1 //===-- Implementation of hcreate -------------------------------*- C++ -*-===// 2 // 3 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions. 4 // See https://llvm.org/LICENSE.txt for license information. 5 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception 6 // 7 //===----------------------------------------------------------------------===// 8 9 #include "src/search/hcreate.h" 10 #include "src/__support/HashTable/randomness.h" 11 #include "src/__support/HashTable/table.h" 12 #include "src/__support/macros/config.h" 13 #include "src/errno/libc_errno.h" 14 #include "src/search/hsearch/global.h" 15 16 namespace LIBC_NAMESPACE_DECL { 17 LLVM_LIBC_FUNCTION(int, hcreate, (size_t capacity)) { 18 // We follow FreeBSD's implementation here. If the global_hash_table is 19 // already initialized, this function will do nothing and return 1. 20 // https://cgit.freebsd.org/src/tree/lib/libc/stdlib/hcreate.c 21 if (internal::global_hash_table != nullptr) 22 return 1; 23 24 uint64_t randomness = internal::randomness::next_random_seed(); 25 internal::HashTable *table = 26 internal::HashTable::allocate(capacity, randomness); 27 if (table == nullptr) { 28 libc_errno = ENOMEM; 29 return 0; 30 } 31 internal::global_hash_table = table; 32 return 1; 33 } 34 35 } // namespace LIBC_NAMESPACE_DECL 36