third_party/pb2json/pb2json.cpp

/*
 * Original code from https://github.com/renenglish/pb2json
 */
#include "pb2json.h"
#include <google/protobuf/message.h>
#include <jansson.h>

std::string Pb2Json::hex_encode(const std::string& input)
{
    static const char* const lut = "0123456789abcdef";
    size_t len = input.length();

    std::string output;
    output.reserve(2 * len);
    for (size_t i = 0; i < len; ++i)
      {
	const unsigned char c = input[i];
	output.push_back(lut[c >> 4]);
	output.push_back(lut[c & 15]);
      }
    return output;
}

char * Pb2Json::pb2json(const google::protobuf::Message &msg)
{
    json_t *root = parse_msg(&msg);
    char *json = json_dumps(root,0);
    json_decref(root);
    return json; // should be freed by caller
}
char * Pb2Json::pb2json( google::protobuf::Message *msg,const char *buf ,int len)
{
    GOOGLE_PROTOBUF_VERIFY_VERSION;
    std::string s (buf,len);
    msg->ParseFromString(s);
    json_t *root = parse_msg(msg);
    char *json = json_dumps(root,0);
    json_decref(root);
    google::protobuf::ShutdownProtobufLibrary();
    return json; // should be freed by caller
}

json_t *Pb2Json::parse_repeated_field(const google::protobuf::Message *msg,
					const google::protobuf::Reflection * ref,
					const google::protobuf::FieldDescriptor *field)
{
    size_t count = ref->FieldSize(*msg,field);
    json_t *arr = json_array();
    if(!arr)return NULL;
    switch(field->cpp_type())
      {
      case google::protobuf::FieldDescriptor::CPPTYPE_DOUBLE:
	for(size_t i = 0 ; i != count ; ++i)
	  {
	    double	value1 = ref->GetRepeatedDouble(*msg,field,i);
	    json_array_append_new(arr,json_real(value1));
	  }
	break;
      case google::protobuf::FieldDescriptor::CPPTYPE_FLOAT:
	for(size_t i = 0 ; i != count ; ++i)
	  {
	    float value2 = ref->GetRepeatedFloat(*msg,field,i);
	    json_array_append_new(arr,json_real(value2));
	  }
	break;
      case google::protobuf::FieldDescriptor::CPPTYPE_INT64:
	for(size_t i = 0 ; i != count ; ++i)
	  {
	    int64_t value3 = ref->GetRepeatedInt64(*msg,field,i);
	    json_array_append_new(arr,json_integer(value3))	;
	  }
	break;
      case google::protobuf::FieldDescriptor::CPPTYPE_UINT64:
	for(size_t i = 0 ; i != count ; ++i)
	  {
	    uint64_t value4 = ref->GetRepeatedUInt64(*msg,field,i);
	    json_array_append_new(arr,json_integer(value4));
	  }
	break;
      case google::protobuf::FieldDescriptor::CPPTYPE_INT32:
	for(size_t i = 0 ; i != count ; ++i)
	  {
	    int32_t value5 = ref->GetRepeatedInt32(*msg,field,i);
	    json_array_append_new(arr,json_integer(value5));
	  }
	break;
      case google::protobuf::FieldDescriptor::CPPTYPE_UINT32:
	for(size_t i = 0 ; i != count ; ++i)
	  {
	    uint32_t value6 = ref->GetRepeatedUInt32(*msg,field,i);
	    json_array_append_new(arr,json_integer(value6));
	  }
	break;
      case google::protobuf::FieldDescriptor::CPPTYPE_BOOL:
	for(size_t i = 0 ; i != count ; ++i)
	  {
	    bool value7 = ref->GetRepeatedBool(*msg,field,i);
	    json_array_append_new(arr,value7?json_true():json_false())	;
	  }
	break;
      case google::protobuf::FieldDescriptor::CPPTYPE_STRING:
	for(size_t i = 0 ; i != count ; ++i)
	  {
	    std::string value8 = ref->GetRepeatedString(*msg,field,i);
	    json_array_append_new(arr,json_string(value8.c_str()));
	  }
	break;
      case google::protobuf::FieldDescriptor::CPPTYPE_MESSAGE:
	for(size_t i = 0 ; i != count ; ++i)
	  {
	    const google::protobuf::Message *value9 = &(ref->GetRepeatedMessage(*msg,field,i));
	    json_array_append_new(arr,parse_msg(value9));
	  }
	break;
      case google::protobuf::FieldDescriptor::CPPTYPE_ENUM:
	for(size_t i = 0 ; i != count ; ++i)
	  {
	    const google::protobuf::EnumValueDescriptor* value10 =
	      ref->GetRepeatedEnum(*msg,field,i);
	    json_array_append_new(arr,json_integer(value10->number()));
	  }
	break;
      default:
	break;
      }
    return arr;
}

json_t *Pb2Json::parse_msg(const google::protobuf::Message *msg)
{
    const google::protobuf::Descriptor *d = msg->GetDescriptor();
    if(!d)return NULL;
    size_t count = d->field_count();
    json_t *root = json_object();
    if(!root)return NULL;
    for (size_t i = 0; i != count ; ++i)
      {
	const google::protobuf::FieldDescriptor *field = d->field(i);
	if(!field)return NULL;

	const google::protobuf::Reflection *ref = msg->GetReflection();
	if(!ref)return NULL;
	const char *name = field->name().c_str();
	if(field->is_repeated())
	  json_object_set_new(root,name,parse_repeated_field(msg,ref,field));
	if(!field->is_repeated() && ref->HasField(*msg,field))
	  {

	    double value1;
	    float value2;
	    int64_t value3;
	    uint64_t value4;
	    int32_t value5;
	    uint32_t value6;
	    bool value7;
	    std::string value8;
	    const google::protobuf::Message *value9;
	    const google::protobuf::EnumValueDescriptor *value10;

	    switch (field->cpp_type())
	      {
	      case google::protobuf::FieldDescriptor::CPPTYPE_DOUBLE:
		value1 = ref->GetDouble(*msg,field);
		json_object_set_new(root,name,json_real(value1));
		break;
	      case google::protobuf::FieldDescriptor::CPPTYPE_FLOAT:
		value2 = ref->GetFloat(*msg,field);
		json_object_set_new(root,name,json_real(value2));
		break;
	      case google::protobuf::FieldDescriptor::CPPTYPE_INT64:
		value3 = ref->GetInt64(*msg,field);
		json_object_set_new(root,name,json_integer(value3))	;
		break;
	      case google::protobuf::FieldDescriptor::CPPTYPE_UINT64:
		value4 = ref->GetUInt64(*msg,field);
		json_object_set_new(root,name,json_integer(value4));
		break;
	      case google::protobuf::FieldDescriptor::CPPTYPE_INT32:
		value5 = ref->GetInt32(*msg,field);
		json_object_set_new(root,name,json_integer(value5));
		break;
	      case google::protobuf::FieldDescriptor::CPPTYPE_UINT32:
		value6 = ref->GetUInt32(*msg,field);
		json_object_set_new(root,name,json_integer(value6));
		break;
	      case google::protobuf::FieldDescriptor::CPPTYPE_BOOL:
		value7 = ref->GetBool(*msg,field);
		json_object_set_new(root,name,value7?json_true():json_false())	;
		break;
	      case google::protobuf::FieldDescriptor::CPPTYPE_STRING:
		if (field->type() == google::protobuf::FieldDescriptor::TYPE_BYTES) {
		  value8 = hex_encode(ref->GetString(*msg,field));
		} else {
		  value8 = ref->GetString(*msg,field);
		}
		json_object_set_new(root,name,json_string(value8.c_str()));
		break;
	      case google::protobuf::FieldDescriptor::CPPTYPE_MESSAGE:
		value9 = &(ref->GetMessage(*msg,field));
		json_object_set_new(root,name,parse_msg(value9));
		break;
	      case google::protobuf::FieldDescriptor::CPPTYPE_ENUM:
		value10 = ref->GetEnum(*msg,field);
		json_object_set_new(root,name,json_integer(value10->number()));
		break;
	      default:
		break;
	      }

	  }

      }
    return root;
}