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1132 lines
41 KiB
C
1132 lines
41 KiB
C
/* Bit operations.
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*
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* Copyright (c) 2009-2012, Salvatore Sanfilippo <antirez at gmail dot com>
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* All rights reserved.
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*
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* Redistribution and use in source and binary forms, with or without
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* modification, are permitted provided that the following conditions are met:
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*
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* * Redistributions of source code must retain the above copyright notice,
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* this list of conditions and the following disclaimer.
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* * Redistributions in binary form must reproduce the above copyright
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* notice, this list of conditions and the following disclaimer in the
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* documentation and/or other materials provided with the distribution.
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* * Neither the name of Redis nor the names of its contributors may be used
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* to endorse or promote products derived from this software without
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* specific prior written permission.
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*
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* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
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* AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
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* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
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* ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
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* LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
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* CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
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* SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
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* INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
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* CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
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* ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
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* POSSIBILITY OF SUCH DAMAGE.
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*/
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#include "server.h"
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/* -----------------------------------------------------------------------------
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* Helpers and low level bit functions.
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* -------------------------------------------------------------------------- */
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/* Count number of bits set in the binary array pointed by 's' and long
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* 'count' bytes. The implementation of this function is required to
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* work with a input string length up to 512 MB. */
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size_t redisPopcount(void *s, long count) {
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size_t bits = 0;
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unsigned char *p = s;
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uint32_t *p4;
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static const unsigned char bitsinbyte[256] = {0,1,1,2,1,2,2,3,1,2,2,3,2,3,3,4,1,2,2,3,2,3,3,4,2,3,3,4,3,4,4,5,1,2,2,3,2,3,3,4,2,3,3,4,3,4,4,5,2,3,3,4,3,4,4,5,3,4,4,5,4,5,5,6,1,2,2,3,2,3,3,4,2,3,3,4,3,4,4,5,2,3,3,4,3,4,4,5,3,4,4,5,4,5,5,6,2,3,3,4,3,4,4,5,3,4,4,5,4,5,5,6,3,4,4,5,4,5,5,6,4,5,5,6,5,6,6,7,1,2,2,3,2,3,3,4,2,3,3,4,3,4,4,5,2,3,3,4,3,4,4,5,3,4,4,5,4,5,5,6,2,3,3,4,3,4,4,5,3,4,4,5,4,5,5,6,3,4,4,5,4,5,5,6,4,5,5,6,5,6,6,7,2,3,3,4,3,4,4,5,3,4,4,5,4,5,5,6,3,4,4,5,4,5,5,6,4,5,5,6,5,6,6,7,3,4,4,5,4,5,5,6,4,5,5,6,5,6,6,7,4,5,5,6,5,6,6,7,5,6,6,7,6,7,7,8};
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/* Count initial bytes not aligned to 32 bit. */
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while((unsigned long)p & 3 && count) {
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bits += bitsinbyte[*p++];
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count--;
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}
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/* Count bits 28 bytes at a time */
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p4 = (uint32_t*)p;
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while(count>=28) {
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uint32_t aux1, aux2, aux3, aux4, aux5, aux6, aux7;
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aux1 = *p4++;
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aux2 = *p4++;
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aux3 = *p4++;
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aux4 = *p4++;
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aux5 = *p4++;
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aux6 = *p4++;
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aux7 = *p4++;
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count -= 28;
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aux1 = aux1 - ((aux1 >> 1) & 0x55555555);
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aux1 = (aux1 & 0x33333333) + ((aux1 >> 2) & 0x33333333);
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aux2 = aux2 - ((aux2 >> 1) & 0x55555555);
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aux2 = (aux2 & 0x33333333) + ((aux2 >> 2) & 0x33333333);
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aux3 = aux3 - ((aux3 >> 1) & 0x55555555);
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aux3 = (aux3 & 0x33333333) + ((aux3 >> 2) & 0x33333333);
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aux4 = aux4 - ((aux4 >> 1) & 0x55555555);
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aux4 = (aux4 & 0x33333333) + ((aux4 >> 2) & 0x33333333);
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aux5 = aux5 - ((aux5 >> 1) & 0x55555555);
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aux5 = (aux5 & 0x33333333) + ((aux5 >> 2) & 0x33333333);
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aux6 = aux6 - ((aux6 >> 1) & 0x55555555);
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aux6 = (aux6 & 0x33333333) + ((aux6 >> 2) & 0x33333333);
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aux7 = aux7 - ((aux7 >> 1) & 0x55555555);
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aux7 = (aux7 & 0x33333333) + ((aux7 >> 2) & 0x33333333);
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bits += ((((aux1 + (aux1 >> 4)) & 0x0F0F0F0F) +
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((aux2 + (aux2 >> 4)) & 0x0F0F0F0F) +
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((aux3 + (aux3 >> 4)) & 0x0F0F0F0F) +
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((aux4 + (aux4 >> 4)) & 0x0F0F0F0F) +
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((aux5 + (aux5 >> 4)) & 0x0F0F0F0F) +
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((aux6 + (aux6 >> 4)) & 0x0F0F0F0F) +
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((aux7 + (aux7 >> 4)) & 0x0F0F0F0F))* 0x01010101) >> 24;
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}
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/* Count the remaining bytes. */
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p = (unsigned char*)p4;
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while(count--) bits += bitsinbyte[*p++];
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return bits;
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}
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/* Return the position of the first bit set to one (if 'bit' is 1) or
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* zero (if 'bit' is 0) in the bitmap starting at 's' and long 'count' bytes.
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*
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* The function is guaranteed to return a value >= 0 if 'bit' is 0 since if
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* no zero bit is found, it returns count*8 assuming the string is zero
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* padded on the right. However if 'bit' is 1 it is possible that there is
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* not a single set bit in the bitmap. In this special case -1 is returned. */
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long redisBitpos(void *s, unsigned long count, int bit) {
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unsigned long *l;
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unsigned char *c;
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unsigned long skipval, word = 0, one;
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long pos = 0; /* Position of bit, to return to the caller. */
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unsigned long j;
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int found;
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/* Process whole words first, seeking for first word that is not
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* all ones or all zeros respectively if we are lookig for zeros
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* or ones. This is much faster with large strings having contiguous
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* blocks of 1 or 0 bits compared to the vanilla bit per bit processing.
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*
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* Note that if we start from an address that is not aligned
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* to sizeof(unsigned long) we consume it byte by byte until it is
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* aligned. */
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/* Skip initial bits not aligned to sizeof(unsigned long) byte by byte. */
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skipval = bit ? 0 : UCHAR_MAX;
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c = (unsigned char*) s;
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found = 0;
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while((unsigned long)c & (sizeof(*l)-1) && count) {
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if (*c != skipval) {
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found = 1;
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break;
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}
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c++;
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count--;
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pos += 8;
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}
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/* Skip bits with full word step. */
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l = (unsigned long*) c;
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if (!found) {
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skipval = bit ? 0 : ULONG_MAX;
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while (count >= sizeof(*l)) {
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if (*l != skipval) break;
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l++;
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count -= sizeof(*l);
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pos += sizeof(*l)*8;
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}
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}
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/* Load bytes into "word" considering the first byte as the most significant
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* (we basically consider it as written in big endian, since we consider the
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* string as a set of bits from left to right, with the first bit at position
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* zero.
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*
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* Note that the loading is designed to work even when the bytes left
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* (count) are less than a full word. We pad it with zero on the right. */
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c = (unsigned char*)l;
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for (j = 0; j < sizeof(*l); j++) {
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word <<= 8;
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if (count) {
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word |= *c;
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c++;
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count--;
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}
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}
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/* Special case:
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* If bits in the string are all zero and we are looking for one,
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* return -1 to signal that there is not a single "1" in the whole
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* string. This can't happen when we are looking for "0" as we assume
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* that the right of the string is zero padded. */
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if (bit == 1 && word == 0) return -1;
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/* Last word left, scan bit by bit. The first thing we need is to
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* have a single "1" set in the most significant position in an
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* unsigned long. We don't know the size of the long so we use a
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* simple trick. */
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one = ULONG_MAX; /* All bits set to 1.*/
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one >>= 1; /* All bits set to 1 but the MSB. */
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one = ~one; /* All bits set to 0 but the MSB. */
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while(one) {
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if (((one & word) != 0) == bit) return pos;
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pos++;
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one >>= 1;
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}
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/* If we reached this point, there is a bug in the algorithm, since
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* the case of no match is handled as a special case before. */
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serverPanic("End of redisBitpos() reached.");
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return 0; /* Just to avoid warnings. */
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}
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/* The following set.*Bitfield and get.*Bitfield functions implement setting
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* and getting arbitrary size (up to 64 bits) signed and unsigned integers
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* at arbitrary positions into a bitmap.
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*
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* The representation considers the bitmap as having the bit number 0 to be
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* the most significant bit of the first byte, and so forth, so for example
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* setting a 5 bits unsigned integer to value 23 at offset 7 into a bitmap
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* previously set to all zeroes, will produce the following representation:
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*
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* +--------+--------+
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* |00000001|01110000|
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* +--------+--------+
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*
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* When offsets and integer sizes are aligned to bytes boundaries, this is the
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* same as big endian, however when such alignment does not exist, its important
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* to also understand how the bits inside a byte are ordered.
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*
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* Note that this format follows the same convention as SETBIT and related
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* commands.
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*/
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void setUnsignedBitfield(unsigned char *p, uint64_t offset, uint64_t bits, uint64_t value) {
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uint64_t byte, bit, byteval, bitval, j;
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for (j = 0; j < bits; j++) {
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bitval = (value & ((uint64_t)1<<(bits-1-j))) != 0;
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byte = offset >> 3;
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bit = 7 - (offset & 0x7);
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byteval = p[byte];
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byteval &= ~(1 << bit);
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byteval |= bitval << bit;
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p[byte] = byteval & 0xff;
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offset++;
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}
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}
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void setSignedBitfield(unsigned char *p, uint64_t offset, uint64_t bits, int64_t value) {
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uint64_t uv = value; /* Casting will add UINT64_MAX + 1 if v is negative. */
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setUnsignedBitfield(p,offset,bits,uv);
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}
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uint64_t getUnsignedBitfield(unsigned char *p, uint64_t offset, uint64_t bits) {
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uint64_t byte, bit, byteval, bitval, j, value = 0;
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for (j = 0; j < bits; j++) {
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byte = offset >> 3;
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bit = 7 - (offset & 0x7);
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byteval = p[byte];
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bitval = (byteval >> bit) & 1;
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value = (value<<1) | bitval;
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offset++;
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}
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return value;
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}
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int64_t getSignedBitfield(unsigned char *p, uint64_t offset, uint64_t bits) {
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int64_t value;
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union {uint64_t u; int64_t i;} conv;
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/* Converting from unsigned to signed is undefined when the value does
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* not fit, however here we assume two's complement and the original value
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* was obtained from signed -> unsigned conversion, so we'll find the
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* most significant bit set if the original value was negative.
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*
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* Note that two's complement is mandatory for exact-width types
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* according to the C99 standard. */
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conv.u = getUnsignedBitfield(p,offset,bits);
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value = conv.i;
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/* If the top significant bit is 1, propagate it to all the
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* higher bits for two's complement representation of signed
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* integers. */
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if (value & ((uint64_t)1 << (bits-1)))
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value |= ((uint64_t)-1) << bits;
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return value;
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}
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/* The following two functions detect overflow of a value in the context
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* of storing it as an unsigned or signed integer with the specified
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* number of bits. The functions both take the value and a possible increment.
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* If no overflow could happen and the value+increment fit inside the limits,
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* then zero is returned, otherwise in case of overflow, 1 is returned,
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* otherwise in case of underflow, -1 is returned.
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*
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* When non-zero is returned (oferflow or underflow), if not NULL, *limit is
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* set to the value the operation should result when an overflow happens,
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* depending on the specified overflow semantics:
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*
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* For BFOVERFLOW_SAT if 1 is returned, *limit it is set maximum value that
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* you can store in that integer. when -1 is returned, *limit is set to the
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* minimum value that an integer of that size can represent.
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*
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* For BFOVERFLOW_WRAP *limit is set by performing the operation in order to
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* "wrap" around towards zero for unsigned integers, or towards the most
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* negative number that is possible to represent for signed integers. */
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#define BFOVERFLOW_WRAP 0
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#define BFOVERFLOW_SAT 1
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#define BFOVERFLOW_FAIL 2 /* Used by the BITFIELD command implementation. */
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int checkUnsignedBitfieldOverflow(uint64_t value, int64_t incr, uint64_t bits, int owtype, uint64_t *limit) {
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uint64_t max = (bits == 64) ? UINT64_MAX : (((uint64_t)1<<bits)-1);
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int64_t maxincr = max-value;
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int64_t minincr = -value;
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if (value > max || (incr > 0 && incr > maxincr)) {
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if (limit) {
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if (owtype == BFOVERFLOW_WRAP) {
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goto handle_wrap;
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} else if (owtype == BFOVERFLOW_SAT) {
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*limit = max;
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}
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}
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return 1;
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} else if (incr < 0 && incr < minincr) {
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if (limit) {
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if (owtype == BFOVERFLOW_WRAP) {
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goto handle_wrap;
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} else if (owtype == BFOVERFLOW_SAT) {
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*limit = 0;
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}
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}
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return -1;
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}
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return 0;
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handle_wrap:
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{
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uint64_t mask = ((uint64_t)-1) << bits;
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uint64_t res = value+incr;
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res &= ~mask;
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*limit = res;
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}
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return 1;
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}
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int checkSignedBitfieldOverflow(int64_t value, int64_t incr, uint64_t bits, int owtype, int64_t *limit) {
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int64_t max = (bits == 64) ? INT64_MAX : (((int64_t)1<<(bits-1))-1);
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int64_t min = (-max)-1;
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/* Note that maxincr and minincr could overflow, but we use the values
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* only after checking 'value' range, so when we use it no overflow
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* happens. */
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int64_t maxincr = max-value;
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int64_t minincr = min-value;
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if (value > max || (bits != 64 && incr > maxincr) || (value >= 0 && incr > 0 && incr > maxincr))
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{
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if (limit) {
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if (owtype == BFOVERFLOW_WRAP) {
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goto handle_wrap;
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} else if (owtype == BFOVERFLOW_SAT) {
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*limit = max;
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}
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}
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return 1;
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} else if (value < min || (bits != 64 && incr < minincr) || (value < 0 && incr < 0 && incr < minincr)) {
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if (limit) {
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if (owtype == BFOVERFLOW_WRAP) {
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goto handle_wrap;
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} else if (owtype == BFOVERFLOW_SAT) {
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*limit = min;
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}
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}
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return -1;
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}
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return 0;
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handle_wrap:
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{
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uint64_t mask = ((uint64_t)-1) << bits;
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uint64_t msb = (uint64_t)1 << (bits-1);
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uint64_t a = value, b = incr, c;
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c = a+b; /* Perform addition as unsigned so that's defined. */
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/* If the sign bit is set, propagate to all the higher order
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* bits, to cap the negative value. If it's clear, mask to
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* the positive integer limit. */
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if (c & msb) {
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c |= mask;
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} else {
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c &= ~mask;
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}
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*limit = c;
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}
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return 1;
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}
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|
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/* Debugging function. Just show bits in the specified bitmap. Not used
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* but here for not having to rewrite it when debugging is needed. */
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void printBits(unsigned char *p, unsigned long count) {
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unsigned long j, i, byte;
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for (j = 0; j < count; j++) {
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byte = p[j];
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for (i = 0x80; i > 0; i /= 2)
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printf("%c", (byte & i) ? '1' : '0');
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printf("|");
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}
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printf("\n");
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}
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/* -----------------------------------------------------------------------------
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* Bits related string commands: GETBIT, SETBIT, BITCOUNT, BITOP.
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* -------------------------------------------------------------------------- */
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#define BITOP_AND 0
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#define BITOP_OR 1
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#define BITOP_XOR 2
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#define BITOP_NOT 3
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|
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#define BITFIELDOP_GET 0
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#define BITFIELDOP_SET 1
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#define BITFIELDOP_INCRBY 2
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|
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/* This helper function used by GETBIT / SETBIT parses the bit offset argument
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* making sure an error is returned if it is negative or if it overflows
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* Redis 512 MB limit for the string value.
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*
|
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* If the 'hash' argument is true, and 'bits is positive, then the command
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* will also parse bit offsets prefixed by "#". In such a case the offset
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* is multiplied by 'bits'. This is useful for the BITFIELD command. */
|
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int getBitOffsetFromArgument(client *c, robj *o, size_t *offset, int hash, int bits) {
|
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long long loffset;
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char *err = "bit offset is not an integer or out of range";
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char *p = o->ptr;
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size_t plen = sdslen(p);
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int usehash = 0;
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|
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/* Handle #<offset> form. */
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if (p[0] == '#' && hash && bits > 0) usehash = 1;
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|
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if (string2ll(p+usehash,plen-usehash,&loffset) == 0) {
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addReplyError(c,err);
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return C_ERR;
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}
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|
|
/* Adjust the offset by 'bits' for #<offset> form. */
|
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if (usehash) loffset *= bits;
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|
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/* Limit offset to 512MB in bytes */
|
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if ((loffset < 0) || ((unsigned long long)loffset >> 3) >= (512*1024*1024))
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{
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addReplyError(c,err);
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return C_ERR;
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}
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|
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*offset = (size_t)loffset;
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return C_OK;
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}
|
|
|
|
/* This helper function for BITFIELD parses a bitfield type in the form
|
|
* <sign><bits> where sign is 'u' or 'i' for unsigned and signed, and
|
|
* the bits is a value between 1 and 64. However 64 bits unsigned integers
|
|
* are reported as an error because of current limitations of Redis protocol
|
|
* to return unsigned integer values greater than INT64_MAX.
|
|
*
|
|
* On error C_ERR is returned and an error is sent to the client. */
|
|
int getBitfieldTypeFromArgument(client *c, robj *o, int *sign, int *bits) {
|
|
char *p = o->ptr;
|
|
char *err = "Invalid bitfield type. Use something like i16 u8. Note that u64 is not supported but i64 is.";
|
|
long long llbits;
|
|
|
|
if (p[0] == 'i') {
|
|
*sign = 1;
|
|
} else if (p[0] == 'u') {
|
|
*sign = 0;
|
|
} else {
|
|
addReplyError(c,err);
|
|
return C_ERR;
|
|
}
|
|
|
|
if ((string2ll(p+1,strlen(p+1),&llbits)) == 0 ||
|
|
llbits < 1 ||
|
|
(*sign == 1 && llbits > 64) ||
|
|
(*sign == 0 && llbits > 63))
|
|
{
|
|
addReplyError(c,err);
|
|
return C_ERR;
|
|
}
|
|
*bits = llbits;
|
|
return C_OK;
|
|
}
|
|
|
|
/* This is an helper function for commands implementations that need to write
|
|
* bits to a string object. The command creates or pad with zeroes the string
|
|
* so that the 'maxbit' bit can be addressed. The object is finally
|
|
* returned. Otherwise if the key holds a wrong type NULL is returned and
|
|
* an error is sent to the client. */
|
|
robj *lookupStringForBitCommand(client *c, size_t maxbit) {
|
|
size_t byte = maxbit >> 3;
|
|
robj *o = lookupKeyWrite(c->db,c->argv[1]);
|
|
|
|
if (o == NULL) {
|
|
o = createObject(OBJ_STRING,sdsnewlen(NULL, byte+1));
|
|
dbAdd(c->db,c->argv[1],o);
|
|
} else {
|
|
if (checkType(c,o,OBJ_STRING)) return NULL;
|
|
o = dbUnshareStringValue(c->db,c->argv[1],o);
|
|
o->ptr = sdsgrowzero(o->ptr,byte+1);
|
|
}
|
|
return o;
|
|
}
|
|
|
|
/* Return a pointer to the string object content, and stores its length
|
|
* in 'len'. The user is required to pass (likely stack allocated) buffer
|
|
* 'llbuf' of at least LONG_STR_SIZE bytes. Such a buffer is used in the case
|
|
* the object is integer encoded in order to provide the representation
|
|
* without usign heap allocation.
|
|
*
|
|
* The function returns the pointer to the object array of bytes representing
|
|
* the string it contains, that may be a pointer to 'llbuf' or to the
|
|
* internal object representation. As a side effect 'len' is filled with
|
|
* the length of such buffer.
|
|
*
|
|
* If the source object is NULL the function is guaranteed to return NULL
|
|
* and set 'len' to 0. */
|
|
unsigned char *getObjectReadOnlyString(robj *o, long *len, char *llbuf) {
|
|
serverAssert(o->type == OBJ_STRING);
|
|
unsigned char *p = NULL;
|
|
|
|
/* Set the 'p' pointer to the string, that can be just a stack allocated
|
|
* array if our string was integer encoded. */
|
|
if (o && o->encoding == OBJ_ENCODING_INT) {
|
|
p = (unsigned char*) llbuf;
|
|
if (len) *len = ll2string(llbuf,LONG_STR_SIZE,(long)o->ptr);
|
|
} else if (o) {
|
|
p = (unsigned char*) o->ptr;
|
|
if (len) *len = sdslen(o->ptr);
|
|
} else {
|
|
if (len) *len = 0;
|
|
}
|
|
return p;
|
|
}
|
|
|
|
/* SETBIT key offset bitvalue */
|
|
void setbitCommand(client *c) {
|
|
robj *o;
|
|
char *err = "bit is not an integer or out of range";
|
|
size_t bitoffset;
|
|
ssize_t byte, bit;
|
|
int byteval, bitval;
|
|
long on;
|
|
|
|
if (getBitOffsetFromArgument(c,c->argv[2],&bitoffset,0,0) != C_OK)
|
|
return;
|
|
|
|
if (getLongFromObjectOrReply(c,c->argv[3],&on,err) != C_OK)
|
|
return;
|
|
|
|
/* Bits can only be set or cleared... */
|
|
if (on & ~1) {
|
|
addReplyError(c,err);
|
|
return;
|
|
}
|
|
|
|
if ((o = lookupStringForBitCommand(c,bitoffset)) == NULL) return;
|
|
|
|
/* Get current values */
|
|
byte = bitoffset >> 3;
|
|
byteval = ((uint8_t*)o->ptr)[byte];
|
|
bit = 7 - (bitoffset & 0x7);
|
|
bitval = byteval & (1 << bit);
|
|
|
|
/* Update byte with new bit value and return original value */
|
|
byteval &= ~(1 << bit);
|
|
byteval |= ((on & 0x1) << bit);
|
|
((uint8_t*)o->ptr)[byte] = byteval;
|
|
signalModifiedKey(c->db,c->argv[1]);
|
|
notifyKeyspaceEvent(NOTIFY_STRING,"setbit",c->argv[1],c->db->id);
|
|
server.dirty++;
|
|
addReply(c, bitval ? shared.cone : shared.czero);
|
|
}
|
|
|
|
/* GETBIT key offset */
|
|
void getbitCommand(client *c) {
|
|
robj *o;
|
|
char llbuf[32];
|
|
size_t bitoffset;
|
|
size_t byte, bit;
|
|
size_t bitval = 0;
|
|
|
|
if (getBitOffsetFromArgument(c,c->argv[2],&bitoffset,0,0) != C_OK)
|
|
return;
|
|
|
|
if ((o = lookupKeyReadOrReply(c,c->argv[1],shared.czero)) == NULL ||
|
|
checkType(c,o,OBJ_STRING)) return;
|
|
|
|
byte = bitoffset >> 3;
|
|
bit = 7 - (bitoffset & 0x7);
|
|
if (sdsEncodedObject(o)) {
|
|
if (byte < sdslen(o->ptr))
|
|
bitval = ((uint8_t*)o->ptr)[byte] & (1 << bit);
|
|
} else {
|
|
if (byte < (size_t)ll2string(llbuf,sizeof(llbuf),(long)o->ptr))
|
|
bitval = llbuf[byte] & (1 << bit);
|
|
}
|
|
|
|
addReply(c, bitval ? shared.cone : shared.czero);
|
|
}
|
|
|
|
/* BITOP op_name target_key src_key1 src_key2 src_key3 ... src_keyN */
|
|
void bitopCommand(client *c) {
|
|
char *opname = c->argv[1]->ptr;
|
|
robj *o, *targetkey = c->argv[2];
|
|
unsigned long op, j, numkeys;
|
|
robj **objects; /* Array of source objects. */
|
|
unsigned char **src; /* Array of source strings pointers. */
|
|
unsigned long *len, maxlen = 0; /* Array of length of src strings,
|
|
and max len. */
|
|
unsigned long minlen = 0; /* Min len among the input keys. */
|
|
unsigned char *res = NULL; /* Resulting string. */
|
|
|
|
/* Parse the operation name. */
|
|
if ((opname[0] == 'a' || opname[0] == 'A') && !strcasecmp(opname,"and"))
|
|
op = BITOP_AND;
|
|
else if((opname[0] == 'o' || opname[0] == 'O') && !strcasecmp(opname,"or"))
|
|
op = BITOP_OR;
|
|
else if((opname[0] == 'x' || opname[0] == 'X') && !strcasecmp(opname,"xor"))
|
|
op = BITOP_XOR;
|
|
else if((opname[0] == 'n' || opname[0] == 'N') && !strcasecmp(opname,"not"))
|
|
op = BITOP_NOT;
|
|
else {
|
|
addReply(c,shared.syntaxerr);
|
|
return;
|
|
}
|
|
|
|
/* Sanity check: NOT accepts only a single key argument. */
|
|
if (op == BITOP_NOT && c->argc != 4) {
|
|
addReplyError(c,"BITOP NOT must be called with a single source key.");
|
|
return;
|
|
}
|
|
|
|
/* Lookup keys, and store pointers to the string objects into an array. */
|
|
numkeys = c->argc - 3;
|
|
src = zmalloc(sizeof(unsigned char*) * numkeys);
|
|
len = zmalloc(sizeof(long) * numkeys);
|
|
objects = zmalloc(sizeof(robj*) * numkeys);
|
|
for (j = 0; j < numkeys; j++) {
|
|
o = lookupKeyRead(c->db,c->argv[j+3]);
|
|
/* Handle non-existing keys as empty strings. */
|
|
if (o == NULL) {
|
|
objects[j] = NULL;
|
|
src[j] = NULL;
|
|
len[j] = 0;
|
|
minlen = 0;
|
|
continue;
|
|
}
|
|
/* Return an error if one of the keys is not a string. */
|
|
if (checkType(c,o,OBJ_STRING)) {
|
|
unsigned long i;
|
|
for (i = 0; i < j; i++) {
|
|
if (objects[i])
|
|
decrRefCount(objects[i]);
|
|
}
|
|
zfree(src);
|
|
zfree(len);
|
|
zfree(objects);
|
|
return;
|
|
}
|
|
objects[j] = getDecodedObject(o);
|
|
src[j] = objects[j]->ptr;
|
|
len[j] = sdslen(objects[j]->ptr);
|
|
if (len[j] > maxlen) maxlen = len[j];
|
|
if (j == 0 || len[j] < minlen) minlen = len[j];
|
|
}
|
|
|
|
/* Compute the bit operation, if at least one string is not empty. */
|
|
if (maxlen) {
|
|
res = (unsigned char*) sdsnewlen(NULL,maxlen);
|
|
unsigned char output, byte;
|
|
unsigned long i;
|
|
|
|
/* Fast path: as far as we have data for all the input bitmaps we
|
|
* can take a fast path that performs much better than the
|
|
* vanilla algorithm. On ARM we skip the fast path since it will
|
|
* result in GCC compiling the code using multiple-words load/store
|
|
* operations that are not supported even in ARM >= v6. */
|
|
j = 0;
|
|
#ifndef USE_ALIGNED_ACCESS
|
|
if (minlen >= sizeof(unsigned long)*4 && numkeys <= 16) {
|
|
unsigned long *lp[16];
|
|
unsigned long *lres = (unsigned long*) res;
|
|
|
|
/* Note: sds pointer is always aligned to 8 byte boundary. */
|
|
memcpy(lp,src,sizeof(unsigned long*)*numkeys);
|
|
memcpy(res,src[0],minlen);
|
|
|
|
/* Different branches per different operations for speed (sorry). */
|
|
if (op == BITOP_AND) {
|
|
while(minlen >= sizeof(unsigned long)*4) {
|
|
for (i = 1; i < numkeys; i++) {
|
|
lres[0] &= lp[i][0];
|
|
lres[1] &= lp[i][1];
|
|
lres[2] &= lp[i][2];
|
|
lres[3] &= lp[i][3];
|
|
lp[i]+=4;
|
|
}
|
|
lres+=4;
|
|
j += sizeof(unsigned long)*4;
|
|
minlen -= sizeof(unsigned long)*4;
|
|
}
|
|
} else if (op == BITOP_OR) {
|
|
while(minlen >= sizeof(unsigned long)*4) {
|
|
for (i = 1; i < numkeys; i++) {
|
|
lres[0] |= lp[i][0];
|
|
lres[1] |= lp[i][1];
|
|
lres[2] |= lp[i][2];
|
|
lres[3] |= lp[i][3];
|
|
lp[i]+=4;
|
|
}
|
|
lres+=4;
|
|
j += sizeof(unsigned long)*4;
|
|
minlen -= sizeof(unsigned long)*4;
|
|
}
|
|
} else if (op == BITOP_XOR) {
|
|
while(minlen >= sizeof(unsigned long)*4) {
|
|
for (i = 1; i < numkeys; i++) {
|
|
lres[0] ^= lp[i][0];
|
|
lres[1] ^= lp[i][1];
|
|
lres[2] ^= lp[i][2];
|
|
lres[3] ^= lp[i][3];
|
|
lp[i]+=4;
|
|
}
|
|
lres+=4;
|
|
j += sizeof(unsigned long)*4;
|
|
minlen -= sizeof(unsigned long)*4;
|
|
}
|
|
} else if (op == BITOP_NOT) {
|
|
while(minlen >= sizeof(unsigned long)*4) {
|
|
lres[0] = ~lres[0];
|
|
lres[1] = ~lres[1];
|
|
lres[2] = ~lres[2];
|
|
lres[3] = ~lres[3];
|
|
lres+=4;
|
|
j += sizeof(unsigned long)*4;
|
|
minlen -= sizeof(unsigned long)*4;
|
|
}
|
|
}
|
|
}
|
|
#endif
|
|
|
|
/* j is set to the next byte to process by the previous loop. */
|
|
for (; j < maxlen; j++) {
|
|
output = (len[0] <= j) ? 0 : src[0][j];
|
|
if (op == BITOP_NOT) output = ~output;
|
|
for (i = 1; i < numkeys; i++) {
|
|
byte = (len[i] <= j) ? 0 : src[i][j];
|
|
switch(op) {
|
|
case BITOP_AND: output &= byte; break;
|
|
case BITOP_OR: output |= byte; break;
|
|
case BITOP_XOR: output ^= byte; break;
|
|
}
|
|
}
|
|
res[j] = output;
|
|
}
|
|
}
|
|
for (j = 0; j < numkeys; j++) {
|
|
if (objects[j])
|
|
decrRefCount(objects[j]);
|
|
}
|
|
zfree(src);
|
|
zfree(len);
|
|
zfree(objects);
|
|
|
|
/* Store the computed value into the target key */
|
|
if (maxlen) {
|
|
o = createObject(OBJ_STRING,res);
|
|
setKey(c->db,targetkey,o);
|
|
notifyKeyspaceEvent(NOTIFY_STRING,"set",targetkey,c->db->id);
|
|
decrRefCount(o);
|
|
} else if (dbDelete(c->db,targetkey)) {
|
|
signalModifiedKey(c->db,targetkey);
|
|
notifyKeyspaceEvent(NOTIFY_GENERIC,"del",targetkey,c->db->id);
|
|
}
|
|
server.dirty++;
|
|
addReplyLongLong(c,maxlen); /* Return the output string length in bytes. */
|
|
}
|
|
|
|
/* BITCOUNT key [start end] */
|
|
void bitcountCommand(client *c) {
|
|
robj *o;
|
|
long start, end, strlen;
|
|
unsigned char *p;
|
|
char llbuf[LONG_STR_SIZE];
|
|
|
|
/* Lookup, check for type, and return 0 for non existing keys. */
|
|
if ((o = lookupKeyReadOrReply(c,c->argv[1],shared.czero)) == NULL ||
|
|
checkType(c,o,OBJ_STRING)) return;
|
|
p = getObjectReadOnlyString(o,&strlen,llbuf);
|
|
|
|
/* Parse start/end range if any. */
|
|
if (c->argc == 4) {
|
|
if (getLongFromObjectOrReply(c,c->argv[2],&start,NULL) != C_OK)
|
|
return;
|
|
if (getLongFromObjectOrReply(c,c->argv[3],&end,NULL) != C_OK)
|
|
return;
|
|
/* Convert negative indexes */
|
|
if (start < 0 && end < 0 && start > end) {
|
|
addReply(c,shared.czero);
|
|
return;
|
|
}
|
|
if (start < 0) start = strlen+start;
|
|
if (end < 0) end = strlen+end;
|
|
if (start < 0) start = 0;
|
|
if (end < 0) end = 0;
|
|
if (end >= strlen) end = strlen-1;
|
|
} else if (c->argc == 2) {
|
|
/* The whole string. */
|
|
start = 0;
|
|
end = strlen-1;
|
|
} else {
|
|
/* Syntax error. */
|
|
addReply(c,shared.syntaxerr);
|
|
return;
|
|
}
|
|
|
|
/* Precondition: end >= 0 && end < strlen, so the only condition where
|
|
* zero can be returned is: start > end. */
|
|
if (start > end) {
|
|
addReply(c,shared.czero);
|
|
} else {
|
|
long bytes = end-start+1;
|
|
|
|
addReplyLongLong(c,redisPopcount(p+start,bytes));
|
|
}
|
|
}
|
|
|
|
/* BITPOS key bit [start [end]] */
|
|
void bitposCommand(client *c) {
|
|
robj *o;
|
|
long bit, start, end, strlen;
|
|
unsigned char *p;
|
|
char llbuf[LONG_STR_SIZE];
|
|
int end_given = 0;
|
|
|
|
/* Parse the bit argument to understand what we are looking for, set
|
|
* or clear bits. */
|
|
if (getLongFromObjectOrReply(c,c->argv[2],&bit,NULL) != C_OK)
|
|
return;
|
|
if (bit != 0 && bit != 1) {
|
|
addReplyError(c, "The bit argument must be 1 or 0.");
|
|
return;
|
|
}
|
|
|
|
/* If the key does not exist, from our point of view it is an infinite
|
|
* array of 0 bits. If the user is looking for the fist clear bit return 0,
|
|
* If the user is looking for the first set bit, return -1. */
|
|
if ((o = lookupKeyRead(c->db,c->argv[1])) == NULL) {
|
|
addReplyLongLong(c, bit ? -1 : 0);
|
|
return;
|
|
}
|
|
if (checkType(c,o,OBJ_STRING)) return;
|
|
p = getObjectReadOnlyString(o,&strlen,llbuf);
|
|
|
|
/* Parse start/end range if any. */
|
|
if (c->argc == 4 || c->argc == 5) {
|
|
if (getLongFromObjectOrReply(c,c->argv[3],&start,NULL) != C_OK)
|
|
return;
|
|
if (c->argc == 5) {
|
|
if (getLongFromObjectOrReply(c,c->argv[4],&end,NULL) != C_OK)
|
|
return;
|
|
end_given = 1;
|
|
} else {
|
|
end = strlen-1;
|
|
}
|
|
/* Convert negative indexes */
|
|
if (start < 0) start = strlen+start;
|
|
if (end < 0) end = strlen+end;
|
|
if (start < 0) start = 0;
|
|
if (end < 0) end = 0;
|
|
if (end >= strlen) end = strlen-1;
|
|
} else if (c->argc == 3) {
|
|
/* The whole string. */
|
|
start = 0;
|
|
end = strlen-1;
|
|
} else {
|
|
/* Syntax error. */
|
|
addReply(c,shared.syntaxerr);
|
|
return;
|
|
}
|
|
|
|
/* For empty ranges (start > end) we return -1 as an empty range does
|
|
* not contain a 0 nor a 1. */
|
|
if (start > end) {
|
|
addReplyLongLong(c, -1);
|
|
} else {
|
|
long bytes = end-start+1;
|
|
long pos = redisBitpos(p+start,bytes,bit);
|
|
|
|
/* If we are looking for clear bits, and the user specified an exact
|
|
* range with start-end, we can't consider the right of the range as
|
|
* zero padded (as we do when no explicit end is given).
|
|
*
|
|
* So if redisBitpos() returns the first bit outside the range,
|
|
* we return -1 to the caller, to mean, in the specified range there
|
|
* is not a single "0" bit. */
|
|
if (end_given && bit == 0 && pos == bytes*8) {
|
|
addReplyLongLong(c,-1);
|
|
return;
|
|
}
|
|
if (pos != -1) pos += start*8; /* Adjust for the bytes we skipped. */
|
|
addReplyLongLong(c,pos);
|
|
}
|
|
}
|
|
|
|
/* BITFIELD key subcommmand-1 arg ... subcommand-2 arg ... subcommand-N ...
|
|
*
|
|
* Supported subcommands:
|
|
*
|
|
* GET <type> <offset>
|
|
* SET <type> <offset> <value>
|
|
* INCRBY <type> <offset> <increment>
|
|
* OVERFLOW [WRAP|SAT|FAIL]
|
|
*/
|
|
|
|
struct bitfieldOp {
|
|
uint64_t offset; /* Bitfield offset. */
|
|
int64_t i64; /* Increment amount (INCRBY) or SET value */
|
|
int opcode; /* Operation id. */
|
|
int owtype; /* Overflow type to use. */
|
|
int bits; /* Integer bitfield bits width. */
|
|
int sign; /* True if signed, otherwise unsigned op. */
|
|
};
|
|
|
|
void bitfieldCommand(client *c) {
|
|
robj *o;
|
|
size_t bitoffset;
|
|
int j, numops = 0, changes = 0;
|
|
struct bitfieldOp *ops = NULL; /* Array of ops to execute at end. */
|
|
int owtype = BFOVERFLOW_WRAP; /* Overflow type. */
|
|
int readonly = 1;
|
|
size_t highest_write_offset = 0;
|
|
|
|
for (j = 2; j < c->argc; j++) {
|
|
int remargs = c->argc-j-1; /* Remaining args other than current. */
|
|
char *subcmd = c->argv[j]->ptr; /* Current command name. */
|
|
int opcode; /* Current operation code. */
|
|
long long i64 = 0; /* Signed SET value. */
|
|
int sign = 0; /* Signed or unsigned type? */
|
|
int bits = 0; /* Bitfield width in bits. */
|
|
|
|
if (!strcasecmp(subcmd,"get") && remargs >= 2)
|
|
opcode = BITFIELDOP_GET;
|
|
else if (!strcasecmp(subcmd,"set") && remargs >= 3)
|
|
opcode = BITFIELDOP_SET;
|
|
else if (!strcasecmp(subcmd,"incrby") && remargs >= 3)
|
|
opcode = BITFIELDOP_INCRBY;
|
|
else if (!strcasecmp(subcmd,"overflow") && remargs >= 1) {
|
|
char *owtypename = c->argv[j+1]->ptr;
|
|
j++;
|
|
if (!strcasecmp(owtypename,"wrap"))
|
|
owtype = BFOVERFLOW_WRAP;
|
|
else if (!strcasecmp(owtypename,"sat"))
|
|
owtype = BFOVERFLOW_SAT;
|
|
else if (!strcasecmp(owtypename,"fail"))
|
|
owtype = BFOVERFLOW_FAIL;
|
|
else {
|
|
addReplyError(c,"Invalid OVERFLOW type specified");
|
|
zfree(ops);
|
|
return;
|
|
}
|
|
continue;
|
|
} else {
|
|
addReply(c,shared.syntaxerr);
|
|
zfree(ops);
|
|
return;
|
|
}
|
|
|
|
/* Get the type and offset arguments, common to all the ops. */
|
|
if (getBitfieldTypeFromArgument(c,c->argv[j+1],&sign,&bits) != C_OK) {
|
|
zfree(ops);
|
|
return;
|
|
}
|
|
|
|
if (getBitOffsetFromArgument(c,c->argv[j+2],&bitoffset,1,bits) != C_OK){
|
|
zfree(ops);
|
|
return;
|
|
}
|
|
|
|
if (opcode != BITFIELDOP_GET) {
|
|
readonly = 0;
|
|
if (highest_write_offset < bitoffset + bits - 1)
|
|
highest_write_offset = bitoffset + bits - 1;
|
|
/* INCRBY and SET require another argument. */
|
|
if (getLongLongFromObjectOrReply(c,c->argv[j+3],&i64,NULL) != C_OK){
|
|
zfree(ops);
|
|
return;
|
|
}
|
|
}
|
|
|
|
/* Populate the array of operations we'll process. */
|
|
ops = zrealloc(ops,sizeof(*ops)*(numops+1));
|
|
ops[numops].offset = bitoffset;
|
|
ops[numops].i64 = i64;
|
|
ops[numops].opcode = opcode;
|
|
ops[numops].owtype = owtype;
|
|
ops[numops].bits = bits;
|
|
ops[numops].sign = sign;
|
|
numops++;
|
|
|
|
j += 3 - (opcode == BITFIELDOP_GET);
|
|
}
|
|
|
|
if (readonly) {
|
|
/* Lookup for read is ok if key doesn't exit, but errors
|
|
* if it's not a string. */
|
|
o = lookupKeyRead(c->db,c->argv[1]);
|
|
if (o != NULL && checkType(c,o,OBJ_STRING)) {
|
|
zfree(ops);
|
|
return;
|
|
}
|
|
} else {
|
|
/* Lookup by making room up to the farest bit reached by
|
|
* this operation. */
|
|
if ((o = lookupStringForBitCommand(c,
|
|
highest_write_offset)) == NULL) {
|
|
zfree(ops);
|
|
return;
|
|
}
|
|
}
|
|
|
|
addReplyArrayLen(c,numops);
|
|
|
|
/* Actually process the operations. */
|
|
for (j = 0; j < numops; j++) {
|
|
struct bitfieldOp *thisop = ops+j;
|
|
|
|
/* Execute the operation. */
|
|
if (thisop->opcode == BITFIELDOP_SET ||
|
|
thisop->opcode == BITFIELDOP_INCRBY)
|
|
{
|
|
/* SET and INCRBY: We handle both with the same code path
|
|
* for simplicity. SET return value is the previous value so
|
|
* we need fetch & store as well. */
|
|
|
|
/* We need two different but very similar code paths for signed
|
|
* and unsigned operations, since the set of functions to get/set
|
|
* the integers and the used variables types are different. */
|
|
if (thisop->sign) {
|
|
int64_t oldval, newval, wrapped, retval;
|
|
int overflow;
|
|
|
|
oldval = getSignedBitfield(o->ptr,thisop->offset,
|
|
thisop->bits);
|
|
|
|
if (thisop->opcode == BITFIELDOP_INCRBY) {
|
|
newval = oldval + thisop->i64;
|
|
overflow = checkSignedBitfieldOverflow(oldval,
|
|
thisop->i64,thisop->bits,thisop->owtype,&wrapped);
|
|
if (overflow) newval = wrapped;
|
|
retval = newval;
|
|
} else {
|
|
newval = thisop->i64;
|
|
overflow = checkSignedBitfieldOverflow(newval,
|
|
0,thisop->bits,thisop->owtype,&wrapped);
|
|
if (overflow) newval = wrapped;
|
|
retval = oldval;
|
|
}
|
|
|
|
/* On overflow of type is "FAIL", don't write and return
|
|
* NULL to signal the condition. */
|
|
if (!(overflow && thisop->owtype == BFOVERFLOW_FAIL)) {
|
|
addReplyLongLong(c,retval);
|
|
setSignedBitfield(o->ptr,thisop->offset,
|
|
thisop->bits,newval);
|
|
} else {
|
|
addReplyNull(c);
|
|
}
|
|
} else {
|
|
uint64_t oldval, newval, wrapped, retval;
|
|
int overflow;
|
|
|
|
oldval = getUnsignedBitfield(o->ptr,thisop->offset,
|
|
thisop->bits);
|
|
|
|
if (thisop->opcode == BITFIELDOP_INCRBY) {
|
|
newval = oldval + thisop->i64;
|
|
overflow = checkUnsignedBitfieldOverflow(oldval,
|
|
thisop->i64,thisop->bits,thisop->owtype,&wrapped);
|
|
if (overflow) newval = wrapped;
|
|
retval = newval;
|
|
} else {
|
|
newval = thisop->i64;
|
|
overflow = checkUnsignedBitfieldOverflow(newval,
|
|
0,thisop->bits,thisop->owtype,&wrapped);
|
|
if (overflow) newval = wrapped;
|
|
retval = oldval;
|
|
}
|
|
/* On overflow of type is "FAIL", don't write and return
|
|
* NULL to signal the condition. */
|
|
if (!(overflow && thisop->owtype == BFOVERFLOW_FAIL)) {
|
|
addReplyLongLong(c,retval);
|
|
setUnsignedBitfield(o->ptr,thisop->offset,
|
|
thisop->bits,newval);
|
|
} else {
|
|
addReplyNull(c);
|
|
}
|
|
}
|
|
changes++;
|
|
} else {
|
|
/* GET */
|
|
unsigned char buf[9];
|
|
long strlen = 0;
|
|
unsigned char *src = NULL;
|
|
char llbuf[LONG_STR_SIZE];
|
|
|
|
if (o != NULL)
|
|
src = getObjectReadOnlyString(o,&strlen,llbuf);
|
|
|
|
/* For GET we use a trick: before executing the operation
|
|
* copy up to 9 bytes to a local buffer, so that we can easily
|
|
* execute up to 64 bit operations that are at actual string
|
|
* object boundaries. */
|
|
memset(buf,0,9);
|
|
int i;
|
|
size_t byte = thisop->offset >> 3;
|
|
for (i = 0; i < 9; i++) {
|
|
if (src == NULL || i+byte >= (size_t)strlen) break;
|
|
buf[i] = src[i+byte];
|
|
}
|
|
|
|
/* Now operate on the copied buffer which is guaranteed
|
|
* to be zero-padded. */
|
|
if (thisop->sign) {
|
|
int64_t val = getSignedBitfield(buf,thisop->offset-(byte*8),
|
|
thisop->bits);
|
|
addReplyLongLong(c,val);
|
|
} else {
|
|
uint64_t val = getUnsignedBitfield(buf,thisop->offset-(byte*8),
|
|
thisop->bits);
|
|
addReplyLongLong(c,val);
|
|
}
|
|
}
|
|
}
|
|
|
|
if (changes) {
|
|
signalModifiedKey(c->db,c->argv[1]);
|
|
notifyKeyspaceEvent(NOTIFY_STRING,"setbit",c->argv[1],c->db->id);
|
|
server.dirty += changes;
|
|
}
|
|
zfree(ops);
|
|
}
|