1 files changed, 20 insertions, 0 deletions
diff --git a/src/utils/mod.rs b/src/utils/mod.rs
new file mode 100644
index 0000000..2ea25e7
--- /dev/null
+++ b/src/utils/mod.rs
@@ -0,0 +1,20 @@
+use crate::disk::inode::INODE_SIZE;
+use crate::{AyaFS, INODE_PER_BLOCK};
+use std::time::{SystemTime, UNIX_EPOCH};
+
+impl AyaFS {
+    pub(crate) fn time_now() -> u32 {
+        SystemTime::now()
+            .duration_since(UNIX_EPOCH)
+            .expect("How can current time be earlier than UNIX_EPOCH?")
+            .as_secs() as u32
+    }
+
+    /// 输入 inode 编号, 返回它对应的 block number 和 block 内 offset
+    pub(crate) fn locate_inode(&self, inode_index: usize) -> (usize, usize) {
+        let block_number =
+            inode_index / INODE_PER_BLOCK + 1 + self.inode_bitmap.length + self.data_bitmap.length;
+        let block_offset = inode_index % INODE_PER_BLOCK * INODE_SIZE;
+        (block_number, block_offset)
+    }
+}