Trait google_cloud_bigquery::storage::array::Array

pub trait Array: Debug + Send + Sync {
Show 14 methods    // Required methods
    fn as_any(&self) -> &(dyn Any + 'static);
    fn to_data(&self) -> ArrayData;
    fn into_data(self) -> ArrayData;
    fn data_type(&self) -> &DataType;
    fn slice(&self, offset: usize, length: usize) -> Arc<dyn Array, Global>;
    fn len(&self) -> usize;
    fn is_empty(&self) -> bool;
    fn offset(&self) -> usize;
    fn nulls(&self) -> Option<&NullBuffer>;
    fn get_buffer_memory_size(&self) -> usize;
    fn get_array_memory_size(&self) -> usize;

    // Provided methods
    fn is_null(&self, index: usize) -> bool { ... }
    fn is_valid(&self, index: usize) -> bool { ... }
    fn null_count(&self) -> usize { ... }
}

Expand description

An array in the arrow columnar format

Required Methods§

fn as_any(&self) -> &(dyn Any + 'static)

Returns the array as Any so that it can be downcasted to a specific implementation.

Example:


let id = Int32Array::from(vec![1, 2, 3, 4, 5]);
let batch = RecordBatch::try_new(
    Arc::new(Schema::new(vec![Field::new("id", DataType::Int32, false)])),
    vec![Arc::new(id)]
).unwrap();

let int32array = batch
    .column(0)
    .as_any()
    .downcast_ref::<Int32Array>()
    .expect("Failed to downcast");

fn to_data(&self) -> ArrayData

Returns the underlying data of this array

fn into_data(self) -> ArrayData

Returns the underlying data of this array

Unlike Array::to_data this consumes self, allowing it avoid unnecessary clones

fn data_type(&self) -> &DataType

Returns a reference to the DataType of this array.

Example:

use arrow_schema::DataType;
use arrow_array::{Array, Int32Array};

let array = Int32Array::from(vec![1, 2, 3, 4, 5]);

assert_eq!(*array.data_type(), DataType::Int32);

fn slice(&self, offset: usize, length: usize) -> Arc<dyn Array, Global>

Returns a zero-copy slice of this array with the indicated offset and length.

Example:

use arrow_array::{Array, Int32Array};

let array = Int32Array::from(vec![1, 2, 3, 4, 5]);
// Make slice over the values [2, 3, 4]
let array_slice = array.slice(1, 3);

assert_eq!(&array_slice, &Int32Array::from(vec![2, 3, 4]));

fn len(&self) -> usize

Returns the length (i.e., number of elements) of this array.

Example:

use arrow_array::{Array, Int32Array};

let array = Int32Array::from(vec![1, 2, 3, 4, 5]);

assert_eq!(array.len(), 5);

fn is_empty(&self) -> bool

Returns whether this array is empty.

Example:

use arrow_array::{Array, Int32Array};

let array = Int32Array::from(vec![1, 2, 3, 4, 5]);

assert_eq!(array.is_empty(), false);

fn offset(&self) -> usize

Returns the offset into the underlying data used by this array(-slice). Note that the underlying data can be shared by many arrays. This defaults to 0.

Example:

use arrow_array::{Array, BooleanArray};

let array = BooleanArray::from(vec![false, false, true, true]);
let array_slice = array.slice(1, 3);

assert_eq!(array.offset(), 0);
assert_eq!(array_slice.offset(), 1);

fn nulls(&self) -> Option<&NullBuffer>

Returns the null buffers of this array if any

fn get_buffer_memory_size(&self) -> usize

Returns the total number of bytes of memory pointed to by this array. The buffers store bytes in the Arrow memory format, and include the data as well as the validity map.

fn get_array_memory_size(&self) -> usize

Returns the total number of bytes of memory occupied physically by this array. This value will always be greater than returned by get_buffer_memory_size() and includes the overhead of the data structures that contain the pointers to the various buffers.

Provided Methods§

fn is_null(&self, index: usize) -> bool

Returns whether the element at index is null. When using this function on a slice, the index is relative to the slice.

Example:

use arrow_array::{Array, Int32Array};

let array = Int32Array::from(vec![Some(1), None]);

assert_eq!(array.is_null(0), false);
assert_eq!(array.is_null(1), true);

fn is_valid(&self, index: usize) -> bool

Returns whether the element at index is not null. When using this function on a slice, the index is relative to the slice.

Example:

use arrow_array::{Array, Int32Array};

let array = Int32Array::from(vec![Some(1), None]);

assert_eq!(array.is_valid(0), true);
assert_eq!(array.is_valid(1), false);

fn null_count(&self) -> usize

Returns the total number of null values in this array.

Example:

use arrow_array::{Array, Int32Array};

// Construct an array with values [1, NULL, NULL]
let array = Int32Array::from(vec![Some(1), None, None]);

assert_eq!(array.null_count(), 2);