Add lifetime to DBPinnableSlice to make sure it cannot outlive DB

src/db.rs

@@ -1665,11 +1665,12 @@ fn to_cpath<P: AsRef<Path>>(path: P) -> Result<CString, Error> {
     }
 }
 
-pub struct DBPinnableSlice {
+pub struct DBPinnableSlice<'a> {
     ptr: *mut ffi::rocksdb_pinnableslice_t,
+    db: PhantomData<&'a DB>
 }
 
-impl Deref for DBPinnableSlice {
+impl<'a> Deref for DBPinnableSlice<'a> {
     type Target = [u8];
 
     fn deref(&self) -> &[u8] {
@@ -1681,7 +1682,7 @@ impl Deref for DBPinnableSlice {
     }
 }
 
-impl Drop for DBPinnableSlice {
+impl<'a> Drop for DBPinnableSlice<'a> {
     fn drop(&mut self) {
         unsafe {
             ffi::rocksdb_pinnableslice_destroy(self.ptr,);
@@ -1689,13 +1690,16 @@ impl Drop for DBPinnableSlice {
     }
 }
 
-impl DBPinnableSlice {
+impl<'a> DBPinnableSlice<'a> {
     /// Used to wrap a PinnableSlice from rocksdb to avoid unnecessary memcpy
     ///
     /// # Unsafe
     /// Requires that the pointer must be generated by rocksdb_get_pinned
-    pub unsafe fn from_c(ptr: *mut ffi::rocksdb_pinnableslice_t) -> DBPinnableSlice {
-        DBPinnableSlice { ptr, }
+    pub unsafe fn from_c(ptr: *mut ffi::rocksdb_pinnableslice_t) -> DBPinnableSlice<'a> {
+        DBPinnableSlice {
+            ptr,
+            db: PhantomData,
+        }
     }
 }