/Users/andrewlamb/Software/arrow-rs/arrow-buffer/src/builder/boolean.rs

Source
// 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::{bit_mask, bit_util, BooleanBuffer, Buffer, MutableBuffer};
use std::ops::Range;

/// Builder for [`BooleanBuffer`]
///
/// # See Also
///
/// * [`NullBuffer`] for building [`BooleanBuffer`]s for representing nulls
///
/// [`NullBuffer`]: crate::NullBuffer
#[derive(Debug)]
pub struct BooleanBufferBuilder {
    buffer: MutableBuffer,
    len: usize,
}

impl BooleanBufferBuilder {
    /// Creates a new `BooleanBufferBuilder` with sufficient space for
    /// `capacity` bits (not bytes).
    ///
    /// The capacity is rounded up to the nearest multiple of 8 for the
    /// allocation.
    #[inline]
    pub fn new(capacity: usize) -> Self {
        let byte_capacity = bit_util::ceil(capacity, 8);
        let buffer = MutableBuffer::new(byte_capacity);
        Self { buffer, len: 0 }
    }

    /// Creates a new `BooleanBufferBuilder` from [`MutableBuffer`] of `len`
    pub fn new_from_buffer(buffer: MutableBuffer, len: usize) -> Self {
        assert!(len <= buffer.len() * 8);
        let mut s = Self {
            len: buffer.len() * 8,
            buffer,
        };
        s.truncate(len);
        s
    }

    /// Returns the length of the buffer
    #[inline]
    pub fn len(&self) -> usize {
        self.len
    }

    /// Sets a bit in the buffer at `index`
    #[inline]
    pub fn set_bit(&mut self, index: usize, v: bool) {
        if v {
            bit_util::set_bit(self.buffer.as_mut(), index);
        } else {
            bit_util::unset_bit(self.buffer.as_mut(), index);
        }
    }

    /// Gets a bit in the buffer at `index`
    #[inline]
    pub fn get_bit(&self, index: usize) -> bool {
        bit_util::get_bit(self.buffer.as_slice(), index)
    }

    /// Returns true if empty
    #[inline]
    pub fn is_empty(&self) -> bool {
        self.len == 0
    }

    /// Returns the capacity of the buffer, in bits (not bytes)
    ///
    /// Note this
    ///
    /// # Example
    /// ```
    /// # use arrow_buffer::builder::BooleanBufferBuilder;
    /// // empty requires 0 bytes
    /// let b = BooleanBufferBuilder::new(0);
    /// assert_eq!(0, b.capacity());
    /// // Creating space for 1 bit results in 64 bytes (space for 512 bits)
    /// // (64 is the minimum allocation size for 64 bit architectures)
    /// let mut b = BooleanBufferBuilder::new(1);
    /// assert_eq!(512, b.capacity());
    /// // 1000 bits requires 128 bytes (space for 1024 bits)
    /// b.append_n(1000, true);
    /// assert_eq!(1024, b.capacity());
    /// ```
    #[inline]
    pub fn capacity(&self) -> usize {
        self.buffer.capacity() * 8
    }

    /// Advances the buffer by `additional` bits
    #[inline]
    pub fn advance(&mut self, additional: usize) {
        let new_len = self.len + additional;
        let new_len_bytes = bit_util::ceil(new_len, 8);
        if new_len_bytes > self.buffer.len() {
            self.buffer.resize(new_len_bytes, 0);
        }
        self.len = new_len;
    }

    /// Truncates the builder to the given length
    ///
    /// If `len` is greater than the buffer's current length, this has no effect
    #[inline]
    pub fn truncate(&mut self, len: usize) {
        if len > self.len {
            return;
        }

        let new_len_bytes = bit_util::ceil(len, 8);
        self.buffer.truncate(new_len_bytes);
        self.len = len;

        let remainder = self.len % 8;
        if remainder != 0 {
            let mask = (1_u8 << remainder).wrapping_sub(1);
            *self.buffer.as_mut().last_mut().unwrap() &= mask;
        }
    }

    /// Reserve space to at least `additional` new bits.
    /// Capacity will be `>= self.len() + additional`.
    /// New bytes are uninitialized and reading them is undefined behavior.
    #[inline]
    pub fn reserve(&mut self, additional: usize) {
        let capacity = self.len + additional;
        if capacity > self.capacity() {
            // convert differential to bytes
            let additional = bit_util::ceil(capacity, 8) - self.buffer.len();
            self.buffer.reserve(additional);
        }
    }

    /// Resizes the buffer, either truncating its contents (with no change in capacity), or
    /// growing it (potentially reallocating it) and writing `false` in the newly available bits.
    #[inline]
    pub fn resize(&mut self, len: usize) {
        match len.checked_sub(self.len) {
            Some(delta) => self.advance(delta),
            None => self.truncate(len),
        }
    }

    /// Appends a boolean `v` into the buffer
    #[inline]
    pub fn append(&mut self, v: bool) {
        self.advance(1);
        if v {
            unsafe { bit_util::set_bit_raw(self.buffer.as_mut_ptr(), self.len - 1) };
        }
    }

    /// Appends n `additional` bits of value `v` into the buffer
    #[inline]
    pub fn append_n(&mut self, additional: usize, v: bool) {
        match v {
            true => {
                let new_len = self.len + additional;
                let new_len_bytes = bit_util::ceil(new_len, 8);
                let cur_remainder = self.len % 8;
                let new_remainder = new_len % 8;

                if cur_remainder != 0 {
                    // Pad last byte with 1s
                    *self.buffer.as_slice_mut().last_mut().unwrap() |= !((1 << cur_remainder) - 1)
                }
                self.buffer.resize(new_len_bytes, 0xFF);
                if new_remainder != 0 {
                    // Clear remaining bits
                    *self.buffer.as_slice_mut().last_mut().unwrap() &= (1 << new_remainder) - 1
                }
                self.len = new_len;
            }
            false => self.advance(additional),
        }
    }

    /// Appends a slice of booleans into the buffer
    #[inline]
    pub fn append_slice(&mut self, slice: &[bool]) {
        let additional = slice.len();
        self.advance(additional);

        let offset = self.len() - additional;
        for (i, v) in slice1.iter1().enumerate1() {
            if *v {
                unsafe { bit_util::set_bit_raw(self.buffer.as_mut_ptr(), offset + i) }
            }
        }
    }

    /// Append `range` bits from `to_set`
    ///
    /// `to_set` is a slice of bits packed LSB-first into `[u8]`
    ///
    /// # Panics
    ///
    /// Panics if `to_set` does not contain `ceil(range.end / 8)` bytes
    pub fn append_packed_range(&mut self, range: Range<usize>, to_set: &[u8]) {
        let offset_write = self.len;
        let len = range.end - range.start;
        self.advance(len);
        bit_mask::set_bits(
            self.buffer.as_slice_mut(),
            to_set,
            offset_write,
            range.start,
            len,
        );
    }

    /// Append [`BooleanBuffer`] to this [`BooleanBufferBuilder`]
    pub fn append_buffer(&mut self, buffer: &BooleanBuffer) {
        let range = buffer.offset()..buffer.offset() + buffer.len();
        self.append_packed_range(range, buffer.values())
    }

    /// Returns the packed bits
    pub fn as_slice(&self) -> &[u8] {
        self.buffer.as_slice()
    }

    /// Returns the packed bits
    pub fn as_slice_mut(&mut self) -> &mut [u8] {
        self.buffer.as_slice_mut()
    }

    /// Creates a [`BooleanBuffer`]
    #[inline]
    pub fn finish(&mut self) -> BooleanBuffer {
        let buf = std::mem::replace(&mut self.buffer, MutableBuffer::new(0));
        let len = std::mem::replace(&mut self.len, 0);
        BooleanBuffer::new(buf.into(), 0, len)
    }

    /// Builds the [BooleanBuffer] without resetting the builder.
    pub fn finish_cloned(&self) -> BooleanBuffer {
        BooleanBuffer::new(Buffer::from_slice_ref(self.as_slice()), 0, self.len)
    }
}

impl From<BooleanBufferBuilder> for Buffer {
    #[inline]
    fn from(builder: BooleanBufferBuilder) -> Self {
        builder.buffer.into()
    }
}

impl From<BooleanBufferBuilder> for BooleanBuffer {
    #[inline]
    fn from(builder: BooleanBufferBuilder) -> Self {
        BooleanBuffer::new(builder.buffer.into(), 0, builder.len)
    }
}

#[cfg(test)]
mod tests {
    use super::*;

    #[test]
    fn test_boolean_buffer_builder_write_bytes() {
        let mut b = BooleanBufferBuilder::new(4);
        b.append(false);
        b.append(true);
        b.append(false);
        b.append(true);
        assert_eq!(4, b.len());
        assert_eq!(512, b.capacity());
        let buffer = b.finish();
        assert_eq!(4, buffer.len());

        // Overallocate capacity
        let mut b = BooleanBufferBuilder::new(8);
        b.append_slice(&[false, true, false, true]);
        assert_eq!(4, b.len());
        assert_eq!(512, b.capacity());
        let buffer = b.finish();
        assert_eq!(4, buffer.len());
    }

    #[test]
    fn test_boolean_buffer_builder_unset_first_bit() {
        let mut buffer = BooleanBufferBuilder::new(4);
        buffer.append(true);
        buffer.append(true);
        buffer.append(false);
        buffer.append(true);
        buffer.set_bit(0, false);
        assert_eq!(buffer.len(), 4);
        assert_eq!(buffer.finish().values(), &[0b1010_u8]);
    }

    #[test]
    fn test_boolean_buffer_builder_unset_last_bit() {
        let mut buffer = BooleanBufferBuilder::new(4);
        buffer.append(true);
        buffer.append(true);
        buffer.append(false);
        buffer.append(true);
        buffer.set_bit(3, false);
        assert_eq!(buffer.len(), 4);
        assert_eq!(buffer.finish().values(), &[0b0011_u8]);
    }

    #[test]
    fn test_boolean_buffer_builder_unset_an_inner_bit() {
        let mut buffer = BooleanBufferBuilder::new(5);
        buffer.append(true);
        buffer.append(true);
        buffer.append(false);
        buffer.append(true);
        buffer.set_bit(1, false);
        assert_eq!(buffer.len(), 4);
        assert_eq!(buffer.finish().values(), &[0b1001_u8]);
    }

    #[test]
    fn test_boolean_buffer_builder_unset_several_bits() {
        let mut buffer = BooleanBufferBuilder::new(5);
        buffer.append(true);
        buffer.append(true);
        buffer.append(true);
        buffer.append(false);
        buffer.append(true);
        buffer.set_bit(1, false);
        buffer.set_bit(2, false);
        assert_eq!(buffer.len(), 5);
        assert_eq!(buffer.finish().values(), &[0b10001_u8]);
    }

    #[test]
    fn test_boolean_buffer_builder_unset_several_bits_bigger_than_one_byte() {
        let mut buffer = BooleanBufferBuilder::new(16);
        buffer.append_n(10, true);
        buffer.set_bit(0, false);
        buffer.set_bit(3, false);
        buffer.set_bit(9, false);
        assert_eq!(buffer.len(), 10);
        assert_eq!(buffer.finish().values(), &[0b11110110_u8, 0b01_u8]);
    }

    #[test]
    fn test_boolean_buffer_builder_flip_several_bits_bigger_than_one_byte() {
        let mut buffer = BooleanBufferBuilder::new(16);
        buffer.append_n(5, true);
        buffer.append_n(5, false);
        buffer.append_n(5, true);
        buffer.set_bit(0, false);
        buffer.set_bit(3, false);
        buffer.set_bit(9, false);
        buffer.set_bit(6, true);
        buffer.set_bit(14, true);
        buffer.set_bit(13, false);
        assert_eq!(buffer.len(), 15);
        assert_eq!(buffer.finish().values(), &[0b01010110_u8, 0b1011100_u8]);
    }

    #[test]
    fn test_bool_buffer_builder_get_first_bit() {
        let mut buffer = BooleanBufferBuilder::new(16);
        buffer.append_n(8, true);
        buffer.append_n(8, false);
        assert!(buffer.get_bit(0));
    }

    #[test]
    fn test_bool_buffer_builder_get_first_bit_not_requires_mutability() {
        let buffer = {
            let mut buffer = BooleanBufferBuilder::new(16);
            buffer.append_n(8, true);
            buffer
        };

        assert!(buffer.get_bit(0));
    }

    #[test]
    fn test_bool_buffer_builder_get_last_bit() {
        let mut buffer = BooleanBufferBuilder::new(16);
        buffer.append_n(8, true);
        buffer.append_n(8, false);
        assert!(!buffer.get_bit(15));
    }

    #[test]
    fn test_bool_buffer_builder_get_an_inner_bit() {
        let mut buffer = BooleanBufferBuilder::new(16);
        buffer.append_n(4, false);
        buffer.append_n(8, true);
        buffer.append_n(4, false);
        assert!(buffer.get_bit(11));
    }

    #[test]
    fn test_bool_buffer_fuzz() {
        use rand::prelude::*;

        let mut buffer = BooleanBufferBuilder::new(12);
        let mut all_bools = vec![];
        let mut rng = rand::rng();

        let src_len = 32;
        let (src, compacted_src) = {
            let src: Vec<_> = std::iter::from_fn(|| Some(rng.next_u32() & 1 == 0))
                .take(src_len)
                .collect();

            let mut compacted_src = BooleanBufferBuilder::new(src_len);
            compacted_src.append_slice(&src);
            (src, compacted_src.finish())
        };

        for _ in 0..100 {
            let a = rng.next_u32() as usize % src_len;
            let b = rng.next_u32() as usize % src_len;

            let start = a.min(b);
            let end = a.max(b);

            buffer.append_packed_range(start..end, compacted_src.values());
            all_bools.extend_from_slice(&src[start..end]);
        }

        let mut compacted = BooleanBufferBuilder::new(all_bools.len());
        compacted.append_slice(&all_bools);

        assert_eq!(buffer.finish(), compacted.finish())
    }

    #[test]
    fn test_boolean_array_builder_resize() {
        let mut builder = BooleanBufferBuilder::new(20);
        builder.append_n(4, true);
        builder.append_n(7, false);
        builder.append_n(2, true);
        builder.resize(20);

        assert_eq!(builder.len(), 20);
        assert_eq!(builder.as_slice(), &[0b00001111, 0b00011000, 0b00000000]);

        builder.resize(5);
        assert_eq!(builder.len(), 5);
        assert_eq!(builder.as_slice(), &[0b00001111]);

        builder.append_n(4, true);
        assert_eq!(builder.len(), 9);
        assert_eq!(builder.as_slice(), &[0b11101111, 0b00000001]);
    }

    #[test]
    fn test_truncate() {
        let b = MutableBuffer::from_iter([true, true, true, true]);
        let mut builder = BooleanBufferBuilder::new_from_buffer(b, 2);
        builder.advance(2);
        let finished = builder.finish();
        assert_eq!(finished.values(), &[0b00000011]);

        let mut builder = BooleanBufferBuilder::new(10);
        builder.append_n(5, true);
        builder.resize(3);
        builder.advance(2);
        let finished = builder.finish();
        assert_eq!(finished.values(), &[0b00000111]);

        let mut builder = BooleanBufferBuilder::new(10);
        builder.append_n(16, true);
        assert_eq!(builder.as_slice(), &[0xFF, 0xFF]);
        builder.truncate(20);
        assert_eq!(builder.as_slice(), &[0xFF, 0xFF]);
        builder.truncate(14);
        assert_eq!(builder.as_slice(), &[0xFF, 0b00111111]);
        builder.append(false);
        builder.append(true);
        assert_eq!(builder.as_slice(), &[0xFF, 0b10111111]);
        builder.append_packed_range(0..3, &[0xFF]);
        assert_eq!(builder.as_slice(), &[0xFF, 0b10111111, 0b00000111]);
        builder.truncate(17);
        assert_eq!(builder.as_slice(), &[0xFF, 0b10111111, 0b00000001]);
        builder.append_packed_range(0..2, &[2]);
        assert_eq!(builder.as_slice(), &[0xFF, 0b10111111, 0b0000101]);
        builder.truncate(8);
        assert_eq!(builder.as_slice(), &[0xFF]);
        builder.resize(14);
        assert_eq!(builder.as_slice(), &[0xFF, 0x00]);
        builder.truncate(0);
        assert_eq!(builder.as_slice(), &[]);
    }

    #[test]
    fn test_boolean_builder_increases_buffer_len() {
        // 00000010 01001000
        let buf = Buffer::from([72_u8, 2_u8]);
        let mut builder = BooleanBufferBuilder::new(8);

        for i in 0..16 {
            if i == 3 || i == 6 || i == 9 {
                builder.append(true);
            } else {
                builder.append(false);
            }
        }
        let buf2 = builder.finish();

        assert_eq!(buf.len(), buf2.inner().len());
        assert_eq!(buf.as_slice(), buf2.values());
    }
}

Coverage Report

Created: 2025-08-26 07:03

Line	Count	Source
1		// Licensed to the Apache Software Foundation (ASF) under one
2		// or more contributor license agreements. See the NOTICE file
3		// distributed with this work for additional information
4		// regarding copyright ownership. The ASF licenses this file
5		// to you under the Apache License, Version 2.0 (the
6		// "License"); you may not use this file except in compliance
7		// with the License. You may obtain a copy of the License at
8		//
9		// http://www.apache.org/licenses/LICENSE-2.0
10		//
11		// Unless required by applicable law or agreed to in writing,
12		// software distributed under the License is distributed on an
13		// "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
14		// KIND, either express or implied. See the License for the
15		// specific language governing permissions and limitations
16		// under the License.
17
18		use crate::{bit_mask, bit_util, BooleanBuffer, Buffer, MutableBuffer};
19		use std::ops::Range;
20
21		/// Builder for [`BooleanBuffer`]
22		///
23		/// # See Also
24		///
25		/// * [`NullBuffer`] for building [`BooleanBuffer`]s for representing nulls
26		///
27		/// [`NullBuffer`]: crate::NullBuffer
28		#[derive(Debug)]
29		pub struct BooleanBufferBuilder {
30		buffer: MutableBuffer,
31		len: usize,
32		}
33
34		impl BooleanBufferBuilder {
35		/// Creates a new `BooleanBufferBuilder` with sufficient space for
36		/// `capacity` bits (not bytes).
37		///
38		/// The capacity is rounded up to the nearest multiple of 8 for the
39		/// allocation.
40		#[inline]
41	207	pub fn new(capacity: usize) -> Self {
42	207	let byte_capacity = bit_util::ceil(capacity, 8);
43	207	let buffer = MutableBuffer::new(byte_capacity);
44	207	Self { buffer, len: 0 }
45	207	}
46
47		/// Creates a new `BooleanBufferBuilder` from [`MutableBuffer`] of `len`
48	0	pub fn new_from_buffer(buffer: MutableBuffer, len: usize) -> Self {
49	0	assert!(len <= buffer.len() * 8);
50	0	let mut s = Self {
51	0	len: buffer.len() * 8,
52	0	buffer,
53	0	};
54	0	s.truncate(len);
55	0	s
56	0	}
57
58		/// Returns the length of the buffer
59		#[inline]
60	37	pub fn len(&self) -> usize {
61	37	self.len
62	37	}
63
64		/// Sets a bit in the buffer at `index`
65		#[inline]
66	11	pub fn set_bit(&mut self, index: usize, v: bool) {
67	11	if v {
68	11	bit_util::set_bit(self.buffer.as_mut(), index);
69	11	} else {
70	0	bit_util::unset_bit(self.buffer.as_mut(), index);
71	0	}
72	11	}
73
74		/// Gets a bit in the buffer at `index`
75		#[inline]
76		pub fn get_bit(&self, index: usize) -> bool {
77		bit_util::get_bit(self.buffer.as_slice(), index)
78		}
79
80		/// Returns true if empty
81		#[inline]
82		pub fn is_empty(&self) -> bool {
83		self.len == 0
84		}
85
86		/// Returns the capacity of the buffer, in bits (not bytes)
87		///
88		/// Note this
89		///
90		/// # Example
91		/// ```
92		/// # use arrow_buffer::builder::BooleanBufferBuilder;
93		/// // empty requires 0 bytes
94		/// let b = BooleanBufferBuilder::new(0);
95		/// assert_eq!(0, b.capacity());
96		/// // Creating space for 1 bit results in 64 bytes (space for 512 bits)
97		/// // (64 is the minimum allocation size for 64 bit architectures)
98		/// let mut b = BooleanBufferBuilder::new(1);
99		/// assert_eq!(512, b.capacity());
100		/// // 1000 bits requires 128 bytes (space for 1024 bits)
101		/// b.append_n(1000, true);
102		/// assert_eq!(1024, b.capacity());
103		/// ```
104		#[inline]
105	0	pub fn capacity(&self) -> usize {
106	0	self.buffer.capacity() * 8
107	0	}
108
109		/// Advances the buffer by `additional` bits
110		#[inline]
111	760	pub fn advance(&mut self, additional: usize) {
112	760	let new_len = self.len + additional;
113	760	let new_len_bytes = bit_util::ceil(new_len, 8);
114	760	if new_len_bytes > self.buffer.len() {
115	153	self.buffer.resize(new_len_bytes, 0);
116	607	}
117	760	self.len = new_len;
118	760	}
119
120		/// Truncates the builder to the given length
121		///
122		/// If `len` is greater than the buffer's current length, this has no effect
123		#[inline]
124	0	pub fn truncate(&mut self, len: usize) {
125	0	if len > self.len {
126	0	return;
127	0	}
128
129	0	let new_len_bytes = bit_util::ceil(len, 8);
130	0	self.buffer.truncate(new_len_bytes);
131	0	self.len = len;
132
133	0	let remainder = self.len % 8;
134	0	if remainder != 0 {
135	0	let mask = (1_u8 << remainder).wrapping_sub(1);
136	0	*self.buffer.as_mut().last_mut().unwrap() &= mask;
137	0	}
138	0	}
139
140		/// Reserve space to at least `additional` new bits.
141		/// Capacity will be `>= self.len() + additional`.
142		/// New bytes are uninitialized and reading them is undefined behavior.
143		#[inline]
144		pub fn reserve(&mut self, additional: usize) {
145		let capacity = self.len + additional;
146		if capacity > self.capacity() {
147		// convert differential to bytes
148		let additional = bit_util::ceil(capacity, 8) - self.buffer.len();
149		self.buffer.reserve(additional);
150		}
151		}
152
153		/// Resizes the buffer, either truncating its contents (with no change in capacity), or
154		/// growing it (potentially reallocating it) and writing `false` in the newly available bits.
155		#[inline]
156	0	pub fn resize(&mut self, len: usize) {
157	0	match len.checked_sub(self.len) {
158	0	Some(delta) => self.advance(delta),
159	0	None => self.truncate(len),
160		}
161	0	}
162
163		/// Appends a boolean `v` into the buffer
164		#[inline]
165	708	pub fn append(&mut self, v: bool) {
166	708	self.advance(1);
167	708	if v {
168	347	unsafe { bit_util::set_bit_raw(self.buffer.as_mut_ptr(), self.len - 1) };
169	361	}
170	708	}
171
172		/// Appends n `additional` bits of value `v` into the buffer
173		#[inline]
174	148	pub fn append_n(&mut self, additional: usize, v: bool) {
175	148	match v {
176		true => {
177	148	let new_len = self.len + additional;
178	148	let new_len_bytes = bit_util::ceil(new_len, 8);
179	148	let cur_remainder = self.len % 8;
180	148	let new_remainder = new_len % 8;
181
182	148	if cur_remainder != 0 {
183		// Pad last byte with 1s
184	17	*self.buffer.as_slice_mut().last_mut().unwrap() \|= !((1 << cur_remainder) - 1)
185	131	}
186	148	self.buffer.resize(new_len_bytes, 0xFF);
187	148	if new_remainder != 0 {
188		// Clear remaining bits
189	99	*self.buffer.as_slice_mut().last_mut().unwrap() &= (1 << new_remainder) - 1
190	49	}
191	148	self.len = new_len;
192		}
193	0	false => self.advance(additional),
194		}
195	148	}
196
197		/// Appends a slice of booleans into the buffer
198		#[inline]
199	1	pub fn append_slice(&mut self, slice: &[bool]) {
200	1	let additional = slice.len();
201	1	self.advance(additional);
202
203	1	let offset = self.len() - additional;
204	5	for (i, v) in slice1 . iter1 (). enumerate1 () {
205	5	if *v {
206	3	unsafe { bit_util::set_bit_raw(self.buffer.as_mut_ptr(), offset + i) }
207	2	}
208		}
209	1	}
210
211		/// Append `range` bits from `to_set`
212		///
213		/// `to_set` is a slice of bits packed LSB-first into `[u8]`
214		///
215		/// # Panics
216		///
217		/// Panics if `to_set` does not contain `ceil(range.end / 8)` bytes
218	45	pub fn append_packed_range(&mut self, range: Range<usize>, to_set: &[u8]) {
219	45	let offset_write = self.len;
220	45	let len = range.end - range.start;
221	45	self.advance(len);
222	45	bit_mask::set_bits(
223	45	self.buffer.as_slice_mut(),
224	45	to_set,
225	45	offset_write,
226	45	range.start,
227	45	len,
228		);
229	45	}
230
231		/// Append [`BooleanBuffer`] to this [`BooleanBufferBuilder`]
232	45	pub fn append_buffer(&mut self, buffer: &BooleanBuffer) {
233	45	let range = buffer.offset()..buffer.offset() + buffer.len();
234	45	self.append_packed_range(range, buffer.values())
235	45	}
236
237		/// Returns the packed bits
238	0	pub fn as_slice(&self) -> &[u8] {
239	0	self.buffer.as_slice()
240	0	}
241
242		/// Returns the packed bits
243	0	pub fn as_slice_mut(&mut self) -> &mut [u8] {
244	0	self.buffer.as_slice_mut()
245	0	}
246
247		/// Creates a [`BooleanBuffer`]
248		#[inline]
249	202	pub fn finish(&mut self) -> BooleanBuffer {
250	202	let buf = std::mem::replace(&mut self.buffer, MutableBuffer::new(0));
251	202	let len = std::mem::replace(&mut self.len, 0);
252	202	BooleanBuffer::new(buf.into(), 0, len)
253	202	}
254
255		/// Builds the [BooleanBuffer] without resetting the builder.
256	0	pub fn finish_cloned(&self) -> BooleanBuffer {
257	0	BooleanBuffer::new(Buffer::from_slice_ref(self.as_slice()), 0, self.len)
258	0	}
259		}
260
261		impl From<BooleanBufferBuilder> for Buffer {
262		#[inline]
263	15	fn from(builder: BooleanBufferBuilder) -> Self {
264	15	builder.buffer.into()
265	15	}
266		}
267
268		impl From<BooleanBufferBuilder> for BooleanBuffer {
269		#[inline]
270		fn from(builder: BooleanBufferBuilder) -> Self {
271		BooleanBuffer::new(builder.buffer.into(), 0, builder.len)
272		}
273		}
274
275		#[cfg(test)]
276		mod tests {
277		use super::*;
278
279		#[test]
280		fn test_boolean_buffer_builder_write_bytes() {
281		let mut b = BooleanBufferBuilder::new(4);
282		b.append(false);
283		b.append(true);
284		b.append(false);
285		b.append(true);
286		assert_eq!(4, b.len());
287		assert_eq!(512, b.capacity());
288		let buffer = b.finish();
289		assert_eq!(4, buffer.len());
290
291		// Overallocate capacity
292		let mut b = BooleanBufferBuilder::new(8);
293		b.append_slice(&[false, true, false, true]);
294		assert_eq!(4, b.len());
295		assert_eq!(512, b.capacity());
296		let buffer = b.finish();
297		assert_eq!(4, buffer.len());
298		}
299
300		#[test]
301		fn test_boolean_buffer_builder_unset_first_bit() {
302		let mut buffer = BooleanBufferBuilder::new(4);
303		buffer.append(true);
304		buffer.append(true);
305		buffer.append(false);
306		buffer.append(true);
307		buffer.set_bit(0, false);
308		assert_eq!(buffer.len(), 4);
309		assert_eq!(buffer.finish().values(), &[0b1010_u8]);
310		}
311
312		#[test]
313		fn test_boolean_buffer_builder_unset_last_bit() {
314		let mut buffer = BooleanBufferBuilder::new(4);
315		buffer.append(true);
316		buffer.append(true);
317		buffer.append(false);
318		buffer.append(true);
319		buffer.set_bit(3, false);
320		assert_eq!(buffer.len(), 4);
321		assert_eq!(buffer.finish().values(), &[0b0011_u8]);
322		}
323
324		#[test]
325		fn test_boolean_buffer_builder_unset_an_inner_bit() {
326		let mut buffer = BooleanBufferBuilder::new(5);
327		buffer.append(true);
328		buffer.append(true);
329		buffer.append(false);
330		buffer.append(true);
331		buffer.set_bit(1, false);
332		assert_eq!(buffer.len(), 4);
333		assert_eq!(buffer.finish().values(), &[0b1001_u8]);
334		}
335
336		#[test]
337		fn test_boolean_buffer_builder_unset_several_bits() {
338		let mut buffer = BooleanBufferBuilder::new(5);
339		buffer.append(true);
340		buffer.append(true);
341		buffer.append(true);
342		buffer.append(false);
343		buffer.append(true);
344		buffer.set_bit(1, false);
345		buffer.set_bit(2, false);
346		assert_eq!(buffer.len(), 5);
347		assert_eq!(buffer.finish().values(), &[0b10001_u8]);
348		}
349
350		#[test]
351		fn test_boolean_buffer_builder_unset_several_bits_bigger_than_one_byte() {
352		let mut buffer = BooleanBufferBuilder::new(16);
353		buffer.append_n(10, true);
354		buffer.set_bit(0, false);
355		buffer.set_bit(3, false);
356		buffer.set_bit(9, false);
357		assert_eq!(buffer.len(), 10);
358		assert_eq!(buffer.finish().values(), &[0b11110110_u8, 0b01_u8]);
359		}
360
361		#[test]
362		fn test_boolean_buffer_builder_flip_several_bits_bigger_than_one_byte() {
363		let mut buffer = BooleanBufferBuilder::new(16);
364		buffer.append_n(5, true);
365		buffer.append_n(5, false);
366		buffer.append_n(5, true);
367		buffer.set_bit(0, false);
368		buffer.set_bit(3, false);
369		buffer.set_bit(9, false);
370		buffer.set_bit(6, true);
371		buffer.set_bit(14, true);
372		buffer.set_bit(13, false);
373		assert_eq!(buffer.len(), 15);
374		assert_eq!(buffer.finish().values(), &[0b01010110_u8, 0b1011100_u8]);
375		}
376
377		#[test]
378		fn test_bool_buffer_builder_get_first_bit() {
379		let mut buffer = BooleanBufferBuilder::new(16);
380		buffer.append_n(8, true);
381		buffer.append_n(8, false);
382		assert!(buffer.get_bit(0));
383		}
384
385		#[test]
386		fn test_bool_buffer_builder_get_first_bit_not_requires_mutability() {
387		let buffer = {
388		let mut buffer = BooleanBufferBuilder::new(16);
389		buffer.append_n(8, true);
390		buffer
391		};
392
393		assert!(buffer.get_bit(0));
394		}
395
396		#[test]
397		fn test_bool_buffer_builder_get_last_bit() {
398		let mut buffer = BooleanBufferBuilder::new(16);
399		buffer.append_n(8, true);
400		buffer.append_n(8, false);
401		assert!(!buffer.get_bit(15));
402		}
403
404		#[test]
405		fn test_bool_buffer_builder_get_an_inner_bit() {
406		let mut buffer = BooleanBufferBuilder::new(16);
407		buffer.append_n(4, false);
408		buffer.append_n(8, true);
409		buffer.append_n(4, false);
410		assert!(buffer.get_bit(11));
411		}
412
413		#[test]
414		fn test_bool_buffer_fuzz() {
415		use rand::prelude::*;
416
417		let mut buffer = BooleanBufferBuilder::new(12);
418		let mut all_bools = vec![];
419		let mut rng = rand::rng();
420
421		let src_len = 32;
422		let (src, compacted_src) = {
423		let src: Vec<_> = std::iter::from_fn(\|\| Some(rng.next_u32() & 1 == 0))
424		.take(src_len)
425		.collect();
426
427		let mut compacted_src = BooleanBufferBuilder::new(src_len);
428		compacted_src.append_slice(&src);
429		(src, compacted_src.finish())
430		};
431
432		for _ in 0..100 {
433		let a = rng.next_u32() as usize % src_len;
434		let b = rng.next_u32() as usize % src_len;
435
436		let start = a.min(b);
437		let end = a.max(b);
438
439		buffer.append_packed_range(start..end, compacted_src.values());
440		all_bools.extend_from_slice(&src[start..end]);
441		}
442
443		let mut compacted = BooleanBufferBuilder::new(all_bools.len());
444		compacted.append_slice(&all_bools);
445
446		assert_eq!(buffer.finish(), compacted.finish())
447		}
448
449		#[test]
450		fn test_boolean_array_builder_resize() {
451		let mut builder = BooleanBufferBuilder::new(20);
452		builder.append_n(4, true);
453		builder.append_n(7, false);
454		builder.append_n(2, true);
455		builder.resize(20);
456
457		assert_eq!(builder.len(), 20);
458		assert_eq!(builder.as_slice(), &[0b00001111, 0b00011000, 0b00000000]);
459
460		builder.resize(5);
461		assert_eq!(builder.len(), 5);
462		assert_eq!(builder.as_slice(), &[0b00001111]);
463
464		builder.append_n(4, true);
465		assert_eq!(builder.len(), 9);
466		assert_eq!(builder.as_slice(), &[0b11101111, 0b00000001]);
467		}
468
469		#[test]
470		fn test_truncate() {
471		let b = MutableBuffer::from_iter([true, true, true, true]);
472		let mut builder = BooleanBufferBuilder::new_from_buffer(b, 2);
473		builder.advance(2);
474		let finished = builder.finish();
475		assert_eq!(finished.values(), &[0b00000011]);
476
477		let mut builder = BooleanBufferBuilder::new(10);
478		builder.append_n(5, true);
479		builder.resize(3);
480		builder.advance(2);
481		let finished = builder.finish();
482		assert_eq!(finished.values(), &[0b00000111]);
483
484		let mut builder = BooleanBufferBuilder::new(10);
485		builder.append_n(16, true);
486		assert_eq!(builder.as_slice(), &[0xFF, 0xFF]);
487		builder.truncate(20);
488		assert_eq!(builder.as_slice(), &[0xFF, 0xFF]);
489		builder.truncate(14);
490		assert_eq!(builder.as_slice(), &[0xFF, 0b00111111]);
491		builder.append(false);
492		builder.append(true);
493		assert_eq!(builder.as_slice(), &[0xFF, 0b10111111]);
494		builder.append_packed_range(0..3, &[0xFF]);
495		assert_eq!(builder.as_slice(), &[0xFF, 0b10111111, 0b00000111]);
496		builder.truncate(17);
497		assert_eq!(builder.as_slice(), &[0xFF, 0b10111111, 0b00000001]);
498		builder.append_packed_range(0..2, &[2]);
499		assert_eq!(builder.as_slice(), &[0xFF, 0b10111111, 0b0000101]);
500		builder.truncate(8);
501		assert_eq!(builder.as_slice(), &[0xFF]);
502		builder.resize(14);
503		assert_eq!(builder.as_slice(), &[0xFF, 0x00]);
504		builder.truncate(0);
505		assert_eq!(builder.as_slice(), &[]);
506		}
507
508		#[test]
509		fn test_boolean_builder_increases_buffer_len() {
510		// 00000010 01001000
511		let buf = Buffer::from([72_u8, 2_u8]);
512		let mut builder = BooleanBufferBuilder::new(8);
513
514		for i in 0..16 {
515		if i == 3 \|\| i == 6 \|\| i == 9 {
516		builder.append(true);
517		} else {
518		builder.append(false);
519		}
520		}
521		let buf2 = builder.finish();
522
523		assert_eq!(buf.len(), buf2.inner().len());
524		assert_eq!(buf.as_slice(), buf2.values());
525		}
526		}