rename and document DC serial number functions

src/DCSerialNumbers.hh

@@ -0,0 +1,23 @@
+#pragma once
+
+#include <stdint.h>
+
+#include <string>
+#include <unordered_map>
+
+// dc_serial_number_is_valid_slow is Sega's implementation;
+// dc_serial_number_is_valid_fast produces identical results but is between 3000
+// and 7500 times faster, depending on the compiler's optimization level.
+bool dc_serial_number_is_valid_slow(
+    const std::string& s, uint8_t domain, uint8_t subdomain = 0xFF);
+bool dc_serial_number_is_valid_fast(
+    const std::string& s, uint8_t domain, uint8_t subdomain = 0xFF);
+bool dc_serial_number_is_valid_fast(
+    uint32_t serial_number, uint8_t domain, uint8_t subdomain = 0xFF);
+bool decoded_dc_serial_number_is_valid_fast(
+    uint32_t serial_number, uint8_t domain, uint8_t subdomain = 0xFF);
+
+std::string generate_dc_serial_number(uint8_t domain, uint8_t subdomain = 0xFF);
+std::unordered_map<uint32_t, std::string> generate_all_dc_serial_numbers(uint8_t domain = 0xFF, uint8_t subdomain = 0xFF);
+
+void dc_serial_number_speed_test(uint64_t seed = 0xFFFFFFFFFFFFFFFF);