1 // Tencent is pleased to support the open source community by making RapidJSON available.
2 //
3 // Copyright (C) 2015 THL A29 Limited, a Tencent company, and Milo Yip. All rights reserved.
4 //
5 // Licensed under the MIT License (the "License"); you may not use this file except
6 // in compliance with the License. You may obtain a copy of the License at
7 //
8 // http://opensource.org/licenses/MIT
9 //
10 // Unless required by applicable law or agreed to in writing, software distributed
11 // under the License is distributed on an "AS IS" BASIS, WITHOUT WARRANTIES OR
12 // CONDITIONS OF ANY KIND, either express or implied. See the License for the
13 // specific language governing permissions and limitations under the License.
14 
15 #include "unittest.h"
16 #include "rapidjson/internal/itoa.h"
17 
18 #ifdef __GNUC__
19 RAPIDJSON_DIAG_PUSH
20 RAPIDJSON_DIAG_OFF(type-limits)
21 #endif
22 
23 using namespace rapidjson::internal;
24 
25 template <typename T>
26 struct Traits {
27 };
28 
29 template <>
30 struct Traits<uint32_t> {
31     enum { kBufferSize = 11 };
32     enum { kMaxDigit = 10 };
NegateTraits33     static uint32_t Negate(uint32_t x) { return x; }
34 };
35 
36 template <>
37 struct Traits<int32_t> {
38     enum { kBufferSize = 12 };
39     enum { kMaxDigit = 10 };
NegateTraits40     static int32_t Negate(int32_t x) { return -x; }
41 };
42 
43 template <>
44 struct Traits<uint64_t> {
45     enum { kBufferSize = 21 };
46     enum { kMaxDigit = 20 };
NegateTraits47     static uint64_t Negate(uint64_t x) { return x; }
48 };
49 
50 template <>
51 struct Traits<int64_t> {
52     enum { kBufferSize = 22 };
53     enum { kMaxDigit = 20 };
NegateTraits54     static int64_t Negate(int64_t x) { return -x; }
55 };
56 
57 template <typename T>
VerifyValue(T value,void (* f)(T,char *),char * (* g)(T,char *))58 static void VerifyValue(T value, void(*f)(T, char*), char* (*g)(T, char*)) {
59     char buffer1[Traits<T>::kBufferSize];
60     char buffer2[Traits<T>::kBufferSize];
61 
62     f(value, buffer1);
63     *g(value, buffer2) = '\0';
64 
65 
66     EXPECT_STREQ(buffer1, buffer2);
67 }
68 
69 template <typename T>
Verify(void (* f)(T,char *),char * (* g)(T,char *))70 static void Verify(void(*f)(T, char*), char* (*g)(T, char*)) {
71     // Boundary cases
72     VerifyValue<T>(0, f, g);
73     VerifyValue<T>((std::numeric_limits<T>::min)(), f, g);
74     VerifyValue<T>((std::numeric_limits<T>::max)(), f, g);
75 
76     // 2^n - 1, 2^n, 10^n - 1, 10^n until overflow
77     for (int power = 2; power <= 10; power += 8) {
78         T i = 1, last;
79         do {
80             VerifyValue<T>(i - 1, f, g);
81             VerifyValue<T>(i, f, g);
82             if (std::numeric_limits<T>::min() < 0) {
83                 VerifyValue<T>(Traits<T>::Negate(i), f, g);
84                 VerifyValue<T>(Traits<T>::Negate(i + 1), f, g);
85             }
86             last = i;
87             if (i > static_cast<T>(std::numeric_limits<T>::max() / static_cast<T>(power)))
88                 break;
89             i *= static_cast<T>(power);
90         } while (last < i);
91     }
92 }
93 
u32toa_naive(uint32_t value,char * buffer)94 static void u32toa_naive(uint32_t value, char* buffer) {
95     char temp[10];
96     char *p = temp;
97     do {
98         *p++ = static_cast<char>(char(value % 10) + '0');
99         value /= 10;
100     } while (value > 0);
101 
102     do {
103         *buffer++ = *--p;
104     } while (p != temp);
105 
106     *buffer = '\0';
107 }
108 
i32toa_naive(int32_t value,char * buffer)109 static void i32toa_naive(int32_t value, char* buffer) {
110     uint32_t u = static_cast<uint32_t>(value);
111     if (value < 0) {
112         *buffer++ = '-';
113         u = ~u + 1;
114     }
115     u32toa_naive(u, buffer);
116 }
117 
u64toa_naive(uint64_t value,char * buffer)118 static void u64toa_naive(uint64_t value, char* buffer) {
119     char temp[20];
120     char *p = temp;
121     do {
122         *p++ = static_cast<char>(char(value % 10) + '0');
123         value /= 10;
124     } while (value > 0);
125 
126     do {
127         *buffer++ = *--p;
128     } while (p != temp);
129 
130     *buffer = '\0';
131 }
132 
i64toa_naive(int64_t value,char * buffer)133 static void i64toa_naive(int64_t value, char* buffer) {
134     uint64_t u = static_cast<uint64_t>(value);
135     if (value < 0) {
136         *buffer++ = '-';
137         u = ~u + 1;
138     }
139     u64toa_naive(u, buffer);
140 }
141 
TEST(itoa,u32toa)142 TEST(itoa, u32toa) {
143     Verify(u32toa_naive, u32toa);
144 }
145 
TEST(itoa,i32toa)146 TEST(itoa, i32toa) {
147     Verify(i32toa_naive, i32toa);
148 }
149 
TEST(itoa,u64toa)150 TEST(itoa, u64toa) {
151     Verify(u64toa_naive, u64toa);
152 }
153 
TEST(itoa,i64toa)154 TEST(itoa, i64toa) {
155     Verify(i64toa_naive, i64toa);
156 }
157 
158 #ifdef __GNUC__
159 RAPIDJSON_DIAG_POP
160 #endif
161