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fix: Remove unsafe uses of from_raw_parts from crc32 and murmur hash functions #554

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fix: Remove unsafe uses of from_raw_parts from crc32 and murmur hash functions #554

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24 changes: 12 additions & 12 deletions core/src/parquet/util/hash_util.rs
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Original file line number Diff line number Diff line change
Expand Up @@ -15,6 +15,8 @@
// specific language governing permissions and limitations
// under the License.

use byteorder::{LittleEndian, ReadBytesExt};

fn hash_(data: &[u8], seed: u32) -> u32 {
#[cfg(any(target_arch = "x86", target_arch = "x86_64"))]
unsafe {
Expand Down Expand Up @@ -45,17 +47,19 @@ const MURMUR_R: i32 = 47;
unsafe fn murmur_hash2_64a(data_bytes: &[u8], seed: u64) -> u64 {
let len = data_bytes.len();
let len_64 = (len / 8) * 8;
let data_bytes_64 =
std::slice::from_raw_parts(&data_bytes[0..len_64] as *const [u8] as *const u64, len / 8);
Comment on lines -48 to -49
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This violates a precondition for from_raw_parts because data_bytes is not guaranteed to be correctly aligned for u64.

let num_u64 = len / 8;

let mut h = seed ^ (MURMUR_PRIME.wrapping_mul(data_bytes.len() as u64));
for v in data_bytes_64 {
let mut k = *v;
let mut offset = 0;
for _ in 0..num_u64 {
let mut buf = &data_bytes[offset..offset + 8];
let mut k = buf.read_u64::<LittleEndian>().unwrap();
k = k.wrapping_mul(MURMUR_PRIME);
k ^= k >> MURMUR_R;
k = k.wrapping_mul(MURMUR_PRIME);
h ^= k;
h = h.wrapping_mul(MURMUR_PRIME);
offset += 8;
}

let data2 = &data_bytes[len_64..];
Expand Down Expand Up @@ -106,16 +110,12 @@ unsafe fn crc32_hash(bytes: &[u8], seed: u32) -> u32 {
let num_words = num_bytes / u32_num_bytes;
num_bytes %= u32_num_bytes;

let bytes_u32: &[u32] = std::slice::from_raw_parts(
&bytes[0..num_words * u32_num_bytes] as *const [u8] as *const u32,
num_words,
);
Comment on lines -109 to -112
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This violates a precondition for from_raw_parts because bytes is not guaranteed to be correctly aligned for u32.


let mut offset = 0;
let mut hash = seed;
while offset < num_words {
hash = _mm_crc32_u32(hash, bytes_u32[offset]);
offset += 1;
for _ in 0..num_words {
let mut buf = &bytes[offset..offset + 4];
hash = _mm_crc32_u32(hash, buf.read_u32::<LittleEndian>().unwrap());
offset += 4;
}

offset = num_words * u32_num_bytes;
Expand Down
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