writer.h

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#ifndef RAPIDJSON_WRITER_H_
#define RAPIDJSON_WRITER_H_
 
#include "rapidjson.h"
#include "internal/stack.h"
#include "internal/strfunc.h"
#include <cstdio>   // snprintf() or _sprintf_s()
#include <new>      // placement new
#include <limits>
 
#ifdef _MSC_VER
#pragma warning(push)
#pragma warning(disable : 4127) // conditional expression is constant
#endif
 
namespace rapidjson {
 
 
template<typename Stream, typename Encoding = UTF8<>, typename Allocator = MemoryPoolAllocator<> >
class Writer {
public:
    typedef typename Encoding::Ch Ch;
 
    Writer(Stream& stream, int precision = 20, Allocator* allocator = 0, size_t levelDepth = kDefaultLevelDepth) :
        stream_(stream), level_stack_(allocator, levelDepth * sizeof(Level))
  {
#if _MSC_VER
    (void) sprintf_s(double_format, sizeof(double_format), "%%0.%dg", precision);
    (void) sprintf_s( long_double_format, sizeof( long_double_format ), "%%0.%dLg", precision );
#else
    (void) snprintf(double_format, sizeof(double_format), "%%0.%dg", precision);
    (void) snprintf( long_double_format, sizeof( long_double_format ), "%%0.%dLg", precision );
#endif
 
  }
 
protected:
  char double_format[32];
  char long_double_format[32];
public:
 
    //@name Implementation of Handler
 
    Writer& Null_()                          { Prefix(kNull_Type);   WriteNull_();          return *this;             }
    Writer& Bool_(bool b)                    { Prefix(b ? kTrueType : kFalseType); WriteBool_(b); return *this; }
    Writer& Int(int i)                      { Prefix(kNumberType); WriteInt(i);         return *this;             }
    Writer& Uint(unsigned u)                { Prefix(kNumberType); WriteUint(u);        return *this;             }
    Writer& Int64(int64_t i64)              { Prefix(kNumberType); WriteInt64(i64);     return *this;           }
    Writer& Uint64(uint64_t u64)            { Prefix(kNumberType); WriteUint64(u64);    return *this;           }
    Writer& Double(double d)                { Prefix(kNumberType); WriteDouble(d);      return *this;           }
    Writer& LongDouble(long double d)       { Prefix(kNumberType); WriteLongDouble(d);      return *this;       }
    Writer& LongLong(long long d)           { Prefix(kNumberType); WriteLongLong(d);        return *this;         }
    Writer& ULongLong(unsigned long long d) { Prefix(kNumberType); WriteULongLong(d);       return *this;         }
 
    Writer& String(const Ch* str, SizeType length, bool copy = false) {
        (void)copy;
        Prefix(kStringType);
        WriteString(str, length);
        return *this;
    }
 
    Writer& StartObject() {
        Prefix(kObjectType);
        new (level_stack_.template Push<Level>()) Level(false);
        WriteStartObject();
        return *this;
    }
 
    Writer& EndObject(SizeType memberCount = 0) {
        (void)memberCount;
        RAPIDJSON_ASSERT(level_stack_.GetSize() >= sizeof(Level));
        RAPIDJSON_ASSERT(!level_stack_.template Top<Level>()->inArray);
        level_stack_.template Pop<Level>(1);
        WriteEndObject();
        return *this;
    }
 
    Writer& StartArray() {
        Prefix(kArrayType);
        new (level_stack_.template Push<Level>()) Level(true);
        WriteStartArray();
        return *this;
    }
 
    Writer& EndArray(SizeType elementCount = 0) {
        (void)elementCount;
        RAPIDJSON_ASSERT(level_stack_.GetSize() >= sizeof(Level));
        RAPIDJSON_ASSERT(level_stack_.template Top<Level>()->inArray);
        level_stack_.template Pop<Level>(1);
        WriteEndArray();
        return *this;
    }
 
    Writer& String(const Ch* str) { return String(str, internal::StrLen(str)); }
 
protected:
    struct Level {
        Level(bool inArray_) : inArray(inArray_), valueCount(0) {}
        bool inArray;       
        size_t valueCount;  
    };
 
    static const size_t kDefaultLevelDepth = 32;
 
    void WriteNull_()  {
        stream_.Put('n'); stream_.Put('u'); stream_.Put('l'); stream_.Put('l');
    }
 
    void WriteBool_(bool b)  {
        if (b) {
            stream_.Put('t'); stream_.Put('r'); stream_.Put('u'); stream_.Put('e');
        }
        else {
            stream_.Put('f'); stream_.Put('a'); stream_.Put('l'); stream_.Put('s'); stream_.Put('e');
        }
    }
 
    void WriteInt(int i) {
        if (i < 0) {
            stream_.Put('-');
            i = -i;
        }
        WriteUint((unsigned)i);
    }
 
    void WriteUint(unsigned u) {
        char buffer[10];
        char *p = buffer;
        do {
            *p++ = (u % 10) + '0';
            u /= 10;
        } while (u > 0);
 
        do {
            --p;
            stream_.Put(*p);
        } while (p != buffer);
    }
 
    void WriteInt64(int64_t i64) {
        if (i64 < 0) {
            stream_.Put('-');
            i64 = -i64;
        }
        WriteUint64((uint64_t)i64);
    }
 
    void WriteUint64(uint64_t u64) {
        char buffer[20];
        char *p = buffer;
        do {
            *p++ = char(u64 % 10) + '0';
            u64 /= 10;
        } while (u64 > 0);
 
        do {
            --p;
            stream_.Put(*p);
        } while (p != buffer);
    }
 
  // cereal Temporary until constexpr support is added in RTM
#ifdef _MSC_VER
  template <class Ch>
  bool characterOk( Ch c )
  {
    return c < 256;
  }
 
  template <>
  bool characterOk<char>( Ch )
  {
    return true;
  }
 
#else
  // As part of a fix for GCC 4.7
  template <class T>
  static constexpr int to_int( T t ){ return t; }
 
  template<class Ch>
  typename std::enable_if < to_int(std::numeric_limits<Ch>::max()) < to_int(256), bool>::type
    characterOk( Ch )
  {
    return true;
  }
 
  template<class Ch>
  typename std::enable_if< to_int(std::numeric_limits<Ch>::max()) >= to_int(256), bool>::type
    characterOk(Ch c)
  { return c < 256; }
#endif
 
    void WriteDouble(double d) {
        char buffer[100];
#if _MSC_VER
        int ret = sprintf_s(buffer, sizeof(buffer), double_format, d);
#else
        int ret = snprintf(buffer, sizeof(buffer), double_format, d);
#endif
        RAPIDJSON_ASSERT(ret >= 1);
        for (int i = 0; i < ret; i++)
            stream_.Put(buffer[i]);
    }
 
    void WriteLongDouble(long double d) {
        char buffer[256];
#if _MSC_VER
        int ret = sprintf_s(buffer, sizeof(buffer), long_double_format, d);
#else
        int ret = snprintf(buffer, sizeof(buffer), long_double_format, d);
#endif
        RAPIDJSON_ASSERT(ret >= 1);
        for (int i = 0; i < ret; i++)
            stream_.Put(buffer[i]);
    }
 
    void WriteLongLong(long long d) {
        char buffer[256];
#if _MSC_VER
        int ret = sprintf_s(buffer, sizeof(buffer), "%lld", d);
#else
        int ret = snprintf(buffer, sizeof(buffer), "%lld", d);
#endif
        RAPIDJSON_ASSERT(ret >= 1);
        for (int i = 0; i < ret; i++)
            stream_.Put(buffer[i]);
    }
 
    void WriteULongLong(unsigned long long d) {
        char buffer[256];
#if _MSC_VER
        int ret = sprintf_s(buffer, sizeof(buffer), "%llu", d);
#else
        int ret = snprintf(buffer, sizeof(buffer), "%llu", d);
#endif
        RAPIDJSON_ASSERT(ret >= 1);
        for (int i = 0; i < ret; i++)
            stream_.Put(buffer[i]);
    }
 
    void WriteString(const Ch* str, SizeType length)  {
        static const char hexDigits[] = "0123456789ABCDEF";
        static const char escape[256] = {
#define Z16 0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0
            //0    1    2    3    4    5    6    7    8    9    A    B    C    D    E    F
            'u', 'u', 'u', 'u', 'u', 'u', 'u', 'u', 'b', 't', 'n', 'u', 'f', 'r', 'u', 'u', // 00
            'u', 'u', 'u', 'u', 'u', 'u', 'u', 'u', 'u', 'u', 'u', 'u', 'u', 'u', 'u', 'u', // 10
              0,   0, '"',   0,   0,   0,   0,   0,   0,   0,   0,   0,   0,   0,   0,   0, // 20
            Z16, Z16,                                                                       // 30~4F
              0,   0,   0,   0,   0,   0,   0,   0,   0,   0,   0,   0,'\\',   0,   0,   0, // 50
            Z16, Z16, Z16, Z16, Z16, Z16, Z16, Z16, Z16, Z16                                // 60~FF
#undef Z16
        };
 
        stream_.Put('\"');
        for (const Ch* p = str; p != str + length; ++p) {
            if ((sizeof(Ch) == 1 || characterOk(*p)) && escape[(unsigned char)*p])  {
            //if ((sizeof(Ch) == 1 || *p < 256) && escape[(unsigned char)*p])  {
                stream_.Put('\\');
                stream_.Put(escape[(unsigned char)*p]);
                if (escape[(unsigned char)*p] == 'u') {
                    stream_.Put('0');
                    stream_.Put('0');
                    stream_.Put(hexDigits[(*p) >> 4]);
                    stream_.Put(hexDigits[(*p) & 0xF]);
                }
            }
            else
                stream_.Put(*p);
        }
        stream_.Put('\"');
    }
 
    void WriteStartObject() { stream_.Put('{'); }
    void WriteEndObject()   { stream_.Put('}'); }
    void WriteStartArray()  { stream_.Put('['); }
    void WriteEndArray()    { stream_.Put(']'); }
 
    void Prefix(Type type) {
        (void)type;
        if (level_stack_.GetSize() != 0) { // this value is not at root
            Level* level = level_stack_.template Top<Level>();
            if (level->valueCount > 0) {
                if (level->inArray)
                    stream_.Put(','); // add comma if it is not the first element in array
                else  // in object
                    stream_.Put((level->valueCount % 2 == 0) ? ',' : ':');
            }
            if (!level->inArray && level->valueCount % 2 == 0)
                RAPIDJSON_ASSERT(type == kStringType);  // if it's in object, then even number should be a name
            level->valueCount++;
        }
        else
            RAPIDJSON_ASSERT(type == kObjectType || type == kArrayType);
    }
 
    Stream& stream_;
    internal::Stack<Allocator> level_stack_;
 
private:
    // Prohibit assignment for VC C4512 warning
    Writer& operator=(const Writer& w);
};
 
} // namespace rapidjson
 
#ifdef _MSC_VER
#pragma warning(pop)
#endif
 
#endif // RAPIDJSON_RAPIDJSON_H_