feat(lsm): start of library

lsm/include/lsm.h

@@ -0,0 +1,67 @@
+#ifndef LSM
+#define LSM
+
+#include <stdint.h>
+
+#define LSM_MAX_SKIP_SIZE 8
+
+typedef enum lsm_error {
+   lsm_error_ok = 0,
+   lsm_error_failed_alloc = 1,
+   lsm_error_not_found = 2
+} lsm_error;
+
+/**
+ * Represents a string (or really any kind of data) with a known length. Data
+ * with length 8 or less is stored inside the pointer, and does not allocate
+ * additional memory.
+ */
+typedef struct lsm_string {
+  uint64_t len;
+  union {
+    void *ptr;
+    char val[8];
+  } str;
+} lsm_string;
+
+/**
+ * The type of an attribute. Each type is represented as a single bit of a
+ * 32-bit integer, so they can be easily combined into a bitmap.
+ */
+typedef enum lsm_attr_type {
+  lsm_attr_type_entry_type = 1 << 0
+} lsm_attr_type;
+
+/**
+ * A single attribute associated with an entry
+ */
+typedef struct lsm_attr {
+  lsm_attr_type type;
+  lsm_string str;
+} lsm_attr;
+
+/**
+ * Represents a collection of attributes for an entry. A collection can only
+ * contain one of each attribute.
+ */
+typedef struct lsm_attr_list {
+  uint64_t count;
+  lsm_attr *items;
+  uint32_t bitmap;
+} lsm_attr_list;
+
+/**
+ * An entry inside an LSM store
+ */
+typedef struct lsm_entry {
+  lsm_string key;
+  lsm_attr_list attrs;
+  lsm_string data;
+} lsm_entry;
+
+/**
+ * A store of entries, which manages its data both in-memory and on disk.
+ */
+typedef struct lsm_store lsm_store;
+
+#endif