embedded: Enforce strict WAL versioning and buffer check (Phase 3 Refinement)

Author: varshith-Git

embedded/src/main.rs

@@ -99,11 +99,14 @@ fn main() -> ! {
         // Validates `wal.rs` logic.
 
         // Construct WAL Packet:
-        // Opcode (0x00) | ID (0) | Dim (16) | [1.0, 0.0, -1.0, 0.5 ...]
-        // 1 + 4 + 2 + (16 * 4) = 7 + 64 = 71 bytes.
-        let mut wal_data: [u8; 71] = [0; 71];
+        // Version (1) | Opcode (0x00) | ID (0) | Dim (16) | [1.0, 0.0, -1.0, 0.5 ...]
+        // 1 + 1 + 4 + 2 + (16 * 4) = 8 + 64 = 72 bytes.
+        let mut wal_data: [u8; 72] = [0; 72];
         let mut idx = 0;
 
+        // Version (1)
+        wal_data[idx] = 0x01; idx += 1;
+
         // Opcode
         wal_data[idx] = 0x00; idx += 1;
         // ID (0)

embedded/src/wal.rs

@@ -20,6 +20,7 @@ use valori_kernel::types::id::RecordId;
 use valori_kernel::types::vector::FxpVector;
 use valori_kernel::types::scalar::FxpScalar;
 
+const WAL_VERSION: u8 = 1;
 const WAL_OP_INSERT: u8 = 0x00;
 
 fn read_u8(buf: &[u8], offset: &mut usize) -> Result<u8, ()> {
@@ -55,6 +56,13 @@ pub fn apply_wal_log<const M: usize, const D: usize, const N: usize, const E: us
     wal_bytes: &[u8]
 ) -> Result<(), ()> {
     let mut offset = 0;
+
+    // 1. Check WAL Version
+    // First byte reserved for format version.
+    let version = read_u8(wal_bytes, &mut offset)?;
+    if version != WAL_VERSION {
+        return Err(()); // Unsupported version
+    }
 
     // Process until buffer exhausted
     while offset < wal_bytes.len() {