merge: getattr opt

lib/filterx/expr-getattr.c

@@ -31,47 +31,74 @@ typedef struct _FilterXGetAttr
   FilterXExpr super;
   FilterXExpr *operand;
   FilterXObject *attr;
+  FilterXObject **path;
 } FilterXGetAttr;
 
+static FilterXObject *
+_eval_operand(FilterXGetAttr *self, FilterXObject **attr)
+{
+  FilterXObject *o = filterx_expr_eval_typed(self->operand);
+
+  if (!o)
+    return NULL;
+
+  *attr = self->attr;
+  if (*attr)
+    return o;
+
+  FilterXObject *next_o;
+  *attr = self->path[0];
+  for (gint i = 0; self->path[i] && self->path[i+1]; i++)
+    {
+      next_o = filterx_object_getattr(o, *attr);
+      if (!o)
+        break;
+      filterx_object_unref(o);
+      o = next_o;
+      *attr = self->path[i+1];
+    }
+  return o;
+}
+
 static FilterXObject *
 _eval_getattr(FilterXExpr *s)
 {
   FilterXGetAttr *self = (FilterXGetAttr *) s;
+  FilterXObject *attr;
 
-  FilterXObject *variable = filterx_expr_eval_typed(self->operand);
-
+  FilterXObject *variable = _eval_operand(self, &attr);
   if (!variable)
     return NULL;
 
-  FilterXObject *attr = filterx_object_getattr(variable, self->attr);
-  if (!attr)
+  FilterXObject *value = filterx_object_getattr(variable, attr);
+  if (!value)
     {
-      filterx_eval_push_error("Attribute lookup failed", s, self->attr);
+      filterx_eval_push_error("Attribute lookup failed", s, attr);
       goto exit;
     }
 exit:
   filterx_object_unref(variable);
-  return attr;
+  return value;
 }
 
 static gboolean
 _unset(FilterXExpr *s)
 {
   FilterXGetAttr *self = (FilterXGetAttr *) s;
-
+  FilterXObject *attr;
   gboolean result = FALSE;
 
-  FilterXObject *variable = filterx_expr_eval_typed(self->operand);
+  FilterXObject *variable = _eval_operand(self, &attr);
   if (!variable)
     return FALSE;
 
   if (variable->readonly)
     {
-      filterx_eval_push_error("Object unset-attr failed, object is readonly", s, self->attr);
+      filterx_eval_push_error("Object unset-attr failed, object is readonly", s, attr);
       goto exit;
     }
 
-  result = filterx_object_unset_key(variable, self->attr);
+  result = filterx_object_unset_key(variable, attr);
 
 exit:
   filterx_object_unref(variable);
@@ -82,22 +109,66 @@ static gboolean
 _isset(FilterXExpr *s)
 {
   FilterXGetAttr *self = (FilterXGetAttr *) s;
-  FilterXObject *variable = filterx_expr_eval_typed(self->operand);
+  FilterXObject *attr;
+  FilterXObject *variable = _eval_operand(self, &attr);
   if (!variable)
     return FALSE;
 
-  gboolean result = filterx_object_is_key_set(variable, self->attr);
+  gboolean result = filterx_object_is_key_set(variable, attr);
 
   filterx_object_unref(variable);
   return result;
 }
 
+static void
+_rollup_child_getattr(FilterXGetAttr *self, FilterXGetAttr *child)
+{
+  /* turn a list of getattrs into a single getattr with a path argument */
+  GPtrArray *path = g_ptr_array_new();
+
+  if (child->attr)
+    {
+      /* if this is an unoptimized FilterXGetAttr, let's use the "attr" member */
+      g_ptr_array_add(path, filterx_object_ref(child->attr));
+      g_assert(child->path == NULL);
+    }
+  else
+    {
+      /* optimized GetAttr, copy the entire path into ours */
+      for (gint i = 0; child->path[i]; i++)
+        {
+          g_ptr_array_add(path, filterx_object_ref(child->path[i]));
+        }
+    }
+
+  /* we are the last getattr so append it to the end */
+  g_ptr_array_add(path, self->attr);
+  /* null termination */
+  g_ptr_array_add(path, NULL);
+
+  /* replace self->attr with self->path */
+  self->attr = NULL;
+  self->path = (FilterXObject **) g_ptr_array_free(path, FALSE);
+}
+
 static FilterXExpr *
 _optimize(FilterXExpr *s)
 {
   FilterXGetAttr *self = (FilterXGetAttr *) s;
 
   self->operand = filterx_expr_optimize(self->operand);
+  if (filterx_expr_is_getattr(self->operand))
+    {
+      FilterXGetAttr *child = (FilterXGetAttr *) self->operand;
+
+      _rollup_child_getattr(self, child);
+      self->operand = filterx_expr_ref(child->operand);
+
+      filterx_expr_unref(&child->super);
+
+      /* we need to return a ref */
+      return filterx_expr_ref(s);
+    }
   return NULL;
 }
 
@@ -125,7 +196,20 @@ static void
 _free(FilterXExpr *s)
 {
   FilterXGetAttr *self = (FilterXGetAttr *) s;
-  filterx_object_unref(self->attr);
+
+  if (self->attr)
+    {
+      filterx_object_unref(self->attr);
+      g_assert(self->path == NULL);
+    }
+  else
+    {
+      for (gint i = 0; self->path[i]; i++)
+        filterx_object_unref(self->path[i]);
+      g_free(self->path);
+      g_assert(self->attr == NULL);
+    }
+
   filterx_expr_unref(self->operand);
   filterx_expr_free_method(s);
 }