xref: /aosp_15_r20/external/leveldb/util/arena_test.cc (revision 9507f98c5f32dee4b5f9e4a38cd499f3ff5c4490)
1 // Copyright (c) 2011 The LevelDB Authors. All rights reserved.
2 // Use of this source code is governed by a BSD-style license that can be
3 // found in the LICENSE file. See the AUTHORS file for names of contributors.
4 
5 #include "util/arena.h"
6 
7 #include "gtest/gtest.h"
8 #include "util/random.h"
9 
10 namespace leveldb {
11 
TEST(ArenaTest,Empty)12 TEST(ArenaTest, Empty) { Arena arena; }
13 
TEST(ArenaTest,Simple)14 TEST(ArenaTest, Simple) {
15   std::vector<std::pair<size_t, char*>> allocated;
16   Arena arena;
17   const int N = 100000;
18   size_t bytes = 0;
19   Random rnd(301);
20   for (int i = 0; i < N; i++) {
21     size_t s;
22     if (i % (N / 10) == 0) {
23       s = i;
24     } else {
25       s = rnd.OneIn(4000)
26               ? rnd.Uniform(6000)
27               : (rnd.OneIn(10) ? rnd.Uniform(100) : rnd.Uniform(20));
28     }
29     if (s == 0) {
30       // Our arena disallows size 0 allocations.
31       s = 1;
32     }
33     char* r;
34     if (rnd.OneIn(10)) {
35       r = arena.AllocateAligned(s);
36     } else {
37       r = arena.Allocate(s);
38     }
39 
40     for (size_t b = 0; b < s; b++) {
41       // Fill the "i"th allocation with a known bit pattern
42       r[b] = i % 256;
43     }
44     bytes += s;
45     allocated.push_back(std::make_pair(s, r));
46     ASSERT_GE(arena.MemoryUsage(), bytes);
47     if (i > N / 10) {
48       ASSERT_LE(arena.MemoryUsage(), bytes * 1.10);
49     }
50   }
51   for (size_t i = 0; i < allocated.size(); i++) {
52     size_t num_bytes = allocated[i].first;
53     const char* p = allocated[i].second;
54     for (size_t b = 0; b < num_bytes; b++) {
55       // Check the "i"th allocation for the known bit pattern
56       ASSERT_EQ(int(p[b]) & 0xff, i % 256);
57     }
58   }
59 }
60 
61 }  // namespace leveldb
62 
63