chore(lsm): some refactoring

lsm/include/lsm.h

@@ -10,6 +10,15 @@
       return res;                                                              \
   }
 
+#define LSM_RES2(x, e)                                                         \
+  {                                                                            \
+    lsm_error res = x;                                                         \
+    if (res != lsm_error_ok) {                                                 \
+      e;                                                                       \
+      return res;                                                              \
+    }                                                                          \
+  }
+
 typedef enum lsm_error {
   lsm_error_ok = 0,
   lsm_error_failed_alloc = 1,

lsm/include/lsm/bt.h

@@ -37,7 +37,7 @@ uint64_t lsm_bt_size(const lsm_bt *bt);
  * @param bt binary tree to search
  * @param key key to search
  */
-lsm_error lsm_bt_search(void **out, lsm_bt *bt, char key);
+lsm_error lsm_bt_search(void **out, const lsm_bt *bt, char key);
 
 /**
  * Insert a new data value into the tree with the given key.

lsm/include/lsm/store.h

@@ -143,7 +143,7 @@ void lsm_store_free(lsm_store *store);
  * @param key key to search
  */
 lsm_error lsm_store_open_read(lsm_entry_handle **out, lsm_store *store,
-                              lsm_str *key);
+                              const lsm_str *key);
 
 /**
  * Open a write handle to the given entry. This handle should only be used for
@@ -155,7 +155,7 @@ lsm_error lsm_store_open_read(lsm_entry_handle **out, lsm_store *store,
  * @param key key to search
  */
 lsm_error lsm_store_open_write(lsm_entry_handle **out, lsm_store *store,
-                               lsm_str *key);
+                              const lsm_str *key);
 
 /**
  * Close an open entry handle.
@@ -193,7 +193,7 @@ void lsm_entry_remove(lsm_entry_handle *handle);
  * @param entry entry to append data to
  * @param data data to append
  */
-lsm_error lsm_entry_data_append(lsm_entry_handle *handle, lsm_str *data);
+lsm_error lsm_entry_data_append(lsm_entry_handle *handle, const lsm_str *data);
 
 /**
  * Same as `lsm_entry_data_append`, except that it takes a direct char array.

lsm/include/lsm/str.h

@@ -107,14 +107,14 @@ uint64_t lsm_str_len(const lsm_str *str);
  *
  * @param str string to return pointer for
  */
-const char *lsm_str_ptr(lsm_str *str);
+const char *lsm_str_ptr(const 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);
+char lsm_str_char(const lsm_str *str, uint64_t index);
 
 /**
  * Take a substring and copy it to a provided string object.
@@ -127,7 +127,7 @@ char lsm_str_char(lsm_str *str, uint64_t index);
  * 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,
+lsm_error lsm_str_substr(lsm_str *out, const lsm_str *str, uint64_t start,
                          uint64_t end);
 
 /**
@@ -141,7 +141,7 @@ lsm_error lsm_str_substr(lsm_str *out, lsm_str *str, uint64_t start,
  * @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 lsm_str_cmp(const lsm_str *s1, uint64_t s1_offset, const lsm_str *s2,
                      uint64_t s2_offset);
 
 /**
@@ -151,7 +151,7 @@ uint64_t lsm_str_cmp(lsm_str *s1, uint64_t s1_offset, lsm_str *s2,
  * @param s2 second string to compare
  * @return true if their values are equal, false otherwise
  */
-bool lsm_str_eq(lsm_str *s1, lsm_str *s2);
+bool lsm_str_eq(const lsm_str *s1, const lsm_str *s2);
 
 /**
  * Truncate an already initialized string in-place.

lsm/include/lsm/trie.h

@@ -30,16 +30,16 @@ void lsm_trie_free(lsm_trie *trie);
  * @param key key to insert data with
  * @param data data to insert
  */
-lsm_error lsm_trie_insert(lsm_trie *trie, lsm_str *key, void *data);
+lsm_error lsm_trie_insert(lsm_trie *trie, const lsm_str *key, void *data);
 
 /**
  * Search for an element in the trie.
  *
- * @param out where to store data opinter, if present
+ * @param out where to store data pointer, if present
  * @param trie trie to search in
  * @param key key to search with
  */
-lsm_error lsm_trie_search(void **data, lsm_trie *trie, lsm_str *key);
+lsm_error lsm_trie_search(void **out, const lsm_trie *trie, const lsm_str *key);
 
 /**
  * Remove an element from the trie.
@@ -48,7 +48,7 @@ lsm_error lsm_trie_search(void **data, lsm_trie *trie, lsm_str *key);
  * @param trie trie to remove from
  * @param key key to remove
  */
-lsm_error lsm_trie_remove(void **data, lsm_trie *trie, lsm_str *key);
+lsm_error lsm_trie_remove(void **out, lsm_trie *trie, const lsm_str *key);
 
 /**
  * Return the size of a trie

lsm/src/bt/lsm_bt.c

@@ -71,19 +71,16 @@ lsm_error lsm_bt_insert(lsm_bt *bt, char key, void *data) {
     return lsm_error_already_present;
   }
 
-  lsm_bt_node *node;
-
-  if (lsm_bt_node_init(&node, key, data) != lsm_error_ok) {
+  if (lsm_bt_node_init(dest, key, data) != lsm_error_ok) {
     return lsm_error_failed_alloc;
   }
 
-  *dest = node;
   bt->size++;
 
   return lsm_error_ok;
 }
 
-lsm_error lsm_bt_search(void **out, lsm_bt *bt, char key) {
+lsm_error lsm_bt_search(void **out, const lsm_bt *bt, char key) {
   lsm_bt_node *node = bt->root;
 
   while ((node != NULL) && (node->key != key)) {

lsm/src/store/lsm_store.c

@@ -14,13 +14,7 @@ lsm_error lsm_store_init(lsm_store **ptr) {
     return lsm_error_failed_alloc;
   }
 
-  lsm_error res = lsm_trie_init(&store->trie);
-
-  if (res != lsm_error_ok) {
-    free(store);
-
-    return res;
-  }
+  LSM_RES2(lsm_trie_init(&store->trie), free(store));
 
   pthread_mutex_init(&store->db.lock, NULL);
   pthread_mutex_init(&store->idx.lock, NULL);
@@ -35,7 +29,7 @@ uint64_t lsm_store_size(const lsm_store *store) {
 }
 
 lsm_error lsm_store_open_read(lsm_entry_handle **out, lsm_store *store,
-                              lsm_str *key) {
+                              const lsm_str *key) {
   lsm_entry_wrapper *wrapper;
 
   LSM_RES(lsm_trie_search((void **)&wrapper, store->trie, key));
@@ -54,13 +48,7 @@ lsm_error lsm_store_open_read(lsm_entry_handle **out, lsm_store *store,
   }
 
   lsm_entry_handle *handle;
-  lsm_error res = lsm_entry_handle_init(&handle);
-
-  if (res != lsm_error_ok) {
-    pthread_rwlock_unlock(&wrapper->lock);
-
-    return res;
-  }
+  LSM_RES2(lsm_entry_handle_init(&handle), pthread_rwlock_unlock(&wrapper->lock));
 
   handle->wrapper = wrapper;
   handle->store = store;
@@ -70,9 +58,8 @@ lsm_error lsm_store_open_read(lsm_entry_handle **out, lsm_store *store,
 }
 
 lsm_error lsm_store_open_write(lsm_entry_handle **out, lsm_store *store,
-                               lsm_str *key) {
+                               const lsm_str *key) {
   lsm_entry_wrapper *wrapper;
-
   LSM_RES(lsm_trie_search((void **)&wrapper, store->trie, key));
 
   // Try to get a write lock on the entry's lock
@@ -90,13 +77,7 @@ lsm_error lsm_store_open_write(lsm_entry_handle **out, lsm_store *store,
   }
 
   lsm_entry_handle *handle;
-  lsm_error res = lsm_entry_handle_init(&handle);
-
-  if (res != lsm_error_ok) {
-    pthread_rwlock_unlock(&wrapper->lock);
-
-    return res;
-  }
+  LSM_RES2(lsm_entry_handle_init(&handle), pthread_rwlock_unlock(&wrapper->lock));
 
   handle->wrapper = wrapper;
   handle->store = store;
@@ -115,16 +96,11 @@ lsm_error lsm_store_insert(lsm_entry_handle **out, lsm_store *store,
   if (lsm_trie_search((void **)&wrapper, store->trie, key) ==
       lsm_error_not_found) {
     LSM_RES(lsm_entry_wrapper_init(&wrapper));
+
     pthread_rwlock_wrlock(&wrapper->lock);
 
-    lsm_error res = lsm_trie_insert(store->trie, key, wrapper);
-
-    // Check if entry isn't already present in advance
-    if (res != lsm_error_ok) {
-      lsm_entry_wrapper_free(wrapper);
-
-      return res;
-    }
+    LSM_RES2(lsm_trie_insert(store->trie, key, wrapper),
+             lsm_entry_wrapper_free(wrapper));
   } else {
     pthread_rwlock_wrlock(&wrapper->lock);
 
@@ -136,13 +112,14 @@ lsm_error lsm_store_insert(lsm_entry_handle **out, lsm_store *store,
   }
 
   lsm_entry *entry;
-  LSM_RES(lsm_entry_init(&entry));
+  LSM_RES2(lsm_entry_init(&entry), pthread_rwlock_unlock(&wrapper->lock));
 
   entry->key = key;
   wrapper->entry = entry;
 
   lsm_entry_handle *handle;
-  LSM_RES(lsm_entry_handle_init(&handle));
+  LSM_RES2(lsm_entry_handle_init(&handle),
+           pthread_rwlock_unlock(&wrapper->lock));
 
   // No need to set the handle's file, as the entry doesn't have any data yet
   handle->wrapper = wrapper;
@@ -160,7 +137,7 @@ void lsm_entry_remove(lsm_entry_handle *handle) {
   handle->states |= lsm_entry_handle_state_removed;
 }
 
-lsm_error lsm_entry_data_append(lsm_entry_handle *handle, lsm_str *data) {
+lsm_error lsm_entry_data_append(lsm_entry_handle *handle, const lsm_str *data) {
   if (lsm_str_len(data) == 0) {
     return lsm_error_ok;
   }

lsm/src/str/lsm_str.c

@@ -110,7 +110,7 @@ void lsm_str_free(lsm_str *str) {
 
 uint64_t lsm_str_len(const lsm_str *str) { return str->len; }
 
-const char *lsm_str_ptr(lsm_str *str) {
+const char *lsm_str_ptr(const lsm_str *str) {
   if (str->len <= 8) {
     return str->data.val;
   } else {
@@ -118,7 +118,7 @@ const char *lsm_str_ptr(lsm_str *str) {
   }
 }
 
-char lsm_str_char(lsm_str *str, uint64_t index) {
+char lsm_str_char(const lsm_str *str, uint64_t index) {
   if (str->len <= 8) {
     return str->data.val[index];
   } else {
@@ -126,7 +126,7 @@ char lsm_str_char(lsm_str *str, uint64_t index) {
   }
 }
 
-lsm_error lsm_str_substr(lsm_str *out, lsm_str *str, uint64_t start,
+lsm_error lsm_str_substr(lsm_str *out, const lsm_str *str, uint64_t start,
                          uint64_t end) {
   // A substring that starts past the string's length will have length 0
   uint64_t len = start < str->len ? end - start : 0;
@@ -153,7 +153,7 @@ lsm_error lsm_str_substr(lsm_str *out, lsm_str *str, uint64_t start,
   return lsm_error_ok;
 }
 
-uint64_t lsm_str_cmp(lsm_str *s1, uint64_t s1_offset, lsm_str *s2,
+uint64_t lsm_str_cmp(const lsm_str *s1, uint64_t s1_offset, const lsm_str *s2,
                      uint64_t s2_offset) {
   uint64_t index = 0;
   uint64_t max_len = MIN(s1->len - s1_offset, s2->len - s2_offset);
@@ -207,7 +207,7 @@ lsm_error lsm_str_split(lsm_str *s, lsm_str *s2, uint64_t index) {
   return lsm_str_truncate(s, index);
 }
 
-bool lsm_str_eq(lsm_str *s1, lsm_str *s2) {
+bool lsm_str_eq(const lsm_str *s1, const lsm_str *s2) {
   if (s1->len != s2->len) {
     return false;
   }

lsm/src/trie/lsm_trie.c

@@ -45,7 +45,7 @@ lsm_error lsm_trie_init(lsm_trie **ptr) {
 
 uint64_t lsm_trie_size(const lsm_trie *trie) { return trie->size; }
 
-lsm_error lsm_trie_insert(lsm_trie *trie, lsm_str *key, void *data) {
+lsm_error lsm_trie_insert(lsm_trie *trie, const lsm_str *key, void *data) {
   // NULL is not allowed as a data value, as it's used to indicate a lack of
   // data
   if (data == NULL) {
@@ -78,18 +78,22 @@ lsm_error lsm_trie_insert(lsm_trie *trie, lsm_str *key, void *data) {
     // here
     if (res == lsm_error_not_found) {
       lsm_trie_node *new_node;
-      res = lsm_trie_node_init(&new_node);
+      LSM_RES(lsm_trie_node_init(&new_node));
+
+      new_node->data = data;
+
+      lsm_str_substr(&new_node->skip, key, index + 1, key_len);
+      res = lsm_bt_insert(&node->bt, c, new_node);
 
       if (res != lsm_error_ok) {
+        lsm_trie_node_free(new_node);
+
         return res;
       }
 
-      new_node->data = data;
       trie->size++;
 
-      lsm_str_substr(&new_node->skip, key, index + 1, key_len);
-
-      return lsm_bt_insert(&node->bt, c, new_node);
+      return lsm_error_ok;
     }
 
     index++;
@@ -101,11 +105,7 @@ lsm_error lsm_trie_insert(lsm_trie *trie, lsm_str *key, void *data) {
 
     if (cmp < lsm_str_len(&next_node->skip)) {
       lsm_trie_node *split_node;
-      res = lsm_trie_node_init(&split_node);
-
-      if (res != lsm_error_ok) {
-        return res;
-      }
+      LSM_RES(lsm_trie_node_init(&split_node));
 
       // split_node replaces the original node as the new child node
       // bottom_node here is always the same value as next_node
@@ -118,7 +118,7 @@ lsm_error lsm_trie_insert(lsm_trie *trie, lsm_str *key, void *data) {
 
       // split_node's skip has not been initialized yet, so we can simply
       // overwrite it with bottom_node's skip
-      split_node->skip = next_node->skip;
+      split_node->skip = bottom_node->skip;
 
       // The new node splits the edge into two parts, so the new split node will
       // have the first part of the skip (minus the one character) as its
@@ -148,7 +148,8 @@ lsm_error lsm_trie_insert(lsm_trie *trie, lsm_str *key, void *data) {
   return lsm_error_ok;
 }
 
-lsm_error lsm_trie_search(void **out, lsm_trie *trie, lsm_str *key) {
+lsm_error lsm_trie_search(void **out, const lsm_trie *trie,
+                          const lsm_str *key) {
   uint64_t key_len = lsm_str_len(key);
 
   if (key_len == 0) {
@@ -199,13 +200,13 @@ lsm_error lsm_trie_search(void **out, lsm_trie *trie, lsm_str *key) {
   return lsm_error_ok;
 }
 
-lsm_error lsm_trie_remove(void **data, lsm_trie *trie, lsm_str *key) {
+lsm_error lsm_trie_remove(void **out, lsm_trie *trie, const lsm_str *key) {
   uint64_t key_len = lsm_str_len(key);
 
   if (key_len == 0) {
     if (trie->root->data != NULL) {
-      if (data != NULL) {
-        *data = trie->root->data;
+      if (out != NULL) {
+        *out = trie->root->data;
       }
 
       trie->root->data = NULL;
@@ -250,8 +251,8 @@ lsm_error lsm_trie_remove(void **data, lsm_trie *trie, lsm_str *key) {
     return lsm_error_not_found;
   }
 
-  if (data != NULL) {
-    *data = child->data;
+  if (out != NULL) {
+    *out = child->data;
   }
 
   child->data = NULL;