row_format_guide.md

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Row Format Guide	1	row_format_guide	Licensed to the Apache Software Foundation (ASF) under one or more contributor license agreements. See the NOTICE file distributed with this work for additional information regarding copyright ownership. The ASF licenses this file to You under the Apache License, Version 2.0 (the "License"); you may not use this file except in compliance with the License. You may obtain a copy of the License at http://www.apache.org/licenses/LICENSE-2.0 Unless required by applicable law or agreed to in writing, software distributed under the License is distributed on an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the License for the specific language governing permissions and limitations under the License.

Row format protocol

Java

public class Bar {
  String f1;
  List<Long> f2;
}

public class Foo {
  int f1;
  List<Integer> f2;
  Map<String, Integer> f3;
  List<Bar> f4;
}

RowEncoder<Foo> encoder = Encoders.bean(Foo.class);
Foo foo = new Foo();
foo.f1 = 10;
foo.f2 = IntStream.range(0, 1000000).boxed().collect(Collectors.toList());
foo.f3 = IntStream.range(0, 1000000).boxed().collect(Collectors.toMap(i -> "k"+i, i->i));
List<Bar> bars = new ArrayList<>(1000000);
for (int i = 0; i < 1000000; i++) {
  Bar bar = new Bar();
  bar.f1 = "s"+i;
  bar.f2 = LongStream.range(0, 10).boxed().collect(Collectors.toList());
  bars.add(bar);
}
foo.f4 = bars;
// Can be zero-copy read by python
BinaryRow binaryRow = encoder.toRow(foo);
// can be data from python
Foo newFoo = encoder.fromRow(binaryRow);
// zero-copy read List<Integer> f2
BinaryArray binaryArray2 = binaryRow.getArray(1);
// zero-copy read List<Bar> f4
BinaryArray binaryArray4 = binaryRow.getArray(3);
// zero-copy read 11th element of `readList<Bar> f4`
BinaryRow barStruct = binaryArray4.getStruct(10);

// zero-copy read 6th of f2 of 11th element of `readList<Bar> f4`
barStruct.getArray(1).getInt64(5);
RowEncoder<Bar> barEncoder = Encoders.bean(Bar.class);
// deserialize part of data.
Bar newBar = barEncoder.fromRow(barStruct);
Bar newBar2 = barEncoder.fromRow(binaryArray4.getStruct(20));

Python

@dataclass
class Bar:
    f1: str
    f2: List[pa.int64]
@dataclass
class Foo:
    f1: pa.int32
    f2: List[pa.int32]
    f3: Dict[str, pa.int32]
    f4: List[Bar]

encoder = pyfury.encoder(Foo)
foo = Foo(f1=10, f2=list(range(1000_000)),
         f3={f"k{i}": i for i in range(1000_000)},
         f4=[Bar(f1=f"s{i}", f2=list(range(10))) for i in range(1000_000)])
binary: bytes = encoder.to_row(foo).to_bytes()
print(f"start: {datetime.datetime.now()}")
foo_row = pyfury.RowData(encoder.schema, binary)
print(foo_row.f2[100000], foo_row.f4[100000].f1, foo_row.f4[200000].f2[5])
print(f"end: {datetime.datetime.now()}")

binary = pickle.dumps(foo)
print(f"pickle start: {datetime.datetime.now()}")
new_foo = pickle.loads(binary)
print(new_foo.f2[100000], new_foo.f4[100000].f1, new_foo.f4[200000].f2[5])
print(f"pickle end: {datetime.datetime.now()}")

Apache Arrow Support

Fury Format also supports automatic conversion from/to Arrow Table/RecordBatch.

Java:

Schema schema = TypeInference.inferSchema(BeanA.class);
ArrowWriter arrowWriter = ArrowUtils.createArrowWriter(schema);
Encoder<BeanA> encoder = Encoders.rowEncoder(BeanA.class);
for (int i = 0; i < 10; i++) {
  BeanA beanA = BeanA.createBeanA(2);
  arrowWriter.write(encoder.toRow(beanA));
}
return arrowWriter.finishAsRecordBatch();

Python:

import pyfury
encoder = pyfury.encoder(Foo)
encoder.to_arrow_record_batch([foo] * 10000)
encoder.to_arrow_table([foo] * 10000)

C++

std::shared_ptr<ArrowWriter> arrow_writer;
EXPECT_TRUE(
    ArrowWriter::Make(schema, ::arrow::default_memory_pool(), &arrow_writer)
        .ok());
for (auto &row : rows) {
  EXPECT_TRUE(arrow_writer->Write(row).ok());
}
std::shared_ptr<::arrow::RecordBatch> record_batch;
EXPECT_TRUE(arrow_writer->Finish(&record_batch).ok());
EXPECT_TRUE(record_batch->Validate().ok());
EXPECT_EQ(record_batch->num_columns(), schema->num_fields());
EXPECT_EQ(record_batch->num_rows(), row_nums);

Schema schema = TypeInference.inferSchema(BeanA.class);
ArrowWriter arrowWriter = ArrowUtils.createArrowWriter(schema);
Encoder<BeanA> encoder = Encoders.rowEncoder(BeanA.class);
for (int i = 0; i < 10; i++) {
  BeanA beanA = BeanA.createBeanA(2);
  arrowWriter.write(encoder.toRow(beanA));
}
return arrowWriter.finishAsRecordBatch();