ClickHouse/src/Processors/Formats/Impl/ArrowBufferedStreams.cpp
2020-07-13 21:25:51 +03:00

110 lines
3.0 KiB
C++

#include "ArrowBufferedStreams.h"
#if USE_ARROW || USE_ORC || USE_PARQUET
#include <IO/ReadBufferFromFileDescriptor.h>
#include <IO/WriteBufferFromString.h>
#include <IO/copyData.h>
#include <arrow/buffer.h>
#include <arrow/io/api.h>
#include <arrow/result.h>
#include <sys/stat.h>
namespace DB
{
ArrowBufferedOutputStream::ArrowBufferedOutputStream(WriteBuffer & out_) : out{out_}, is_open{true}
{
}
arrow::Status ArrowBufferedOutputStream::Close()
{
is_open = false;
return arrow::Status::OK();
}
arrow::Result<int64_t> ArrowBufferedOutputStream::Tell() const
{
return arrow::Result<int64_t>(total_length);
}
arrow::Status ArrowBufferedOutputStream::Write(const void * data, int64_t length)
{
out.write(reinterpret_cast<const char *>(data), length);
total_length += length;
return arrow::Status::OK();
}
RandomAccessFileFromSeekableReadBuffer::RandomAccessFileFromSeekableReadBuffer(SeekableReadBuffer & in_, off_t file_size_)
: in{in_}, file_size{file_size_}, is_open{true}
{
}
arrow::Result<int64_t> RandomAccessFileFromSeekableReadBuffer::GetSize()
{
return arrow::Result<int64_t>(file_size);
}
arrow::Status RandomAccessFileFromSeekableReadBuffer::Close()
{
is_open = false;
return arrow::Status::OK();
}
arrow::Result<int64_t> RandomAccessFileFromSeekableReadBuffer::Tell() const
{
return arrow::Result<int64_t>(in.getPosition());
}
arrow::Result<int64_t> RandomAccessFileFromSeekableReadBuffer::Read(int64_t nbytes, void * out)
{
int64_t bytes_read = in.readBig(reinterpret_cast<char *>(out), nbytes);
return arrow::Result<int64_t>(bytes_read);
}
arrow::Result<std::shared_ptr<arrow::Buffer>> RandomAccessFileFromSeekableReadBuffer::Read(int64_t nbytes)
{
auto buffer_status = arrow::AllocateBuffer(nbytes);
ARROW_RETURN_NOT_OK(buffer_status);
auto shared_buffer = std::shared_ptr<arrow::Buffer>(std::move(std::move(*buffer_status)));
size_t n = in.readBig(reinterpret_cast<char *>(shared_buffer->mutable_data()), nbytes);
auto read_buffer = arrow::SliceBuffer(shared_buffer, 0, n);
return arrow::Result<std::shared_ptr<arrow::Buffer>>(shared_buffer);
}
arrow::Status RandomAccessFileFromSeekableReadBuffer::Seek(int64_t position)
{
in.seek(position, SEEK_SET);
return arrow::Status::OK();
}
std::shared_ptr<arrow::io::RandomAccessFile> asArrowFile(ReadBuffer & in)
{
if (auto * fd_in = dynamic_cast<ReadBufferFromFileDescriptor *>(&in))
{
struct stat stat;
auto res = ::fstat(fd_in->getFD(), &stat);
// if fd is a regular file i.e. not stdin
if (res == 0 && S_ISREG(stat.st_mode))
return std::make_shared<RandomAccessFileFromSeekableReadBuffer>(*fd_in, stat.st_size);
}
// fallback to loading the entire file in memory
std::string file_data;
{
WriteBufferFromString file_buffer(file_data);
copyData(in, file_buffer);
}
return std::make_shared<arrow::io::BufferReader>(arrow::Buffer::FromString(std::move(file_data)));
}
}
#endif