--- a/Cargo.toml	Wed May 15 19:29:56 2024 +0200
+++ b/Cargo.toml	Sat Jun 15 12:26:12 2024 +0200
@@ -9,14 +9,14 @@
 keywords = ["LevelDB", "key-value", "database", "SSTable", "Google"]
 license = "MIT"
 publish = true
-edition = "2018"
+edition = "2021"
 include = ["src/**/*", "src/*", "Cargo.toml", "LICENSE", "README.md"]
 
 [lib]
 crate-type = ["cdylib", "rlib"]
 
 [dependencies]
-crc = "1.8"
+crc = "3.2"
 integer-encoding = "3.0"
 rand = "0.8.5"
 snap = "1.0"

--- a/examples/stresstest/src/main.rs	Wed May 15 19:29:56 2024 +0200
+++ b/examples/stresstest/src/main.rs	Sat Jun 15 12:26:12 2024 +0200
@@ -16,7 +16,7 @@
         let (k, v) = (gen_string(KEY_LEN), gen_string(VAL_LEN));
 
         db.put(k.as_bytes(), v.as_bytes()).unwrap();
-        if i % (n/100) == 0 {
+        if i % (n / 100) == 0 {
             println!("{}/100 ...", i * 100 / n);
             db.flush().unwrap();
         }

--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/src/crc.rs	Sat Jun 15 12:26:12 2024 +0200
@@ -0,0 +1,11 @@
+const CRC: crc::Crc<u32, crc::Table<1>> = crc::Crc::<u32, crc::Table<1>>::new(&crc::CRC_32_ISCSI);
+
+pub(crate) fn crc32(data: impl AsRef<[u8]>) -> u32 {
+    let mut digest = CRC.digest();
+    digest.update(data.as_ref());
+    digest.finalize()
+}
+
+pub(crate) fn digest() -> crc::Digest<'static, u32> {
+    CRC.digest()
+}

--- a/src/db_impl.rs	Wed May 15 19:29:56 2024 +0200
+++ b/src/db_impl.rs	Sat Jun 15 12:26:12 2024 +0200
@@ -567,7 +567,8 @@
     /// make_room_for_write checks if the memtable has become too large, and triggers a compaction
     /// if it's the case.
     fn make_room_for_write(&mut self, force: bool) -> Result<()> {
-        if !force && self.mem.approx_mem_usage() < self.opt.write_buffer_size || self.mem.len() == 0 {
+        if !force && self.mem.approx_mem_usage() < self.opt.write_buffer_size || self.mem.len() == 0
+        {
             Ok(())
         } else {
             // Create new memtable.

--- a/src/lib.rs	Wed May 15 19:29:56 2024 +0200
+++ b/src/lib.rs	Sat Jun 15 12:26:12 2024 +0200
@@ -23,8 +23,6 @@
 
 #![allow(dead_code)]
 
-extern crate crc;
-
 #[cfg(feature = "fs")]
 extern crate errno;
 
@@ -50,6 +48,7 @@
 mod blockhandle;
 mod cache;
 mod cmp;
+mod crc;
 
 #[cfg(feature = "fs")]
 mod disk_env;
@@ -80,8 +79,8 @@
 mod db_impl;
 mod db_iter;
 
+pub mod compressor;
 pub mod env;
-pub mod compressor;
 
 #[cfg(feature = "async")]
 pub use asyncdb::AsyncDB;

--- a/src/log.rs	Wed May 15 19:29:56 2024 +0200
+++ b/src/log.rs	Sat Jun 15 12:26:12 2024 +0200
@@ -3,12 +3,11 @@
 //! A record is a bytestring: [checksum: uint32, length: uint16, type: uint8, data: [u8]]
 //! checksum is the crc32 sum of type and data; type is one of RecordType::{Full/First/Middle/Last}
 
+use crate::crc;
 use crate::error::{err, Result, StatusCode};
 
 use std::io::{Read, Write};
 
-use crc::crc32;
-use crc::Hasher32;
 use integer_encoding::FixedInt;
 use integer_encoding::FixedIntWriter;
 
@@ -25,19 +24,16 @@
 
 pub struct LogWriter<W: Write> {
     dst: W,
-    digest: crc32::Digest,
     current_block_offset: usize,
     block_size: usize,
 }
 
 impl<W: Write> LogWriter<W> {
     pub fn new(writer: W) -> LogWriter<W> {
-        let digest = crc32::Digest::new(crc32::CASTAGNOLI);
         LogWriter {
             dst: writer,
             current_block_offset: 0,
             block_size: BLOCK_SIZE,
-            digest,
         }
     }
 
@@ -49,8 +45,7 @@
         w
     }
 
-    pub fn add_record(&mut self, r: &[u8]) -> Result<usize> {
-        let mut record = &r[..];
+    pub fn add_record(&mut self, mut record: &[u8]) -> Result<usize> {
         let mut first_frag = true;
         let mut result = Ok(0);
         while result.is_ok() && !record.is_empty() {
@@ -94,11 +89,11 @@
     fn emit_record(&mut self, t: RecordType, data: &[u8], len: usize) -> Result<usize> {
         assert!(len < 256 * 256);
 
-        self.digest.reset();
-        self.digest.write(&[t as u8]);
-        self.digest.write(&data[0..len]);
+        let mut digest = crc::digest();
+        digest.update(&[t as u8]);
+        digest.update(&data[0..len]);
 
-        let chksum = mask_crc(self.digest.sum32());
+        let chksum = mask_crc(digest.finalize());
 
         let mut s = 0;
         s += self.dst.write(&chksum.encode_fixed_vec())?;
@@ -119,7 +114,6 @@
 pub struct LogReader<R: Read> {
     // TODO: Wrap src in a buffer to enhance read performance.
     src: R,
-    digest: crc32::Digest,
     blk_off: usize,
     blocksize: usize,
     head_scratch: [u8; 7],
@@ -134,7 +128,6 @@
             blocksize: BLOCK_SIZE,
             checksums: chksum,
             head_scratch: [0; 7],
-            digest: crc32::Digest::new(crc32::CASTAGNOLI),
         }
     }
 
@@ -195,10 +188,10 @@
     }
 
     fn check_integrity(&mut self, typ: u8, data: &[u8], expected: u32) -> bool {
-        self.digest.reset();
-        self.digest.write(&[typ]);
-        self.digest.write(data);
-        unmask_crc(expected) == self.digest.sum32()
+        let mut digest = crc::digest();
+        digest.update(&[typ]);
+        digest.update(data);
+        unmask_crc(expected) == digest.finalize()
     }
 }
 
@@ -220,15 +213,17 @@
 
     #[test]
     fn test_crc_mask_crc() {
-        let crc = crc32::checksum_castagnoli("abcde".as_bytes());
-        assert_eq!(crc, unmask_crc(mask_crc(crc)));
-        assert!(crc != mask_crc(crc));
+        let mut digest = crc::digest();
+        digest.update("abcde".as_bytes());
+        let sum = digest.finalize();
+        assert_eq!(sum, unmask_crc(mask_crc(sum)));
+        assert!(sum != mask_crc(sum));
     }
 
     #[test]
     fn test_crc_sanity() {
-        assert_eq!(0x8a9136aa, crc32::checksum_castagnoli(&[0 as u8; 32]));
-        assert_eq!(0x62a8ab43, crc32::checksum_castagnoli(&[0xff as u8; 32]));
+        assert_eq!(0x8a9136aa, crc::crc32(&[0_u8; 32]));
+        assert_eq!(0x62a8ab43, crc::crc32(&[0xff_u8; 32]));
     }
 
     #[test]

--- a/src/skipmap.rs	Wed May 15 19:29:56 2024 +0200
+++ b/src/skipmap.rs	Sat Jun 15 12:26:12 2024 +0200
@@ -273,7 +273,9 @@
         // assigning its value to new.next...
         new.next = unsafe { (*current).next.take() };
         // ...and then setting the previous element's next field to the new node
-        unsafe { let _ = replace(&mut (*current).next, Some(new)); };
+        unsafe {
+            let _ = replace(&mut (*current).next, Some(new));
+        };
     }
     /// Runs through the skipmap and prints everything including addresses
     fn dbg_print(&self) {

--- a/src/table_block.rs	Wed May 15 19:29:56 2024 +0200
+++ b/src/table_block.rs	Sat Jun 15 12:26:12 2024 +0200
@@ -1,5 +1,6 @@
 use crate::block::Block;
 use crate::blockhandle::BlockHandle;
+use crate::crc;
 use crate::env::RandomAccess;
 use crate::error::{err, Result, StatusCode};
 use crate::filter;
@@ -8,7 +9,6 @@
 use crate::options::Options;
 use crate::table_builder;
 
-use crc::crc32::{self, Hasher32};
 use integer_encoding::FixedInt;
 
 /// Reads the data for the specified block handle from a file.
@@ -79,8 +79,8 @@
 
 /// Verify checksum of block
 fn verify_table_block(data: &[u8], compression: u8, want: u32) -> bool {
-    let mut digest = crc32::Digest::new(crc32::CASTAGNOLI);
-    digest.write(data);
-    digest.write(&[compression; 1]);
-    digest.sum32() == want
+    let mut digest = crc::digest();
+    digest.update(data);
+    digest.update(&[compression; 1]);
+    digest.finalize() == want
 }

--- a/src/table_builder.rs	Wed May 15 19:29:56 2024 +0200
+++ b/src/table_builder.rs	Sat Jun 15 12:26:12 2024 +0200
@@ -3,6 +3,7 @@
 use crate::blockhandle::BlockHandle;
 use crate::cmp::InternalKeyCmp;
 use crate::compressor::{self, Compressor, CompressorId};
+use crate::crc;
 use crate::error::Result;
 use crate::filter::{InternalFilterPolicy, NoFilterPolicy};
 use crate::filter_block::FilterBlockBuilder;
@@ -14,8 +15,6 @@
 use std::io::Write;
 use std::rc::Rc;
 
-use crc::crc32;
-use crc::Hasher32;
 use integer_encoding::FixedIntWriter;
 
 pub const FOOTER_LENGTH: usize = 40;
@@ -209,14 +208,14 @@
         let (ctype, compressor) = compressor_id_pair;
         let data = compressor.encode(block)?;
 
-        let mut digest = crc32::Digest::new(crc32::CASTAGNOLI);
+        let mut digest = crc::digest();
 
-        digest.write(&data);
-        digest.write(&[ctype; TABLE_BLOCK_COMPRESS_LEN]);
+        digest.update(&data);
+        digest.update(&[ctype; TABLE_BLOCK_COMPRESS_LEN]);
 
         self.dst.write(&data)?;
         self.dst.write(&[ctype; TABLE_BLOCK_COMPRESS_LEN])?;
-        self.dst.write_fixedint(mask_crc(digest.sum32()))?;
+        self.dst.write_fixedint(mask_crc(digest.finalize()))?;
 
         let handle = BlockHandle::new(self.offset, data.len());
         self.offset += data.len() + TABLE_BLOCK_COMPRESS_LEN + TABLE_BLOCK_CKSUM_LEN;