d87eea35fa
This is the first step in preparation for: https://discourse.llvm.org/t/rfc-make-clang-builtin-math-functions-constexpr-with-llvm-libc-to-support-c-23-constexpr-math-functions/86450
51 lines
1.7 KiB
C++
51 lines
1.7 KiB
C++
//===-- Implementation of hsearch -------------------------------*- C++ -*-===//
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//
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// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
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// See https://llvm.org/LICENSE.txt for license information.
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// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
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//
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//===----------------------------------------------------------------------===//
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#include "src/search/hsearch.h"
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#include "src/__support/HashTable/randomness.h"
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#include "src/__support/HashTable/table.h"
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#include "src/__support/libc_errno.h"
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#include "src/__support/macros/config.h"
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#include "src/search/hsearch/global.h"
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namespace LIBC_NAMESPACE_DECL {
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LLVM_LIBC_FUNCTION(ENTRY *, hsearch, (ENTRY item, ACTION action)) {
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ENTRY *result = nullptr;
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if (internal::global_hash_table == nullptr) {
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// If global_hash_table is null, we create a new hash table with a minimal
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// capacity. Such hashtable will be expanded as needed.
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uint64_t randomness = internal::randomness::next_random_seed();
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internal::global_hash_table = internal::HashTable::allocate(0, randomness);
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}
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// In rare cases, the global hashtable may still fail to allocate. We treat it
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// as ESRCH or ENOMEM depending on the action.
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switch (action) {
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case FIND:
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result = internal::global_hash_table
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? internal::global_hash_table->find(item.key)
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: nullptr;
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if (result == nullptr) {
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libc_errno = ESRCH;
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}
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break;
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case ENTER:
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result =
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internal::global_hash_table
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? internal::HashTable::insert(internal::global_hash_table, item)
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: nullptr;
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if (result == nullptr) {
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libc_errno = ENOMEM;
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}
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break;
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}
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return result;
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}
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} // namespace LIBC_NAMESPACE_DECL
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