You may wish to look at the documentation on hadoop pipes, which provide a interface for writing c++ map/reduce applications and a mechanism to pass key/value data to C++ from hadoop.
The framework will read and write sequence file or mapfiles, and provide key/value pairs to the map function and reduce function and accept key value pairs from them. I have not personally used pipes, so I do not speak from experience, but from reading src/mapred/org/apache/hadoop/mapred/pipes/PipesMapRunner.java it is clear that standard hadoop inputs are handled and the materialized key and value pairs passed to the map method of the pipes job. On Tue, Feb 24, 2009 at 7:41 PM, Anh Vũ Nguyễn <[email protected]> wrote: > Thanks for your help. I read your answer and then forgot to thank you. > Sorry > about that. > Regards, > Vu Nguyen. > > On 2/6/09, Enis Soztutar <[email protected]> wrote: > > > > There is currently no way to read MapFiles in any language other than > Java. > > You can write a JNI wrapper similar to libhdfs. > > Alternatively, you can also write the complete stack from scratch, > however > > this might prove very difficult or impossible. You might want to check > the > > ObjectFile/TFile specifications for which binary compatible > reader/writers > > can be developed in any language : > > > > https://issues.apache.org/jira/browse/HADOOP-3315 > > > > Enis > > > > Anh Vũ Nguyễn wrote: > > > >> Hi, everybody. I am writing a project in C++ and want to use the power > of > >> MapFile class(which belongs to org.apache.hadoop.io) of hadoop. Can you > >> please tell me how can I write code in C++ using MapFile or there is no > >> way > >> to use API org.apache.hadoop.io in c++ (libhdfs only helps with > >> org.apache.hadoop.fs). > >> Thanks in advance! > >> > >> > >> > > >
