commit 752d9ce8b51a672a0355c537ff13a3b958e84d88
Author: hladu357 <ondrej.hladuvka@gmail.com>
Date:   Wed Jun 5 14:40:59 2024 +0200

    basic insert

diff --git a/trie/Makefile b/trie/Makefile
new file mode 100644
index 0000000..fda9e48
--- /dev/null
+++ b/trie/Makefile
@@ -0,0 +1,2 @@
+trie: trie.c trie.h
+	gcc trie.c -Wall -pedantic -std=c89 -o trie
\ No newline at end of file
diff --git a/trie/trie.c b/trie/trie.c
new file mode 100644
index 0000000..f143e45
--- /dev/null
+++ b/trie/trie.c
@@ -0,0 +1,107 @@
+#include "trie.h"
+
+#define INPUT_FILE "../data/routing-data"
+#define READ_MODE "r"
+#define GET_BIT(key, bit) (( key[ bit / (sizeof(unsigned) * 8) ] & (1 << ((sizeof(unsigned) * 8 - 1) - (bit % (sizeof(unsigned) * 8)))) ) != 0 )
+
+
+trie_node_t create_node() {
+    trie_node_t ret = calloc(1, sizeof(struct trie_node)); /* sets null childs and invalid */
+    return ret;
+}
+
+trie_holder_t create_holder() {
+    trie_holder_t ret = malloc(sizeof(struct trie_holder));
+    ret->_size = 0;
+    ret->_root = create_node();
+    return ret;
+}
+
+int trie_insert(trie_holder_t t, const unsigned key[4], int val, int mask) {
+    trie_node_t iter = t->_root;
+    trie_node_t* next = &t->_root;
+    int i = 0;
+    
+    for (;i <= 128 - mask; ++i) {
+        if (!*(next = GET_BIT(key, i) ? &iter->_l : &iter->_r))
+            *next = create_node();
+        
+        iter = *next;
+    }
+    
+    if (iter->_rule_valid == VALID_RULE) {
+        printf("WARNING: conflicting rule %x:%x:%x:%x", key[0], key[1], key[2], key[3]);
+        printf("/%d %d\n", mask, val);
+        return 0;
+    }
+
+    iter->_rule_valid = VALID_RULE;
+    iter->_rule = val;
+
+    /* printf("inserted rule: %x:%x:%x:%x", key[0], key[1], key[2], key[3]); */
+    /* printf("/%d %d\n", mask, val); */
+    return 1;
+}
+
+int trie_search(trie_holder_t t, const unsigned key[4]) {
+    return 0;
+}
+
+
+/*------------------------------------------------------------*/
+
+
+int parse_line(unsigned key[4], int* val, int* mask, FILE* f) { /*! assumes only good input */
+    
+    unsigned short* tmp = (unsigned short*)key;
+    memset(tmp, 0, sizeof(short[8]));
+
+    fscanf(f, "%hx:%hx:%hx:%hx:%hx:%hx:%hx:%hx", &tmp[0], &tmp[1], &tmp[2], &tmp[3], &tmp[4], &tmp[5], &tmp[6], &tmp[7]);
+    if (feof(f)) return 0; /* ends with newline */
+    while (fgetc(f) != '/');
+    
+    fscanf(f, "%d %d", mask, val);
+
+    /* printf("Loaded address: %x:%x:%x:%x", key[0], key[1], key[2], key[3]); */
+    /* printf("/%d %d\n", *mask, *val); */
+
+    return !feof(f);
+}
+
+int load_input(trie_holder_t t) {
+    int val;
+    int mask;
+    unsigned key[4];
+
+    FILE* f;
+    int cnt = 0;
+    
+    if (!(f = fopen(INPUT_FILE, READ_MODE)))
+        perror("cant open input file");
+    
+    while (parse_line(key, &val, &mask, f)) {
+        trie_insert(t, key, val, mask);
+        ++cnt;
+    }
+    return cnt;
+}
+
+int main() {
+    trie_holder_t t = create_holder();
+
+    /*
+    unsigned key[4] = {8927349, 9872346, 898097878, 928398629};
+    int i;
+       00000000100010000011100001110101 00000000100101101010001111011010 00110101100001111110001011010110 00110111010101100011110100100101
+       00000000100010000011100001110101 00000000100101101010001111011010 00110101100001111110001011010110 00110111010101100011110100100101
+    
+    for (i = 0; i < 128; ++i) {
+        printf("%d", GET_BIT(key, i));
+    }
+    printf("\n");
+    return 0;
+    */
+
+    printf("Loaded %d rules\n", load_input(t) );
+    return 0;
+}
\ No newline at end of file
diff --git a/trie/trie.h b/trie/trie.h
new file mode 100644
index 0000000..d0f75bf
--- /dev/null
+++ b/trie/trie.h
@@ -0,0 +1,44 @@
+#ifndef TRIE_HEADER_843762518432898246756
+#define TRIE_HEADER_843762518432898246756
+
+#include "stdio.h"
+#include "stdlib.h"
+#include "string.h"
+
+union ipv6 {
+    unsigned short s[8];
+    unsigned long l[2];
+};
+
+#define VALID_RULE 1
+#define INVALID_RULE 0
+
+struct trie_node {
+    struct trie_node*   _l;
+    struct trie_node*   _r;
+    int           _rule:31;
+    unsigned _rule_valid:1;
+};
+
+struct trie_holder {
+    struct trie_node* _root;
+    size_t _size;
+};
+
+typedef struct trie_node*     trie_node_t;
+typedef struct trie_holder*   trie_holder_t;
+typedef union  ipv6           ipv6_t;
+typedef int                   rule_t;
+
+struct trie_holder* create_holder();
+struct trie_node* create_node();
+
+int destory_holder(struct trie_holder*);
+int destory_node(struct trie_node*);
+
+int trie_insert(struct trie_holder*, const unsigned key[4], int val, int mask);
+rule_t trie_search(struct trie_holder*, const unsigned key[4]);
+
+
+ 
+#endif
\ No newline at end of file