xref: /llvm-project/libc/test/src/__support/HashTable/table_test.cpp (revision e59582b6f8f1be3e675866f6a5d661eb4c8ed448)
1 //===-- Unittests for table -----------------------------------------------===//
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/__support/CPP/bit.h" // bit_ceil
10 #include "src/__support/HashTable/randomness.h"
11 #include "src/__support/HashTable/table.h"
12 #include "src/__support/macros/config.h"
13 #include "test/UnitTest/Test.h"
14 
15 namespace LIBC_NAMESPACE_DECL {
16 namespace internal {
17 TEST(LlvmLibcTableTest, AllocationAndDeallocation) {
18   size_t caps[] = {0, 1, 2, 3, 4, 7, 11, 37, 1024, 5261, 19999};
19   const char *keys[] = {"",         "a",         "ab",        "abc",
20                         "abcd",     "abcde",     "abcdef",    "abcdefg",
21                         "abcdefgh", "abcdefghi", "abcdefghij"};
22   for (size_t i : caps) {
23     HashTable *table = HashTable::allocate(i, 1);
24     ASSERT_NE(table, static_cast<HashTable *>(nullptr));
25     for (const char *key : keys) {
26       ASSERT_EQ(table->find(key), static_cast<ENTRY *>(nullptr));
27     }
28     HashTable::deallocate(table);
29   }
30   ASSERT_EQ(HashTable::allocate(-1, 0), static_cast<HashTable *>(nullptr));
31   HashTable::deallocate(nullptr);
32 }
33 
34 TEST(LlvmLibcTableTest, Iteration) {
35   constexpr size_t TEST_SIZE = 512;
36   size_t counter[TEST_SIZE];
37   struct key {
38     uint8_t bytes[3];
39   } keys[TEST_SIZE];
40   HashTable *table = HashTable::allocate(0, 0x7f7f7f7f7f7f7f7f);
41   ASSERT_NE(table, static_cast<HashTable *>(nullptr));
42   for (size_t i = 0; i < TEST_SIZE; ++i) {
43     counter[i] = 0;
44     if (i >= 256) {
45       keys[i].bytes[0] = 2;
46       keys[i].bytes[1] = i % 256;
47       keys[i].bytes[2] = 0;
48     } else {
49       keys[i].bytes[0] = 1;
50       keys[i].bytes[1] = i;
51       keys[i].bytes[2] = 0;
52     }
53     HashTable::insert(table, {reinterpret_cast<char *>(keys[i].bytes),
54                               reinterpret_cast<void *>((size_t)i)});
55   }
56 
57   size_t count = 0;
58   for (const ENTRY &e : *table) {
59     size_t data = reinterpret_cast<size_t>(e.data);
60     ++counter[data];
61     ++count;
62   }
63   ASSERT_EQ(count, TEST_SIZE);
64   for (size_t i = 0; i < TEST_SIZE; ++i) {
65     ASSERT_EQ(counter[i], static_cast<size_t>(1));
66   }
67   HashTable::deallocate(table);
68 }
69 
70 // Check if resize works correctly. This test actually covers two things:
71 // - The sizes are indeed growing.
72 // - The sizes are growing rapidly enough to reach the upper bound.
73 TEST(LlvmLibcTableTest, GrowthSequence) {
74   size_t cap = capacity_to_entries(0);
75   // right shift 4 to avoid overflow ssize_t.
76   while (cap < static_cast<size_t>(-1) >> 4u) {
77     size_t hint = cap / 8 * 7 + 1;
78     size_t new_cap = capacity_to_entries(hint);
79     ASSERT_GT(new_cap, cap);
80     cap = new_cap;
81   }
82 }
83 
84 TEST(LlvmLibcTableTest, Insertion) {
85   struct key {
86     char bytes[2];
87   } keys[256];
88   for (size_t k = 0; k < 256; ++k) {
89     keys[k].bytes[0] = static_cast<char>(k);
90     keys[k].bytes[1] = 0;
91   }
92   constexpr size_t CAP = cpp::bit_ceil((sizeof(Group) + 1) * 8 / 7) / 8 * 7;
93   static_assert(CAP + 1 < 256, "CAP is too large for this test.");
94   HashTable *table =
95       HashTable::allocate(sizeof(Group) + 1, randomness::next_random_seed());
96   ASSERT_NE(table, static_cast<HashTable *>(nullptr));
97 
98   // insert to full capacity.
99   for (size_t i = 0; i < CAP; ++i) {
100     ASSERT_NE(HashTable::insert(table, {keys[i].bytes, keys[i].bytes}),
101               static_cast<ENTRY *>(nullptr));
102   }
103 
104   // One more insert should grow the table successfully. We test the value
105   // here because the grow finishes with a fastpath insertion that is different
106   // from the normal insertion.
107   ASSERT_EQ(HashTable::insert(table, {keys[CAP].bytes, keys[CAP].bytes})->data,
108             static_cast<void *>(keys[CAP].bytes));
109 
110   for (size_t i = 0; i <= CAP; ++i) {
111     ASSERT_EQ(strcmp(table->find(keys[i].bytes)->key, keys[i].bytes), 0);
112   }
113   for (size_t i = CAP + 1; i < 256; ++i) {
114     ASSERT_EQ(table->find(keys[i].bytes), static_cast<ENTRY *>(nullptr));
115   }
116 
117   // do not replace old value
118   for (size_t i = 0; i <= CAP; ++i) {
119     ASSERT_NE(
120         HashTable::insert(table, {keys[i].bytes, reinterpret_cast<void *>(i)}),
121         static_cast<ENTRY *>(nullptr));
122   }
123   for (size_t i = 0; i <= CAP; ++i) {
124     ASSERT_EQ(table->find(keys[i].bytes)->data,
125               reinterpret_cast<void *>(keys[i].bytes));
126   }
127 
128   HashTable::deallocate(table);
129 }
130 
131 } // namespace internal
132 } // namespace LIBC_NAMESPACE_DECL
133