1 //===- llvm/unittest/DebugInfo/PDB/HashTableTest.cpp ----------------------===//
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 "llvm/DebugInfo/PDB/Native/HashTable.h"
10 
11 #include "llvm/DebugInfo/PDB/Native/Hash.h"
12 #include "llvm/DebugInfo/PDB/Native/NamedStreamMap.h"
13 #include "llvm/Support/Allocator.h"
14 #include "llvm/Support/BinaryByteStream.h"
15 #include "llvm/Support/BinaryStreamReader.h"
16 #include "llvm/Support/BinaryStreamWriter.h"
17 #include "llvm/Support/StringSaver.h"
18 #include "llvm/Testing/Support/Error.h"
19 
20 #include "gtest/gtest.h"
21 
22 #include <vector>
23 
24 using namespace llvm;
25 using namespace llvm::pdb;
26 using namespace llvm::support;
27 
28 namespace {
29 
30 struct IdentityHashTraits {
31   uint32_t hashLookupKey(uint32_t N) const { return N; }
32   uint32_t storageKeyToLookupKey(uint32_t N) const { return N; }
33   uint32_t lookupKeyToStorageKey(uint32_t N) { return N; }
34 };
35 
36 template <class T = uint32_t>
37 class HashTableInternals : public HashTable<T> {
38 public:
39   using HashTable<T>::Buckets;
40   using HashTable<T>::Present;
41   using HashTable<T>::Deleted;
42 };
43 }
44 
45 TEST(HashTableTest, TestSimple) {
46   HashTableInternals<> Table;
47   EXPECT_EQ(0u, Table.size());
48   EXPECT_GT(Table.capacity(), 0u);
49 
50   IdentityHashTraits Traits;
51   Table.set_as(3u, 7, Traits);
52   EXPECT_EQ(1u, Table.size());
53   ASSERT_NE(Table.end(), Table.find_as(3u, Traits));
54   EXPECT_EQ(7u, Table.get(3u, Traits));
55 }
56 
57 TEST(HashTableTest, TestCollision) {
58   HashTableInternals<> Table;
59   EXPECT_EQ(0u, Table.size());
60   EXPECT_GT(Table.capacity(), 0u);
61 
62   // We use knowledge of the hash table's implementation details to make sure
63   // to add another value that is the equivalent to the first value modulo the
64   // hash table's capacity.
65   uint32_t N1 = Table.capacity() + 1;
66   uint32_t N2 = 2 * N1;
67 
68   IdentityHashTraits Traits;
69   Table.set_as(N1, 7, Traits);
70   Table.set_as(N2, 12, Traits);
71   EXPECT_EQ(2u, Table.size());
72   ASSERT_NE(Table.end(), Table.find_as(N1, Traits));
73   ASSERT_NE(Table.end(), Table.find_as(N2, Traits));
74 
75   EXPECT_EQ(7u, Table.get(N1, Traits));
76   EXPECT_EQ(12u, Table.get(N2, Traits));
77 }
78 
79 TEST(HashTableTest, TestRemove) {
80   HashTableInternals<> Table;
81   EXPECT_EQ(0u, Table.size());
82   EXPECT_GT(Table.capacity(), 0u);
83 
84   IdentityHashTraits Traits;
85   Table.set_as(1u, 2, Traits);
86   Table.set_as(3u, 4, Traits);
87   EXPECT_EQ(2u, Table.size());
88   ASSERT_NE(Table.end(), Table.find_as(1u, Traits));
89   ASSERT_NE(Table.end(), Table.find_as(3u, Traits));
90 
91   EXPECT_EQ(2u, Table.get(1u, Traits));
92   EXPECT_EQ(4u, Table.get(3u, Traits));
93 }
94 
95 TEST(HashTableTest, TestCollisionAfterMultipleProbes) {
96   HashTableInternals<> Table;
97   EXPECT_EQ(0u, Table.size());
98   EXPECT_GT(Table.capacity(), 0u);
99 
100   // Probing looks for the first available slot.  A slot may already be filled
101   // as a result of an item with a *different* hash value already being there.
102   // Test that when this happens, the probe still finds the value.
103   uint32_t N1 = Table.capacity() + 1;
104   uint32_t N2 = N1 + 1;
105   uint32_t N3 = 2 * N1;
106 
107   IdentityHashTraits Traits;
108   Table.set_as(N1, 7, Traits);
109   Table.set_as(N2, 11, Traits);
110   Table.set_as(N3, 13, Traits);
111   EXPECT_EQ(3u, Table.size());
112   ASSERT_NE(Table.end(), Table.find_as(N1, Traits));
113   ASSERT_NE(Table.end(), Table.find_as(N2, Traits));
114   ASSERT_NE(Table.end(), Table.find_as(N3, Traits));
115 
116   EXPECT_EQ(7u, Table.get(N1, Traits));
117   EXPECT_EQ(11u, Table.get(N2, Traits));
118   EXPECT_EQ(13u, Table.get(N3, Traits));
119 }
120 
121 TEST(HashTableTest, Grow) {
122   // So that we are independent of the load factor, `capacity` items, which is
123   // guaranteed to trigger a grow.  Then verify that the size is the same, the
124   // capacity is larger, and all the original items are still in the table.
125 
126   HashTableInternals<> Table;
127   IdentityHashTraits Traits;
128   uint32_t OldCapacity = Table.capacity();
129   for (uint32_t I = 0; I < OldCapacity; ++I) {
130     Table.set_as(OldCapacity + I * 2 + 1, I * 2 + 3, Traits);
131   }
132   EXPECT_EQ(OldCapacity, Table.size());
133   EXPECT_GT(Table.capacity(), OldCapacity);
134   for (uint32_t I = 0; I < OldCapacity; ++I) {
135     ASSERT_NE(Table.end(), Table.find_as(OldCapacity + I * 2 + 1, Traits));
136     EXPECT_EQ(I * 2 + 3, Table.get(OldCapacity + I * 2 + 1, Traits));
137   }
138 }
139 
140 TEST(HashTableTest, Serialization) {
141   HashTableInternals<> Table;
142   IdentityHashTraits Traits;
143   uint32_t Cap = Table.capacity();
144   for (uint32_t I = 0; I < Cap; ++I) {
145     Table.set_as(Cap + I * 2 + 1, I * 2 + 3, Traits);
146   }
147 
148   std::vector<uint8_t> Buffer(Table.calculateSerializedLength());
149   MutableBinaryByteStream Stream(Buffer, little);
150   BinaryStreamWriter Writer(Stream);
151   EXPECT_THAT_ERROR(Table.commit(Writer), Succeeded());
152   // We should have written precisely the number of bytes we calculated earlier.
153   EXPECT_EQ(Buffer.size(), Writer.getOffset());
154 
155   HashTableInternals<> Table2;
156   BinaryStreamReader Reader(Stream);
157   EXPECT_THAT_ERROR(Table2.load(Reader), Succeeded());
158   // We should have read precisely the number of bytes we calculated earlier.
159   EXPECT_EQ(Buffer.size(), Reader.getOffset());
160 
161   EXPECT_EQ(Table.size(), Table2.size());
162   EXPECT_EQ(Table.capacity(), Table2.capacity());
163   EXPECT_EQ(Table.Buckets, Table2.Buckets);
164   EXPECT_EQ(Table.Present, Table2.Present);
165   EXPECT_EQ(Table.Deleted, Table2.Deleted);
166 }
167 
168 TEST(HashTableTest, NamedStreamMap) {
169   std::vector<StringRef> Streams = {"One",  "Two", "Three", "Four",
170                                     "Five", "Six", "Seven"};
171   StringMap<uint32_t> ExpectedIndices;
172   for (uint32_t I = 0; I < Streams.size(); ++I)
173     ExpectedIndices[Streams[I]] = I + 1;
174 
175   // To verify the hash table actually works, we want to verify that insertion
176   // order doesn't matter.  So try inserting in every possible order of 7 items.
177   do {
178     NamedStreamMap NSM;
179     for (StringRef S : Streams)
180       NSM.set(S, ExpectedIndices[S]);
181 
182     EXPECT_EQ(Streams.size(), NSM.size());
183 
184     uint32_t N;
185     EXPECT_TRUE(NSM.get("One", N));
186     EXPECT_EQ(1U, N);
187 
188     EXPECT_TRUE(NSM.get("Two", N));
189     EXPECT_EQ(2U, N);
190 
191     EXPECT_TRUE(NSM.get("Three", N));
192     EXPECT_EQ(3U, N);
193 
194     EXPECT_TRUE(NSM.get("Four", N));
195     EXPECT_EQ(4U, N);
196 
197     EXPECT_TRUE(NSM.get("Five", N));
198     EXPECT_EQ(5U, N);
199 
200     EXPECT_TRUE(NSM.get("Six", N));
201     EXPECT_EQ(6U, N);
202 
203     EXPECT_TRUE(NSM.get("Seven", N));
204     EXPECT_EQ(7U, N);
205   } while (std::next_permutation(Streams.begin(), Streams.end()));
206 }
207 
208 struct FooBar {
209   uint32_t X;
210   uint32_t Y;
211 
212   bool operator==(const FooBar &RHS) const {
213     return X == RHS.X && Y == RHS.Y;
214   }
215 };
216 
217 struct FooBarHashTraits {
218   std::vector<char> Buffer;
219 
220   FooBarHashTraits() { Buffer.push_back(0); }
221 
222   uint32_t hashLookupKey(StringRef S) const {
223     return llvm::pdb::hashStringV1(S);
224   }
225 
226   StringRef storageKeyToLookupKey(uint32_t N) const {
227     if (N >= Buffer.size())
228       return StringRef();
229 
230     return StringRef(Buffer.data() + N);
231   }
232 
233   uint32_t lookupKeyToStorageKey(StringRef S) {
234     uint32_t N = Buffer.size();
235     Buffer.insert(Buffer.end(), S.begin(), S.end());
236     Buffer.push_back('\0');
237     return N;
238   }
239 };
240 
241 TEST(HashTableTest, NonTrivialValueType) {
242   HashTableInternals<FooBar> Table;
243   FooBarHashTraits Traits;
244   uint32_t Cap = Table.capacity();
245   for (uint32_t I = 0; I < Cap; ++I) {
246     FooBar F;
247     F.X = I;
248     F.Y = I + 1;
249     Table.set_as(utostr(I), F, Traits);
250   }
251 
252   std::vector<uint8_t> Buffer(Table.calculateSerializedLength());
253   MutableBinaryByteStream Stream(Buffer, little);
254   BinaryStreamWriter Writer(Stream);
255   EXPECT_THAT_ERROR(Table.commit(Writer), Succeeded());
256   // We should have written precisely the number of bytes we calculated earlier.
257   EXPECT_EQ(Buffer.size(), Writer.getOffset());
258 
259   HashTableInternals<FooBar> Table2;
260   BinaryStreamReader Reader(Stream);
261   EXPECT_THAT_ERROR(Table2.load(Reader), Succeeded());
262   // We should have read precisely the number of bytes we calculated earlier.
263   EXPECT_EQ(Buffer.size(), Reader.getOffset());
264 
265   EXPECT_EQ(Table.size(), Table2.size());
266   EXPECT_EQ(Table.capacity(), Table2.capacity());
267   EXPECT_EQ(Table.Buckets, Table2.Buckets);
268   EXPECT_EQ(Table.Present, Table2.Present);
269   EXPECT_EQ(Table.Deleted, Table2.Deleted);
270 }
271