ClickHouse/dbms/src/DataStreams/JSONRowOutputStream.cpp
2013-05-16 12:52:09 +00:00

95 lines
1.9 KiB
C++

#include <DB/DataStreams/JSONRowOutputStream.h>
#include <DB/IO/WriteHelpers.h>
namespace DB
{
using Poco::SharedPtr;
JSONRowOutputStream::JSONRowOutputStream(WriteBuffer & ostr_, const Block & sample_)
: ostr(ostr_), field_number(0), row_count(0)
{
NamesAndTypesList columns(sample_.getColumnsList());
fields.assign(columns.begin(), columns.end());
}
void JSONRowOutputStream::writePrefix()
{
writeCString("{\n", ostr);
writeCString("\t\"meta\":\n", ostr);
writeCString("\t[\n", ostr);
for (size_t i = 0; i < fields.size(); ++i)
{
writeCString("\t\t{\n", ostr);
writeCString("\t\t\t\"name\": ", ostr);
writeDoubleQuotedString(fields[i].first, ostr);
writeCString(",\n", ostr);
writeCString("\t\t\t\"type\": ", ostr);
writeDoubleQuotedString(fields[i].second->getName(), ostr);
writeChar('\n', ostr);
writeCString("\t\t}", ostr);
if (i + 1 < fields.size())
writeChar(',', ostr);
writeChar('\n', ostr);
}
writeCString("\t],\n", ostr);
writeChar('\n', ostr);
writeCString("\t\"data\":\n", ostr);
writeCString("\t[\n", ostr);
}
void JSONRowOutputStream::writeField(const Field & field)
{
writeCString("\t\t\t", ostr);
writeDoubleQuotedString(fields[field_number].first, ostr);
writeCString(": ", ostr);
fields[field_number].second->serializeTextJSON(field, ostr);
++field_number;
}
void JSONRowOutputStream::writeFieldDelimiter()
{
writeCString(",\n", ostr);
}
void JSONRowOutputStream::writeRowStartDelimiter()
{
if (row_count > 0)
writeCString(",\n", ostr);
writeCString("\t\t{\n", ostr);
}
void JSONRowOutputStream::writeRowEndDelimiter()
{
writeChar('\n', ostr);
writeCString("\t\t}", ostr);
field_number = 0;
++row_count;
}
void JSONRowOutputStream::writeSuffix()
{
writeChar('\n', ostr);
writeCString("\t],\n", ostr);
writeChar('\n', ostr);
writeCString("\t\"rows\": ", ostr);
writeIntText(row_count, ostr);
writeChar('\n', ostr);
writeCString("}\n", ostr);
}
}