On Mon, Jun 15, 2020 at 11:24 PM Rares Vernica <rvern...@gmail.com> wrote:
>
> I was able to reproduce my issue in a small, fully-contained, program. Here
> is the source code:
>
> #include <arrow/builder.h>
> #include <arrow/io/file.h>
> #include <arrow/ipc/writer.h>
> #include <arrow/record_batch.h>
>
> arrow::Status foo() {
> std::shared_ptr<arrow::io::OutputStream> arrowStream;
> std::shared_ptr<arrow::ipc::RecordBatchWriter> arrowWriter;
> std::shared_ptr<arrow::RecordBatch> arrowBatch;
> std::shared_ptr<arrow::RecordBatchReader> arrowReader;
>
> std::vector<std::shared_ptr<arrow::Field>> arrowFields(2);
> arrowFields[0] = arrow::field("foo", arrow::int64());
> arrowFields[1] = arrow::field("bar", arrow::int64());
> std::shared_ptr<arrow::Schema> arrowSchema = arrow::schema(arrowFields);
>
> std::vector<std::shared_ptr<arrow::Array>> arrowArrays(2);
> arrow::Int64Builder arrowBuilder;
> for (int i = 0; i < 2; i++) {
> for (int j = 0; j < 21; j++)
> if (i && (j % 2))
> arrowBuilder.AppendNull();
> else
> arrowBuilder.Append(j);
> ARROW_RETURN_NOT_OK(arrowBuilder.Finish(&arrowArrays[i]));
> }
> arrowBatch = arrow::RecordBatch::Make(arrowSchema,
> arrowArrays[0]->length(), arrowArrays);
>
> ARROW_ASSIGN_OR_RAISE(arrowStream,
> arrow::io::FileOutputStream::Open("/tmp/foo"));
> ARROW_ASSIGN_OR_RAISE(arrowWriter,
> arrow::ipc::NewStreamWriter(arrowStream.get(), arrowSchema));
> ARROW_RETURN_NOT_OK(arrowWriter->WriteRecordBatch(*arrowBatch));
> ARROW_RETURN_NOT_OK(arrowWriter->Close());
> ARROW_RETURN_NOT_OK(arrowStream->Close());
>
> return arrow::Status::OK();
> }
>
> int main() {
> foo();
> }
>
> I compile and run it like this:
>
> > g++ -std=c++11 src/foo.cpp -larrow && ./a.out && ll /tmp/foo
> -rw-r--r--. 1 root root 720 Jun 16 04:16 /tmp/foo
>
> The file is small and I can't read it from PyArrow:
>
> > python -c "import pyarrow;
> pyarrow.ipc.open_file('/tmp/foo').read_pandas()"
Here is your problem. Try `pyarrow.ipc.open_stream`.
> Traceback (most recent call last):
> File "<string>", line 1, in <module>
> File "/usr/local/lib/python2.7/dist-packages/pyarrow/ipc.py", line 156,
> in open_file
> return RecordBatchFileReader(source, footer_offset=footer_offset)
> File "/usr/local/lib/python2.7/dist-packages/pyarrow/ipc.py", line 99, in
> __init__
> self._open(source, footer_offset=footer_offset)
> File "pyarrow/ipc.pxi", line 398, in
> pyarrow.lib._RecordBatchFileReader._open
> File "pyarrow/error.pxi", line 84, in pyarrow.lib.check_status
> pyarrow.lib.ArrowInvalid: File is too small: 8
>
> Here is the Arrow and G++ version:
>
> > dpkg -s libarrow-dev
> Package: libarrow-dev
> Status: install ok installed
> Priority: optional
> Section: libdevel
> Installed-Size: 38738
> Maintainer: Apache Arrow Developers <dev@arrow.apache.org>
> Architecture: amd64
> Multi-Arch: same
> Source: apache-arrow
> Version: 0.17.1-1
> Depends: libarrow17 (= 0.17.1-1)
>
> > g++ --version
> g++ (Ubuntu 5.4.0-6ubuntu1~16.04.12) 5.4.0 20160609
>
> Does this make sense?
>
> Cheers,
> Rares
>
>
> On Mon, Jun 15, 2020 at 10:45 AM Rares Vernica <rvern...@gmail.com> wrote:
>
> > This is the compiler:
> >
> > > g++ --version
> > g++ (Ubuntu 5.4.0-6ubuntu1~16.04.12) 5.4.0 20160609
> >
> > And this is how I compile the code:
> >
> > g++ -W -Wextra -Wall -Wno-unused-parameter -Wno-variadic-macros
> > -Wno-strict-aliasing -Wno-long-long -Wno-unused -fPIC -D_STDC_FORMAT_MACROS
> > -Wno-system-headers -O3 -g -DNDEBUG -D_STDC_LIMIT_MACROS
> > -fno-omit-frame-pointer -std=c++14 -DCPP11 -DARROW_NO_DEPRECATED_API
> > -DUSE_ARROW -I. -DPROJECT_ROOT="\"/opt/scidb/19.11\""
> > -I"/opt/scidb/19.11/3rdparty/boost/include/" -I"/opt/scidb/19.11/include"
> > -c PhysicalAioSave.cpp -o PhysicalAioSave.o
> >
> > g++ -W -Wextra -Wall -Wno-unused-parameter -Wno-variadic-macros
> > -Wno-strict-aliasing -Wno-long-long -Wno-unused -fPIC -D_STDC_FORMAT_MACROS
> > -Wno-system-headers -O3 -g -DNDEBUG -D_STDC_LIMIT_MACROS
> > -fno-omit-frame-pointer -std=c++14 -DCPP11 -DARROW_NO_DEPRECATED_API
> > -DUSE_ARROW -I. -DPROJECT_ROOT="\"/opt/scidb/19.11\""
> > -I"/opt/scidb/19.11/3rdparty/boost/include/" -I"/opt/scidb/19.11/include"
> > -o libaccelerated_io_tools.so plugin.o LogicalSplit.o PhysicalSplit.o
> > LogicalParse.o PhysicalParse.o LogicalAioInput.o PhysicalAioInput.o
> > LogicalAioSave.o PhysicalAioSave.o Functions.o -shared
> > -Wl,-soname,libaccelerated_io_tools.so -L.
> > -L"/opt/scidb/19.11/3rdparty/boost/lib" -L"/opt/scidb/19.11/lib"
> > -Wl,-rpath,/opt/scidb/19.11/lib -lm -larrow
> >
> > We targeted 0.16.0 because we are still stuck on Python 2.7 and PyPI still
> > has PyArrow binaries for 2.7.
> >
> > Anyway, I temporarily upgraded to 0.17.1 but the result is the same. I
> > also fixed all the deprecation warnings but that did not help either.
> >
> > Setting a breakpoint might be a challenge since this code runs as a
> > plug-in, but I'll try to isolate this further.
> >
> > Thanks!
> > Rares
> >
> >
> >
> >
> > On Mon, Jun 15, 2020 at 9:15 AM Wes McKinney <wesmck...@gmail.com> wrote:
> >
> >> What compiler are you using?
> >>
> >> In 0.16.0 (what you said you were targeting, though it would be better
> >> for you to upgrade to 0.17.1) schema is written in the CheckStarted
> >> function here
> >>
> >>
> >> https://github.com/apache/arrow/blob/apache-arrow-0.16.0/cpp/src/arrow/ipc/writer.cc#L972
> >>
> >> Status CheckStarted() {
> >> if (!started_) {
> >> return Start();
> >> }
> >> return Status::OK();
> >> }
> >>
> >> started_ is set to false by a default member initializer in the
> >> protected block. Maybe you should set a breakpoint in this function
> >> and see if for some reason started_ is true on the first invocation
> >> (in which case it makes me wonder if there is something
> >> not-fully-C++11-compliant about your toolchain).
> >>
> >> Otherwise I'm a bit stumped since there are lots of production
> >> applications that use this code.
> >>
> >> On Mon, Jun 15, 2020 at 11:01 AM Rares Vernica <rvern...@gmail.com>
> >> wrote:
> >> >
> >> > Sure, here is briefly what I'm doing:
> >> >
> >> > bool append = false;
> >> > std::shared_ptr<arrow::io::OutputStream> arrowStream;
> >> > auto arrowResult = arrow::io::FileOutputStream::Open(fileName,
> >> append);
> >> > arrowStream = arrowResult.ValueOrDie();
> >> >
> >> > std::shared_ptr<arrow::ipc::RecordBatchWriter> arrowWriter;
> >> > std::shared_ptr<arrow::RecordBatch> arrowBatch;
> >> > std::shared_ptr<arrow::RecordBatchReader> arrowReader;
> >> >
> >> > std::shared_ptr<arrow::Schema> arrowSchema = attributes2ArrowSchema(
> >> > inputSchema, settings.isAttsOnly());
> >> > ARROW_RETURN_NOT_OK(
> >> > arrow::ipc::RecordBatchStreamWriter::Open(
> >> > arrowStream.get(), arrowSchema, &arrowWriter));
> >> >
> >> > // Setup "arrowReader" using BufferReader and
> >> RecordBatchStreamReader
> >> > ARROW_RETURN_NOT_OK(arrowReader->ReadNext(&arrowBatch));
> >> > ARROW_RETURN_NOT_OK(
> >> > arrowWriter->WriteRecordBatch(*arrowBatch));
> >> > ARROW_RETURN_NOT_OK(arrowWriter->Close());
> >> > ARROW_RETURN_NOT_OK(arrowStream->Close());
> >> >
> >> > On Mon, Jun 15, 2020 at 6:26 AM Wes McKinney <wesmck...@gmail.com>
> >> wrote:
> >> >
> >> > > Can you show the code you are writing? The first thing the stream
> >> writer
> >> > > does before writing any record batch is write the schema. It sounds
> >> like
> >> > > you are using arrow::ipc::WriteRecordBatch somewhere.
> >> > >
> >> > > On Sun, Jun 14, 2020, 11:44 PM Rares Vernica <rvern...@gmail.com>
> >> wrote:
> >> > >
> >> > > > Hello,
> >> > > >
> >> > > > I have a RecordBatch that I would like to write to a file. I'm using
> >> > > > FileOutputStream::Open to open the file and
> >> RecordBatchStreamWriter::Open
> >> > > > to open the stream. I write a record batch with WriteRecordBatch.
> >> > > Finally,
> >> > > > I close the RecordBatchWriter and OutputStream.
> >> > > >
> >> > > > The resulting file size is exactly the size of the Buffer used to
> >> store
> >> > > the
> >> > > > RecordBatch. It looks like it is missing the schema. When I try to
> >> open
> >> > > the
> >> > > > resulting file from PyArrow I get:
> >> > > >
> >> > > > >>> pa.ipc.open_file('/tmp/1')
> >> > > > pyarrow.lib.ArrowInvalid: File is too small: 6
> >> > > >
> >> > > > $ ll /tmp/1
> >> > > > -rw-r--r--. 1 root root 720 Jun 15 03:54 /tmp/1
> >> > > >
> >> > > > How can I write the schema as well?
> >> > > >
> >> > > > I was browsing the documentation at
> >> > > > https://arrow.apache.org/docs/cpp/index.html but I can't locate
> >> any C++
> >> > > > documentation about RecordBatchStreamWriter or RecordBatchWriter.
> >> Is this
> >> > > > intentional?
> >> > > >
> >> > > > Thank you!
> >> > > > Rares
> >> > > >
> >> > >
> >>
> >
