1 #ifndef RAPIDJSON_WRITER_H_ 2 #define RAPIDJSON_WRITER_H_ 3 4 #include "rapidjson.h" 5 #include "internal/stack.h" 6 #include "internal/strfunc.h" 7 #include <cstdio> // snprintf() or _sprintf_s() 8 #include <new> // placement new 9 10 #ifdef _MSC_VER 11 #pragma warning(push) 12 #pragma warning(disable : 4127) // conditional expression is constant 13 #endif 14 15 namespace rapidjson { 16 17 //! JSON writer 18 /*! Writer implements the concept Handler. 19 It generates JSON text by events to an output stream. 20 21 User may programmatically calls the functions of a writer to generate JSON text. 22 23 On the other side, a writer can also be passed to objects that generates events, 24 25 for example Reader::Parse() and Document::Accept(). 26 27 \tparam Stream Type of ouptut stream. 28 \tparam Encoding Encoding of both source strings and output. 29 \implements Handler 30 */ 31 template<typename Stream, typename Encoding = UTF8<>, typename Allocator = MemoryPoolAllocator<> > 32 class Writer { 33 public: 34 typedef typename Encoding::Ch Ch; 35 36 Writer(Stream& stream, Allocator* allocator = 0, size_t levelDepth = kDefaultLevelDepth) : stream_(stream)37 stream_(stream), level_stack_(allocator, levelDepth * sizeof(Level)) {} 38 39 //@name Implementation of Handler 40 //@{ Null()41 Writer& Null() { Prefix(kNullType); WriteNull(); return *this; } Bool(bool b)42 Writer& Bool(bool b) { Prefix(b ? kTrueType : kFalseType); WriteBool(b); return *this; } Int(int i)43 Writer& Int(int i) { Prefix(kNumberType); WriteInt(i); return *this; } Uint(unsigned u)44 Writer& Uint(unsigned u) { Prefix(kNumberType); WriteUint(u); return *this; } Int64(int64_t i64)45 Writer& Int64(int64_t i64) { Prefix(kNumberType); WriteInt64(i64); return *this; } Uint64(uint64_t u64)46 Writer& Uint64(uint64_t u64) { Prefix(kNumberType); WriteUint64(u64); return *this; } Double(double d)47 Writer& Double(double d) { Prefix(kNumberType); WriteDouble(d); return *this; } 48 49 Writer& String(const Ch* str, SizeType length, bool copy = false) { 50 (void)copy; 51 Prefix(kStringType); 52 WriteString(str, length); 53 return *this; 54 } 55 StartObject()56 Writer& StartObject() { 57 Prefix(kObjectType); 58 new (level_stack_.template Push<Level>()) Level(false); 59 WriteStartObject(); 60 return *this; 61 } 62 63 Writer& EndObject(SizeType memberCount = 0) { 64 (void)memberCount; 65 RAPIDJSON_ASSERT(level_stack_.GetSize() >= sizeof(Level)); 66 RAPIDJSON_ASSERT(!level_stack_.template Top<Level>()->inArray); 67 level_stack_.template Pop<Level>(1); 68 WriteEndObject(); 69 return *this; 70 } 71 StartArray()72 Writer& StartArray() { 73 Prefix(kArrayType); 74 new (level_stack_.template Push<Level>()) Level(true); 75 WriteStartArray(); 76 return *this; 77 } 78 79 Writer& EndArray(SizeType elementCount = 0) { 80 (void)elementCount; 81 RAPIDJSON_ASSERT(level_stack_.GetSize() >= sizeof(Level)); 82 RAPIDJSON_ASSERT(level_stack_.template Top<Level>()->inArray); 83 level_stack_.template Pop<Level>(1); 84 WriteEndArray(); 85 return *this; 86 } 87 //@} 88 89 //! Simpler but slower overload. String(const Ch * str)90 Writer& String(const Ch* str) { return String(str, internal::StrLen(str)); } 91 92 protected: 93 //! Information for each nested level 94 struct Level { LevelLevel95 Level(bool inArray_) : inArray(inArray_), valueCount(0) {} 96 bool inArray; //!< true if in array, otherwise in object 97 size_t valueCount; //!< number of values in this level 98 }; 99 100 static const size_t kDefaultLevelDepth = 32; 101 WriteNull()102 void WriteNull() { 103 stream_.Put('n'); stream_.Put('u'); stream_.Put('l'); stream_.Put('l'); 104 } 105 WriteBool(bool b)106 void WriteBool(bool b) { 107 if (b) { 108 stream_.Put('t'); stream_.Put('r'); stream_.Put('u'); stream_.Put('e'); 109 } 110 else { 111 stream_.Put('f'); stream_.Put('a'); stream_.Put('l'); stream_.Put('s'); stream_.Put('e'); 112 } 113 } 114 WriteInt(int i)115 void WriteInt(int i) { 116 if (i < 0) { 117 stream_.Put('-'); 118 i = -i; 119 } 120 WriteUint((unsigned)i); 121 } 122 WriteUint(unsigned u)123 void WriteUint(unsigned u) { 124 char buffer[10]; 125 char *p = buffer; 126 do { 127 *p++ = (u % 10) + '0'; 128 u /= 10; 129 } while (u > 0); 130 131 do { 132 --p; 133 stream_.Put(*p); 134 } while (p != buffer); 135 } 136 WriteInt64(int64_t i64)137 void WriteInt64(int64_t i64) { 138 if (i64 < 0) { 139 stream_.Put('-'); 140 i64 = -i64; 141 } 142 WriteUint64((uint64_t)i64); 143 } 144 WriteUint64(uint64_t u64)145 void WriteUint64(uint64_t u64) { 146 char buffer[20]; 147 char *p = buffer; 148 do { 149 *p++ = char(u64 % 10) + '0'; 150 u64 /= 10; 151 } while (u64 > 0); 152 153 do { 154 --p; 155 stream_.Put(*p); 156 } while (p != buffer); 157 } 158 159 //! \todo Optimization with custom double-to-string converter. WriteDouble(double d)160 void WriteDouble(double d) { 161 char buffer[100]; 162 #if _MSC_VER 163 int ret = sprintf_s(buffer, sizeof(buffer), "%g", d); 164 #else 165 int ret = snprintf(buffer, sizeof(buffer), "%g", d); 166 #endif 167 RAPIDJSON_ASSERT(ret >= 1); 168 for (int i = 0; i < ret; i++) 169 stream_.Put(buffer[i]); 170 } 171 WriteString(const Ch * str,SizeType length)172 void WriteString(const Ch* str, SizeType length) { 173 static const char hexDigits[] = "0123456789ABCDEF"; 174 static const char escape[256] = { 175 #define Z16 0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0 176 //0 1 2 3 4 5 6 7 8 9 A B C D E F 177 'u', 'u', 'u', 'u', 'u', 'u', 'u', 'u', 'b', 't', 'n', 'u', 'f', 'r', 'u', 'u', // 00 178 'u', 'u', 'u', 'u', 'u', 'u', 'u', 'u', 'u', 'u', 'u', 'u', 'u', 'u', 'u', 'u', // 10 179 0, 0, '"', 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, // 20 180 Z16, Z16, // 30~4F 181 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,'\\', 0, 0, 0, // 50 182 Z16, Z16, Z16, Z16, Z16, Z16, Z16, Z16, Z16, Z16 // 60~FF 183 #undef Z16 184 }; 185 186 stream_.Put('\"'); 187 for (const Ch* p = str; p != str + length; ++p) { 188 if ((sizeof(Ch) == 1 || *p < 256) && escape[(unsigned char)*p]) { 189 stream_.Put('\\'); 190 stream_.Put(escape[(unsigned char)*p]); 191 if (escape[(unsigned char)*p] == 'u') { 192 stream_.Put('0'); 193 stream_.Put('0'); 194 stream_.Put(hexDigits[(*p) >> 4]); 195 stream_.Put(hexDigits[(*p) & 0xF]); 196 } 197 } 198 else 199 stream_.Put(*p); 200 } 201 stream_.Put('\"'); 202 } 203 WriteStartObject()204 void WriteStartObject() { stream_.Put('{'); } WriteEndObject()205 void WriteEndObject() { stream_.Put('}'); } WriteStartArray()206 void WriteStartArray() { stream_.Put('['); } WriteEndArray()207 void WriteEndArray() { stream_.Put(']'); } 208 Prefix(Type type)209 void Prefix(Type type) { 210 (void)type; 211 if (level_stack_.GetSize() != 0) { // this value is not at root 212 Level* level = level_stack_.template Top<Level>(); 213 if (level->valueCount > 0) { 214 if (level->inArray) 215 stream_.Put(','); // add comma if it is not the first element in array 216 else // in object 217 stream_.Put((level->valueCount % 2 == 0) ? ',' : ':'); 218 } 219 if (!level->inArray && level->valueCount % 2 == 0) 220 RAPIDJSON_ASSERT(type == kStringType); // if it's in object, then even number should be a name 221 level->valueCount++; 222 } 223 else 224 RAPIDJSON_ASSERT(type == kObjectType || type == kArrayType); 225 } 226 227 Stream& stream_; 228 internal::Stack<Allocator> level_stack_; 229 230 private: 231 // Prohibit assignment for VC C4512 warning 232 Writer& operator=(const Writer& w); 233 }; 234 235 } // namespace rapidjson 236 237 #ifdef _MSC_VER 238 #pragma warning(pop) 239 #endif 240 241 #endif // RAPIDJSON_RAPIDJSON_H_ 242