1 /*
2  * Copyright (C) 2014 The Android Open Source Project
3  *
4  * Licensed under the Apache License, Version 2.0 (the "License");
5  * you may not use this file except in compliance with the License.
6  * You may obtain a copy of the License at
7  *
8  *      http://www.apache.org/licenses/LICENSE-2.0
9  *
10  * Unless required by applicable law or agreed to in writing, software
11  * distributed under the License is distributed on an "AS IS" BASIS,
12  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13  * See the License for the specific language governing permissions and
14  * limitations under the License.
15  */
16 
17 #include <gtest/gtest.h>
18 
19 #include <search.h>
20 
int_cmp(const void * lhs,const void * rhs)21 static int int_cmp(const void* lhs, const void* rhs) {
22   return *reinterpret_cast<const int*>(rhs) - *reinterpret_cast<const int*>(lhs);
23 }
24 
TEST(search,lfind_lsearch)25 TEST(search, lfind_lsearch) {
26   int xs[10];
27   memset(xs, 0, sizeof(xs));
28   size_t x_size = 0;
29 
30   int needle;
31 
32   // lfind(3) can't find '2' in the empty table.
33   needle = 2;
34   ASSERT_EQ(nullptr, lfind(&needle, xs, &x_size, sizeof(xs[0]), int_cmp));
35   ASSERT_EQ(0U, x_size);
36 
37   // lsearch(3) will add it.
38   ASSERT_EQ(&xs[0], lsearch(&needle, xs, &x_size, sizeof(xs[0]), int_cmp));
39   ASSERT_EQ(2, xs[0]);
40   ASSERT_EQ(1U, x_size);
41 
42   // And then lfind(3) can find it.
43   ASSERT_EQ(&xs[0], lfind(&needle, xs, &x_size, sizeof(xs[0]), int_cmp));
44   ASSERT_EQ(1U, x_size);
45 
46   // Inserting a duplicate does nothing (but returns the existing element).
47   ASSERT_EQ(&xs[0], lsearch(&needle, xs, &x_size, sizeof(xs[0]), int_cmp));
48   ASSERT_EQ(1U, x_size);
49 }
50 
51 struct node {
nodenode52   node(const char* s) : s(strdup(s)) {}
53 
54   char* s;
55 };
56 
node_cmp(const void * lhs,const void * rhs)57 static int node_cmp(const void* lhs, const void* rhs) {
58   return strcmp(reinterpret_cast<const node*>(lhs)->s, reinterpret_cast<const node*>(rhs)->s);
59 }
60 
61 static std::vector<std::string> g_nodes;
62 
node_walk(const void * p,VISIT order,int)63 static void node_walk(const void* p, VISIT order, int) {
64   const node* n = *reinterpret_cast<const node* const*>(p);
65   if (order == postorder || order == leaf)  {
66     g_nodes.push_back(n->s);
67   }
68 }
69 
70 static size_t g_free_calls;
71 
node_free(void * p)72 static void node_free(void* p) {
73   node* n = reinterpret_cast<node*>(p);
74   free(n->s);
75   ++g_free_calls;
76 }
77 
TEST(search,tfind_tsearch_twalk_tdestroy)78 TEST(search, tfind_tsearch_twalk_tdestroy) {
79   void* root = nullptr;
80 
81   node n1("z");
82   node n2("a");
83   node n3("m");
84 
85   // tfind(3) can't find anything in the empty tree.
86   ASSERT_EQ(nullptr, tfind(&n1, &root, node_cmp));
87   ASSERT_EQ(nullptr, tfind(&n2, &root, node_cmp));
88   ASSERT_EQ(nullptr, tfind(&n3, &root, node_cmp));
89 
90   // tsearch(3) inserts and returns a pointer to a new node.
91   void* i1 = tsearch(&n1, &root, node_cmp);
92   ASSERT_NE(nullptr, i1);
93 
94   // ...which tfind(3) will then return.
95   ASSERT_EQ(i1, tfind(&n1, &root, node_cmp));
96   ASSERT_EQ(nullptr, tfind(&n2, &root, node_cmp));
97   ASSERT_EQ(nullptr, tfind(&n3, &root, node_cmp));
98 
99   // Add the other nodes.
100   ASSERT_NE(nullptr, tsearch(&n2, &root, node_cmp));
101   ASSERT_NE(nullptr, tsearch(&n3, &root, node_cmp));
102 
103   // Use twalk(3) to iterate over the nodes.
104   g_nodes.clear();
105   twalk(root, node_walk);
106   ASSERT_EQ(3U, g_nodes.size());
107   ASSERT_EQ("a", g_nodes[0]);
108   ASSERT_EQ("m", g_nodes[1]);
109   ASSERT_EQ("z", g_nodes[2]);
110 
111   // tdestroy(3) removes nodes under a node, calling our callback to destroy each one.
112   g_free_calls = 0;
113   tdestroy(root, node_free);
114   ASSERT_EQ(3U, g_free_calls);
115 }
116 
117 struct pod_node {
pod_nodepod_node118   pod_node(int i) : i(i) {}
119   int i;
120 };
121 
pod_node_cmp(const void * lhs,const void * rhs)122 static int pod_node_cmp(const void* lhs, const void* rhs) {
123   return reinterpret_cast<const pod_node*>(rhs)->i - reinterpret_cast<const pod_node*>(lhs)->i;
124 }
125 
TEST(search,tdelete)126 TEST(search, tdelete) {
127   void* root = nullptr;
128 
129   pod_node n1(123);
130   ASSERT_NE(nullptr, tsearch(&n1, &root, pod_node_cmp));
131 
132   // tdelete(3) leaks n1.
133   pod_node not_there(456);
134   ASSERT_EQ(nullptr, tdelete(&not_there, &root, pod_node_cmp));
135   ASSERT_NE(nullptr, tdelete(&n1, &root, pod_node_cmp));
136 }
137 
138 struct q_node {
q_nodeq_node139   q_node(int i) : i(i) {}
140 
141   q_node* next;
142   q_node* prev;
143 
144   int i;
145 };
146 
TEST(search,insque_remque)147 TEST(search, insque_remque) {
148   q_node zero(0);
149   q_node one(1);
150   q_node two(2);
151 
152   // Linear (not circular).
153 
154   insque(&zero, NULL);
155   insque(&one, &zero);
156   insque(&two, &one);
157 
158   int expected = 0;
159   for (q_node* q = &zero; q != NULL; q = q->next) {
160     ASSERT_EQ(expected, q->i);
161     ++expected;
162   }
163   ASSERT_EQ(3, expected);
164 
165   for (q_node* q = &two; q != NULL; q = q->prev) {
166     --expected;
167     ASSERT_EQ(expected, q->i);
168   }
169   ASSERT_EQ(0, expected);
170 
171   q_node* head = &zero;
172 
173   remque(&one);
174   ASSERT_EQ(0, head->i);
175   ASSERT_EQ(2, head->next->i);
176   ASSERT_EQ(nullptr, head->next->next);
177 
178   remque(&two);
179   ASSERT_EQ(0, head->i);
180   ASSERT_EQ(nullptr, head->next);
181 
182   remque(&zero);
183 
184   // Circular.
185 
186   zero.next = &zero;
187   zero.prev = &zero;
188 
189   insque(&one, &zero);
190   insque(&two, &one);
191 
192   ASSERT_EQ(0, head->i);
193   ASSERT_EQ(1, head->next->i);
194   ASSERT_EQ(2, head->next->next->i);
195   ASSERT_EQ(0, head->next->next->next->i);
196   ASSERT_EQ(1, head->next->next->next->next->i);
197   ASSERT_EQ(2, head->next->next->next->next->next->i);
198 
199   remque(&one);
200   ASSERT_EQ(0, head->i);
201   ASSERT_EQ(2, head->next->i);
202   ASSERT_EQ(0, head->next->next->i);
203   ASSERT_EQ(2, head->next->next->next->i);
204 
205   remque(&two);
206   ASSERT_EQ(0, head->i);
207   ASSERT_EQ(0, head->next->i);
208 
209   remque(&zero);
210 }
211