[Feature] Implement conditional learning for classifiers

Issue: #613

diff --git a/src/libstat/stat_process.c b/src/libstat/stat_process.c
index 486d82c084d343c8545cd1ea40f75097855cf04a..dc00184295d3db7d23668373709f2f272f66b09f 100644 (file)
--- a/src/libstat/stat_process.c
+++ b/src/libstat/stat_process.c
@@ -435,7 +435,13 @@ rspamd_stat_classifiers_learn (struct rspamd_stat_ctx *st_ctx,
 {
        struct rspamd_classifier *cl;
        guint i;
-       gboolean learned = FALSE, too_small = FALSE, too_large = FALSE;
+       gboolean learned = FALSE, too_small = FALSE, too_large = FALSE,
+                       conditionally_skipped = FALSE;
+       lua_State *L;
+       struct rspamd_task **ptask;
+       GList *cur;
+       gint cb_ref;
+       gchar *cond_str = NULL;
 
        /* Check whether we have learned that file */
        for (i = 0; i < st_ctx->classifiers->len; i ++) {
@@ -471,6 +477,47 @@ rspamd_stat_classifiers_learn (struct rspamd_stat_ctx *st_ctx,
                        continue;
                }
 
+               /* Check all conditions for this classifier */
+               cur = cl->cfg->learn_conditions;
+               L = task->cfg->lua_state;
+
+               while (cur) {
+                       cb_ref = GPOINTER_TO_INT (cur->data);
+
+                       lua_rawgeti (L, LUA_REGISTRYINDEX, cb_ref);
+                       /* Push task and two booleans: is_spam and is_unlearn */
+                       ptask = lua_newuserdata (L, sizeof (*ptask));
+                       *ptask = task;
+                       rspamd_lua_setclass (L, "rspamd{task}", -1);
+                       lua_pushboolean (L, spam);
+                       lua_pushboolean (L,
+                                       task->flags & RSPAMD_TASK_FLAG_UNLEARN ? true : false);
+
+                       if (lua_pcall (L, 3, LUA_MULTRET, 0) != 0) {
+                               msg_err_task ("call to %s failed: %s",
+                                               "condition callback",
+                                               lua_tostring (L, -1));
+                       }
+                       else {
+                               if (lua_isboolean (L, 1)) {
+                                       if (!lua_toboolean (L, 1)) {
+                                               conditionally_skipped = TRUE;
+                                               /* Also check for error string if needed */
+                                               if (lua_isstring (L, 2)) {
+                                                       cond_str = rspamd_mempool_strdup (task->task_pool,
+                                                                       lua_tostring (L, 2));
+                                               }
+
+                                               lua_settop (L, 0);
+                                               continue; /* Go to the next classifier */
+                                       }
+                               }
+                       }
+
+                       lua_settop (L, 0);
+                       cur = g_list_next (cur);
+               }
+
                if (cl->subrs->learn_spam_func (cl, task->tokens, task, spam,
                                task->flags & RSPAMD_TASK_FLAG_UNLEARN, err)) {
                        learned = TRUE;
@@ -496,6 +543,14 @@ rspamd_stat_classifiers_learn (struct rspamd_stat_ctx *st_ctx,
                                        task->tokens->len,
                                        cl->cfg->min_tokens);
                }
+               else if (conditionally_skipped) {
+                       g_set_error (err, rspamd_stat_quark (), 410,
+                                       "<%s> is skipped for %s classifier: "
+                                       "%s",
+                                       task->message_id,
+                                       cl->cfg->name,
+                                       cond_str ? cond_str : "unknown reason");
+               }
        }
 
        return learned;