ceph/src/rapidjson/example/jsonx/jsonx.cpp

   1 // JSON to JSONx conversion exmaple, using SAX API.
   2 // JSONx is an IBM standard format to represent JSON as XML.
   3 // https://www-01.ibm.com/support/knowledgecenter/SS9H2Y_7.1.0/com.ibm.dp.doc/json_jsonx.html
   4 // This example parses JSON text from stdin with validation,
   5 // and convert to JSONx format to stdout.
   6 // Need compile with -D__STDC_FORMAT_MACROS for defining PRId64 and PRIu64 macros.
   7
   8 #include "rapidjson/reader.h"
   9 #include "rapidjson/stringbuffer.h"
  10 #include "rapidjson/filereadstream.h"
  11 #include "rapidjson/filewritestream.h"
  12 #include "rapidjson/error/en.h"
  13 #include <cstdio>
  14
  15 using namespace rapidjson;
  16
  17 // For simplicity, this example only read/write in UTF-8 encoding
  18 template <typename OutputStream>
  19 class JsonxWriter {
  20 public:
  21     JsonxWriter(OutputStream& os) : os_(os), name_(), level_(0), hasName_(false) {
  22     }
  23
  24     bool Null() {
  25         return WriteStartElement("null", true);
  26     }
  27
  28     bool Bool(bool b) {
  29         return
  30             WriteStartElement("boolean") &&
  31             WriteString(b ? "true" : "false") &&
  32             WriteEndElement("boolean");
  33     }
  34
  35     bool Int(int i) {
  36         char buffer[12];
  37         return WriteNumberElement(buffer, sprintf(buffer, "%d", i));
  38     }
  39
  40     bool Uint(unsigned i) {
  41         char buffer[11];
  42         return WriteNumberElement(buffer, sprintf(buffer, "%u", i));
  43     }
  44
  45     bool Int64(int64_t i) {
  46         char buffer[21];
  47         return WriteNumberElement(buffer, sprintf(buffer, "%" PRId64, i));
  48     }
  49
  50     bool Uint64(uint64_t i) {
  51         char buffer[21];
  52         return WriteNumberElement(buffer, sprintf(buffer, "%" PRIu64, i));
  53     }
  54
  55     bool Double(double d) {
  56         char buffer[30];
  57         return WriteNumberElement(buffer, sprintf(buffer, "%.17g", d));
  58     }
  59
  60     bool RawNumber(const char* str, SizeType length, bool) {
  61         return
  62             WriteStartElement("number") &&
  63             WriteEscapedText(str, length) &&
  64             WriteEndElement("number");
  65     }
  66
  67     bool String(const char* str, SizeType length, bool) {
  68         return
  69             WriteStartElement("string") &&
  70             WriteEscapedText(str, length) &&
  71             WriteEndElement("string");
  72     }
  73
  74     bool StartObject() {
  75         return WriteStartElement("object");
  76     }
  77
  78     bool Key(const char* str, SizeType length, bool) {
  79         // backup key to name_
  80         name_.Clear();
  81         for (SizeType i = 0; i < length; i++)
  82             name_.Put(str[i]);
  83         hasName_ = true;
  84         return true;
  85     }
  86
  87     bool EndObject(SizeType) {
  88         return WriteEndElement("object");
  89     }
  90
  91     bool StartArray() {
  92         return WriteStartElement("array");
  93     }
  94
  95     bool EndArray(SizeType) {
  96         return WriteEndElement("array");
  97     }
  98
  99 private:
 100     bool WriteString(const char* s) {
 101         while (*s)
 102             os_.Put(*s++);
 103         return true;
 104     }
 105
 106     bool WriteEscapedAttributeValue(const char* s, size_t length) {
 107         for (size_t i = 0; i < length; i++) {
 108             switch (s[i]) {
 109                 case '&': WriteString("&amp;"); break;
 110                 case '<': WriteString("&lt;"); break;
 111                 case '"': WriteString("&quot;"); break;
 112                 default: os_.Put(s[i]); break;
 113             }
 114         }
 115         return true;
 116     }
 117
 118     bool WriteEscapedText(const char* s, size_t length) {
 119         for (size_t i = 0; i < length; i++) {
 120             switch (s[i]) {
 121                 case '&': WriteString("&amp;"); break;
 122                 case '<': WriteString("&lt;"); break;
 123                 default: os_.Put(s[i]); break;
 124             }
 125         }
 126         return true;
 127     }
 128
 129     bool WriteStartElement(const char* type, bool emptyElement = false) {
 130         if (level_ == 0)
 131             if (!WriteString("<?xml version=\"1.0\" encoding=\"UTF-8\"?>"))
 132                 return false;
 133
 134         if (!WriteString("<json:") || !WriteString(type))
 135             return false;
 136
 137         // For root element, need to add declarations
 138         if (level_ == 0) {
 139             if (!WriteString(
 140                 " xsi:schemaLocation=\"http://www.datapower.com/schemas/json jsonx.xsd\""
 141                 " xmlns:xsi=\"http://www.w3.org/2001/XMLSchema-instance\""
 142                 " xmlns:json=\"http://www.ibm.com/xmlns/prod/2009/jsonx\""))
 143                 return false;
 144         }
 145
 146         if (hasName_) {
 147             hasName_ = false;
 148             if (!WriteString(" name=\"") ||
 149                 !WriteEscapedAttributeValue(name_.GetString(), name_.GetSize()) ||
 150                 !WriteString("\""))
 151                 return false;
 152         }
 153
 154         if (emptyElement)
 155             return WriteString("/>");
 156         else {
 157             level_++;
 158             return WriteString(">");
 159         }
 160     }
 161
 162     bool WriteEndElement(const char* type) {
 163         if (!WriteString("</json:") ||
 164             !WriteString(type) ||
 165             !WriteString(">"))
 166             return false;
 167
 168         // For the last end tag, flush the output stream.
 169         if (--level_ == 0)
 170             os_.Flush();
 171
 172         return true;
 173     }
 174
 175     bool WriteNumberElement(const char* buffer, int length) {
 176         if (!WriteStartElement("number"))
 177             return false;
 178         for (int j = 0; j < length; j++)
 179             os_.Put(buffer[j]);
 180         return WriteEndElement("number");
 181     }
 182
 183     OutputStream& os_;
 184     StringBuffer name_;
 185     unsigned level_;
 186     bool hasName_;
 187 };
 188
 189 int main(int, char*[]) {
 190     // Prepare JSON reader and input stream.
 191     Reader reader;
 192     char readBuffer[65536];
 193     FileReadStream is(stdin, readBuffer, sizeof(readBuffer));
 194
 195     // Prepare JSON writer and output stream.
 196     char writeBuffer[65536];
 197     FileWriteStream os(stdout, writeBuffer, sizeof(writeBuffer));
 198     JsonxWriter<FileWriteStream> writer(os);
 199
 200     // JSON reader parse from the input stream and let writer generate the output.
 201     if (!reader.Parse(is, writer)) {
 202         fprintf(stderr, "\nError(%u): %s\n", static_cast<unsigned>(reader.GetErrorOffset()), GetParseError_En(reader.GetParseErrorCode()));
 203         return 1;
 204     }
 205
 206     return 0;
 207 }