mariadb/newbrt/x1764.c

#ident "$Id$"
#ident "Copyright (c) 2007, 2008, 2009 Tokutek Inc.  All rights reserved."
#ident "The technology is licensed by the Massachusetts Institute of Technology, Rutgers State University of New Jersey, and the Research Foundation of State University of New York at Stony Brook under United States of America Serial No. 11/760379 and to the patents and/or patent applications resulting from it."

#include "includes.h"

#define PRINT 0

u_int32_t x1764_memory (const void *buf, int len)
{
    const u_int64_t *lbuf=buf;
    u_int64_t c=0;
    while (len>=8) {
	c = c*17 + *lbuf;
	if (PRINT) printf("%d: c=%016" PRIx64 " sum=%016" PRIx64 "\n", __LINE__, *lbuf, c);
	lbuf++;
	len-=8;
    }
    if (len>0) {
	const u_int8_t *cbuf=(u_int8_t*)lbuf;
	int i;
	u_int64_t input=0;
	for (i=0; i<len; i++) {
	    input |= ((u_int64_t)(cbuf[i]))<<(8*i);
	}
	c = c*17 + input;
    }
    return (c&0xFFFFFFFF) ^ (c>>32);
}

void x1764_init(struct x1764 *l) {
    l->sum=0;
    l->input=0;
    l->n_input_bytes=0;
}

void x1764_add (struct x1764 *l, const void *vbuf, int len) {
    if (PRINT) printf("%d: n_input_bytes=%d len=%d\n", __LINE__, l->n_input_bytes, len);
    int n_input_bytes = l->n_input_bytes;
    const unsigned char *cbuf = vbuf;
    // Special case short inputs
    if (len==1) {
	u_int64_t input = l->input | ((u_int64_t)(*cbuf))<<(8*n_input_bytes);
	n_input_bytes++;
	if (n_input_bytes==8) {
	    l->sum = l->sum*17 + input;
	    l->n_input_bytes = 0;
	    l->input = 0;
	} else {
	    l->input = input;
	    l->n_input_bytes = n_input_bytes;
	}
	return;
    } else if (len==2) {
	u_int64_t input = l->input;
	u_int64_t thisv = ((u_int64_t)(*(u_int16_t*)cbuf));
	if (n_input_bytes==7) {
	    l->sum = l->sum*17 + (input | (thisv<<(8*7)));
	    l->input = thisv>>8;
	    l->n_input_bytes = 1;
	} else if (n_input_bytes==6) {
	    l->sum = l->sum*17 + (input | (thisv<<(8*6)));
	    l->input = 0;
	    l->n_input_bytes = 0;
	} else {
	    l->input = input | (thisv<<(8*n_input_bytes));
	    l->n_input_bytes += 2;
	}
	return;
    }

    u_int64_t sum;
    //assert(len>=0);
    if (n_input_bytes) {
	u_int64_t input = l->input;
	if (len>=8) {
	    sum = l->sum;
	    while (len>=8) {
		u_int64_t thisv = *(u_int64_t*)cbuf;
		input |= thisv<<(8*n_input_bytes);
		sum = sum*17 + input;
		if (PRINT) printf("%d: input=%016" PRIx64 " sum=%016" PRIx64 "\n", __LINE__, input, sum);
		input = thisv>>(8*(8-n_input_bytes));
		if (PRINT) printf("%d: input=%016" PRIx64 "\n", __LINE__, input);
		len-=8;
		cbuf+=8;
		// n_input_bytes remains unchanged
		if (PRINT) printf("%d: n_input_bytes=%d len=%d\n", __LINE__, l->n_input_bytes, len);
	    }
	    l->sum = sum;
	}
	if (len>=4) {
	    u_int64_t thisv = *(u_int32_t*)cbuf;
	    if (n_input_bytes<4) {
		input |= thisv<<(8*n_input_bytes);
		if (PRINT) printf("%d: input=%016" PRIx64 "\n", __LINE__, input);
		n_input_bytes+=4;
	    } else {
		input |= thisv<<(8*n_input_bytes);
		l->sum = l->sum*17 + input;
		if (PRINT) printf("%d: input=%016" PRIx64 " sum=%016" PRIx64 "\n", __LINE__, input, l->sum);
		input = thisv>>(8*(8-n_input_bytes));
		n_input_bytes-=4;
		if (PRINT) printf("%d: input=%016" PRIx64 " n_input_bytes=%d\n", __LINE__, input, n_input_bytes);
	    }
	    len-=4;
	    cbuf+=4;
	    if (PRINT) printf("%d: len=%d\n", __LINE__, len);
	}
	//assert(n_input_bytes<=8);
	while (n_input_bytes<8 && len) {
	    input |= ((u_int64_t)(*cbuf))<<(8*n_input_bytes);
	    n_input_bytes++;
	    cbuf++;
	    len--;
	}
	//assert(len>=0);
	if (n_input_bytes<8) {
	    //assert(len==0);
	    l->input = input;
	    l->n_input_bytes = n_input_bytes;
	    if (PRINT) printf("%d: n_input_bytes=%d\n", __LINE__, l->n_input_bytes);
	    return;
	}
	sum = l->sum*17 + input;
    } else {
	//assert(len>=0);
	sum = l->sum;
    }
    //assert(len>=0);
    while (len>=8) {
	sum = sum*17 + *(u_int64_t*)cbuf;
	cbuf+=8;
	len -=8;
    }
    l->sum = sum;
    n_input_bytes = 0;
    u_int64_t input;
    l->n_input_bytes = len;
    // Surprisingly, the loop is the fastest on bradley's laptop.
    if (1) {
	int i;
	input=0;
	for (i=0; i<len; i++) {
	    input |= ((u_int64_t)(cbuf[i]))<<(8*i);
	}
    } else if (0) {
	switch (len) {
	case 7: input = ((u_int64_t)(*(u_int32_t*)(cbuf))) | (((u_int64_t)(*(u_int16_t*)(cbuf+4)))<<32) | (((u_int64_t)(*(cbuf+4)))<<48); break;
	case 6: input = ((u_int64_t)(*(u_int32_t*)(cbuf))) | (((u_int64_t)(*(u_int16_t*)(cbuf+4)))<<32); break;
	case 5: input = ((u_int64_t)(*(u_int32_t*)(cbuf))) | (((u_int64_t)(*(cbuf+4)))<<32); break;
	case 4: input = ((u_int64_t)(*(u_int32_t*)(cbuf))); break;
	case 3: input = ((u_int64_t)(*(u_int16_t*)(cbuf))) | (((u_int64_t)(*(cbuf+2)))<<16); break;
	case 2: input = ((u_int64_t)(*(u_int16_t*)(cbuf))); break;
	case 1: input = ((u_int64_t)(*cbuf)); break;
	case 0: input = 0;                      break;
	default: abort();
	}
    } else {
	input=0;
	int i=0;
	if (len>=4) { input  = ((u_int64_t)(*(u_int32_t*)(cbuf)));        cbuf+=4; len-=4; i=4;}
	if (len>=2) { input |= ((u_int64_t)(*(u_int16_t*)(cbuf)))<<(i*8); cbuf+=2; len-=2; i+=2; }
	if (len>=1) { input |= ((u_int64_t)(*(u_int8_t *)(cbuf)))<<(i*8); /*cbuf+=1; len-=1; i++;*/ }
    }
    l->input = input;
    if (PRINT) printf("%d: n_input_bytes=%d\n", __LINE__, l->n_input_bytes);
}
u_int32_t x1764_finish (struct x1764 *l) {
    if (PRINT) printf("%d: n_input_bytes=%d\n", __LINE__, l->n_input_bytes);
    int len = l->n_input_bytes;
    if (len>0) {
	l->sum = l->sum*17 + l->input;
    }
    return (l->sum &0xffffffff) ^ (l->sum>>32);
}