add

Author: mxsm

rocketmq-common/src/utils/crc32_utils.rs

@@ -15,30 +15,71 @@
  * limitations under the License.
  */
 
-use crc32fast::Hasher;
+ use crc32fast::Hasher;
 
-// Calculate the CRC32 checksum for the given byte array
-pub fn crc32(buf: &[u8]) -> u32 {
-    //crc32fast::hash(buf)
-    let mut hasher = Hasher::new();
-    hasher.update(buf);
-    let checksum = hasher.finalize();
-    checksum & 0x7FFFFFFF
-}
-
-#[cfg(test)]
-mod tests {
-    use super::*;
-
-    #[test]
-    fn test_crc32_negative() {
-        let buf = [1, 2, 3, 4, 5];
-        assert_ne!(crc32(&buf), 0xFFFFFFFF);
-    }
-
-    #[test]
-    fn test_crc32_empty_buffer() {
-        let buf: [u8; 0] = [];
-        assert_eq!(crc32(&buf), 0);
-    }
-}
+ // Calculate the CRC32 checksum for the given byte array
+ pub fn crc32(buf: &[u8]) -> u32 {
+     //crc32fast::hash(buf)
+     let mut hasher = Hasher::new();
+     hasher.update(buf);
+     hasher.finalize()
+ }
+ 
+ pub fn crc32_bytes_offset(array: &[u8], offset: usize, length: usize) -> u32 {
+     if !array.is_empty() && offset < array.len() && offset + length <= array.len() {
+         let mut hasher = Hasher::new();
+         hasher.update(&array[offset..offset + length]);
+         return hasher.finalize();
+     }
+     0
+ }
+ 
+ pub fn crc32_bytebuffer(byte_buffer: &mut Vec<u8>) -> u32 {
+     let mut hasher = Hasher::new();
+     hasher.update(byte_buffer.as_slice());
+     hasher.finalize()
+ }
+ 
+ pub fn crc32_bytebuffers(byte_buffers: &mut Vec<Vec<u8>>) -> u32 {
+     let mut hasher = Hasher::new();
+     for buffer in byte_buffers {
+         hasher.update(buffer.as_slice());
+     }
+     hasher.finalize()
+ }
+ 
+ #[cfg(test)]
+ mod tests {
+     use super::*;
+ 
+     #[test]
+     fn crc32_calculates_correct_checksum() {
+         let buf = [1, 2, 3, 4, 5];
+         assert_eq!(crc32(&buf), 1191942644);
+     }
+ 
+     #[test]
+     fn crc32_bytes_offset_calculates_correct_checksum() {
+         let buf = [1, 2, 3, 4, 5];
+         assert_eq!(crc32_bytes_offset(&buf, 1, 3), 3498416806);
+     }
+ 
+     #[test]
+     fn crc32_bytes_offset_returns_zero_for_empty_array() {
+         let buf: [u8; 0] = [];
+         assert_eq!(crc32_bytes_offset(&buf, 0, 0), 0);
+     }
+ 
+     #[test]
+     fn crc32_bytebuffer_calculates_correct_checksum() {
+         let mut buf = vec![1, 2, 3, 4, 5];
+         assert_eq!(crc32_bytebuffer(&mut buf), 1191942644);
+     }
+ 
+     #[test]
+     fn crc32_bytebuffers_calculates_correct_checksum() {
+         let mut bufs = vec![vec![1, 2, 3], vec![4, 5]];
+         assert_eq!(crc32_bytebuffers(&mut bufs), 1191942644);
+     }
+ }
+