/* Copyright (c) 2000, 2024, Oracle and/or its affiliates. This program is free software; you can redistribute it and/or modify it under the terms of the GNU General Public License, version 2.0, as published by the Free Software Foundation. This program is designed to work with certain software (including but not limited to OpenSSL) that is licensed under separate terms, as designated in a particular file or component or in included license documentation. The authors of MySQL hereby grant you an additional permission to link the program and your derivative works with the separately licensed software that they have either included with the program or referenced in the documentation. This program is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License, version 2.0, for more details. You should have received a copy of the GNU General Public License along with this program; if not, write to the Free Software Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA */ // Hash implementation used for tab completion. // TODO: Use a trie or similar instead. #include "client/completion_hash.h" #include "m_string.h" #include "my_alloc.h" #include "my_inttypes.h" #include "my_sys.h" #include "mysql/service_mysql_alloc.h" static uint hashpjw(const char *arKey, uint nKeyLength) { uint h = 0, g, i; for (i = 0; i < nKeyLength; i++) { h = (h << 4) + arKey[i]; if ((g = (h & 0xF0000000))) { h = h ^ (g >> 24); h = h ^ g; } } return h; } int completion_hash_init(HashTable *ht, uint nSize) { ht->arBuckets = (Bucket **)my_malloc(PSI_NOT_INSTRUMENTED, nSize * sizeof(Bucket *), MYF(MY_ZEROFILL | MY_WME)); if (!ht->arBuckets) { ht->initialized = 0; return FAILURE; } ::new ((void *)&ht->mem_root) MEM_ROOT(PSI_NOT_INSTRUMENTED, 8192); ht->pHashFunction = hashpjw; ht->nTableSize = nSize; ht->initialized = 1; return SUCCESS; } int completion_hash_update(HashTable *ht, const char *arKey, uint nKeyLength, const char *str) { uint h, nIndex; Bucket *p; h = ht->pHashFunction(arKey, nKeyLength); nIndex = h % ht->nTableSize; if (nKeyLength <= 0) { return FAILURE; } p = ht->arBuckets[nIndex]; while (p) { if ((p->h == h) && (p->nKeyLength == nKeyLength)) { if (!memcmp(p->arKey, arKey, nKeyLength)) { entry *n; if (!(n = (entry *)ht->mem_root.Alloc(sizeof(entry)))) return FAILURE; n->pNext = p->pData; n->str = str; p->pData = n; p->count++; return SUCCESS; } } p = p->pNext; } if (!(p = (Bucket *)ht->mem_root.Alloc(sizeof(Bucket)))) return FAILURE; p->arKey = arKey; p->nKeyLength = nKeyLength; p->h = h; if (!(p->pData = (entry *)ht->mem_root.Alloc(sizeof(entry)))) return FAILURE; p->pData->str = str; p->pData->pNext = nullptr; p->count = 1; p->pNext = ht->arBuckets[nIndex]; ht->arBuckets[nIndex] = p; return SUCCESS; } static Bucket *completion_hash_find(HashTable *ht, const char *arKey, uint nKeyLength) { uint h, nIndex; Bucket *p; h = ht->pHashFunction(arKey, nKeyLength); nIndex = h % ht->nTableSize; p = ht->arBuckets[nIndex]; while (p) { if ((p->h == h) && (p->nKeyLength == nKeyLength)) { if (!memcmp(p->arKey, arKey, nKeyLength)) { return p; } } p = p->pNext; } return (Bucket *)nullptr; } int completion_hash_exists(HashTable *ht, char *arKey, uint nKeyLength) { uint h, nIndex; Bucket *p; h = ht->pHashFunction(arKey, nKeyLength); nIndex = h % ht->nTableSize; p = ht->arBuckets[nIndex]; while (p) { if ((p->h == h) && (p->nKeyLength == nKeyLength)) { if (!strcmp(p->arKey, arKey)) { return 1; } } p = p->pNext; } return 0; } Bucket *find_all_matches(HashTable *ht, const char *str, uint length, uint *res_length) { Bucket *b; b = completion_hash_find(ht, str, length); if (!b) { *res_length = 0; return (Bucket *)nullptr; } else { *res_length = length; return b; } } Bucket *find_longest_match(HashTable *ht, char *str, uint length, uint *res_length) { Bucket *b, *return_b; const char *s; uint count; uint lm; b = completion_hash_find(ht, str, length); if (!b) { *res_length = 0; return (Bucket *)nullptr; } count = b->count; lm = length; s = b->pData->str; return_b = b; while (s[lm] != 0 && (b = completion_hash_find(ht, s, lm + 1))) { if (b->count < count) { *res_length = lm; return return_b; } return_b = b; lm++; } *res_length = lm; return return_b; } void completion_hash_clean(HashTable *ht) { ht->mem_root.Clear(); memset(ht->arBuckets, 0, ht->nTableSize * sizeof(Bucket *)); } void completion_hash_free(HashTable *ht) { completion_hash_clean(ht); my_free(ht->arBuckets); } void add_word(HashTable *ht, const char *str) { int i; const char *pos = str; for (i = 1; *pos; i++, pos++) completion_hash_update(ht, str, i, str); }