optimizations

Cargo.toml

@@ -19,13 +19,13 @@ exclude = [
 ]
 
 [dependencies]
-libc = "0.2"
-memmap2 = "0.7"
-page_size = "0.5"
-fs2 = "0.4"
-sha3 = "0.10"
-bytes = "1"
-bumpalo = "3.12.0"
+libc = "0.2.149"
+memmap2 = "0.9.0"
+page_size = "0.6.0"
+fs4 = "0.7.0"
+bytes = "1.5.0"
+bumpalo = "3.14.0"
+fnv = "1.0.7"
 
 [dev-dependencies]
 bytes = { version = "1", features = ["serde"] }

src/db.rs

@@ -7,7 +7,7 @@ use std::{
     sync::{Arc, Mutex, RwLock},
 };
 
-use fs2::FileExt;
+use fs4::FileExt;
 use memmap2::Mmap;
 use page_size::get as get_page_size;
 

src/meta.rs

@@ -1,13 +1,7 @@
-use std::io::Write;
-
-// use std::mem::size_of;
-use bytes::BufMut;
-use sha3::{Digest, Sha3_256};
-
+use fnv::FnvHasher;
+use std::hash::Hasher;
 use crate::{bucket::BucketMeta, page::PageID};
 
-// const META_SIZE: usize = size_of::<Meta>();
-
 #[repr(C)]
 #[derive(Debug, Clone)]
 pub(crate) struct Meta {
@@ -19,41 +13,32 @@ pub(crate) struct Meta {
     pub(crate) num_pages: PageID,
     pub(crate) freelist_page: PageID,
     pub(crate) tx_id: u64,
-    pub(crate) hash: [u8; 32],
+    pub(crate) hash: u64,
 }
 
 impl Meta {
     pub(crate) fn valid(&self) -> bool {
         self.hash == self.hash_self()
     }
 
-    pub(crate) fn hash_self(&self) -> [u8; 32] {
-        let mut hash_result: [u8; 32] = [0; 32];
-        let mut hasher = Sha3_256::new();
-        hasher.update(self.bytes());
-        let hash = hasher.finalize();
-        assert_eq!(hash.len(), 32);
-        hash_result.copy_from_slice(&hash[..]);
-        hash_result
-    }
+    pub(crate) fn hash_self(&self) -> u64 {
+        let mut hasher = FnvHasher::default();
 
-    fn bytes(&self) -> bytes::Bytes {
-        let buf = bytes::BytesMut::new();
-        let mut w = buf.writer();
-        let _ = w.write(&self.meta_page.to_be_bytes());
-        let _ = w.write(&self.magic.to_be_bytes());
-        let _ = w.write(&self.version.to_be_bytes());
-        let _ = w.write(&self.pagesize.to_be_bytes());
-        let _ = w.write(&self.root.root_page.to_be_bytes());
-        let _ = w.write(&self.root.next_int.to_be_bytes());
-        let _ = w.write(&self.num_pages.to_be_bytes());
-        let _ = w.write(&self.freelist_page.to_be_bytes());
-        let _ = w.write(&self.tx_id.to_be_bytes());
+        hasher.write(&self.meta_page.to_be_bytes());
+        hasher.write(&self.magic.to_be_bytes());
+        hasher.write(&self.version.to_be_bytes());
+        hasher.write(&self.pagesize.to_be_bytes());
+        hasher.write(&self.root.root_page.to_be_bytes());
+        hasher.write(&self.root.next_int.to_be_bytes());
+        hasher.write(&self.num_pages.to_be_bytes());
+        hasher.write(&self.freelist_page.to_be_bytes());
+        hasher.write(&self.tx_id.to_be_bytes());
 
-        w.into_inner().freeze()
+        hasher.finish()
     }
 }
 
+
 #[cfg(test)]
 mod tests {
     use super::*;
@@ -72,20 +57,17 @@ mod tests {
             num_pages: 13,
             freelist_page: 3,
             tx_id: 8,
-            hash: [0; 32],
+            hash: 64,
         };
 
         assert!(!meta.valid());
         meta.hash = meta.hash_self();
-        assert!(meta.valid());
         assert_eq!(meta.hash, meta.hash_self());
-        // modify the last property before the hash
-        // to change the hash
+
         meta.tx_id = 88;
         assert_ne!(meta.hash, meta.hash_self());
-        // reset hash and make sure it is still valid
+
         meta.hash = meta.hash_self();
-        assert!(meta.valid());
         assert_eq!(meta.hash, meta.hash_self());
     }
 }