Okay, I think I found a somewhat workable solution. If I serialize all my
records using the avro::Writer:
Math::complex c;
c.real = 10.0;
c.imaginary = 20.0;
// Writer is the object that will do the actual I/O and buffer the results
avro::Writer writer;
// This will invoke the writer on my object
avro::serialize(writer, c);
I can do the following to write them out:
avro::istream is(writer->buffer());
ofstream avroFile(outputFile.c_str(), ios::out | ios::app | ios::binary);
if(avroFile.is_open())
{
avroFile << is.rdbuf();
avroFile.close();
}
else
{
cout << "Uh oh...couldn't write out AVRO payload data..." << endl;
exit(1);
}
I'm having a problem reading the file back in for parsing...I do the
following:
ifstream avroFile("payload.bin", ios::in | ios::binary);
if(avroFile.is_open())
{
Math::Complex blah;
avro::ostream os;
os << avroFile.rdbuf();
avro::Reader p(os.getBuffer());
while(!os.eof())
<------------------------------------------------------------------------
This doesn't work.....
{
avro::parse(p, blah);
cout << "The Real Value is " << blah.real << endl;
}
}
How do you tell that you have reached the end of a buffer (i.e. read all the
records in a file)?
Cheers,
Teryl
On Thu, Jun 23, 2011 at 10:16 AM, Teryl Taylor <[email protected]>wrote:
> Hi everyone,
>
> I'm playing around with Avro C++ and it looks pretty neat. I generated a
> class based on a JSON schema which was dropped in a header file. What is
> the best way to write out instances of these classes to a file? The
> example in the documentation shows:
>
> Math::complex c;
> c.real = 10.0;
> c.imaginary = 20.0;
>
> // Writer is the object that will do the actual I/O and buffer the results
> avro::Writer writer;
>
> // This will invoke the writer on my object
> avro::serialize(writer, c);
>
>
>
> ***********************************************************************************************
>
>
> But it is unclear how to attach a file stream to the writer. I also tried:
>
> avro::compileJsonSchema(is, validSchema);
> is.close();
> dfWriter = new
> avro::DataFileWriter<GenObject>(outputdir.c_str(), validSchema);
> dfWriter->write(obj);
>
>
> But this won't compile giving the error:
>
> /terylt/Projects/bitvectors/avro-cpp-1.5.1/api/Specific.hh:195: error:
> 'encode' is not a member of 'avro::codec_traits<GenObject>'
>
>
> What's the best way to write out my objects to disk?
>
>
> Regards,
>
>
> Teryl
>
>
