async db: postcard

lib/src/async_db.rs

@@ -24,9 +24,9 @@ use fmmap::tokio::{AsyncMmapFile, AsyncMmapFileExt, AsyncOptions};
 
 type LSize = u32;
 const LEN_SIZE: usize = std::mem::size_of::<LSize>();
-const BINCODE_CFG: bincode::config::Configuration = bincode::config::standard();
 
-use crate::util::BincodeVecWriter;
+use serde::{de::DeserializeOwned, Serialize};
+
 use crate::util::ErrorToString;
 
 pub struct WriterOpts {
@@ -42,18 +42,18 @@ impl Default for WriterOpts {
             compress_lvl: Level::Default,
             data_buf_size: 500 * 1024 * 1024,
             out_buf_size: 200 * 1024 * 1024,
-            current_buf_size: 100 * 1024,
+            current_buf_size: 1024 * 1024,
         }
     }
 }
 
 pub struct Writer<T>
 where
-    T: bincode::Encode,
+    T: Serialize,
 {
     out: io::BufWriter<fs::File>,
     data_buf: Vec<u8>,
-    cur_buf_item: BincodeVecWriter,
+    cur_buf_item: Vec<u8>,
     table: Vec<LSize>,
     compress_lvl: Level,
     _t: PhantomData<Arc<T>>,
@@ -61,14 +61,13 @@ where
 
 impl<T> Writer<T>
 where
-    T: bincode::Encode,
+    T: Serialize,
 {
     pub async fn new<P: AsRef<Path>>(path: P, opts: WriterOpts) -> Result<Self, String> {
         let out = fs::File::create(path).await.str_err()?;
         let out = io::BufWriter::with_capacity(opts.out_buf_size, out);
         let data_buf: Vec<u8> = Vec::with_capacity(opts.data_buf_size);
-        let cur_buf_item: Vec<u8> = Vec::with_capacity(opts.current_buf_size);
-        let cur_buf_item = BincodeVecWriter::new(cur_buf_item);
+        let cur_buf_item: Vec<u8> = vec![0; opts.current_buf_size];
 
         let compress_lvl = opts.compress_lvl;
 
@@ -88,16 +87,16 @@ where
         self.push_by_ref(&item).await
     }
 
+    #[allow(clippy::useless_asref)]
     pub async fn push_by_ref(&mut self, item: &T) -> Result<(), String> {
         let pos: LSize = self.data_buf.len() as LSize;
+        let cur_item_data = postcard::to_slice(item, self.cur_buf_item.as_mut_slice()).str_err()?;
 
-        bincode::encode_into_writer(item, &mut self.cur_buf_item, BINCODE_CFG).str_err()?;
-
-        let mut zencoder = ZstdEncoder::with_quality(&self.cur_buf_item[..], self.compress_lvl);
+        let mut zencoder = ZstdEncoder::with_quality(cur_item_data.as_ref(), self.compress_lvl);
         io::copy(&mut zencoder, &mut self.data_buf)
             .await
             .str_err()?;
-        self.cur_buf_item.clear();
+        cur_item_data.fill(0);
 
         self.table.push(pos);
 
@@ -159,7 +158,7 @@ use pin_project::pin_project;
 /// only work when ..push.poll() returns Ready immediately
 pub struct WriterSink<'a, T>
 where
-    T: bincode::Encode,
+    T: Serialize,
 {
     #[pin]
     writer: &'a mut Writer<T>,
@@ -168,7 +167,7 @@ where
 
 impl<'a, T> Sink<T> for WriterSink<'a, T>
 where
-    T: bincode::Encode,
+    T: Serialize,
 {
     type Error = String;
 
@@ -213,7 +212,7 @@ where
 
 pub struct Reader<T>
 where
-    T: bincode::Decode,
+    T: DeserializeOwned,
 {
     mmap: AsyncMmapFile,
     count: usize,
@@ -223,7 +222,7 @@ where
 
 impl<T> Reader<T>
 where
-    T: bincode::Decode,
+    T: DeserializeOwned,
 {
     pub async fn new<P: AsRef<Path>>(path: P) -> Result<Self, String> {
         let mmap = AsyncOptions::new()
@@ -292,10 +291,10 @@ where
         decoder.read_to_end(data_buf).await.str_err()?;
 
         // decode item
-        let item: (T, usize) = bincode::decode_from_slice(data_buf, BINCODE_CFG).str_err()?;
+        let (item, _): (T, _) = postcard::take_from_bytes(data_buf).str_err()?;
 
         data_buf.clear();
-        Ok(item.0)
+        Ok(item)
     }
 
     /// get item at index
@@ -311,7 +310,7 @@ where
 
 pub struct ReaderStream<'a, T>
 where
-    T: bincode::Decode,
+    T: DeserializeOwned,
 {
     reader: &'a Reader<T>,
     index: Option<usize>,
@@ -319,7 +318,7 @@ where
 
 impl<'a, T> ReaderStream<'a, T>
 where
-    T: bincode::Decode,
+    T: DeserializeOwned,
 {
     fn new(reader: &'a Reader<T>) -> Self {
         ReaderStream {
@@ -331,7 +330,7 @@ where
 
 impl<'a, T> Stream for ReaderStream<'a, T>
 where
-    T: bincode::Decode,
+    T: DeserializeOwned,
 {
     type Item = T;
 
@@ -375,7 +374,7 @@ where
 
 pub struct BufReader<T>
 where
-    T: bincode::Decode,
+    T: DeserializeOwned,
 {
     inner: Reader<T>,
     buf: Vec<u8>,
@@ -383,7 +382,7 @@ where
 
 impl<T> BufReader<T>
 where
-    T: bincode::Decode,
+    T: DeserializeOwned,
 {
     pub async fn new<P: AsRef<Path>>(path: P, buf_size: usize) -> Result<Self, String> {
         match Reader::<T>::new(path).await {
@@ -410,7 +409,7 @@ where
 
 impl<T> From<Reader<T>> for BufReader<T>
 where
-    T: bincode::Decode,
+    T: DeserializeOwned,
 {
     fn from(inner: Reader<T>) -> Self {
         Self {
@@ -422,7 +421,7 @@ where
 
 impl<T> From<BufReader<T>> for Reader<T>
 where
-    T: bincode::Decode,
+    T: DeserializeOwned,
 {
     fn from(value: BufReader<T>) -> Self {
         value.into_inner()
@@ -431,7 +430,7 @@ where
 
 impl<T> Deref for BufReader<T>
 where
-    T: bincode::Decode,
+    T: DeserializeOwned,
 {
     type Target = Reader<T>;
     fn deref(&self) -> &Self::Target {
@@ -441,7 +440,7 @@ where
 
 pub struct BufReaderStream<T>
 where
-    T: bincode::Decode,
+    T: DeserializeOwned,
 {
     reader: BufReader<T>,
     index: Option<usize>,
@@ -449,7 +448,7 @@ where
 
 impl<T> BufReaderStream<T>
 where
-    T: bincode::Decode,
+    T: DeserializeOwned,
 {
     fn new(reader: BufReader<T>) -> Self {
         BufReaderStream {
@@ -473,7 +472,7 @@ where
 
 impl<T> Stream for BufReaderStream<T>
 where
-    T: bincode::Decode,
+    T: DeserializeOwned,
 {
     type Item = T;
 
@@ -516,9 +515,10 @@ where
 mod test {
     use super::*;
     use core::fmt::Debug;
+    use serde_derive::Deserialize;
     use tempfile::tempdir;
 
-    #[derive(bincode::Encode, bincode::Decode, Clone, Debug, PartialEq, Eq, PartialOrd, Ord)]
+    #[derive(Serialize, Deserialize, Clone, Debug, PartialEq, Eq, PartialOrd, Ord)]
     struct TestData {
         num: u64,
         test: String,