51 lines · cpp
1//===-- Implementation of hsearch -------------------------------*- 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-exception6//7//===----------------------------------------------------------------------===//8 9#include "src/search/hsearch.h"10#include "src/__support/HashTable/randomness.h"11#include "src/__support/HashTable/table.h"12#include "src/__support/libc_errno.h"13#include "src/__support/macros/config.h"14#include "src/search/hsearch/global.h"15 16namespace LIBC_NAMESPACE_DECL {17LLVM_LIBC_FUNCTION(ENTRY *, hsearch, (ENTRY item, ACTION action)) {18 ENTRY *result = nullptr;19 if (internal::global_hash_table == nullptr) {20 // If global_hash_table is null, we create a new hash table with a minimal21 // capacity. Such hashtable will be expanded as needed.22 uint64_t randomness = internal::randomness::next_random_seed();23 internal::global_hash_table = internal::HashTable::allocate(0, randomness);24 }25 26 // In rare cases, the global hashtable may still fail to allocate. We treat it27 // as ESRCH or ENOMEM depending on the action.28 switch (action) {29 case FIND:30 result = internal::global_hash_table31 ? internal::global_hash_table->find(item.key)32 : nullptr;33 if (result == nullptr) {34 libc_errno = ESRCH;35 }36 break;37 case ENTER:38 result =39 internal::global_hash_table40 ? internal::HashTable::insert(internal::global_hash_table, item)41 : nullptr;42 if (result == nullptr) {43 libc_errno = ENOMEM;44 }45 break;46 }47 return result;48}49 50} // namespace LIBC_NAMESPACE_DECL51