Move code to the "src" subdirectory

src/crc.c

@@ -0,0 +1,67 @@
+#include <stdio.h>
+
+unsigned long _crcTable[256];
+int _crcTableInitialized = 0;
+
+#define CRC32_POLYNOMIAL	0xEDB88320L
+
+void CRCTable_Init() {
+	int i;
+	int j;
+	unsigned long crc;
+
+	if (_crcTableInitialized) {
+		return;
+	}
+	_crcTableInitialized = 1;
+
+	for (i = 0; i < 256; i++) {
+		crc = i;
+		for (j = 8; j > 0; j--) {
+			if (crc & 1)
+				crc = (crc >> 1) ^ CRC32_POLYNOMIAL;
+			else
+				crc >>= 1;
+		}
+		_crcTable[i] = crc;
+	}
+}
+
+unsigned long CRC_BufferInternal(unsigned char *buffer, int len,
+		unsigned long crc) {
+	unsigned char *p;
+
+	// Calcular CRC del buffer
+	p = (unsigned char*) buffer;
+	while (len-- != 0) {
+		unsigned long termA = (crc >> 8) & 0x00FFFFFFL;
+		unsigned long termB = _crcTable[((int) crc ^ *p++) & 0xff];
+		crc = termA ^ termB;
+	}
+
+	return (crc);
+}
+
+unsigned long CRC_Buffer(unsigned char *buffer, int len, unsigned long crc) {
+	CRCTable_Init();
+	return (CRC_BufferInternal(buffer, len, crc));
+}
+
+unsigned long CRC_File(FILE *file) {
+	unsigned long crc;
+	unsigned char buffer[512];
+
+	CRCTable_Init();
+
+	crc = 0xFFFFFFFFL;
+	for (;;) {
+		// Llenar el buffer
+		int count = fread(buffer, 1, 512, file);
+		if (count == 0)
+			break;
+
+		// Calcular CRC del buffer
+		crc = CRC_BufferInternal(buffer, count, crc);
+	}
+	return (crc ^= 0xFFFFFFFFL);
+}