From fea72a49aa4cfdf749d8293a031761896f2e4c8f Mon Sep 17 00:00:00 2001
From: Vsevolod Stakhov <vsevolod@highsecure.ru>
Date: Thu, 19 Mar 2015 10:04:56 +0000
Subject: [PATCH] Write optimizator for plus operator.

---
 src/libutil/expression.c | 152 ++++++++++++++++++++++++++++++++++++++-
 1 file changed, 150 insertions(+), 2 deletions(-)

diff --git a/src/libutil/expression.c b/src/libutil/expression.c
index e103b5b60..113b87eca 100644
--- a/src/libutil/expression.c
+++ b/src/libutil/expression.c
@@ -549,8 +549,11 @@ err:
 gint
 rspamd_process_expression (struct rspamd_expression *expr, gpointer data)
 {
-	struct rspamd_expression_elt *elt, *st_elt[2], *ev;
-	guint i;
+	struct rspamd_expression_elt *elt, *st_elt[2], *ev, *lim = NULL,
+			*cmp_op = NULL, *check;
+	guint i, j, cmp_pos = 0;
+	gint cur_value = 0;
+	gboolean done = FALSE;
 
 	g_assert (expr != NULL);
 	/* Ensure that stack is empty at this point */
@@ -563,6 +566,10 @@ rspamd_process_expression (struct rspamd_expression *expr, gpointer data)
 		if (elt->type == ELT_ATOM || elt->type == ELT_LIMIT) {
 			/* Push this value to the stack without processing */
 			rspamd_expr_stack_push (expr, elt);
+			if (elt->type == ELT_LIMIT) {
+				/* Save for optimizator */
+				lim = elt;
+			}
 		}
 		else {
 			/*
@@ -621,6 +628,147 @@ rspamd_process_expression (struct rspamd_expression *expr, gpointer data)
 					rspamd_expr_stack_push (expr, ev);
 				}
 				break;
+			case OP_PLUS: {
+				/* First we search for a comparision operator */
+				if (lim == NULL || cmp_op == NULL) {
+					for (j = i + 1; j < expr->expressions->len; j ++) {
+						check = &g_array_index (expr->expressions,
+								struct rspamd_expression_elt, j);
+						if (check->type == ELT_LIMIT && lim == NULL) {
+							lim = check;
+						}
+						else if (check->type == ELT_OP && check->p.op >= OP_LT &&
+							cmp_op == NULL) {
+							cmp_op = check;
+							cmp_pos = j;
+						}
+
+						if (cmp_op && lim) {
+							break;
+						}
+					}
+				}
+				g_assert (cmp_op != NULL && lim != NULL);
+
+				g_assert (expr->expression_stack->len > 1);
+				st_elt[0] = rspamd_expr_stack_pop (expr);
+				st_elt[1] = rspamd_expr_stack_pop (expr);
+				ev = CHOSE_OPERAND (st_elt[0], st_elt[1]);
+				PROCESS_ELT (expr, ev);
+				cur_value = ev->value;
+				ev = CHOOSE_REMAIN (st_elt[0], st_elt[1], ev);
+				PROCESS_ELT (expr, ev);
+				cur_value += ev->value;
+				ev->value = cur_value;
+				/* Now we can check the value against limit */
+				switch (cmp_op->p.op) {
+				case OP_LT:
+					if (cur_value >= lim->p.lim.val) {
+						ev->value = 0;
+						rspamd_expr_stack_push (expr, ev);
+						done = TRUE;
+					}
+					break;
+				case OP_LE:
+					if (cur_value > lim->p.lim.val) {
+						ev->value = 0;
+						rspamd_expr_stack_push (expr, ev);
+						done = TRUE;
+					}
+					break;
+				case OP_GT:
+					if (cur_value > lim->p.lim.val) {
+						ev->value = 1;
+						rspamd_expr_stack_push (expr, ev);
+						done = TRUE;
+					}
+					break;
+				case OP_GE:
+					if (cur_value >= lim->p.lim.val) {
+						ev->value = 1;
+						rspamd_expr_stack_push (expr, ev);
+						done = TRUE;
+					}
+					break;
+				default:
+					rspamd_expr_stack_push (expr, ev);
+					break;
+				}
+				/* If we done, then we go forward and skip remaining items */
+				if (done) {
+					i = cmp_pos + 1;
+					done = FALSE;
+					lim = NULL;
+					cur_value = 0;
+					cmp_op = NULL;
+				}
+				break;
+			}
+			case OP_LT:
+			case OP_LE:
+			case OP_GT:
+			case OP_GE: {
+				g_assert (expr->expression_stack->len > 1);
+				st_elt[0] = rspamd_expr_stack_pop (expr);
+				st_elt[1] = rspamd_expr_stack_pop (expr);
+
+				if (st_elt[0]->type == ELT_LIMIT) {
+					lim = st_elt[0];
+					ev = st_elt[1];
+				}
+				else {
+					lim = st_elt[1];
+					ev = st_elt[0];
+				}
+
+				g_assert (lim->type == ELT_LIMIT && ev->type == ELT_ATOM);
+				cur_value = ev->value;
+
+				switch (elt->p.op) {
+				case OP_LT:
+					if (cur_value >= lim->p.lim.val) {
+						ev->value = 0;
+					}
+					else {
+						ev->value = 1;
+					}
+					break;
+				case OP_LE:
+					if (cur_value > lim->p.lim.val) {
+						ev->value = 0;
+					}
+					else {
+						ev->value = 1;
+					}
+					break;
+				case OP_GT:
+					if (cur_value > lim->p.lim.val) {
+						ev->value = 1;
+					}
+					else {
+						ev->value = 0;
+					}
+					break;
+				case OP_GE:
+					if (cur_value >= lim->p.lim.val) {
+						ev->value = 1;
+					}
+					else {
+						ev->value = 0;
+					}
+					break;
+				default:
+					g_assert (0);
+					break;
+				}
+
+				done = FALSE;
+				lim = NULL;
+				cur_value = 0;
+				cmp_op = NULL;
+				rspamd_expr_stack_push (expr, ev);
+				break;
+			}
 			default:
 				g_assert (0);
 				break;
-- 
2.39.5