// 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.
//! Contains functionality to load an ArrayData from the C Data Interface
use std::convert::TryFrom;
use crate::{
error::{ArrowError, Result},
ffi,
};
use super::ArrayData;
impl TryFrom<ffi::ArrowArray> for ArrayData {
type Error = ArrowError;
fn try_from(value: ffi::ArrowArray) -> Result<Self> {
let data_type = value.data_type()?;
let len = value.len();
let offset = value.offset();
let null_count = value.null_count();
let buffers = value.buffers()?;
let null_bit_buffer = value.null_bit_buffer();
Ok(ArrayData::new(
data_type,
len,
Some(null_count),
null_bit_buffer,
offset,
buffers,
// this is empty because ffi still does not support it.
// this is ok because FFI only supports datatypes without childs
vec![],
))
}
}
impl TryFrom<ArrayData> for ffi::ArrowArray {
type Error = ArrowError;
fn try_from(value: ArrayData) -> Result<Self> {
let len = value.len();
let offset = value.offset() as usize;
let null_count = value.null_count();
let buffers = value.buffers().to_vec();
let null_buffer = value.null_buffer().cloned();
unsafe {
ffi::ArrowArray::try_new(
value.data_type(),
len,
null_count,
null_buffer,
offset,
buffers,
// this is empty because ffi still does not support it.
// this is ok because FFI only supports datatypes without childs
vec![],
)
}
}
}
#[cfg(test)]
mod tests {
use crate::error::Result;
use crate::{
array::{Array, ArrayData, Int64Array, UInt32Array, UInt64Array},
ffi::ArrowArray,
};
use std::convert::TryFrom;
fn test_round_trip(expected: &ArrayData) -> Result<()> {
// create a `ArrowArray` from the data.
let d1 = ArrowArray::try_from(expected.clone())?;
// here we export the array as 2 pointers. We would have no control over ownership if it was not for
// the release mechanism.
let (array, schema) = ArrowArray::into_raw(d1);
// simulate an external consumer by being the consumer
let d1 = unsafe { ArrowArray::try_from_raw(array, schema) }?;
let result = &ArrayData::try_from(d1)?;
assert_eq!(result, expected);
Ok(())
}
#[test]
fn test_u32() -> Result<()> {
let data = UInt32Array::from(vec![Some(2), None, Some(1), None]).data();
test_round_trip(data.as_ref())
}
#[test]
fn test_u64() -> Result<()> {
let data = UInt64Array::from(vec![Some(2), None, Some(1), None]).data();
test_round_trip(data.as_ref())
}
#[test]
fn test_i64() -> Result<()> {
let data = Int64Array::from(vec![Some(2), None, Some(1), None]).data();
test_round_trip(data.as_ref())
}
}