| // 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. |
| |
| //! Defines a bitmap, which is used to track which values in an Arrow array are null. |
| //! This is called a "validity bitmap" in the Arrow documentation. |
| |
| use crate::buffer::Buffer; |
| use crate::error::Result; |
| use crate::util::bit_util; |
| use std::mem; |
| |
| use std::ops::{BitAnd, BitOr}; |
| |
| #[derive(Debug, Clone)] |
| pub struct Bitmap { |
| pub(crate) bits: Buffer, |
| } |
| |
| impl Bitmap { |
| pub fn new(num_bits: usize) -> Self { |
| let num_bytes = num_bits / 8 + if num_bits % 8 > 0 { 1 } else { 0 }; |
| let r = num_bytes % 64; |
| let len = if r == 0 { |
| num_bytes |
| } else { |
| num_bytes + 64 - r |
| }; |
| Bitmap { |
| bits: Buffer::from(&vec![0xFF; len]), |
| } |
| } |
| |
| pub fn len(&self) -> usize { |
| self.bits.len() |
| } |
| |
| pub fn is_empty(&self) -> bool { |
| self.bits.is_empty() |
| } |
| |
| pub fn is_set(&self, i: usize) -> bool { |
| assert!(i < (self.bits.len() << 3)); |
| unsafe { bit_util::get_bit_raw(self.bits.as_ptr(), i) } |
| } |
| |
| pub fn buffer_ref(&self) -> &Buffer { |
| &self.bits |
| } |
| |
| pub fn into_buffer(self) -> Buffer { |
| self.bits |
| } |
| |
| /// Returns the total number of bytes of memory occupied by the buffers owned by this [Bitmap]. |
| pub fn get_buffer_memory_size(&self) -> usize { |
| self.bits.capacity() |
| } |
| |
| /// Returns the total number of bytes of memory occupied physically by this [Bitmap]. |
| pub fn get_array_memory_size(&self) -> usize { |
| self.bits.capacity() + mem::size_of_val(self) |
| } |
| } |
| |
| impl<'a, 'b> BitAnd<&'b Bitmap> for &'a Bitmap { |
| type Output = Result<Bitmap>; |
| |
| fn bitand(self, rhs: &'b Bitmap) -> Result<Bitmap> { |
| Ok(Bitmap::from((&self.bits & &rhs.bits)?)) |
| } |
| } |
| |
| impl<'a, 'b> BitOr<&'b Bitmap> for &'a Bitmap { |
| type Output = Result<Bitmap>; |
| |
| fn bitor(self, rhs: &'b Bitmap) -> Result<Bitmap> { |
| Ok(Bitmap::from((&self.bits | &rhs.bits)?)) |
| } |
| } |
| |
| impl From<Buffer> for Bitmap { |
| fn from(buf: Buffer) -> Self { |
| Self { bits: buf } |
| } |
| } |
| |
| impl PartialEq for Bitmap { |
| fn eq(&self, other: &Self) -> bool { |
| // buffer equality considers capacity, but here we want to only compare |
| // actual data contents |
| let self_len = self.bits.len(); |
| let other_len = other.bits.len(); |
| if self_len != other_len { |
| return false; |
| } |
| self.bits.as_slice()[..self_len] == other.bits.as_slice()[..self_len] |
| } |
| } |
| |
| #[cfg(test)] |
| mod tests { |
| use super::*; |
| |
| #[test] |
| fn test_bitmap_length() { |
| assert_eq!(64, Bitmap::new(63 * 8).len()); |
| assert_eq!(64, Bitmap::new(64 * 8).len()); |
| assert_eq!(128, Bitmap::new(65 * 8).len()); |
| } |
| |
| #[test] |
| fn test_bitwise_and() { |
| let bitmap1 = Bitmap::from(Buffer::from([0b01101010])); |
| let bitmap2 = Bitmap::from(Buffer::from([0b01001110])); |
| assert_eq!( |
| Bitmap::from(Buffer::from([0b01001010])), |
| (&bitmap1 & &bitmap2).unwrap() |
| ); |
| } |
| |
| #[test] |
| fn test_bitwise_or() { |
| let bitmap1 = Bitmap::from(Buffer::from([0b01101010])); |
| let bitmap2 = Bitmap::from(Buffer::from([0b01001110])); |
| assert_eq!( |
| Bitmap::from(Buffer::from([0b01101110])), |
| (&bitmap1 | &bitmap2).unwrap() |
| ); |
| } |
| |
| #[test] |
| fn test_bitmap_is_set() { |
| let bitmap = Bitmap::from(Buffer::from([0b01001010])); |
| assert_eq!(false, bitmap.is_set(0)); |
| assert_eq!(true, bitmap.is_set(1)); |
| assert_eq!(false, bitmap.is_set(2)); |
| assert_eq!(true, bitmap.is_set(3)); |
| assert_eq!(false, bitmap.is_set(4)); |
| assert_eq!(false, bitmap.is_set(5)); |
| assert_eq!(true, bitmap.is_set(6)); |
| assert_eq!(false, bitmap.is_set(7)); |
| } |
| } |