filterx-eval: extract context begin/end code as macros

Although this code has a single user, it is relatively complex, relies on arcane mechanics of FilterXScope and FilterXEvalContext. Hide it and delegate it to show where it belongs. These have become macros, as we need to use the caller's stack frame to allocate the scope. Signed-off-by: Balazs Scheidler <balazs.scheidler@axoflow.com>
axoflow · Jan 24, 2025 · 0138d38 · 0138d38
1 parent eb2b716
commit 0138d38
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Showing 2 changed files with 66 additions and 53 deletions.
diff --git a/lib/filterx/filterx-eval.h b/lib/filterx/filterx-eval.h
@@ -121,5 +121,30 @@ filterx_eval_store_weak_ref(FilterXObject *object)
     }
 }
 
+#define FILTERX_EVAL_BEGIN_CONTEXT(eval_context, previous_context) \
+  do { \
+    FilterXScope *scope = NULL; \
+    gboolean local_scope = FALSE; \
+    \
+    if (previous_context) \
+      scope = filterx_scope_reuse(previous_context->scope); \
+    \
+    if (!scope) \
+      { \
+        gsize alloc_size = filterx_scope_get_alloc_size(); \
+        scope = g_alloca(alloc_size); \
+        filterx_scope_init_instance(scope, alloc_size, path_options->filterx_context ? path_options->filterx_context->scope : NULL); \
+        local_scope = TRUE; \
+      } \
+    filterx_eval_init_context(&eval_context, path_options->filterx_context, scope, msg); \
+    do
+
+
+#define FILTERX_EVAL_END_CONTEXT(eval_context) \
+    while(0); \
+    filterx_eval_deinit_context(&eval_context); \
+    if (local_scope) \
+      filterx_scope_clear(scope); \
+  } while(0)
 
 #endif
diff --git a/lib/filterx/filterx-pipe.c b/lib/filterx/filterx-pipe.c
@@ -64,63 +64,51 @@ log_filterx_pipe_queue(LogPipe *s, LogMessage *msg, const LogPathOptions *path_o
 {
   LogFilterXPipe *self = (LogFilterXPipe *) s;
   FilterXEvalContext eval_context;
-  LogPathOptions local_path_options;
-  FilterXEvalResult eval_res;
-  gboolean local_scope = FALSE;
-
-  path_options = log_path_options_chain(&local_path_options, path_options);
-
-  FilterXScope *scope = NULL;
-  if (path_options->filterx_context)
-    scope = filterx_scope_reuse(path_options->filterx_context->scope);
-
-  if (!scope)
-    {
-      gsize alloc_size = filterx_scope_get_alloc_size();
-      scope = g_alloca(alloc_size);
-      filterx_scope_init_instance(scope, alloc_size, path_options->filterx_context ? path_options->filterx_context->scope : NULL);
-      local_scope = TRUE;
-    }
-  filterx_eval_init_context(&eval_context, path_options->filterx_context, scope, msg);
-
-  msg_trace(">>>>>> filterx rule evaluation begin",
-            evt_tag_str("rule", self->name),
-            log_pipe_location_tag(s),
-            evt_tag_msg_reference(msg));
+  FilterXEvalContext *previous_context = path_options->filterx_context;
 
   NVTable *payload = nv_table_ref(msg->payload);
-  eval_res = filterx_eval_exec(&eval_context, self->block);
-
-  msg_trace("<<<<<< filterx rule evaluation result",
-            filterx_format_eval_result(eval_res),
-            evt_tag_str("rule", self->name),
-            log_pipe_location_tag(s),
-            evt_tag_int("dirty", filterx_scope_is_dirty(eval_context.scope)),
-            evt_tag_msg_reference(msg));
-
-  local_path_options.filterx_context = &eval_context;
-  switch (eval_res)
+  FILTERX_EVAL_BEGIN_CONTEXT(eval_context, previous_context)
     {
-    case FXE_SUCCESS:
-      log_pipe_forward_msg(s, msg, path_options);
-      break;
-
-    case FXE_FAILURE:
-      if (path_options->matched)
-        (*path_options->matched) = FALSE;
-    /* FALLTHROUGH */
-    case FXE_DROP:
-      log_msg_drop(msg, path_options, AT_PROCESSED);
-      break;
-
-    default:
-      g_assert_not_reached();
-      break;
+      FilterXEvalResult eval_res;
+      LogPathOptions local_path_options;
+
+      path_options = log_path_options_chain(&local_path_options, path_options);
+
+      msg_trace(">>>>>> filterx rule evaluation begin",
+                evt_tag_str("rule", self->name),
+                log_pipe_location_tag(s),
+                evt_tag_msg_reference(msg));
+
+      eval_res = filterx_eval_exec(&eval_context, self->block);
+
+      msg_trace("<<<<<< filterx rule evaluation result",
+                filterx_format_eval_result(eval_res),
+                evt_tag_str("rule", self->name),
+                log_pipe_location_tag(s),
+                evt_tag_int("dirty", filterx_scope_is_dirty(eval_context.scope)),
+                evt_tag_msg_reference(msg));
+
+      local_path_options.filterx_context = &eval_context;
+      switch (eval_res)
+        {
+        case FXE_SUCCESS:
+          log_pipe_forward_msg(s, msg, path_options);
+          break;
+
+        case FXE_FAILURE:
+          if (path_options->matched)
+            (*path_options->matched) = FALSE;
+        /* FALLTHROUGH */
+        case FXE_DROP:
+          log_msg_drop(msg, path_options, AT_PROCESSED);
+          break;
+
+        default:
+          g_assert_not_reached();
+          break;
+        }
     }
-
-  filterx_eval_deinit_context(&eval_context);
-  if (local_scope)
-    filterx_scope_clear(scope);
+  FILTERX_EVAL_END_CONTEXT(eval_context);
   nv_table_unref(payload);
 }