feat: support download persistent cache task from parents (#950)

Signed-off-by: Gaius <[email protected]>

Cargo.toml

@@ -30,7 +30,7 @@ dragonfly-client-backend = { path = "dragonfly-client-backend", version = "0.2.5
 dragonfly-client-util = { path = "dragonfly-client-util", version = "0.2.5" }
 dragonfly-client-init = { path = "dragonfly-client-init", version = "0.2.5" }
 thiserror = "1.0"
-dragonfly-api = "=2.1.9"
+dragonfly-api = "=2.1.12"
 reqwest = { version = "0.12.4", features = [
     "stream",
     "native-tls",

dragonfly-client-storage/src/lib.rs

@@ -517,6 +517,144 @@ impl Storage {
         self.metadata.piece_id(task_id, number)
     }
 
+    /// download_persistent_cache_piece_started updates the metadata of the persistent cache piece and writes
+    /// the data of piece to file when the persistent cache piece downloads started.
+    #[instrument(skip_all)]
+    pub async fn download_persistent_cache_piece_started(
+        &self,
+        piece_id: &str,
+        number: u32,
+    ) -> Result<metadata::Piece> {
+        // Wait for the piece to be finished.
+        match self
+            .wait_for_persistent_cache_piece_finished(piece_id)
+            .await
+        {
+            Ok(piece) => Ok(piece),
+            // If piece is not found or wait timeout, create piece metadata.
+            Err(_) => self.metadata.download_piece_started(piece_id, number),
+        }
+    }
+
+    /// download_persistent_cache_piece_from_parent_finished is used for downloading persistent cache piece from parent.
+    #[instrument(skip_all)]
+    pub async fn download_persistent_cache_piece_from_parent_finished<
+        R: AsyncRead + Unpin + ?Sized,
+    >(
+        &self,
+        piece_id: &str,
+        task_id: &str,
+        offset: u64,
+        expected_digest: &str,
+        parent_id: &str,
+        reader: &mut R,
+    ) -> Result<metadata::Piece> {
+        let response = self
+            .content
+            .write_piece_with_crc32_castagnoli(task_id, offset, reader)
+            .await?;
+
+        let length = response.length;
+        let digest = Digest::new(Algorithm::Crc32, response.hash);
+
+        // Check the digest of the piece.
+        if expected_digest != digest.to_string() {
+            return Err(Error::DigestMismatch(
+                expected_digest.to_string(),
+                digest.to_string(),
+            ));
+        }
+
+        self.metadata.download_piece_finished(
+            piece_id,
+            offset,
+            length,
+            digest.to_string().as_str(),
+            Some(parent_id.to_string()),
+        )
+    }
+
+    /// download_persistent_cache_piece_failed updates the metadata of the persistent cache piece when the persistent cache piece downloads failed.
+    #[instrument(skip_all)]
+    pub fn download_persistent_cache_piece_failed(&self, piece_id: &str) -> Result<()> {
+        self.metadata.download_piece_failed(piece_id)
+    }
+
+    /// upload_persistent_cache_piece updates the metadata of the piece and_then
+    /// returns the data of the piece.
+    #[instrument(skip_all)]
+    pub async fn upload_persistent_cache_piece(
+        &self,
+        piece_id: &str,
+        task_id: &str,
+        range: Option<Range>,
+    ) -> Result<impl AsyncRead> {
+        // Wait for the persistent cache piece to be finished.
+        self.wait_for_persistent_cache_piece_finished(piece_id)
+            .await?;
+
+        // Start uploading the persistent cache task.
+        self.metadata
+            .upload_persistent_cache_task_started(task_id)?;
+
+        // Get the persistent cache piece metadata and return the content of the persistent cache piece.
+        match self.metadata.get_piece(piece_id) {
+            Ok(Some(piece)) => {
+                match self
+                    .content
+                    .read_piece(task_id, piece.offset, piece.length, range)
+                    .await
+                {
+                    Ok(reader) => {
+                        // Finish uploading the persistent cache task.
+                        self.metadata
+                            .upload_persistent_cache_task_finished(task_id)?;
+                        Ok(reader)
+                    }
+                    Err(err) => {
+                        // Failed uploading the persistent cache task.
+                        self.metadata.upload_persistent_cache_task_failed(task_id)?;
+                        Err(err)
+                    }
+                }
+            }
+            Ok(None) => {
+                // Failed uploading the persistent cache task.
+                self.metadata.upload_persistent_cache_task_failed(task_id)?;
+                Err(Error::PieceNotFound(piece_id.to_string()))
+            }
+            Err(err) => {
+                // Failed uploading the persistent cache task.
+                self.metadata.upload_persistent_cache_task_failed(task_id)?;
+                Err(err)
+            }
+        }
+    }
+
+    /// get_persistent_cache_piece returns the persistent cache piece metadata.
+    #[instrument(skip_all)]
+    pub fn get_persistent_cache_piece(&self, piece_id: &str) -> Result<Option<metadata::Piece>> {
+        self.metadata.get_piece(piece_id)
+    }
+
+    /// is_persistent_cache_piece_exists returns whether the persistent cache piece exists.
+    #[instrument(skip_all)]
+    pub fn is_persistent_cache_piece_exists(&self, piece_id: &str) -> Result<bool> {
+        self.metadata.is_piece_exists(piece_id)
+    }
+
+    /// get_persistent_cache_pieces returns the persistent cache piece metadatas.
+    pub fn get_persistent_cache_pieces(&self, task_id: &str) -> Result<Vec<metadata::Piece>> {
+        self.metadata.get_pieces(task_id)
+    }
+
+    /// persistent_cache_piece_id returns the persistent cache piece id.
+    #[inline]
+    #[instrument(skip_all)]
+    pub fn persistent_cache_piece_id(&self, task_id: &str, number: u32) -> String {
+        self.metadata.piece_id(task_id, number)
+    }
+
     /// wait_for_piece_finished waits for the piece to be finished.
     #[instrument(skip_all)]
     async fn wait_for_piece_finished(&self, piece_id: &str) -> Result<metadata::Piece> {
@@ -552,4 +690,43 @@ impl Storage {
             }
         }
     }
+
+    /// wait_for_persistent_cache_piece_finished waits for the persistent cache piece to be finished.
+    #[instrument(skip_all)]
+    async fn wait_for_persistent_cache_piece_finished(
+        &self,
+        piece_id: &str,
+    ) -> Result<metadata::Piece> {
+        // Initialize the timeout of piece.
+        let piece_timeout = tokio::time::sleep(self.config.download.piece_timeout);
+        tokio::pin!(piece_timeout);
+
+        // Initialize the interval of piece.
+        let mut wait_for_piece_count = 0;
+        let mut interval = tokio::time::interval(DEFAULT_WAIT_FOR_PIECE_FINISHED_INTERVAL);
+        loop {
+            tokio::select! {
+                _ = interval.tick() => {
+                    let piece = self
+                        .get_persistent_cache_piece(piece_id)?
+                        .ok_or_else(|| Error::PieceNotFound(piece_id.to_string()))?;
+
+                    // If the piece is finished, return.
+                    if piece.is_finished() {
+                        debug!("wait piece finished success");
+                        return Ok(piece);
+                    }
+
+                    if wait_for_piece_count > 0 {
+                        debug!("wait piece finished");
+                    }
+                    wait_for_piece_count += 1;
+                }
+                _ = &mut piece_timeout => {
+                    self.metadata.wait_for_piece_finished_failed(piece_id).unwrap_or_else(|err| error!("delete piece metadata failed: {}", err));
+                    return Err(Error::WaitForPieceFinishedTimeout(piece_id.to_string()));
+                }
+            }
+        }
+    }
 }

dragonfly-client-util/src/id_generator/mod.rs

@@ -153,8 +153,15 @@ impl IDGenerator {
             hasher.write(application.as_bytes());
         }
 
-        // Generate the persistent cache task id.
-        Ok(hasher.finish().to_string())
+        // Generate the task id by wyhash.
+        let id = hasher.finish().to_string();
+
+        // Generate the persistent cache task ID. The original ID is too short, so we calculate the SHA-256
+        // hash to ensure it can be prefix-searched by the storage engine.
+        let mut hasher = Sha256::new();
+        hasher.update(id);
+
+        Ok(hex::encode(hasher.finalize()))
     }
 
     /// peer_id generates the peer id.
@@ -263,21 +270,21 @@ mod tests {
                 "This is a test file",
                 Some("tag1"),
                 Some("app1"),
-                "15288906590529426257",
+                "ed401a8aa6b9a47b426d2aa01245127d9ac2d1b7974ca866719da59b5456ac4d",
             ),
             (
                 IDGenerator::new("127.0.0.1".to_string(), "localhost".to_string(), false),
                 "This is a test file",
                 None,
                 Some("app1"),
-                "16142504978820333826",
+                "4cbb2c5142f609e98a7d9a887c6404c7432475a52d6c64c52d543b5614a99c63",
             ),
             (
                 IDGenerator::new("127.0.0.1".to_string(), "localhost".to_string(), false),
                 "This is a test file",
                 Some("tag1"),
                 None,
-                "3790865882910844849",
+                "65094f31f9997904f779a27ed0d1ce460c9c4082f214e7626a179f2ea491d34e",
             ),
         ];