libluna+kernel: Make CRC32 a class

kernel/src/fs/GPT.cpp

@@ -66,6 +66,9 @@ namespace GPT
     {
         header.checksum = 0;
 
-        return CRC32::checksum((u8*)&header, 0x5c);
+        CRC32 crc;
+        crc.append((u8*)&header, 0x5c);
+
+        return crc.digest();
     }
 }

libluna/include/luna/CRC32.h

@@ -1,7 +1,13 @@
 #pragma once
 #include <luna/Types.h>
 
-namespace CRC32
+class CRC32
 {
-    u32 checksum(const u8* data, usize size);
+  public:
-}
+    void append(const u8* data, usize size);
+
+    u32 digest();
+
+  private:
+    u32 m_checksum = 0xffffffffu;
+};

libluna/src/CRC32.cpp

@@ -33,18 +33,16 @@ static const u32 crc_table[] = {
     0xb40bbe37, 0xc30c8ea1, 0x5a05df1b, 0x2d02ef8d
 };
 
-namespace CRC32
+void CRC32::append(const u8* data, usize size)
 {
-    u32 checksum(const u8* data, usize size)
+    for (usize i = 0; i < size; i++)
     {
-        u32 crc = 0xffffffffu;
+        const u32 index = (m_checksum & 0xff) ^ data[i];
-
+        m_checksum = (m_checksum >> 8) ^ (crc_table[index]);
-        for (usize i = 0; i < size; i++)
-        {
-            const u32 index = (crc & 0xff) ^ data[i];
-            crc = (crc >> 8) ^ (crc_table[index]);
-        }
-
-        return ~crc;
     }
 }
+
+u32 CRC32::digest()
+{
+    return ~m_checksum;
+}