feat(lsm): start store entry implementation

lsm/src/_include/lsm/store_internal.h

@@ -0,0 +1,22 @@
+#ifndef LSM_STORE_INTERNAL
+#define LSM_STORE_INTERNAL
+
+#include "lsm/store.h"
+#include "lsm/str_internal.h"
+
+typedef struct lsm_attr {
+  lsm_attr_type type;
+  lsm_str str;
+} lsm_attr;
+
+struct lsm_entry {
+  lsm_str key;
+  struct {
+    uint64_t count;
+    uint64_t bitmap;
+    lsm_attr *items;
+  } attrs;
+  lsm_str data;
+};
+
+#endif

lsm/src/store/lsm_store_entry.c

@@ -0,0 +1,37 @@
+#include <stdlib.h>
+
+#include "lsm.h"
+#include "lsm/store_internal.h"
+
+lsm_error lsm_entry_init(lsm_entry **ptr) {
+  lsm_entry *entry = calloc(1, sizeof(lsm_entry));
+
+  if (entry == NULL) {
+    return lsm_error_failed_alloc;
+  }
+
+  *ptr = entry;
+
+  return lsm_error_ok;
+}
+
+bool lsm_entry_attr_present(lsm_entry *entry, lsm_attr_type type) {
+  return (entry->attrs.bitmap & type) != 0;
+}
+
+lsm_error lsm_entry_attr_get(lsm_str **out, lsm_entry *entry,
+                             lsm_attr_type type) {
+  if (!lsm_entry_attr_present(entry, type)) {
+    return lsm_error_not_found;
+  }
+
+  for (uint64_t i = 0; i < entry->attrs.count; i++) {
+    if (entry->attrs.items[i].type == type) {
+      *out = &entry->attrs.items[i].str;
+
+      return lsm_error_ok;
+    }
+  }
+
+  return lsm_error_not_found;
+}