feat(lsm): possibly implemented trie insert

lsm/include/lsm.h

@@ -9,7 +9,8 @@ typedef enum lsm_error {
   lsm_error_ok = 0,
   lsm_error_failed_alloc = 1,
   lsm_error_not_found = 2,
-  lsm_error_already_present = 3
+  lsm_error_already_present = 3,
+  lsm_error_null_value = 4
 } lsm_error;
 
 /*typedef struct lsm_string { */

lsm/include/lsm/bt.h

@@ -48,4 +48,14 @@ lsm_error lsm_bt_insert(lsm_bt *bt, char key, void *data);
  */
 lsm_error lsm_bt_remove(void **out, lsm_bt *bt, char key);
 
+/**
+ * Replace the data at an existing key with new data, returning the old.
+ *
+ * @param out address to write old data pointer to
+ * @param bt binary tree to replace in
+ * @param key key to replace at
+ * @param data new data to store
+ */
+lsm_error lsm_bt_replace(void **out, lsm_bt *bt, char key, void *data);
+
 #endif

lsm/include/lsm/str.h

@@ -57,4 +57,65 @@ void lsm_str_free(lsm_str *str);
  */
 uint64_t lsm_str_len(lsm_str *str);
 
+/**
+ * Return a pointer to the string's underlying char array. Note that this array
+ * will *not* neccessarily be null-terminatd.
+ *
+ * @param str string to return pointer for
+ */
+const char *lsm_str_ptr(lsm_str *str);
+
+/**
+ * Returns the character at the specified position.
+ *
+ * @index index of character to return
+ */
+char lsm_str_char(lsm_str *str, uint64_t index);
+
+/**
+ * Take a substring and copy it to a provided string object.
+ *
+ * @param out string to store new substring in. The contents of this string will
+ * be replaced.
+ * @param str string to take substring from
+ * @param start inclusive start index for the substring. If this is greater than
+ * or equal to the string's length, out will be a zero-length string.
+ * @param end exclusive end index for the substring
+ */
+lsm_error lsm_str_substr(lsm_str *out, lsm_str *str, uint64_t start,
+                         uint64_t end);
+
+/**
+ * Return the first index where s1 and s2 differ, starting at their respective
+ * offsets. If both strings are equal (or one is a prefix of the other), the
+ * result will be the length of the shortest string. The returned value is
+ * relative to the given offets.
+ *
+ * @param s1 string to compare
+ * @param s1_offset offset inside s1 to start comparing from
+ * @param s2 string to compare s1 to
+ * @param s2_offset offset inside s2 to start comparing from
+ */
+uint64_t lsm_str_cmp(lsm_str *s1, uint64_t s1_offset, lsm_str *s2,
+                     uint64_t s2_offset);
+
+/**
+ * Truncate a string in-place.
+ *
+ * @param s string to truncate
+ * @param new_len new length of the string. If new_len is >= the original
+ * length, this function does nothing.
+ */
+lsm_error lsm_str_truncate(lsm_str *s, uint64_t new_len);
+
+/**
+ * Split s at the specified index, saving the second half the string in s2.
+ *
+ * @param s string to split
+ * @param s2 string to store second part of s
+ * @param index position to split string. If index is the length of s or
+ * greater, s2 will simply be an empty string.
+ */
+lsm_error lsm_str_split(lsm_str *s, lsm_str *s2, uint64_t index);
+
 #endif