Jefffrey commented on code in PR #17093: URL: https://github.com/apache/datafusion/pull/17093#discussion_r2357199334
########## datafusion/spark/src/function/hash/utils.rs: ########## @@ -0,0 +1,614 @@ +// 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 arrow::array::{ + Array, ArrayAccessor, ArrayIter, ArrayRef, ArrowPrimitiveType, BinaryViewArray, + BooleanArray, Date32Array, Date64Array, Decimal128Array, Decimal256Array, + DictionaryArray, DurationMicrosecondArray, DurationMillisecondArray, + DurationNanosecondArray, DurationSecondArray, FixedSizeBinaryArray, Float32Array, + Float64Array, GenericBinaryArray, Int16Array, Int32Array, Int64Array, Int8Array, + IntervalDayTimeArray, IntervalMonthDayNanoArray, IntervalYearMonthArray, + LargeListArray, LargeListViewArray, LargeStringArray, ListArray, ListViewArray, + MapArray, PrimitiveArray, StringArray, StringViewArray, StructArray, + Time32MillisecondArray, Time32SecondArray, Time64MicrosecondArray, + Time64NanosecondArray, TimestampMicrosecondArray, TimestampMillisecondArray, + TimestampNanosecondArray, TimestampSecondArray, UInt16Array, UInt32Array, + UInt64Array, UInt8Array, UnionArray, +}; +use arrow::datatypes::{ + i256, ArrowDictionaryKeyType, DataType, Int16Type, Int32Type, Int64Type, Int8Type, + IntervalDayTime, IntervalMonthDayNano, IntervalUnit, TimeUnit, UInt16Type, + UInt32Type, UInt64Type, UInt8Type, +}; +use bigdecimal::num_traits::{Float, ToBytes}; +use datafusion_common::{exec_err, DataFusionError, Result}; +use std::sync::Arc; + +fn hash_impl<T, H: Copy>( + arr: ArrayIter<impl ArrayAccessor<Item = T>>, + seed: &mut [H], + func: impl Fn(H, T) -> H, +) -> Result<()> { + let len = arr.len(); + if len != seed.len() { + return exec_err!("Array length mismatch: {} != {}", len, seed.len()); + } + for (hash, elem) in seed.iter_mut().zip(arr) { + if let Some(elem) = elem { + *hash = func(*hash, elem); + } + } + Ok(()) +} + +fn try_hash_impl<T, H: Copy>( + arr: ArrayIter<impl ArrayAccessor<Item = T>>, + seed: &mut [H], + func: impl Fn(H, T) -> Result<H>, +) -> Result<()> { + let len = arr.len(); + if len != seed.len() { + return exec_err!("Array length mismatch: {} != {}", len, seed.len()); + } + for (hash, elem) in seed.iter_mut().zip(arr) { + if let Some(elem) = elem { + *hash = func(*hash, elem)?; + } + } + Ok(()) +} + +pub trait SparkHasher<H: Copy + std::fmt::Debug> { + fn oneshot(seed: H, data: &[u8]) -> H; + + fn hash_boolean(arr: &BooleanArray, seed: &mut [H]) -> Result<()> { + let true_bytes = 1_i32.to_le_bytes(); + let false_bytes = 0_i32.to_le_bytes(); + hash_impl(arr.iter(), seed, |seed, v| { + if v { + Self::oneshot(seed, &true_bytes) + } else { + Self::oneshot(seed, &false_bytes) + } + })?; + Ok(()) + } + + fn hash_primitive<T, U>(arr: &PrimitiveArray<T>, seed: &mut [H]) -> Result<()> + where + T: ArrowPrimitiveType, + U: ToBytes + From<T::Native>, + { + hash_impl(arr.iter(), seed, |seed, v| { + let bytes = U::from(v).to_le_bytes(); + Self::oneshot(seed, bytes.as_ref()) + })?; + Ok(()) + } + + fn try_hash_primitive<T, U>(arr: &PrimitiveArray<T>, seed: &mut [H]) -> Result<()> + where + T: ArrowPrimitiveType, + U: ToBytes + TryFrom<T::Native>, + <U as TryFrom<T::Native>>::Error: std::fmt::Display, + { + try_hash_impl(arr.iter(), seed, |seed, v| { + let uv = + U::try_from(v).map_err(|e| DataFusionError::Execution(e.to_string()))?; + let bytes = uv.to_le_bytes(); + Ok(Self::oneshot(seed, bytes.as_ref())) + })?; + Ok(()) + } + + fn hash_primitive_float<T, U>(arr: &PrimitiveArray<T>, seed: &mut [H]) -> Result<()> + where + T: ArrowPrimitiveType, + T::Native: ToBytes + Float, + U: ToBytes + Default, + { + let neg_zero = T::Native::neg_zero(); + let neg_zero_bytes = U::to_le_bytes(&U::default()); + + hash_impl(arr.iter(), seed, |seed, v| { + if v == neg_zero { + Self::oneshot(seed, neg_zero_bytes.as_ref()) + } else { + let bytes = v.to_le_bytes(); + Self::oneshot(seed, bytes.as_ref()) + } + })?; + Ok(()) + } + + fn hash_bytes<T>(iter: ArrayIter<T>, seed: &mut [H]) -> Result<()> + where + T: ArrayAccessor, + T::Item: AsRef<[u8]>, + { + hash_impl(iter, seed, |seed, v| Self::oneshot(seed, v.as_ref()))?; + Ok(()) + } + + fn hash_list<T>(iter: ArrayIter<T>, seed: &mut [H]) -> Result<()> + where + T: ArrayAccessor<Item = ArrayRef>, + { + try_hash_impl(iter, seed, |seed, v| { + let len = v.len(); + let mut result = [seed; 1]; + for i in 0..len { + let slice = v.slice(i, 1); + Self::hash(&slice, &mut result)?; + } + Ok(result[0]) + })?; + Ok(()) + } + + fn hash_map<T>(iter: ArrayIter<T>, seed: &mut [H]) -> Result<()> + where + T: ArrayAccessor<Item = StructArray>, + { + try_hash_impl(iter, seed, |seed, v| { + let len = v.len(); + let mut result = [seed; 1]; + for i in 0..len { + let slice = v.slice(i, 1); + Self::hash(slice.column(0), &mut result)?; + Self::hash(slice.column(1), &mut result)?; + } + Ok(result[0]) + })?; + Ok(()) + } + + fn hash_struct(arr: &StructArray, seed: &mut [H]) -> Result<()> { + Self::hash_arrays(arr.columns(), seed) + } + + fn hash_arrays(arr: &[ArrayRef], seed: &mut [H]) -> Result<()> { + for arr in arr { + Self::hash(arr, seed)?; + } + Ok(()) + } + + fn hash_dictionary<T>(arr: &DictionaryArray<T>, seed: &mut [H]) -> Result<()> + where + T: ArrowDictionaryKeyType, + { + let len = arr.len(); + if len != seed.len() { + return exec_err!("Array length mismatch: {} != {}", len, seed.len()); + } + + for (i, seed) in seed.iter_mut().enumerate().take(arr.len()) { + if arr.is_null(i) { + continue; + } + let mut result = [*seed; 1]; + + let value = arr.values().slice(i, 1); + let key: Arc<dyn Array> = Arc::new(arr.keys().slice(i, 1)); + + for j in 0..key.len() { + let value = value.slice(j, 1); + let key = key.slice(j, 1); + Self::hash(&key, &mut result)?; + Self::hash(&value, &mut result)?; + } + *seed = result[0]; + } + Ok(()) + } + + fn hash_union(arr: &UnionArray, seed: &mut [H]) -> Result<()> { + let len = arr.len(); + if len != seed.len() { + return exec_err!("Array length mismatch: {} != {}", len, seed.len()); + } + + for (i, seed) in seed.iter_mut().enumerate().take(len) { + let value = arr.value(i); + let mut result = [*seed; 1]; + for i in 0..value.len() { + let elem = value.slice(i, 1); + Self::hash(&elem, &mut result)?; + } + *seed = result[0]; + } + Ok(()) + } + + /// Computes the xxHash64 hash of the given data + fn hash(arr: &ArrayRef, seed: &mut [H]) -> Result<()> { + match arr.data_type() { + DataType::Null => { + // do nothing + } + DataType::Boolean => { + let arr = arr.as_any().downcast_ref::<BooleanArray>().unwrap(); + Self::hash_boolean(arr, seed)?; + } + DataType::Int8 => { + let arr = arr.as_any().downcast_ref::<Int8Array>().unwrap(); + Self::hash_primitive::<_, i32>(arr, seed)?; + } + DataType::UInt8 => { + let arr = arr.as_any().downcast_ref::<UInt8Array>().unwrap(); + Self::hash_primitive::<_, i32>(arr, seed)?; + } + DataType::Int16 => { + let arr = arr.as_any().downcast_ref::<Int16Array>().unwrap(); + Self::hash_primitive::<_, i32>(arr, seed)?; + } + DataType::UInt16 => { + let arr = arr.as_any().downcast_ref::<UInt16Array>().unwrap(); + Self::hash_primitive::<_, i32>(arr, seed)?; + } + DataType::Int32 => { + let arr = arr.as_any().downcast_ref::<Int32Array>().unwrap(); + Self::hash_primitive::<_, i32>(arr, seed)?; + } + DataType::UInt32 => { + let arr = arr.as_any().downcast_ref::<UInt32Array>().unwrap(); + Self::hash_primitive::<_, u32>(arr, seed)?; + } + DataType::Int64 => { + let arr = arr.as_any().downcast_ref::<Int64Array>().unwrap(); + Self::hash_primitive::<_, i64>(arr, seed)?; + } + DataType::UInt64 => { + let arr = arr.as_any().downcast_ref::<UInt64Array>().unwrap(); + Self::hash_primitive::<_, u64>(arr, seed)?; + } Review Comment: Sorry, but this doesn't explain anything to me 🙁 -- This is an automated message from the Apache Git Service. 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