Merge pull request #53 from QuasarApp/production_game

added constexper crc 32 hash fucntion

crc32constexper.h

@@ -0,0 +1,83 @@
+/*
+ * Copyright (C) 2025-2025 QuasarApp.
+ * Distributed under the lgplv3 software license, see the accompanying
+ * Everyone is permitted to copy and distribute verbatim copies
+ * of this license document, but changing it is not allowed.
+*/
+
+#ifndef CRC32CONSTEXPER_H
+#define CRC32CONSTEXPER_H
+
+
+#include <array>
+#include <cstddef>
+#include <cstdint>
+
+namespace QuasarAppUtils {
+
+/**
+ * @brief generateCrc32Table This method generate crc32 table for fast calculate crc32 hash.
+ * @param polynomial This is polynomial for crc32 hash.
+ * @return return table for fast calculate crc32 hash.
+ * @note This method is constexpr and available in compile time.
+ */
+constexpr std::array<uint32_t, 256> generateCrc32Table(uint32_t polynomial = 0xEDB88320) {
+    std::array<uint32_t, 256> table{};
+    for (uint32_t i = 0; i < 256; ++i) {
+        uint32_t crc = i;
+        for (int j = 0; j < 8; ++j) {
+            crc = (crc >> 1) ^ (-(crc & 1) & polynomial);
+        }
+        table[i] = crc;
+    }
+    return table;
+}
+
+/**
+ * @brief crc32Table This is crc32 table for fast calculate crc32 hash.
+ * @note This table is used for fast calculate crc32 hash.
+ */
+constexpr std::array<uint32_t, 256> crc32Table = generateCrc32Table();
+
+/**
+ * @brief calculateCrc32 This method calculate crc32 hash for data.
+ * @param data This is data for calculate crc32 hash.
+ * @param size This is size of data.
+ * @param initialCrc This is initial crc value.
+ * @return return crc32 hash for data.
+ * @note This method is constexpr and available in compile time.
+ */
+constexpr uint32_t calculateCrc32(const char* data, size_t size, uint32_t initialCrc = 0xFFFFFFFF) {
+    uint32_t crc = initialCrc;
+    for (size_t i = 0; i < size; ++i) {
+        crc = crc32Table[(crc ^ data[i]) & 0xFF] ^ (crc >> 8);
+    }
+    return crc ^ 0xFFFFFFFF;
+}
+
+/**
+ * @brief calculateCrc16 This method calculate crc16 hash for data.
+ * @param data This is data for calculate crc16 hash.
+ * @param size This is size of data.
+ * @param initialCrc This is initial crc value.
+ * @return return crc16 hash for data.
+ * @note This method is constexpr and available in compile time.
+ */
+constexpr uint16_t calculateCrc16(const char* data, size_t size, uint32_t initialCrc = 0xFFFFFFFF) {
+    return calculateCrc32(data, size, initialCrc) % 0xFFFF;
+}
+
+/**
+ * @brief calculateCrc8 This method calculate crc8 hash for data.
+ * @param data This is data for calculate crc8 hash.
+ * @param size This is size of data.
+ * @param initialCrc This is initial crc value.
+ * @return return crc8 hash for data.
+ * @note This method is constexpr and available in compile time.
+ */
+constexpr uint16_t calculateCrc8(const char* data, size_t size, uint32_t initialCrc = 0xFFFFFFFF) {
+    return calculateCrc32(data, size, initialCrc) % 0xFF;
+}
+}
+
+#endif // CRC32CONSTEXPER_H