Add ArrowStream input and output format

src/Processors/Formats/Impl/ArrowBlockInputFormat.cpp

@@ -16,12 +16,12 @@ namespace DB
 
 namespace ErrorCodes
 {
-    extern const int BAD_ARGUMENTS;
+    extern const int UNKNOWN_EXCEPTION;
     extern const int CANNOT_READ_ALL_DATA;
 }
 
-ArrowBlockInputFormat::ArrowBlockInputFormat(ReadBuffer & in_, const Block & header_)
+ArrowBlockInputFormat::ArrowBlockInputFormat(ReadBuffer & in_, const Block & header_, bool stream_)
-    : IInputFormat(header_, in_)
+    : IInputFormat(header_, in_), stream{stream_}
 {
     prepareReader();
 }
@@ -31,11 +31,21 @@ Chunk ArrowBlockInputFormat::generate()
     Chunk res;
     const Block & header = getPort().getHeader();
 
-    if (record_batch_current >= record_batch_total)
+    if (!stream && record_batch_current >= record_batch_total)
         return res;
 
     std::vector<std::shared_ptr<arrow::RecordBatch>> single_batch(1);
-    arrow::Status read_status = file_reader->ReadRecordBatch(record_batch_current, &single_batch[0]);
+    arrow::Status read_status;
+    if (stream)
+    {
+        read_status = stream_reader->ReadNext(&single_batch[0]);
+    }
+    else
+    {
+        read_status = file_reader->ReadRecordBatch(record_batch_current, &single_batch[0]);
+        if (!single_batch[0])
+            return res;
+    }
     if (!read_status.ok())
         throw Exception{"Error while reading batch of Arrow data: " + read_status.ToString(),
                         ErrorCodes::CANNOT_READ_ALL_DATA};
@@ -57,16 +67,30 @@ void ArrowBlockInputFormat::resetParser()
 {
     IInputFormat::resetParser();
 
+    if (stream)
+        stream_reader.reset();
+    else
         file_reader.reset();
     prepareReader();
 }
 
 void ArrowBlockInputFormat::prepareReader()
 {
-    arrow::Status open_status = arrow::ipc::RecordBatchFileReader::Open(asArrowFile(in), &file_reader);
+    arrow::Status status;
-    if (!open_status.ok())
+
-        throw Exception(open_status.ToString(), ErrorCodes::BAD_ARGUMENTS);
+    if (stream)
+        status = arrow::ipc::RecordBatchStreamReader::Open(asArrowFile(in), &stream_reader);
+    else
+        status = arrow::ipc::RecordBatchFileReader::Open(asArrowFile(in), &file_reader);
+
+    if (!status.ok())
+        throw Exception{"Error while opening a table: " + status.ToString(), ErrorCodes::UNKNOWN_EXCEPTION};
+
+    if (stream)
+        record_batch_total = -1;
+    else
         record_batch_total = file_reader->num_record_batches();
+
     record_batch_current = 0;
 }
 
@@ -79,7 +103,17 @@ void registerInputFormatProcessorArrow(FormatFactory &factory)
            const RowInputFormatParams & /* params */,
            const FormatSettings & /* format_settings */)
         {
-                return std::make_shared<ArrowBlockInputFormat>(buf, sample);
+            return std::make_shared<ArrowBlockInputFormat>(buf, sample, false);
+        });
+
+    factory.registerInputFormatProcessor(
+        "ArrowStream",
+        [](ReadBuffer & buf,
+           const Block & sample,
+           const RowInputFormatParams & /* params */,
+           const FormatSettings & /* format_settings */)
+        {
+            return std::make_shared<ArrowBlockInputFormat>(buf, sample, true);
         });
 }
 

src/Processors/Formats/Impl/ArrowBlockInputFormat.h

@@ -4,6 +4,7 @@
 
 #include <Processors/Formats/IInputFormat.h>
 
+namespace arrow { class RecordBatchReader; }
 namespace arrow::ipc { class RecordBatchFileReader; }
 
 namespace DB
@@ -14,7 +15,7 @@ class ReadBuffer;
 class ArrowBlockInputFormat : public IInputFormat
 {
 public:
-    ArrowBlockInputFormat(ReadBuffer & in_, const Block & header_);
+    ArrowBlockInputFormat(ReadBuffer & in_, const Block & header_, bool stream_);
 
     void resetParser() override;
 
@@ -24,12 +25,13 @@ protected:
     Chunk generate() override;
 
 private:
-    void prepareReader();
+    bool stream;
-
+    std::shared_ptr<arrow::RecordBatchReader> stream_reader;
-private:
     std::shared_ptr<arrow::ipc::RecordBatchFileReader> file_reader;
     int record_batch_total = 0;
     int record_batch_current = 0;
+
+    void prepareReader();
 };
 
 }

src/Processors/Formats/Impl/ArrowBlockOutputFormat.cpp

@@ -15,8 +15,8 @@ namespace ErrorCodes
     extern const int UNKNOWN_EXCEPTION;
 }
 
-ArrowBlockOutputFormat::ArrowBlockOutputFormat(WriteBuffer & out_, const Block & header_, const FormatSettings & format_settings_)
+ArrowBlockOutputFormat::ArrowBlockOutputFormat(WriteBuffer & out_, const Block & header_, bool stream_, const FormatSettings & format_settings_)
-    : IOutputFormat(header_, out_), format_settings{format_settings_}, arrow_ostream{std::make_shared<ArrowBufferedOutputStream>(out_)}
+    : IOutputFormat(header_, out_), stream{stream_}, format_settings{format_settings_}, arrow_ostream{std::make_shared<ArrowBufferedOutputStream>(out_)}
 {
 }
 
@@ -29,12 +29,7 @@ void ArrowBlockOutputFormat::consume(Chunk chunk)
     CHColumnToArrowColumn::chChunkToArrowTable(arrow_table, header, chunk, columns_num, "Arrow");
 
     if (!writer)
-    {
+        prepareWriter(arrow_table->schema());
-        // TODO: should we use arrow::ipc::IpcOptions::alignment?
-        auto status = arrow::ipc::RecordBatchFileWriter::Open(arrow_ostream.get(), arrow_table->schema(), &writer);
-        if (!status.ok())
-            throw Exception{"Error while opening a table: " + status.ToString(), ErrorCodes::UNKNOWN_EXCEPTION};
-    }
 
     // TODO: calculate row_group_size depending on a number of rows and table size
     auto status = writer->WriteTable(*arrow_table, format_settings.arrow.row_group_size);
@@ -53,6 +48,20 @@ void ArrowBlockOutputFormat::finalize()
     }
 }
 
+void ArrowBlockOutputFormat::prepareWriter(const std::shared_ptr<arrow::Schema> & schema)
+{
+    arrow::Status status;
+
+    // TODO: should we use arrow::ipc::IpcOptions::alignment?
+    if (stream)
+        status = arrow::ipc::RecordBatchStreamWriter::Open(arrow_ostream.get(), schema, &writer);
+    else
+        status = arrow::ipc::RecordBatchFileWriter::Open(arrow_ostream.get(), schema, &writer);
+
+    if (!status.ok())
+        throw Exception{"Error while opening a table writer: " + status.ToString(), ErrorCodes::UNKNOWN_EXCEPTION};
+}
+
 void registerOutputFormatProcessorArrow(FormatFactory & factory)
 {
     factory.registerOutputFormatProcessor(
@@ -62,7 +71,17 @@ void registerOutputFormatProcessorArrow(FormatFactory & factory)
            FormatFactory::WriteCallback,
            const FormatSettings & format_settings)
         {
-            return std::make_shared<ArrowBlockOutputFormat>(buf, sample, format_settings);
+            return std::make_shared<ArrowBlockOutputFormat>(buf, sample, false, format_settings);
+        });
+
+    factory.registerOutputFormatProcessor(
+        "ArrowStream",
+        [](WriteBuffer & buf,
+           const Block & sample,
+           FormatFactory::WriteCallback,
+           const FormatSettings & format_settings)
+        {
+            return std::make_shared<ArrowBlockOutputFormat>(buf, sample, true, format_settings);
         });
 }
 

src/Processors/Formats/Impl/ArrowBlockOutputFormat.h

@@ -6,6 +6,7 @@
 #include <Processors/Formats/IOutputFormat.h>
 #include "ArrowBufferedStreams.h"
 
+namespace arrow { class Schema; }
 namespace arrow::ipc { class RecordBatchWriter; }
 
 namespace DB
@@ -14,7 +15,7 @@ namespace DB
 class ArrowBlockOutputFormat : public IOutputFormat
 {
 public:
-    ArrowBlockOutputFormat(WriteBuffer & out_, const Block & header_, const FormatSettings & format_settings_);
+    ArrowBlockOutputFormat(WriteBuffer & out_, const Block & header_, bool stream_, const FormatSettings & format_settings_);
 
     String getName() const override { return "ArrowBlockOutputFormat"; }
     void consume(Chunk) override;
@@ -23,9 +24,12 @@ public:
     String getContentType() const override { return "application/octet-stream"; }
 
 private:
+    bool stream;
     const FormatSettings format_settings;
     std::shared_ptr<ArrowBufferedOutputStream> arrow_ostream;
     std::shared_ptr<arrow::ipc::RecordBatchWriter> writer;
+
+    void prepareWriter(const std::shared_ptr<arrow::Schema> & schema);
 };
 
 }