From 7a748cadbb2e2ce8c0e045cb8fbd77ccbd47459f Mon Sep 17 00:00:00 2001
From: Chuyan Zhang <me@zcy.moe>
Date: Tue, 17 Oct 2023 23:07:21 -0700
Subject: initial commit

---
 src/block_device/memory_disk.rs | 34 ++++++++++++++++++++++++++++++++++
 src/block_device/mod.rs         |  7 +++++++
 2 files changed, 41 insertions(+)
 create mode 100644 src/block_device/memory_disk.rs
 create mode 100644 src/block_device/mod.rs

(limited to 'src/block_device')

diff --git a/src/block_device/memory_disk.rs b/src/block_device/memory_disk.rs
new file mode 100644
index 0000000..4cffaf2
--- /dev/null
+++ b/src/block_device/memory_disk.rs
@@ -0,0 +1,34 @@
+use std::cell::RefCell;
+use crate::block_device::{BLOCK_SIZE, BlockDevice};
+
+#[repr(C)]
+pub struct MemoryDisk {
+    /// Emulating a block device with a segment of RAM,
+    /// which is 64MiB == 4KiB per block * 16384 blocks
+    pub arena: RefCell<Vec<u8>>,
+}
+
+impl MemoryDisk {
+    pub fn new() -> Self {
+        Self {
+            arena: RefCell::new(vec![0u8; BLOCK_SIZE * 16384]),
+        }
+    }
+
+}
+
+impl BlockDevice for MemoryDisk {
+    fn read(&self, block_id: usize, buffer: &mut [u8]) {
+        let block_front = block_id * BLOCK_SIZE;
+        let block_back = block_front + BLOCK_SIZE;
+        let arena = self.arena.borrow();
+        buffer.copy_from_slice(&arena[block_front..block_back]);
+    }
+
+    fn write(&self, block_id: usize, buffer: &[u8]) {
+        let block_front = block_id * BLOCK_SIZE;
+        let block_back = block_front + BLOCK_SIZE;
+        let mut arena = self.arena.borrow_mut();
+        arena[block_front..block_back].copy_from_slice(buffer);
+    }
+}
\ No newline at end of file
diff --git a/src/block_device/mod.rs b/src/block_device/mod.rs
new file mode 100644
index 0000000..9d52e53
--- /dev/null
+++ b/src/block_device/mod.rs
@@ -0,0 +1,7 @@
+pub mod memory_disk;
+
+pub const BLOCK_SIZE: usize = 4096;
+pub trait BlockDevice {
+    fn read(&self, block_id: usize, buffer: &mut [u8]);
+    fn write(&self, block_id: usize, buffer: &[u8]);
+}
-- 
cgit v1.2.3-70-g09d2