From: Geoffrey Allott <geoffrey@allott.email>
Date: Sat, 20 Aug 2022 22:21:20 +0000 (+0100)
Subject: refactoring/simplifying
X-Git-Url: https://git.pointlesshacks.com/?a=commitdiff_plain;h=6887a83858b8f2419f69d92878c4fa1d62d4e0e1;p=tANS.git

refactoring/simplifying
---

diff --git a/src/stree.c b/src/stree.c
index eeed567..66f9544 100644
--- a/src/stree.c
+++ b/src/stree.c
@@ -82,25 +82,14 @@ static bool node_edge_present(const struct node *self, const uint8_t *str, size_
     return false;
 }
 
-static bool node_edge_present_2(const struct node *self, uint8_t edge, size_t len, const uint8_t *str, size_t i)
+static bool node_edge_next_present(const struct node *self, size_t len, const uint8_t *str, size_t i)
 {
-    const struct node *node;
-
-    for (node = self->son; node; node = node->brother)
-        if (str[node->from] == edge)
-            return str[node->from+len] == str[i];
-    return false;
+    return str[self->from+len] == str[i];
 }
 
-static bool node_edge_end(const struct node *self, uint8_t edge, size_t len, const uint8_t *str)
+static bool node_edge_end(const struct node *self, size_t len)
 {
-    const struct node *node;
-
-    for (node = self->son; node; node = node->brother)
-        if (str[node->from] == edge)
-            return node->from + len >= node->to;
-
-    return false;
+    return self && self->from + len >= self->to;
 }
 
 static struct node *node_edge(struct node *self, uint8_t edge, const uint8_t *str)
@@ -147,7 +136,7 @@ int stree_encode(size_t len, const uint8_t *in, uint8_t *out, size_t *aux)
     struct node *root;
     struct node *prev;
     struct node *active_node;
-    uint8_t active_edge = '^';
+    struct node *active_edge = (struct node *) 0;
     size_t active_len = 0;
     size_t rem = 0;
     size_t i;
@@ -168,52 +157,38 @@ int stree_encode(size_t len, const uint8_t *in, uint8_t *out, size_t *aux)
         cont = false;
         while (rem > 0 && !cont) {
             if (active_len == 0) {
-                if (!node_edge_present(active_node, in, i)) {
+                if (node_edge_present(active_node, in, i))
+                    cont = true;
+                else {
                     node_init(nodes + n, i);
                     node_add_son(active_node, nodes + n);
                     ++n;
                     --rem;
-                    if (active_node != root) {
-                        active_node = active_node->link ? active_node->link : root;
-                        if (active_node == root) {
-                            active_len = rem - 1;
-                            active_edge = in[i-active_len];
-                        }
-                    }
-                } else {
-                    active_edge = in[i];
-                    ++active_len;
-                    cont = true;
                 }
             } else if (active_len > 0) {
-                if (!node_edge_present_2(active_node, active_edge, active_len, in, i)) {
+                if (node_edge_next_present(active_edge, active_len, in, i))
+                    cont = true;
+                else {
                     node_init(nodes + n + 1, i);
-                    node_split_son(active_node, active_edge, active_len, nodes + n, nodes + n + 1, in);
-                    if (prev) {
-                        prev->link = nodes + n;
-                    }
+                    node_split_son(active_node, in[active_edge->from], active_len, nodes + n, nodes + n + 1, in);
+                    if (prev) prev->link = nodes + n;
                     prev = nodes + n;
                     n += 2;
                     --rem;
                     if (active_node == root) {
                         --active_len;
-                        active_edge = in[i-active_len];
-                    } else {
-                        active_node = active_node->link ? active_node->link : root;
-                        if (active_node == root) {
-                            active_len = rem - 1;
-                            active_edge = in[i-active_len];
-                        }
                     }
-                } else {
-                    ++active_len;
-                    cont = true;
                 }
             }
-            while (node_edge_end(active_node, active_edge, active_len, in)) {
-                active_node = node_edge(active_node, active_edge, in);
+            if (!cont && active_node != root) {
+                active_node = active_node->link ? active_node->link : (active_len = rem - 1, root);
+            }
+            active_edge = node_edge(active_node, in[i-active_len], in);
+            if (cont) ++active_len;
+            while (node_edge_end(active_edge, active_len)) {
+                active_node = active_edge;
                 active_len -= active_node->to - active_node->from;
-                active_edge = in[i-active_len];
+                active_edge = node_edge(active_node, in[i-active_len], in);
             }
         }
     }