feat(lsm): added trie search

lsm/src/str/lsm_str.c

@@ -44,6 +44,33 @@ lsm_error lsm_str_init(lsm_str **ptr, char *s) {
   return lsm_error_ok;
 }
 
+lsm_error lsm_str_init_copy(lsm_str **ptr, char *s) {
+  lsm_str *str = calloc(1, sizeof(lsm_str));
+
+  if (str == NULL) {
+    return lsm_error_failed_alloc;
+  }
+
+  str->len = strlen(s);
+
+  if (str->len <= 8) {
+    memcpy(str->data.val, s, str->len);
+  } else {
+    char *buf = malloc(str->len * sizeof(char));
+
+    if (buf == NULL) {
+      return lsm_error_failed_alloc;
+    }
+
+    memcpy(buf, s, str->len);
+    str->data.ptr = buf;
+  }
+
+  *ptr = str;
+
+  return lsm_error_ok;
+}
+
 void lsm_str_zero(lsm_str *str) {
   if (str->len > 8) {
     free(str->data.ptr);

lsm/src/trie/lsm_trie.c

@@ -118,6 +118,8 @@ lsm_error lsm_trie_insert(lsm_trie *trie, lsm_str *key, void *data) {
     index += cmp;
   }
 
+  // This catches the edge case where the exact node for the string is already
+  // present in the trie
   if (node->data != NULL) {
     return lsm_error_already_present;
   }
@@ -126,3 +128,51 @@ lsm_error lsm_trie_insert(lsm_trie *trie, lsm_str *key, void *data) {
 
   return lsm_error_ok;
 }
+
+lsm_error lsm_trie_search(void **data, lsm_trie *trie, lsm_str *key) {
+  uint64_t key_len = lsm_str_len(key);
+
+  if (key_len == 0) {
+    if (trie->root->data != NULL) {
+      *data = trie->root->data;
+
+      return lsm_error_ok;
+    } else {
+      return lsm_error_not_found;
+    }
+  }
+
+  uint64_t index = 0;
+  lsm_trie_node *node = trie->root;
+  lsm_trie_node *next_node;
+  lsm_error res;
+
+  while (index < key_len) {
+    char c = lsm_str_char(key, index);
+    res = lsm_bt_search((void **)&next_node, &node->bt, c);
+
+    if (res != lsm_error_ok) {
+      return res;
+    }
+
+    index++;
+
+    uint64_t cmp = lsm_str_cmp(key, index, &next_node->skip, 0);
+
+    // If we end in the middle of an edge, we definitely haven't found the node
+    if (cmp != lsm_str_len(&next_node->skip)) {
+      return lsm_error_not_found;
+    }
+
+    node = next_node;
+    index += cmp;
+  }
+
+  if (node->data == NULL) {
+    return lsm_error_not_found;
+  }
+
+  *data = node->data;
+
+  return lsm_error_ok;
+}