tustvold commented on code in PR #3553: URL: https://github.com/apache/arrow-rs/pull/3553#discussion_r1084297101
########## arrow-array/src/builder/generic_byte_run_builder.rs: ########## @@ -0,0 +1,499 @@ +// 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. + +use crate::types::bytes::ByteArrayNativeType; +use std::{any::Any, sync::Arc}; + +use crate::{ + types::{ + BinaryType, ByteArrayType, LargeBinaryType, LargeUtf8Type, RunEndIndexType, + Utf8Type, + }, + ArrayRef, ArrowPrimitiveType, RunArray, +}; + +use super::{ArrayBuilder, GenericByteBuilder, PrimitiveBuilder}; + +use arrow_buffer::ArrowNativeType; + +/// Array builder for [`RunArray`] for String and Binary types. +/// +/// # Example: +/// +/// ``` +/// +/// # use arrow_array::builder::GenericByteRunBuilder; +/// # use arrow_array::{GenericByteArray, BinaryArray}; +/// # use arrow_array::types::{BinaryType, Int16Type}; +/// # use arrow_array::{Array, Int16Array}; +/// +/// let mut builder = +/// GenericByteRunBuilder::<Int16Type, BinaryType>::new(); +/// builder.append_value(b"abc"); +/// builder.append_value(b"abc"); +/// builder.append_null(); +/// builder.append_value(b"def"); +/// let array = builder.finish(); +/// +/// assert_eq!( +/// array.run_ends(), +/// &Int16Array::from(vec![Some(2), Some(3), Some(4)]) +/// ); +/// +/// let av = array.values(); +/// +/// assert!(!av.is_null(0)); +/// assert!(av.is_null(1)); +/// assert!(!av.is_null(2)); +/// +/// // Values are polymorphic and so require a downcast. +/// let ava: &BinaryArray = av.as_any().downcast_ref::<BinaryArray>().unwrap(); +/// +/// assert_eq!(ava.value(0), b"abc"); +/// assert_eq!(ava.value(2), b"def"); +/// ``` +#[derive(Debug)] +pub struct GenericByteRunBuilder<R, V> +where + R: ArrowPrimitiveType, + V: ByteArrayType, +{ + run_ends_builder: PrimitiveBuilder<R>, + values_builder: GenericByteBuilder<V>, + current_value: Vec<u8>, + has_current_value: bool, + current_run_end_index: usize, + prev_run_end_index: usize, +} + +impl<R, V> Default for GenericByteRunBuilder<R, V> +where + R: ArrowPrimitiveType, + V: ByteArrayType, +{ + fn default() -> Self { + Self::new() + } +} + +impl<R, V> GenericByteRunBuilder<R, V> +where + R: ArrowPrimitiveType, + V: ByteArrayType, +{ + /// Creates a new `GenericByteRunBuilder` + pub fn new() -> Self { + Self { + run_ends_builder: PrimitiveBuilder::new(), + values_builder: GenericByteBuilder::<V>::new(), + current_value: Vec::new(), + has_current_value: false, + current_run_end_index: 0, + prev_run_end_index: 0, + } + } + + /// Creates a new `GenericByteRunBuilder` with the provided capacity + /// + /// `capacity`: the expected number of run-end encoded values. + /// `data_capacity`: the expected number of bytes of run end encoded values + pub fn with_capacity(capacity: usize, data_capacity: usize) -> Self { + Self { + run_ends_builder: PrimitiveBuilder::with_capacity(capacity), + values_builder: GenericByteBuilder::<V>::with_capacity( + capacity, + data_capacity, + ), + current_value: Vec::new(), + has_current_value: false, + current_run_end_index: 0, + prev_run_end_index: 0, + } + } +} + +impl<R, V> ArrayBuilder for GenericByteRunBuilder<R, V> +where + R: RunEndIndexType, + V: ByteArrayType, +{ + /// Returns the builder as a non-mutable `Any` reference. + fn as_any(&self) -> &dyn Any { + self + } + + /// Returns the builder as a mutable `Any` reference. + fn as_any_mut(&mut self) -> &mut dyn Any { + self + } + + /// Returns the boxed builder as a box of `Any`. + fn into_box_any(self: Box<Self>) -> Box<dyn Any> { + self + } + + /// Returns the number of array slots in the builder + fn len(&self) -> usize { + let mut len = self.run_ends_builder.len(); + // If there is an ongoing run yet to be added, include it in the len + if self.prev_run_end_index != self.current_run_end_index { + len += 1; + } + len + } + + /// Returns whether the number of array slots is zero + fn is_empty(&self) -> bool { + self.current_run_end_index == 0 + } + + /// Builds the array and reset this builder. + fn finish(&mut self) -> ArrayRef { + Arc::new(self.finish()) + } + + /// Builds the array without resetting the builder. + fn finish_cloned(&self) -> ArrayRef { + Arc::new(self.finish_cloned()) + } +} + +impl<R, V> GenericByteRunBuilder<R, V> +where + R: RunEndIndexType, + V: ByteArrayType, +{ + /// Appends optional value to the logical array encoded by the RunArray. + pub fn append_option(&mut self, input_value: Option<impl AsRef<V::Native>>) { + match input_value { + Some(value) => self.append_value(value), + None => self.append_null(), + } + } + + /// Appends value to the logical array encoded by the RunArray. + pub fn append_value(&mut self, input_value: impl AsRef<V::Native>) { + let value: &[u8] = input_value.as_ref().as_ref(); + if !self.has_current_value { + self.append_run_end(); + self.current_value.extend_from_slice(value); + self.has_current_value = true; + } else if self.current_value.as_slice() != value { + self.append_run_end(); + self.current_value.clear(); + self.current_value.extend_from_slice(value); + } + self.current_run_end_index += 1; + } + + /// Appends null to the logical array encoded by the RunArray. + pub fn append_null(&mut self) { + if self.has_current_value { + self.append_run_end(); + self.current_value.clear(); + self.has_current_value = false; + } + self.current_run_end_index += 1; + } + + /// Creates the RunArray and resets the builder. + /// Panics if RunArray cannot be built. + pub fn finish(&mut self) -> RunArray<R> { + // write the last run end to the array. + self.append_run_end(); + + // reset the run end index to zero. + self.current_value.clear(); + self.has_current_value = false; + self.current_run_end_index = 0; + self.prev_run_end_index = 0; + + // build the run encoded array by adding run_ends and values array as its children. + let run_ends_array = self.run_ends_builder.finish(); + let values_array = self.values_builder.finish(); + RunArray::<R>::try_new(&run_ends_array, &values_array).unwrap() + } + + /// Creates the RunArray and without resetting the builder. + /// Panics if RunArray cannot be built. + pub fn finish_cloned(&self) -> RunArray<R> { + let mut run_ends_array = self.run_ends_builder.finish_cloned(); + let mut values_array = self.values_builder.finish_cloned(); + + // Add current run if one exists + if self.prev_run_end_index != self.current_run_end_index { + let mut run_end_builder = run_ends_array.into_builder().unwrap(); + let mut values_builder = values_array.into_builder().unwrap(); + self.append_run_end_with_builders(&mut run_end_builder, &mut values_builder); + run_ends_array = run_end_builder.finish(); + values_array = values_builder.finish(); + } + + RunArray::<R>::try_new(&run_ends_array, &values_array).unwrap() + } + + // Appends the current run to the array. + fn append_run_end(&mut self) { + // empty array or the function called without appending any value. + if self.current_run_end_index == 0 + || self.prev_run_end_index == self.current_run_end_index + { + return; + } + let run_end_index = R::Native::from_usize(self.current_run_end_index) + .unwrap_or_else(|| panic!( + "Cannot convert the value {} from `usize` to native form of arrow datatype {}", + self.current_run_end_index, + R::DATA_TYPE + )); + self.run_ends_builder.append_value(run_end_index); + if self.has_current_value { + let slice = self.current_value.as_slice(); + let native = unsafe { + // As self.current_value is created from V::Native. The value V::Native can be + // built back from the bytes without validations + V::Native::from_bytes_unchecked(slice) + }; + self.values_builder.append_value(native); + } else { + self.values_builder.append_null(); + } + self.prev_run_end_index = self.current_run_end_index; + } + + // Similar to `append_run_end` but on custom builders. + fn append_run_end_with_builders( + &self, + run_ends_builder: &mut PrimitiveBuilder<R>, + values_builder: &mut GenericByteBuilder<V>, + ) { + let run_end_index = R::Native::from_usize(self.current_run_end_index) + .unwrap_or_else(|| panic!( + "Cannot convert the value {} from `usize` to native form of arrow datatype {}", + self.current_run_end_index, + R::DATA_TYPE + )); + run_ends_builder.append_value(run_end_index); + if self.has_current_value { + let slice = self.current_value.as_slice(); + let native = unsafe { + // As self.current_value is created from V::Native. The value V::Native can be + // built back from the bytes without validations + V::Native::from_bytes_unchecked(slice) + }; + values_builder.append_value(native); + } else { + values_builder.append_null(); + } + } +} + +/// Array builder for [`RunArray`] that encodes strings ([`Utf8Type`]). +/// +/// ``` +/// // Create a run-end encoded array with run-end indexes data type as `i16`. +/// // The encoded values are Strings. +/// +/// # use arrow_array::builder::StringRunBuilder; +/// # use arrow_array::{Int16Array, StringArray}; +/// # use arrow_array::types::Int16Type; +/// +/// let mut builder = StringRunBuilder::<Int16Type>::new(); +/// +/// // The builder builds the dictionary value by value +/// builder.append_value("abc"); +/// builder.append_null(); +/// builder.append_value("def"); +/// builder.append_value("def"); +/// builder.append_value("abc"); +/// let array = builder.finish(); +/// +/// assert_eq!( +/// array.run_ends(), +/// &Int16Array::from(vec![Some(1), Some(2), Some(4), Some(5)]) +/// ); +/// +/// // Values are polymorphic and so require a downcast. +/// let av = array.values(); +/// let ava: &StringArray = av.as_any().downcast_ref::<StringArray>().unwrap(); +/// +/// assert_eq!(ava.value(0), "abc"); +/// assert!(av.is_null(1)); +/// assert_eq!(ava.value(2), "def"); +/// assert_eq!(ava.value(3), "abc"); +/// +/// ``` +pub type StringRunBuilder<K> = GenericByteRunBuilder<K, Utf8Type>; + +/// Array builder for [`RunArray`] that encodes large strings ([`LargeUtf8Type`]). See [`StringRunBuilder`] for an example. +pub type LargeStringRunBuilder<K> = GenericByteRunBuilder<K, LargeUtf8Type>; + +/// Array builder for [`RunArray`] that encodes binary values([`BinaryType`]). +/// +/// ``` +/// // Create a run-end encoded array with run-end indexes data type as `i16`. +/// // The encoded data is binary values. +/// +/// # use arrow_array::builder::BinaryRunBuilder; +/// # use arrow_array::{BinaryArray, Int16Array}; +/// # use arrow_array::types::Int16Type; +/// +/// let mut builder = BinaryRunBuilder::<Int16Type>::new(); +/// +/// // The builder builds the dictionary value by value +/// builder.append_value(b"abc"); +/// builder.append_null(); +/// builder.append_value(b"def"); +/// builder.append_value(b"def"); +/// builder.append_value(b"abc"); +/// let array = builder.finish(); +/// +/// assert_eq!( +/// array.run_ends(), +/// &Int16Array::from(vec![Some(1), Some(2), Some(4), Some(5)]) +/// ); +/// +/// // Values are polymorphic and so require a downcast. +/// let av = array.values(); +/// let ava: &BinaryArray = av.as_any().downcast_ref::<BinaryArray>().unwrap(); +/// +/// assert_eq!(ava.value(0), b"abc"); +/// assert!(av.is_null(1)); +/// assert_eq!(ava.value(2), b"def"); +/// assert_eq!(ava.value(3), b"abc"); +/// +/// ``` +pub type BinaryRunBuilder<K> = GenericByteRunBuilder<K, BinaryType>; + +/// Array builder for [`RunArray`] that encodes large binary values([`LargeBinaryType`]). +/// See documentation of [`BinaryRunBuilder`] for an example. +pub type LargeBinaryRunBuilder<K> = GenericByteRunBuilder<K, LargeBinaryType>; + +#[cfg(test)] +mod tests { + use super::*; + + use crate::array::Array; + use crate::types::Int16Type; + use crate::GenericByteArray; + use crate::Int16Array; + use crate::Int16RunArray; + + fn test_bytes_run_buider<T>(values: Vec<&T::Native>) + where + T: ByteArrayType, + <T as ByteArrayType>::Native: PartialEq, + <T as ByteArrayType>::Native: AsRef<<T as ByteArrayType>::Native>, + { + let mut builder = GenericByteRunBuilder::<Int16Type, T>::new(); + builder.append_value(values[0]); + builder.append_value(values[0]); + builder.append_value(values[0]); + builder.append_null(); + builder.append_null(); + builder.append_value(values[1]); + builder.append_value(values[1]); + let array = builder.finish(); + + assert_eq!( + array.run_ends(), + &Int16Array::from(vec![Some(3), Some(5), Some(7)]) + ); + + // Values are polymorphic and so require a downcast. + let av = array.values(); + let ava: &GenericByteArray<T> = + av.as_any().downcast_ref::<GenericByteArray<T>>().unwrap(); + + assert_eq!(*ava.value(0), *values[0]); + assert!(ava.is_null(1)); + assert_eq!(*ava.value(2), *values[1]); + } + + #[test] + fn test_string_run_buider() { + test_bytes_run_buider::<Utf8Type>(vec!["abc", "def"]); + } + + #[test] + fn test_binary_run_buider() { + test_bytes_run_buider::<BinaryType>(vec![b"abc", b"def"]); + } + + fn test_bytes_run_buider_finish_cloned<T>(values: Vec<&T::Native>) + where + T: ByteArrayType, + <T as ByteArrayType>::Native: PartialEq, + <T as ByteArrayType>::Native: AsRef<<T as ByteArrayType>::Native>, + { + let mut builder = GenericByteRunBuilder::<Int16Type, T>::new(); + + builder.append_value(values[0]); + builder.append_null(); + builder.append_value(values[1]); + builder.append_value(values[1]); + builder.append_value(values[0]); + let mut array: Int16RunArray = builder.finish_cloned(); + + assert_eq!( + array.run_ends(), + &Int16Array::from(vec![Some(1), Some(2), Some(4), Some(5)]) + ); + + // Values are polymorphic and so require a downcast. + let av = array.values(); + let ava: &GenericByteArray<T> = + av.as_any().downcast_ref::<GenericByteArray<T>>().unwrap(); + + assert_eq!(ava.value(0), values[0]); + assert!(ava.is_null(1)); + assert_eq!(ava.value(2), values[1]); + assert_eq!(ava.value(3), values[0]); + + builder.append_value(values[0]); + builder.append_value(values[0]); + builder.append_value(values[1]); + + array = builder.finish(); + + assert_eq!( + array.run_ends(), + &Int16Array::from(vec![Some(1), Some(2), Some(4), Some(7), Some(8),]) + ); Review Comment: ```suggestion ); assert_eq!(array.len(), 8); assert_eq!(array.null_count(), 0); ``` -- This is an automated message from the Apache Git Service. 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