Refactor some crc functions / usage

lib/framework/crc.cpp

@@ -38,7 +38,14 @@
 // crcTable[i] = crcTable[i>>1]<<1 ^ ((crcTable[i>>1]>>31 ^ (i & 0x01))*crcTable[1]);
 static const uint32_t crcTable[256] = {0x00000000, 0x04C11DB7, 0x09823B6E, 0x0D4326D9, 0x130476DC, 0x17C56B6B, 0x1A864DB2, 0x1E475005, 0x2608EDB8, 0x22C9F00F, 0x2F8AD6D6, 0x2B4BCB61, 0x350C9B64, 0x31CD86D3, 0x3C8EA00A, 0x384FBDBD, 0x4C11DB70, 0x48D0C6C7, 0x4593E01E, 0x4152FDA9, 0x5F15ADAC, 0x5BD4B01B, 0x569796C2, 0x52568B75, 0x6A1936C8, 0x6ED82B7F, 0x639B0DA6, 0x675A1011, 0x791D4014, 0x7DDC5DA3, 0x709F7B7A, 0x745E66CD, 0x9823B6E0, 0x9CE2AB57, 0x91A18D8E, 0x95609039, 0x8B27C03C, 0x8FE6DD8B, 0x82A5FB52, 0x8664E6E5, 0xBE2B5B58, 0xBAEA46EF, 0xB7A96036, 0xB3687D81, 0xAD2F2D84, 0xA9EE3033, 0xA4AD16EA, 0xA06C0B5D, 0xD4326D90, 0xD0F37027, 0xDDB056FE, 0xD9714B49, 0xC7361B4C, 0xC3F706FB, 0xCEB42022, 0xCA753D95, 0xF23A8028, 0xF6FB9D9F, 0xFBB8BB46, 0xFF79A6F1, 0xE13EF6F4, 0xE5FFEB43, 0xE8BCCD9A, 0xEC7DD02D, 0x34867077, 0x30476DC0, 0x3D044B19, 0x39C556AE, 0x278206AB, 0x23431B1C, 0x2E003DC5, 0x2AC12072, 0x128E9DCF, 0x164F8078, 0x1B0CA6A1, 0x1FCDBB16, 0x018AEB13, 0x054BF6A4, 0x0808D07D, 0x0CC9CDCA, 0x7897AB07, 0x7C56B6B0, 0x71159069, 0x75D48DDE, 0x6B93DDDB, 0x6F52C06C, 0x6211E6B5, 0x66D0FB02, 0x5E9F46BF, 0x5A5E5B08, 0x571D7DD1, 0x53DC6066, 0x4D9B3063, 0x495A2DD4, 0x44190B0D, 0x40D816BA, 0xACA5C697, 0xA864DB20, 0xA527FDF9, 0xA1E6E04E, 0xBFA1B04B, 0xBB60ADFC, 0xB6238B25, 0xB2E29692, 0x8AAD2B2F, 0x8E6C3698, 0x832F1041, 0x87EE0DF6, 0x99A95DF3, 0x9D684044, 0x902B669D, 0x94EA7B2A, 0xE0B41DE7, 0xE4750050, 0xE9362689, 0xEDF73B3E, 0xF3B06B3B, 0xF771768C, 0xFA325055, 0xFEF34DE2, 0xC6BCF05F, 0xC27DEDE8, 0xCF3ECB31, 0xCBFFD686, 0xD5B88683, 0xD1799B34, 0xDC3ABDED, 0xD8FBA05A, 0x690CE0EE, 0x6DCDFD59, 0x608EDB80, 0x644FC637, 0x7A089632, 0x7EC98B85, 0x738AAD5C, 0x774BB0EB, 0x4F040D56, 0x4BC510E1, 0x46863638, 0x42472B8F, 0x5C007B8A, 0x58C1663D, 0x558240E4, 0x51435D53, 0x251D3B9E, 0x21DC2629, 0x2C9F00F0, 0x285E1D47, 0x36194D42, 0x32D850F5, 0x3F9B762C, 0x3B5A6B9B, 0x0315D626, 0x07D4CB91, 0x0A97ED48, 0x0E56F0FF, 0x1011A0FA, 0x14D0BD4D, 0x19939B94, 0x1D528623, 0xF12F560E, 0xF5EE4BB9, 0xF8AD6D60, 0xFC6C70D7, 0xE22B20D2, 0xE6EA3D65, 0xEBA91BBC, 0xEF68060B, 0xD727BBB6, 0xD3E6A601, 0xDEA580D8, 0xDA649D6F, 0xC423CD6A, 0xC0E2D0DD, 0xCDA1F604, 0xC960EBB3, 0xBD3E8D7E, 0xB9FF90C9, 0xB4BCB610, 0xB07DABA7, 0xAE3AFBA2, 0xAAFBE615, 0xA7B8C0CC, 0xA379DD7B, 0x9B3660C6, 0x9FF77D71, 0x92B45BA8, 0x9675461F, 0x8832161A, 0x8CF30BAD, 0x81B02D74, 0x857130C3, 0x5D8A9099, 0x594B8D2E, 0x5408ABF7, 0x50C9B640, 0x4E8EE645, 0x4A4FFBF2, 0x470CDD2B, 0x43CDC09C, 0x7B827D21, 0x7F436096, 0x7200464F, 0x76C15BF8, 0x68860BFD, 0x6C47164A, 0x61043093, 0x65C52D24, 0x119B4BE9, 0x155A565E, 0x18197087, 0x1CD86D30, 0x029F3D35, 0x065E2082, 0x0B1D065B, 0x0FDC1BEC, 0x3793A651, 0x3352BBE6, 0x3E119D3F, 0x3AD08088, 0x2497D08D, 0x2056CD3A, 0x2D15EBE3, 0x29D4F654, 0xC5A92679, 0xC1683BCE, 0xCC2B1D17, 0xC8EA00A0, 0xD6AD50A5, 0xD26C4D12, 0xDF2F6BCB, 0xDBEE767C, 0xE3A1CBC1, 0xE760D676, 0xEA23F0AF, 0xEEE2ED18, 0xF0A5BD1D, 0xF464A0AA, 0xF9278673, 0xFDE69BC4, 0x89B8FD09, 0x8D79E0BE, 0x803AC667, 0x84FBDBD0, 0x9ABC8BD5, 0x9E7D9662, 0x933EB0BB, 0x97FFAD0C, 0xAFB010B1, 0xAB710D06, 0xA6322BDF, 0xA2F33668, 0xBCB4666D, 0xB8757BDA, 0xB5365D03, 0xB1F740B4};
 
-uint32_t crcSum(uint32_t crc, const void *data_, size_t dataLen)
+namespace wz {
+
+uint32_t crc_init()
+{
+	return 0x00000000;
+}
+
+uint32_t crc_update(uint32_t crc, const void *data_, size_t dataLen)
 {
 	const char *data = (const char *)data_;  // Aliasing rules say that this must be read as a char, not as an an uint8_t.
 
@@ -50,6 +57,8 @@ uint32_t crcSum(uint32_t crc, const void *data_, size_t dataLen)
 	return crc;
 }
 
+} // namespace wz
+
 uint32_t crcSumU16(uint32_t crc, const uint16_t *data, size_t dataLen)
 {
 	while (dataLen-- > 0)

lib/framework/crc.h

@@ -27,7 +27,12 @@
 #include <functional>
 #include <nlohmann/json_fwd.hpp>
 
-uint32_t crcSum(uint32_t crc, const void *data, size_t dataLen);
+namespace wz {
+	uint32_t crc_init();
+	uint32_t crc_update(uint32_t crc, const void *data, size_t dataLen);
+}
+
+// older crc functions - do not combine with the ones above
 uint32_t crcSumU16(uint32_t crc, const uint16_t *data, size_t dataLen);
 uint32_t crcSumI16(uint32_t crc, const int16_t *data, size_t dataLen);
 uint32_t crcSumVector2i(uint32_t crc, const Vector2i *data, size_t dataLen);

lib/netplay/sync_debug.cpp

@@ -57,8 +57,8 @@ struct SyncDebugString : public SyncDebugEntry
 	void set(uint32_t& crc, char const* f, char const* string)
 	{
 		function = f;
-		crc = crcSum(crc, function, strlen(function) + 1);
-		crc = crcSum(crc, string, strlen(string) + 1);
+		crc = wz::crc_update(crc, function, strlen(function) + 1);
+		crc = wz::crc_update(crc, string, strlen(string) + 1);
 	}
 	int snprint(char* buf, size_t bufSize, char const*& string) const
 	{
@@ -77,9 +77,9 @@ struct SyncDebugValueChange : public SyncDebugEntry
 		newValue = nv;
 		id = i;
 		uint32_t valueBytes = htonl(newValue);
-		crc = crcSum(crc, function, strlen(function) + 1);
-		crc = crcSum(crc, variableName, strlen(variableName) + 1);
-		crc = crcSum(crc, &valueBytes, 4);
+		crc = wz::crc_update(crc, function, strlen(function) + 1);
+		crc = wz::crc_update(crc, variableName, strlen(variableName) + 1);
+		crc = wz::crc_update(crc, &valueBytes, 4);
 	}
 	int snprint(char* buf, size_t bufSize) const
 	{
@@ -107,7 +107,7 @@ struct SyncDebugIntList : public SyncDebugEntry
 		{
 			valueBytes[n] = htonl(ints[n]);
 		}
-		crc = crcSum(crc, valueBytes, 4 * numInts);
+		crc = wz::crc_update(crc, valueBytes, 4 * numInts);
 	}
 	int snprint(char* buf, size_t bufSize, int const*& ints) const
 	{
@@ -183,7 +183,7 @@ struct SyncDebugLog
 	{
 		log.clear();
 		time = 0;
-		crc = 0x00000000;
+		crc = wz::crc_init();
 		//printf("Freeing %d strings, %d valueChanges, %d intLists, %d chars, %d ints\n", (int)strings.size(), (int)valueChanges.size(), (int)intLists.size(), (int)chars.size(), (int)ints.size());
 		strings.clear();
 		valueChanges.clear();
@@ -355,7 +355,7 @@ void _syncDebugBacktrace(const char* function)
 #endif
 
 	// Use CRC of something platform-independent, to avoid false positive desynchs.
-	backupCrc = ~crcSum(~backupCrc, function, strlen(function) + 1);
+	backupCrc = ~wz::crc_update(~backupCrc, function, strlen(function) + 1);
 	syncDebugLog[syncDebugNext].setCrc(backupCrc);
 }
 

src/data.cpp

@@ -63,10 +63,9 @@ uint32_t	DataHash[DATA_MAXDATA] = {0};
 *	This is almost the same routine that Pumpkin had, minus the ugly bug :)
 *	And minus the old algorithm and debugging trace, replaced with a simple CRC...
 */
-static UDWORD	hashBuffer(const uint8_t *pData, uint32_t size)
+static void hashBuffer(const uint8_t *pData, uint32_t size, uint32_t &crc)
 {
 	char nl = '\n';
-	uint32_t crc = 0;
 	uint32_t i, j;
 	uint32_t lines = 0;
 	uint32_t bytes = 0;
@@ -77,35 +76,26 @@ static UDWORD	hashBuffer(const uint8_t *pData, uint32_t size)
 
 		if (i != j)  // CRC non-empty lines only.
 		{
-			crc = crcSum(crc, pData + i, j - i);  // CRC the line.
-			crc = crcSum(crc, &nl, 1);            // CRC the line ending.
+			crc = wz::crc_update(crc, pData + i, j - i);  // CRC the line.
+			crc = wz::crc_update(crc, &nl, 1);            // CRC the line ending.
 
 			++lines;
 			bytes += j - i + 1;
 		}
 	}
 	debug(LOG_NET, "The size of the old buffer (%u bytes - %d stripped), New buffer size of %u bytes, %u non-empty lines.", size, size - bytes, bytes, lines);
-
-	return ~crc;
 }
 
 // create the hash for that data block.
 // Data should be converted to Network byte order
 void calcDataHash(const uint8_t *pBuffer, uint32_t size, uint32_t index)
 {
-	const uint32_t oldHash = DataHash[index];
-
 	if (!bMultiPlayer)
 	{
 		return;
 	}
 
-	DataHash[index] += hashBuffer(pBuffer, size);
-
-	if (!DataHash[index] && oldHash)
-	{
-		debug(LOG_NET, "The new hash is 0, the old hash was %u. We added the negated value!", oldHash);
-	}
+	hashBuffer(pBuffer, size, DataHash[index]);
 
 	debug(LOG_NET, "DataHash[%2u] = %08x", index, DataHash[index]);
 
@@ -123,7 +113,7 @@ void resetDataHash()
 	UDWORD i;
 	for (i = 0; i < DATA_MAXDATA; i++)
 	{
-		DataHash[i] = 0;
+		DataHash[i] = wz::crc_init();
 	}
 	debug(LOG_NET, "== Hash is reset ==");
 }