fix: panic when using FastPFOR::new (#53)

Both `page_size` and `block_size` don't make sense to have as zero

Author: CommanderStorm

benches/fastpfor_benchmark.rs

@@ -1,10 +1,12 @@
 use core::ops::Range;
+use std::hint::black_box;
+use std::io::Cursor;
+use std::num::NonZeroU32;
+
 use criterion::{criterion_group, criterion_main, BenchmarkId, Criterion, Throughput};
 use fastpfor::rust::{FastPFOR, Integer, BLOCK_SIZE_128, BLOCK_SIZE_256, DEFAULT_PAGE_SIZE};
 use rand::rngs::StdRng;
 use rand::{RngExt as _, SeedableRng};
-use std::hint::black_box;
-use std::io::Cursor;
 
 const SIZES: &[usize; 2] = &[1024, 4096];
 const SEED: u64 = 456;
@@ -92,7 +94,7 @@ fn compress_data(codec: &mut FastPFOR, data: &[u32]) -> usize {
 }
 
 /// Helper function to compress data and return compressed buffer
-fn prepare_compressed_data(data: &[u32], block_size: u32) -> Vec<u32> {
+fn prepare_compressed_data(data: &[u32], block_size: NonZeroU32) -> Vec<u32> {
     let mut codec = FastPFOR::new(DEFAULT_PAGE_SIZE, block_size);
     let mut compressed = vec![0u32; data.len() * 2];
     let mut input_offset = Cursor::new(0);

src/rust/integer_compression/fastpfor.rs

@@ -1,21 +1,22 @@
 use std::io::Cursor;
+use std::num::NonZeroU32;
 
 use crate::rust::cursor::IncrementCursor;
 use crate::rust::integer_compression::{bitpacking, helpers};
 use crate::rust::{FastPForResult, Integer, Skippable};
 use bytes::{Buf as _, BufMut as _, BytesMut};
 
 /// Block size constant for 256 integers per block
-pub const BLOCK_SIZE_256: u32 = 256;
+pub const BLOCK_SIZE_256: NonZeroU32 = NonZeroU32::new(256).unwrap();
 
 /// Block size constant for 128 integers per block
-pub const BLOCK_SIZE_128: u32 = 128;
+pub const BLOCK_SIZE_128: NonZeroU32 = NonZeroU32::new(128).unwrap();
 
 /// Overhead cost (in bits) for storing each exception's position in the block
 const OVERHEAD_OF_EACH_EXCEPT: u32 = 8;
 
 /// Default page size in number of integers
-pub const DEFAULT_PAGE_SIZE: u32 = 65536;
+pub const DEFAULT_PAGE_SIZE: NonZeroU32 = NonZeroU32::new(65536).unwrap();
 
 /// Fast Patched Frame-of-Reference ([`FastPFOR`](https://github.com/lemire/FastPFor)) integer compression codec.
 ///
@@ -74,7 +75,7 @@ impl Skippable for FastPFOR {
         output_offset: &mut Cursor<u32>,
         num: u32,
     ) -> FastPForResult<()> {
-        if inlength == 0 && self.block_size == BLOCK_SIZE_128 {
+        if inlength == 0 && self.block_size == BLOCK_SIZE_128.get() {
             // Return early if there is no data to uncompress and block size is 128
             return Ok(());
         }
@@ -143,7 +144,9 @@ impl FastPFOR {
     /// Creates codec with specified page and block sizes.
     ///
     /// Pre-allocates buffers for metadata and exception storage.
-    pub fn new(page_size: u32, block_size: u32) -> FastPFOR {
+    pub fn new(page_size: NonZeroU32, block_size: NonZeroU32) -> FastPFOR {
+        let page_size = page_size.get();
+        let block_size = block_size.get();
         FastPFOR {
             page_size,
             block_size,
@@ -453,7 +456,7 @@ mod tests {
     fn fastpfor_test() {
         let mut codec1 = FastPFOR::default();
         let mut codec2 = FastPFOR::default();
-        let mut data = vec![0u32; BLOCK_SIZE_256 as usize];
+        let mut data = vec![0u32; BLOCK_SIZE_256.get() as usize];
         data[126] = -1i32 as u32;
         let mut out_buf = vec![0; data.len() * 4];
         let mut input_offset = Cursor::new(0);
@@ -483,7 +486,9 @@ mod tests {
             .unwrap();
         let answer = out_buf_uncomp[..output_offset.position() as usize].to_vec();
 
-        for k in 0..BLOCK_SIZE_256 {
+        assert_eq!(answer.len(), BLOCK_SIZE_256.get() as usize);
+        assert_eq!(data.len(), BLOCK_SIZE_256.get() as usize);
+        for k in 0..BLOCK_SIZE_256.get() {
             assert_eq!(answer[k as usize], data[k as usize], "bug in {k}");
         }
     }
@@ -492,10 +497,7 @@ mod tests {
     fn fastpfor_test_128() {
         let mut codec1 = FastPFOR::new(DEFAULT_PAGE_SIZE, BLOCK_SIZE_128);
         let mut codec2 = FastPFOR::new(DEFAULT_PAGE_SIZE, BLOCK_SIZE_128);
-        let mut data = vec![0; BLOCK_SIZE_128 as usize];
-        for i in 0..BLOCK_SIZE_128 {
-            data[i as usize] = 0;
-        }
+        let mut data = vec![0; BLOCK_SIZE_128.get() as usize];
         data[126] = -1i32 as u32;
         let mut out_buf = vec![0; data.len() * 4];
         let mut input_offset = Cursor::new(0);
@@ -525,7 +527,9 @@ mod tests {
             .unwrap();
         let answer = out_buf_uncomp[..output_offset.position() as usize].to_vec();
 
-        for k in 0..BLOCK_SIZE_128 {
+        assert_eq!(answer.len(), BLOCK_SIZE_128.get() as usize);
+        assert_eq!(data.len(), BLOCK_SIZE_128.get() as usize);
+        for k in 0..BLOCK_SIZE_128.get() {
             assert_eq!(answer[k as usize], data[k as usize], "bug in {k}");
         }
     }

tests/basic_tests.rs

@@ -2,6 +2,7 @@
 #![allow(clippy::needless_range_loop)]
 
 use std::io::Cursor;
+use std::num::NonZeroU32;
 
 use fastpfor::rust::{
     fast_pack, fast_unpack, Composition, FastPFOR, Integer, VariableByte, BLOCK_SIZE_128,
@@ -381,10 +382,10 @@ fn test_random_numbers() {
 #[test]
 fn test_fastpfor_headless_compress_unfit_pagesize() {
     // The input size is a multiple of 128 but does not fit the page size
-    let test_input_size = 512 + BLOCK_SIZE_128;
-    let page_size = 512;
+    let test_input_size = BLOCK_SIZE_128.checked_add(512).unwrap();
+    let page_size = NonZeroU32::new(512).unwrap();
 
-    let input: Vec<u32> = (0..test_input_size).collect();
+    let input: Vec<u32> = (0..test_input_size.get()).collect();
     let mut output: Vec<u32> = vec![0; input.len()];
     let mut decoded: Vec<u32> = vec![0; input.len()];
     let mut input_offset = Cursor::new(0u32);
@@ -419,8 +420,8 @@ fn test_fastpfor_headless_compress_unfit_pagesize() {
 
 #[test]
 fn test_exception_value_vector_resizes() {
-    let page_size = 512;
-    let test_input_size = page_size * 2;
+    let page_size = NonZeroU32::new(512).unwrap();
+    let test_input_size = page_size.get() * 2;
 
     // every even index value is large which will trigger exception buffer to be resize
     let input: Vec<u32> = (0..test_input_size)

tests/cpp_compat_tests.rs

@@ -15,7 +15,7 @@ fn test_rust_decompresses_cpp_encoded_data() {
     let mut codec_rs = rust::FastPFOR::new(rust::DEFAULT_PAGE_SIZE, rust::BLOCK_SIZE_128);
 
     for n in test_input_sizes() {
-        for input in get_test_cases(n + rust::BLOCK_SIZE_128 as usize) {
+        for input in get_test_cases(n + rust::BLOCK_SIZE_128.get() as usize) {
             // Buffer for the C++ encoded
             let mut compressed_buffer = vec![0; input.len()];
 
@@ -58,7 +58,7 @@ fn test_rust_and_cpp_fastpfor32_compression_matches() {
     let mut codec_rs = rust::FastPFOR::new(rust::DEFAULT_PAGE_SIZE, rust::BLOCK_SIZE_128);
 
     for n in test_input_sizes() {
-        for input in get_test_cases(n + rust::BLOCK_SIZE_128 as usize) {
+        for input in get_test_cases(n + rust::BLOCK_SIZE_128.get() as usize) {
             // Buffer for the C++ encoded
             let mut compressed_buffer = vec![0; input.len()];