fix: ensure checksum is consistent with crc crate with arbitary seed …

…value Signed-off-by: lizhanhui <[email protected]>
qdrant · Nov 18, 2023 · ec3448e · ec3448e
1 parent 181547a
commit ec3448e
Showing 1 changed file with 19 additions and 4 deletions.
diff --git a/src/segment.rs b/src/segment.rs
@@ -262,9 +262,10 @@ impl Segment {
                 if offset + HEADER_LEN + padded_len + CRC_LEN > capacity {
                     break;
                 }
-                let mut digest = crc32c::Crc32cHasher::new(crc);
-                digest.write(&segment[offset..offset + HEADER_LEN + padded_len]);
-                let entry_crc = digest.finish() as u32;
+                let entry_crc = crc32c::crc32c_append(
+                    !crc.reverse_bits(),
+                    &segment[offset..offset + HEADER_LEN + padded_len],
+                );
                 let stored_crc =
                     LittleEndian::read_u32(&segment[offset + HEADER_LEN + padded_len..]);
                 if entry_crc != stored_crc {
@@ -898,9 +899,23 @@ mod test {
             let mut digest = castagnoli.digest();
             digest.update(&buffer);
             let crc1 = digest.finalize();
-
             let crc2 = crc32c::crc32c(&buffer);
+            assert_eq!(crc1, crc2);
+        });
+    }
+
+    #[test]
+    fn test_crc32c_with_arbitrary_initial_value() {
+        let mut buffer = [0u8; 8192];
+        let castagnoli = crc::Crc::<u32>::new(&crc::CRC_32_ISCSI);
+
+        (0..1024).for_each(|seed| {
+            OsRng.fill_bytes(&mut buffer);
+            let mut digest = castagnoli.digest_with_initial(seed);
+            digest.update(&buffer);
+            let crc1 = digest.finalize();
 
+            let crc2 = crc32c::crc32c_append(!seed.reverse_bits(), &buffer);
             assert_eq!(crc1, crc2);
         });
     }