/*************************************************************************** * _ _ ____ _ * Project ___| | | | _ \| | * / __| | | | |_) | | * | (__| |_| | _ <| |___ * \___|\___/|_| \_\_____| * * Copyright (C) Daniel Stenberg, , et al. * * This software is licensed as described in the file COPYING, which * you should have received as part of this distribution. The terms * are also available at https://curl.se/docs/copyright.html. * * You may opt to use, copy, modify, merge, publish, distribute and/or sell * copies of the Software, and permit persons to whom the Software is * furnished to do so, under the terms of the COPYING file. * * This software is distributed on an "AS IS" basis, WITHOUT WARRANTY OF ANY * KIND, either express or implied. * * SPDX-License-Identifier: curl * ***************************************************************************/ #include "curl_setup.h" #include "uint-bset.h" /* The last 3 #include files should be in this order */ #include "curl_printf.h" #include "curl_memory.h" #include "memdebug.h" #ifdef DEBUGBUILD #define CURL_UINT_BSET_MAGIC 0x62757473 #endif void Curl_uint_bset_init(struct uint_bset *bset) { memset(bset, 0, sizeof(*bset)); #ifdef DEBUGBUILD bset->init = CURL_UINT_BSET_MAGIC; #endif } CURLcode Curl_uint_bset_resize(struct uint_bset *bset, unsigned int nmax) { unsigned int nslots = (nmax + 63) / 64; DEBUGASSERT(bset->init == CURL_UINT_BSET_MAGIC); if(nslots != bset->nslots) { curl_uint64_t *slots = calloc(nslots, sizeof(curl_uint64_t)); if(!slots) return CURLE_OUT_OF_MEMORY; if(bset->slots) { memcpy(slots, bset->slots, (CURLMIN(nslots, bset->nslots) * sizeof(curl_uint64_t))); free(bset->slots); } bset->slots = slots; bset->nslots = nslots; } return CURLE_OK; } void Curl_uint_bset_destroy(struct uint_bset *bset) { DEBUGASSERT(bset->init == CURL_UINT_BSET_MAGIC); free(bset->slots); memset(bset, 0, sizeof(*bset)); } unsigned int Curl_uint_bset_capacity(struct uint_bset *bset) { return bset->nslots * 64; } unsigned int Curl_uint_bset_count(struct uint_bset *bset) { unsigned int i; unsigned int n = 0; for(i = 0; i < bset->nslots; ++i) { if(bset->slots[i]) n += CURL_POPCOUNT64(bset->slots[i]); } return n; } bool Curl_uint_bset_empty(struct uint_bset *bset) { unsigned int i; for(i = 0; i < bset->nslots; ++i) { if(bset->slots[i]) return FALSE; } return TRUE; } void Curl_uint_bset_clear(struct uint_bset *bset) { if(bset->nslots) memset(bset->slots, 0, bset->nslots * sizeof(curl_uint64_t)); } bool Curl_uint_bset_add(struct uint_bset *bset, unsigned int i) { unsigned int islot = i / 64; if(islot >= bset->nslots) return FALSE; bset->slots[islot] |= ((curl_uint64_t)1 << (i % 64)); return TRUE; } void Curl_uint_bset_remove(struct uint_bset *bset, unsigned int i) { size_t islot = i / 64; if(islot < bset->nslots) bset->slots[islot] &= ~((curl_uint64_t)1 << (i % 64)); } bool Curl_uint_bset_contains(struct uint_bset *bset, unsigned int i) { unsigned int islot = i / 64; if(islot >= bset->nslots) return FALSE; return (bset->slots[islot] & ((curl_uint64_t)1 << (i % 64))) != 0; } bool Curl_uint_bset_first(struct uint_bset *bset, unsigned int *pfirst) { unsigned int i; for(i = 0; i < bset->nslots; ++i) { if(bset->slots[i]) { *pfirst = (i * 64) + CURL_CTZ64(bset->slots[i]); return TRUE; } } *pfirst = UINT_MAX; /* a value we cannot store */ return FALSE; } bool Curl_uint_bset_next(struct uint_bset *bset, unsigned int last, unsigned int *pnext) { unsigned int islot; curl_uint64_t x; ++last; /* look for number one higher than last */ islot = last / 64; /* the slot this would be in */ if(islot < bset->nslots) { /* shift away the bits we already iterated in this slot */ x = (bset->slots[islot] >> (last % 64)); if(x) { /* more bits set, next is `last` + trailing0s of the shifted slot */ *pnext = last + CURL_CTZ64(x); return TRUE; } /* no more bits set in the last slot, scan forward */ for(islot = islot + 1; islot < bset->nslots; ++islot) { if(bset->slots[islot]) { *pnext = (islot * 64) + CURL_CTZ64(bset->slots[islot]); return TRUE; } } } *pnext = UINT_MAX; /* a value we cannot store */ return FALSE; } #ifdef CURL_POPCOUNT64_IMPLEMENT unsigned int Curl_popcount64(curl_uint64_t x) { /* Compute the "Hamming Distance" between 'x' and 0, * which is the number of set bits in 'x'. * See: https://en.wikipedia.org/wiki/Hamming_weight */ const curl_uint64_t m1 = CURL_OFF_TU_C(0x5555555555555555); /* 0101+ */ const curl_uint64_t m2 = CURL_OFF_TU_C(0x3333333333333333); /* 00110011+ */ const curl_uint64_t m4 = CURL_OFF_TU_C(0x0f0f0f0f0f0f0f0f); /* 00001111+ */ /* 1 + 256^1 + 256^2 + 256^3 + ... + 256^7 */ const curl_uint64_t h01 = CURL_OFF_TU_C(0x0101010101010101); x -= (x >> 1) & m1; /* replace every 2 bits with bits present */ x = (x & m2) + ((x >> 2) & m2); /* replace every nibble with bits present */ x = (x + (x >> 4)) & m4; /* replace every byte with bits present */ /* top 8 bits of x + (x<<8) + (x<<16) + (x<<24) + ... which makes the * top byte the sum of all individual 8 bytes, throw away the rest */ return (unsigned int)((x * h01) >> 56); } #endif /* CURL_POPCOUNT64_IMPLEMENT */ #ifdef CURL_CTZ64_IMPLEMENT unsigned int Curl_ctz64(curl_uint64_t x) { /* count trailing zeros in a curl_uint64_t. * divide and conquer to find the number of lower 0 bits */ const curl_uint64_t ml32 = CURL_OFF_TU_C(0xFFFFFFFF); /* lower 32 bits */ const curl_uint64_t ml16 = CURL_OFF_TU_C(0x0000FFFF); /* lower 16 bits */ const curl_uint64_t ml8 = CURL_OFF_TU_C(0x000000FF); /* lower 8 bits */ const curl_uint64_t ml4 = CURL_OFF_TU_C(0x0000000F); /* lower 4 bits */ const curl_uint64_t ml2 = CURL_OFF_TU_C(0x00000003); /* lower 2 bits */ unsigned int n; if(!x) return 64; n = 1; if(!(x & ml32)) { n = n + 32; x = x >> 32; } if(!(x & ml16)) { n = n + 16; x = x >> 16; } if(!(x & ml8)) { n = n + 8; x = x >> 8; } if(!(x & ml4)) { n = n + 4; x = x >> 4; } if(!(x & ml2)) { n = n + 2; x = x >> 2; } return n - (unsigned int)(x & 1); } #endif /* CURL_CTZ64_IMPLEMENT */