How to compile Apache Avro C++ example - c++

Question

Probably a newbie mistake, but can anyone please tell me what I'm doing wrong here?
Any help is much appreciated.
I wrote this simple Makefile:
CC=g++
INC=-I/usr/local/avro-cpp-1.7.2 -I/usr/local/boost_1_53_0
cpx : generated.cc
$(CC) -o cpx generated.cc $(INC)
Which generates these the errors:
g++ -o cpx generated.cc -I/usr/local/avro-cpp-1.7.2 -I/usr/local/boost_1_53_0
/tmp/ccYymUVo.o: In function `main':
generated.cc:(.text+0x84): undefined reference to `avro::memoryOutputStream(unsigned long)'
generated.cc:(.text+0xb0): undefined reference to `avro::binaryEncoder()'
generated.cc:(.text+0x11e): undefined reference to `avro::memoryInputStream(avro::OutputStream const&)'
generated.cc:(.text+0x150): undefined reference to `avro::binaryDecoder()'
collect2: ld returned 1 exit status
make: *** [cpx] Error 1
Here's the source as supplied in the Avro examples directory:
#############################
# cpx.hh
#############################
#ifndef CPX_HH_1278398428__H_
#define CPX_HH_1278398428__H_
#include "boost/any.hpp"
#include "avro/Specific.hh"
#include "avro/Encoder.hh"
#include "avro/Decoder.hh"
namespace c {
struct cpx {
double re;
double im;
};
}
namespace avro {
template<> struct codec_traits<c::cpx> {
static void encode(Encoder& e, const c::cpx& v) {
avro::encode(e, v.re);
avro::encode(e, v.im);
}
static void decode(Decoder& d, c::cpx& v) {
avro::decode(d, v.re);
avro::decode(d, v.im);
}
};
}
#endif
and
#############################
# generated.cc
#############################
#include "cpx.hh"
#include "avro/Encoder.hh"
#include "avro/Decoder.hh"
int
main()
{
std::auto_ptr<avro::OutputStream> out = avro::memoryOutputStream();
avro::EncoderPtr e = avro::binaryEncoder();
e->init(*out);
c::cpx c1;
c1.re = 1.0;
c1.im = 2.13;
avro::encode(*e, c1);
std::auto_ptr<avro::InputStream> in = avro::memoryInputStream(*out);
avro::DecoderPtr d = avro::binaryDecoder();
d->init(*in);
c::cpx c2;
avro::decode(*d, c2);
std::cout << '(' << c2.re << ", " << c2.im << ')' << std::endl;
return 0;
}
Thanks.

Answer 1

1)
in your output, you don't link against the avrocpp library, although your comments about the LD_LIBRARY_PATH suggest that you got the link to work, but the example program failed to find the library when executing. Your compile line needs the linker option: -l avrocpp
2)
If the avrocpp library .so is not installed in a path that your runtime linker is configured to search, you can add the library path into the binary itself with the linker option -rpath.
Example 1: Assuming your avrocpp library is installed in /usr/local/lib (i.e. /usr/local/lib/libavrocpp.so), and your runtime linker doesn't look in /usr/local/lib, add the rpath by adding this option to your compiler command line:
-Wl,-rpath,/usr/local/lib
Example 2: Assuming your avrocpp library is installed in /usr/local/avro-cpp-1.7.2/lib (i.e. /usr/local/avro-cpp-1.7.2/lib/libavrocpp.so), add the rpath by adding this option to your compiler command line:
-Wl,-rpath,/usr/local/avro-cpp-1.7.2/lib

Answer 2

Try using avrogencpp with options -i < schema_file > -o < header_file >

Answer 3

Download and compile the Avro c++ sources https://stackoverflow.com/questions/40889705/how-to-compile-apache-avro-c-on-windows (this will generate the "avrogencpp.exe")
Download avro-tools http://avro.apache.org/releases.html#Download, and (with java installed)
run:
java -jar avro-tools-1.8.1.jar idl file.avdl > file.json
Edit the generated json file and delete the following
If you have any lines preceding the required structs at the beginning, delete them. (I had "protocol": "file", "namespace" : "some_optional_namespace", "types" :)
messages entry (at the bottom)
If you have multiple structs defined in the same json file, surround them all with "[ ]" (you should have commas between the different structs and make sure the last struct as not proceeded with a ","
Run
avrogencpp.exe -p - -n some_optional_namespace -U --input file.json --output file.hh