feat: impl Logstore::read by LogFile::create_stream (#124)

* feat: bridge LogStore::read to LogFile::create_stream

* fix some CR comments

src/log-store/src/fs/file.rs

@@ -274,10 +274,10 @@ impl LogFile {
     pub async fn replay(&mut self) -> Result<(usize, Id)> {
         let log_name = self.name.to_string();
         let previous_offset = self.flush_offset.load(Ordering::Relaxed);
+        let ns = LocalNamespace::default();
         let mut stream = self.create_stream(
             // TODO(hl): LocalNamespace should be filled
-            LocalNamespace::default(),
-            0,
+            &ns, 0,
         );
 
         let mut last_offset = 0usize;
@@ -313,7 +313,11 @@ impl LogFile {
     /// ### Notice
     /// If the entry with start entry id is not present, the first generated entry will start with
     /// the first entry with an id greater than `start_entry_id`.
-    pub fn create_stream(&self, _ns: impl Namespace, start_entry_id: u64) -> impl EntryStream + '_ {
+    pub fn create_stream(
+        &self,
+        _ns: &impl Namespace,
+        start_entry_id: u64,
+    ) -> impl EntryStream<Entry = EntryImpl, Error = Error> + '_ {
         let length = self.flush_offset.load(Ordering::Relaxed);
 
         let s = stream!({

src/log-store/src/fs/log.rs

@@ -3,9 +3,13 @@ use std::path::Path;
 use std::sync::Arc;
 
 use arc_swap::ArcSwap;
+use async_stream::stream;
 use common_telemetry::{error, info, warn};
+use futures::pin_mut;
+use futures::StreamExt;
 use snafu::{OptionExt, ResultExt};
 use store_api::logstore::entry::{Encode, Id};
+use store_api::logstore::entry_stream::SendableEntryStream;
 use store_api::logstore::LogStore;
 use tokio::sync::RwLock;
 
@@ -167,7 +171,7 @@ impl LogStore for LocalFileLogStore {
 
     async fn append(
         &self,
-        _ns: Self::Namespace,
+        _ns: &Self::Namespace,
         mut entry: Self::Entry,
     ) -> Result<Self::AppendResponse> {
         // TODO(hl): configurable retry times
@@ -208,11 +212,24 @@ impl LogStore for LocalFileLogStore {
 
     async fn read(
         &self,
-        _ns: Self::Namespace,
-        _id: Id,
-    ) -> Result<store_api::logstore::entry_stream::SendableEntryStream<'_, Self::Entry, Self::Error>>
-    {
-        todo!()
+        ns: Self::Namespace,
+        id: Id,
+    ) -> Result<SendableEntryStream<'_, Self::Entry, Self::Error>> {
+        let files = self.files.read().await;
+
+        let s = stream!({
+            for (start_id, file) in files.iter() {
+                if *start_id >= id {
+                    let s = file.create_stream(&ns, *start_id);
+                    pin_mut!(s);
+                    while let Some(entries) = s.next().await {
+                        yield entries;
+                    }
+                }
+            }
+        });
+
+        Ok(Box::pin(s))
     }
 
     async fn create_namespace(&mut self, _ns: Self::Namespace) -> Result<()> {
@@ -248,13 +265,11 @@ mod tests {
         };
 
         let logstore = LocalFileLogStore::open(&config).await.unwrap();
+        let ns = LocalNamespace::default();
         assert_eq!(
             0,
             logstore
-                .append(
-                    LocalNamespace::default(),
-                    EntryImpl::new(generate_data(100)),
-                )
+                .append(&ns, EntryImpl::new(generate_data(100)),)
                 .await
                 .unwrap()
                 .entry_id
@@ -263,10 +278,7 @@ mod tests {
         assert_eq!(
             1,
             logstore
-                .append(
-                    LocalNamespace::default(),
-                    EntryImpl::new(generate_data(100)),
-                )
+                .append(&ns, EntryImpl::new(generate_data(100)),)
                 .await
                 .unwrap()
                 .entry_id
@@ -296,18 +308,15 @@ mod tests {
             log_file_dir: dir.path().to_str().unwrap().to_string(),
         };
         let logstore = LocalFileLogStore::open(&config).await.unwrap();
+        let ns = LocalNamespace::default();
         let id = logstore
-            .append(
-                LocalNamespace::default(),
-                EntryImpl::new(generate_data(100)),
-            )
+            .append(&ns, EntryImpl::new(generate_data(100)))
             .await
             .unwrap()
             .entry_id;
         assert_eq!(0, id);
 
-        let active_file = logstore.active_file();
-        let stream = active_file.create_stream(LocalNamespace::default(), 0);
+        let stream = logstore.read(ns, 0).await.unwrap();
         tokio::pin!(stream);
 
         let entries = stream.next().await.unwrap().unwrap();

src/log-store/src/fs/noop.rs

@@ -17,7 +17,7 @@ impl LogStore for NoopLogStore {
 
     async fn append(
         &self,
-        _ns: Self::Namespace,
+        _ns: &Self::Namespace,
         mut _e: Self::Entry,
     ) -> Result<Self::AppendResponse> {
         Ok(AppendResponseImpl {

src/storage/src/wal.rs

@@ -127,7 +127,7 @@ impl<S: LogStore> Wal<S> {
 
         let res = self
             .store
-            .append(ns, e)
+            .append(&ns, e)
             .await
             .map_err(BoxedError::new)
             .context(error::WriteWalSnafu { name: self.name() })?;

src/store-api/src/logstore.rs

@@ -21,7 +21,7 @@ pub trait LogStore: Send + Sync + 'static + std::fmt::Debug {
     /// Append an `Entry` to WAL with given namespace
     async fn append(
         &self,
-        ns: Self::Namespace,
+        ns: &Self::Namespace,
         mut e: Self::Entry,
     ) -> Result<Self::AppendResponse, Self::Error>;
 
@@ -32,7 +32,7 @@ pub trait LogStore: Send + Sync + 'static + std::fmt::Debug {
         e: Vec<Self::Entry>,
     ) -> Result<Id, Self::Error>;
 
-    // Create a new `EntryStream` to asynchronously generates `Entry`.
+    // Create a new `EntryStream` to asynchronously generates `Entry` with ids starting from `id`.
     async fn read(
         &self,
         ns: Self::Namespace,