#include <ctype.h>
#include <stdlib.h>
#include <string.h>
#include "cliphash.h"

#ifdef STANDALONE
#define CLIP_DLLEXPORT
#else
#include "clip.h"
#endif

#define USE_CRC

  /* ============================================================= */
  /*  COPYRIGHT (C) 1986 Gary S. Brown.  You may use this program, or       */
  /*  code or tables extracted from it, as desired without restriction.     */
  /*                                                                        */
  /*  First, the polynomial itself and its table of feedback terms.  The    */
  /*  polynomial is                                                         */
  /*  X^32+X^26+X^23+X^22+X^16+X^12+X^11+X^10+X^8+X^7+X^5+X^4+X^2+X^1+X^0   */
  /*                                                                        */
  /*  Note that we take it "backwards" and put the highest-order term in    */
  /*  the lowest-order bit.  The X^32 term is "implied"; the LSB is the     */
  /*  X^31 term, etc.  The X^0 term (usually shown as "+1") results in      */
  /*  the MSB being 1.                                                      */
  /*                                                                        */
  /*  Note that the usual hardware shift register implementation, which     */
  /*  is what we're using (we're merely optimizing it by doing eight-bit    */
  /*  chunks at a time) shifts bits into the lowest-order term.  In our     */
  /*  implementation, that means shifting towards the right.  Why do we     */
  /*  do it this way?  Because the calculated CRC must be transmitted in    */
  /*  order from highest-order term to lowest-order term.  UARTs transmit   */
  /*  characters in order from LSB to MSB.  By storing the CRC this way,    */
  /*  we hand it to the UART in the order low-byte to high-byte; the UART   */
  /*  sends each low-bit to hight-bit; and the result is transmission bit   */
  /*  by bit from highest- to lowest-order term without requiring any bit   */
  /*  shuffling on our part.  Reception works similarly.                    */
  /*                                                                        */
  /*  The feedback terms table consists of 256, 32-bit entries.  Notes:     */
  /*                                                                        */
  /*      The table can be generated at runtime if desired; code to do so   */
  /*      is shown later.  It might not be obvious, but the feedback        */
  /*      terms simply represent the results of eight shift/xor opera-      */
  /*      tions for all combinations of data and CRC register values.       */
  /*                                                                        */
  /*      The values must be right-shifted by eight bits by the "updcrc"    */
  /*      logic; the shift must be unsigned (bring in zeroes).  On some     */
  /*      hardware you could probably optimize the shift in assembler by    */
  /*      using byte-swap instructions.                                     */
  /*      polynomial $edb88320                                              */
  /*                                                                        */
  /*  --------------------------------------------------------------------  */

static unsigned long crc32_tab[] =
{
	0x00000000L, 0x77073096L, 0xee0e612cL, 0x990951baL, 0x076dc419L,
	0x706af48fL, 0xe963a535L, 0x9e6495a3L, 0x0edb8832L, 0x79dcb8a4L,
	0xe0d5e91eL, 0x97d2d988L, 0x09b64c2bL, 0x7eb17cbdL, 0xe7b82d07L,
	0x90bf1d91L, 0x1db71064L, 0x6ab020f2L, 0xf3b97148L, 0x84be41deL,
	0x1adad47dL, 0x6ddde4ebL, 0xf4d4b551L, 0x83d385c7L, 0x136c9856L,
	0x646ba8c0L, 0xfd62f97aL, 0x8a65c9ecL, 0x14015c4fL, 0x63066cd9L,
	0xfa0f3d63L, 0x8d080df5L, 0x3b6e20c8L, 0x4c69105eL, 0xd56041e4L,
	0xa2677172L, 0x3c03e4d1L, 0x4b04d447L, 0xd20d85fdL, 0xa50ab56bL,
	0x35b5a8faL, 0x42b2986cL, 0xdbbbc9d6L, 0xacbcf940L, 0x32d86ce3L,
	0x45df5c75L, 0xdcd60dcfL, 0xabd13d59L, 0x26d930acL, 0x51de003aL,
	0xc8d75180L, 0xbfd06116L, 0x21b4f4b5L, 0x56b3c423L, 0xcfba9599L,
	0xb8bda50fL, 0x2802b89eL, 0x5f058808L, 0xc60cd9b2L, 0xb10be924L,
	0x2f6f7c87L, 0x58684c11L, 0xc1611dabL, 0xb6662d3dL, 0x76dc4190L,
	0x01db7106L, 0x98d220bcL, 0xefd5102aL, 0x71b18589L, 0x06b6b51fL,
	0x9fbfe4a5L, 0xe8b8d433L, 0x7807c9a2L, 0x0f00f934L, 0x9609a88eL,
	0xe10e9818L, 0x7f6a0dbbL, 0x086d3d2dL, 0x91646c97L, 0xe6635c01L,
	0x6b6b51f4L, 0x1c6c6162L, 0x856530d8L, 0xf262004eL, 0x6c0695edL,
	0x1b01a57bL, 0x8208f4c1L, 0xf50fc457L, 0x65b0d9c6L, 0x12b7e950L,
	0x8bbeb8eaL, 0xfcb9887cL, 0x62dd1ddfL, 0x15da2d49L, 0x8cd37cf3L,
	0xfbd44c65L, 0x4db26158L, 0x3ab551ceL, 0xa3bc0074L, 0xd4bb30e2L,
	0x4adfa541L, 0x3dd895d7L, 0xa4d1c46dL, 0xd3d6f4fbL, 0x4369e96aL,
	0x346ed9fcL, 0xad678846L, 0xda60b8d0L, 0x44042d73L, 0x33031de5L,
	0xaa0a4c5fL, 0xdd0d7cc9L, 0x5005713cL, 0x270241aaL, 0xbe0b1010L,
	0xc90c2086L, 0x5768b525L, 0x206f85b3L, 0xb966d409L, 0xce61e49fL,
	0x5edef90eL, 0x29d9c998L, 0xb0d09822L, 0xc7d7a8b4L, 0x59b33d17L,
	0x2eb40d81L, 0xb7bd5c3bL, 0xc0ba6cadL, 0xedb88320L, 0x9abfb3b6L,
	0x03b6e20cL, 0x74b1d29aL, 0xead54739L, 0x9dd277afL, 0x04db2615L,
	0x73dc1683L, 0xe3630b12L, 0x94643b84L, 0x0d6d6a3eL, 0x7a6a5aa8L,
	0xe40ecf0bL, 0x9309ff9dL, 0x0a00ae27L, 0x7d079eb1L, 0xf00f9344L,
	0x8708a3d2L, 0x1e01f268L, 0x6906c2feL, 0xf762575dL, 0x806567cbL,
	0x196c3671L, 0x6e6b06e7L, 0xfed41b76L, 0x89d32be0L, 0x10da7a5aL,
	0x67dd4accL, 0xf9b9df6fL, 0x8ebeeff9L, 0x17b7be43L, 0x60b08ed5L,
	0xd6d6a3e8L, 0xa1d1937eL, 0x38d8c2c4L, 0x4fdff252L, 0xd1bb67f1L,
	0xa6bc5767L, 0x3fb506ddL, 0x48b2364bL, 0xd80d2bdaL, 0xaf0a1b4cL,
	0x36034af6L, 0x41047a60L, 0xdf60efc3L, 0xa867df55L, 0x316e8eefL,
	0x4669be79L, 0xcb61b38cL, 0xbc66831aL, 0x256fd2a0L, 0x5268e236L,
	0xcc0c7795L, 0xbb0b4703L, 0x220216b9L, 0x5505262fL, 0xc5ba3bbeL,
	0xb2bd0b28L, 0x2bb45a92L, 0x5cb36a04L, 0xc2d7ffa7L, 0xb5d0cf31L,
	0x2cd99e8bL, 0x5bdeae1dL, 0x9b64c2b0L, 0xec63f226L, 0x756aa39cL,
	0x026d930aL, 0x9c0906a9L, 0xeb0e363fL, 0x72076785L, 0x05005713L,
	0x95bf4a82L, 0xe2b87a14L, 0x7bb12baeL, 0x0cb61b38L, 0x92d28e9bL,
	0xe5d5be0dL, 0x7cdcefb7L, 0x0bdbdf21L, 0x86d3d2d4L, 0xf1d4e242L,
	0x68ddb3f8L, 0x1fda836eL, 0x81be16cdL, 0xf6b9265bL, 0x6fb077e1L,
	0x18b74777L, 0x88085ae6L, 0xff0f6a70L, 0x66063bcaL, 0x11010b5cL,
	0x8f659effL, 0xf862ae69L, 0x616bffd3L, 0x166ccf45L, 0xa00ae278L,
	0xd70dd2eeL, 0x4e048354L, 0x3903b3c2L, 0xa7672661L, 0xd06016f7L,
	0x4969474dL, 0x3e6e77dbL, 0xaed16a4aL, 0xd9d65adcL, 0x40df0b66L,
	0x37d83bf0L, 0xa9bcae53L, 0xdebb9ec5L, 0x47b2cf7fL, 0x30b5ffe9L,
	0xbdbdf21cL, 0xcabac28aL, 0x53b39330L, 0x24b4a3a6L, 0xbad03605L,
	0xcdd70693L, 0x54de5729L, 0x23d967bfL, 0xb3667a2eL, 0xc4614ab8L,
	0x5d681b02L, 0x2a6f2b94L, 0xb40bbe37L, 0xc30c8ea1L, 0x5a05df1bL,
	0x2d02ef8dL
};

static int crc16_tab[] =
{
      0x0000, 0xC0C1, 0xC181, 0x0140, 0xC301, 0x03C0, 0x0280, 0xC241,
      0xC601, 0x06C0, 0x0780, 0xC741, 0x0500, 0xC5C1, 0xC481, 0x0440,
      0xCC01, 0x0CC0, 0x0D80, 0xCD41, 0x0F00, 0xCFC1, 0xCE81, 0x0E40,
      0x0A00, 0xCAC1, 0xCB81, 0x0B40, 0xC901, 0x09C0, 0x0880, 0xC841,
      0xD801, 0x18C0, 0x1980, 0xD941, 0x1B00, 0xDBC1, 0xDA81, 0x1A40,
      0x1E00, 0xDEC1, 0xDF81, 0x1F40, 0xDD01, 0x1DC0, 0x1C80, 0xDC41,
      0x1400, 0xD4C1, 0xD581, 0x1540, 0xD701, 0x17C0, 0x1680, 0xD641,
      0xD201, 0x12C0, 0x1380, 0xD341, 0x1100, 0xD1C1, 0xD081, 0x1040,
      0xF001, 0x30C0, 0x3180, 0xF141, 0x3300, 0xF3C1, 0xF281, 0x3240,
      0x3600, 0xF6C1, 0xF781, 0x3740, 0xF501, 0x35C0, 0x3480, 0xF441,
      0x3C00, 0xFCC1, 0xFD81, 0x3D40, 0xFF01, 0x3FC0, 0x3E80, 0xFE41,
      0xFA01, 0x3AC0, 0x3B80, 0xFB41, 0x3900, 0xF9C1, 0xF881, 0x3840,
      0x2800, 0xE8C1, 0xE981, 0x2940, 0xEB01, 0x2BC0, 0x2A80, 0xEA41,
      0xEE01, 0x2EC0, 0x2F80, 0xEF41, 0x2D00, 0xEDC1, 0xEC81, 0x2C40,
      0xE401, 0x24C0, 0x2580, 0xE541, 0x2700, 0xE7C1, 0xE681, 0x2640,
      0x2200, 0xE2C1, 0xE381, 0x2340, 0xE101, 0x21C0, 0x2080, 0xE041,
      0xA001, 0x60C0, 0x6180, 0xA141, 0x6300, 0xA3C1, 0xA281, 0x6240,
      0x6600, 0xA6C1, 0xA781, 0x6740, 0xA501, 0x65C0, 0x6480, 0xA441,
      0x6C00, 0xACC1, 0xAD81, 0x6D40, 0xAF01, 0x6FC0, 0x6E80, 0xAE41,
      0xAA01, 0x6AC0, 0x6B80, 0xAB41, 0x6900, 0xA9C1, 0xA881, 0x6840,
      0x7800, 0xB8C1, 0xB981, 0x7940, 0xBB01, 0x7BC0, 0x7A80, 0xBA41,
      0xBE01, 0x7EC0, 0x7F80, 0xBF41, 0x7D00, 0xBDC1, 0xBC81, 0x7C40,
      0xB401, 0x74C0, 0x7580, 0xB541, 0x7700, 0xB7C1, 0xB681, 0x7640,
      0x7200, 0xB2C1, 0xB381, 0x7340, 0xB101, 0x71C0, 0x7080, 0xB041,
      0x5000, 0x90C1, 0x9181, 0x5140, 0x9301, 0x53C0, 0x5280, 0x9241,
      0x9601, 0x56C0, 0x5780, 0x9741, 0x5500, 0x95C1, 0x9481, 0x5440,
      0x9C01, 0x5CC0, 0x5D80, 0x9D41, 0x5F00, 0x9FC1, 0x9E81, 0x5E40,
      0x5A00, 0x9AC1, 0x9B81, 0x5B40, 0x9901, 0x59C0, 0x5880, 0x9841,
      0x8801, 0x48C0, 0x4980, 0x8941, 0x4B00, 0x8BC1, 0x8A81, 0x4A40,
      0x4E00, 0x8EC1, 0x8F81, 0x4F40, 0x8D01, 0x4DC0, 0x4C80, 0x8C41,
      0x4400, 0x84C1, 0x8581, 0x4540, 0x8701, 0x47C0, 0x4680, 0x8641,
      0x8201, 0x42C0, 0x4380, 0x8341, 0x4100, 0x81C1, 0x8081, 0x4040
};

CLIP_DLLEXPORT long
_clip_hashbytes16(long seed, const char *bytes, int len)
{
	unsigned int i;
	unsigned short crc16val;
	unsigned char *s = (unsigned char *) bytes;

	crc16val = (unsigned short) seed;
	for ( i=0; i<len; i++ )
		crc16val = (crc16val >> 8) ^ crc16_tab[ (crc16val & 0xff) ^ s[i] ];

	return crc16val;
}

CLIP_DLLEXPORT long
_clip_hashbytes32(long seed, const char *bytes, int len)
{
	unsigned int i;
	unsigned long crc32val;
	unsigned char *s = (unsigned char *) bytes;

	crc32val = (unsigned long) seed;
	for (i = 0; i < len; i++)
	{
		crc32val =
			crc32_tab[(crc32val ^ s[i]) & 0xff] ^
			(crc32val >> 8);
	}
	return crc32val;
}

CLIP_DLLEXPORT long
_clip_hashbytes(long seed, const char *bytes, int len)
{
#ifdef USE_CRC
	return _clip_hashbytes32(seed, bytes, len);
#else
	unsigned long h = seed;
	unsigned long g;


	while (len)
	{
		h = (h << 4) + *bytes;
		++bytes;
		--len;
		if ((g = h & 0xf0000000) != 0)
			h = (h ^ (g >> 24)) ^ g;
	}
	h |= 0x40000000;
	return h;
#endif
}


static int
is_hex(int b)
{
	switch(b)
	{
	case '0':
	case '1':
	case '2':
	case '3':
	case '4':
	case '5':
	case '6':
	case '7':
	case '8':
	case '9':
	case 'a':
	case 'A':
	case 'b':
	case 'B':
	case 'c':
	case 'C':
	case 'd':
	case 'D':
	case 'e':
	case 'E':
	case 'f':
	case 'F':
		return 1;
	default:
		return 0;
	}
}

CLIP_DLLEXPORT long
_clip_casehashbytes(long seed, const char *bytes, int len)
{
#ifdef USE_CRC
	unsigned int i;
	unsigned long crc32val;
	unsigned char *s = (unsigned char *) bytes;

	/* 0xXXXXXXXX handled specially */
	if (seed == 0 && len==10 && bytes[0]=='0' && toupper(bytes[1])=='X'
		 && is_hex(bytes[2]) && is_hex(bytes[3]) && is_hex(bytes[4]) && is_hex(bytes[5])
		 && is_hex(bytes[6]) && is_hex(bytes[7]) && is_hex(bytes[8]) && is_hex(bytes[9])
		)
	{
		crc32val = strtoul((const char *)s,0,16);
		return crc32val;
	}

	crc32val = (unsigned long) seed;
	for (i = 0; i < len; i++)
	{
		crc32val =
			crc32_tab[(crc32val ^ ((unsigned char) toupper(s[i]))) & 0xff] ^
			(crc32val >> 8);
	}
	return crc32val;
#else
	unsigned long h = seed;
	unsigned long g;

	while (len)
	{
		h = (h << 4) + toupper(*bytes);
		++bytes;
		--len;
		if ((g = h & 0xf0000000) != 0)
			h = (h ^ (g >> 24)) ^ g;
	}
	h |= 0x40000000;
	return h;
#endif
}

CLIP_DLLEXPORT long
_clip_hashstr(const char *x)
{
	return _clip_hashbytes(0, x, strlen(x));
}

CLIP_DLLEXPORT long
_clip_casehashstr(const char *x)
{
	return _clip_casehashbytes(0, x, strlen(x));
}

/* trim head and tail spaces */
CLIP_DLLEXPORT long
_clip_hashword(const char *x, int l)
{
	const char *e;

	for (e = x + l; x<e && isspace(*x) ; x++)
		;
	for(; e>x && isspace(e[-1]); e--)
		;

	return _clip_hashbytes(0, x, e - x);
}

CLIP_DLLEXPORT long
_clip_casehashword(const char *x, int l)
{
	const char *e;

	for (e = x + l; x<e && isspace(*x) ; x++)
		;
	for(; e>x && isspace(e[-1]); e--)
		;

	return _clip_casehashbytes(0, x, e - x);
}

