refactor: init

senbei-crypto/src/crc32.rs

@@ -0,0 +1,33 @@
+const fn build_table() -> [u32; 256] {
+    let mut table = [0u32; 256];
+    let mut i = 0;
+    while i < 256 {
+        let mut c = i as u32;
+        let mut k = 0;
+        while k < 8 {
+            c = if c & 1 != 0 {
+                0xEDB8_8320 ^ (c >> 1)
+            } else {
+                c >> 1
+            };
+            k += 1;
+        }
+        table[i] = c;
+        i += 1;
+    }
+    table
+}
+
+const TABLE: [u32; 256] = build_table();
+
+pub fn append(initial: u32, data: &[u8]) -> u32 {
+    let mut crc = !initial;
+    for &b in data {
+        crc = TABLE[((crc ^ b as u32) & 0xFF) as usize] ^ (crc >> 8);
+    }
+    !crc
+}
+
+pub fn compute(data: &[u8]) -> u32 {
+    append(0, data)
+}