (local_vars, varname);
+
+      if (!var_value)
+        var_value = gst_structure_get_string (global_vars, varname);
+
+      if (!var_value) {
+        g_error
+            ("Trying to use undefined variable : %s (\nlocals: %s\nglobals: %s\n)",
+            varname, gst_structure_to_string (local_vars),
+            gst_structure_to_string (global_vars));
+
+        return NULL;
+      }
+    }
+
+    tmp = g_strdup_printf ("\\$\\(%s\\)", varname);
+    replace_regex = g_regex_new (tmp, 0, 0, NULL);
+    g_free (tmp);
+    tmpstring = string;
+    string = g_regex_replace (replace_regex, string, -1, 0, var_value, 0, NULL);
+
+    GST_INFO ("Setting variable %s to %s", varname, var_value);
+    g_free (tmpstring);
+    g_regex_unref (replace_regex);
+    g_free (pvarname);
+    g_free (varname);
+
+    g_match_info_next (match_info, NULL);
+  }
+  g_match_info_free (match_info);
+
+  return string;
+}

validate/gst/validate/gst-validate-utils.h

@@ -69,5 +69,6 @@ void gst_validate_spin_on_fault_signals (void);
 
 GST_VALIDATE_API
 gboolean gst_validate_element_matches_target (GstElement * element, GstStructure * s);
+gchar * gst_validate_replace_variables_in_string (GstStructure * local_vars, const gchar * in_string);
 
 #endif