| 1 | //===-- Implementation of hsearch -------------------------------*- C++ -*-===// |
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| 2 | // |
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| 3 | // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions. |
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| 4 | // See https://llvm.org/LICENSE.txt for license information. |
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| 5 | // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception |
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| 6 | // |
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| 7 | //===----------------------------------------------------------------------===// |
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| 8 | |
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| 9 | #include "src/search/hsearch.h" |
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| 10 | #include "src/__support/HashTable/randomness.h" |
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| 11 | #include "src/__support/HashTable/table.h" |
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| 12 | #include "src/__support/libc_errno.h" |
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| 13 | #include "src/__support/macros/config.h" |
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| 14 | #include "src/search/hsearch/global.h" |
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| 15 | |
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| 16 | namespace LIBC_NAMESPACE_DECL { |
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| 17 | LLVM_LIBC_FUNCTION(ENTRY *, hsearch, (ENTRY item, ACTION action)) { |
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| 18 | ENTRY *result = nullptr; |
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| 19 | if (internal::global_hash_table == nullptr) { |
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| 20 | // If global_hash_table is null, we create a new hash table with a minimal |
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| 21 | // capacity. Such hashtable will be expanded as needed. |
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| 22 | uint64_t randomness = internal::randomness::next_random_seed(); |
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| 23 | internal::global_hash_table = internal::HashTable::allocate(0, randomness); |
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| 24 | } |
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| 25 | |
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| 26 | // In rare cases, the global hashtable may still fail to allocate. We treat it |
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| 27 | // as ESRCH or ENOMEM depending on the action. |
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| 28 | switch (action) { |
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| 29 | case FIND: |
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| 30 | result = internal::global_hash_table |
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| 31 | ? internal::global_hash_table->find(item.key) |
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| 32 | : nullptr; |
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| 33 | if (result == nullptr) { |
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| 34 | libc_errno = ESRCH; |
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| 35 | } |
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| 36 | break; |
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| 37 | case ENTER: |
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| 38 | result = |
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| 39 | internal::global_hash_table |
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| 40 | ? internal::HashTable::insert(internal::global_hash_table, item) |
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| 41 | : nullptr; |
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| 42 | if (result == nullptr) { |
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| 43 | libc_errno = ENOMEM; |
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| 44 | } |
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| 45 | break; |
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| 46 | } |
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| 47 | return result; |
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| 48 | } |
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| 49 | |
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| 50 | } // namespace LIBC_NAMESPACE_DECL |
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| 51 | |
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