Use sourcecode for libjuice

thirdparty/libjuice/src/crc32.c

@@ -0,0 +1,38 @@
+/**
+ * Copyright (c) 2020 Paul-Louis Ageneau
+ *
+ * This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at https://mozilla.org/MPL/2.0/.
+ */
+
+#include "crc32.h"
+
+#define CRC32_REVERSED_POLY 0xEDB88320
+#define CRC32_INIT 0xFFFFFFFF
+#define CRC32_XOR 0xFFFFFFFF
+
+static uint32_t crc32_byte(uint32_t crc) {
+	for (int i = 0; i < 8; ++i)
+		if (crc & 1)
+			crc = (crc >> 1) ^ CRC32_REVERSED_POLY;
+		else
+			crc = (crc >> 1);
+	return crc;
+}
+
+static uint32_t crc32_table(const uint8_t *p, size_t size, uint32_t *table) {
+	uint32_t crc = CRC32_INIT;
+	while (size--)
+		crc = table[(uint8_t)(crc & 0xFF) ^ *p++] ^ (crc >> 8);
+	return crc ^ CRC32_XOR;
+}
+
+JUICE_EXPORT uint32_t juice_crc32(const void *data, size_t size) {
+	static uint32_t table[256] = {0};
+	if (table[0] == 0)
+		for (uint32_t i = 0; i < 256; ++i)
+			table[i] = crc32_byte(i);
+
+	return crc32_table(data, size, table);
+}