feat(cluster): add clustered storage backend with QUIC transport, erasure coding, and shard management

rust/src/storage.rs

@@ -10,6 +10,7 @@ use tokio::fs;
 use tokio::io::{AsyncReadExt, AsyncSeekExt, AsyncWriteExt, BufWriter};
 use uuid::Uuid;
 
+use crate::cluster::coordinator::DistributedStore;
 use crate::error::StorageError;
 
 // ============================
@@ -795,6 +796,196 @@ impl FileStore {
     }
 }
 
+// ============================
+// StorageBackend enum
+// ============================
+
+/// Unified storage backend that dispatches to either standalone (FileStore)
+/// or clustered (DistributedStore) storage.
+pub enum StorageBackend {
+    Standalone(FileStore),
+    Clustered(DistributedStore),
+}
+
+impl StorageBackend {
+    pub fn policies_dir(&self) -> std::path::PathBuf {
+        match self {
+            StorageBackend::Standalone(fs) => fs.policies_dir(),
+            StorageBackend::Clustered(_) => PathBuf::from(".policies"), // TODO: proper policies in cluster mode
+        }
+    }
+
+    pub async fn initialize(&self) -> Result<()> {
+        match self {
+            StorageBackend::Standalone(fs) => fs.initialize().await,
+            StorageBackend::Clustered(_) => Ok(()), // Cluster init happens separately
+        }
+    }
+
+    pub async fn reset(&self) -> Result<()> {
+        match self {
+            StorageBackend::Standalone(fs) => fs.reset().await,
+            StorageBackend::Clustered(_) => Ok(()), // TODO: cluster reset
+        }
+    }
+
+    pub async fn list_buckets(&self) -> Result<Vec<BucketInfo>> {
+        match self {
+            StorageBackend::Standalone(fs) => fs.list_buckets().await,
+            StorageBackend::Clustered(ds) => ds.list_buckets().await,
+        }
+    }
+
+    pub async fn bucket_exists(&self, bucket: &str) -> bool {
+        match self {
+            StorageBackend::Standalone(fs) => fs.bucket_exists(bucket).await,
+            StorageBackend::Clustered(ds) => ds.bucket_exists(bucket).await,
+        }
+    }
+
+    pub async fn create_bucket(&self, bucket: &str) -> Result<()> {
+        match self {
+            StorageBackend::Standalone(fs) => fs.create_bucket(bucket).await,
+            StorageBackend::Clustered(ds) => ds.create_bucket(bucket).await,
+        }
+    }
+
+    pub async fn delete_bucket(&self, bucket: &str) -> Result<()> {
+        match self {
+            StorageBackend::Standalone(fs) => fs.delete_bucket(bucket).await,
+            StorageBackend::Clustered(ds) => ds.delete_bucket(bucket).await,
+        }
+    }
+
+    pub async fn put_object(
+        &self,
+        bucket: &str,
+        key: &str,
+        body: Incoming,
+        metadata: HashMap<String, String>,
+    ) -> Result<PutResult> {
+        match self {
+            StorageBackend::Standalone(fs) => fs.put_object(bucket, key, body, metadata).await,
+            StorageBackend::Clustered(ds) => ds.put_object(bucket, key, body, metadata).await,
+        }
+    }
+
+    pub async fn get_object(
+        &self,
+        bucket: &str,
+        key: &str,
+        range: Option<(u64, u64)>,
+    ) -> Result<GetResult> {
+        match self {
+            StorageBackend::Standalone(fs) => fs.get_object(bucket, key, range).await,
+            StorageBackend::Clustered(ds) => ds.get_object(bucket, key, range).await,
+        }
+    }
+
+    pub async fn head_object(&self, bucket: &str, key: &str) -> Result<HeadResult> {
+        match self {
+            StorageBackend::Standalone(fs) => fs.head_object(bucket, key).await,
+            StorageBackend::Clustered(ds) => ds.head_object(bucket, key).await,
+        }
+    }
+
+    pub async fn delete_object(&self, bucket: &str, key: &str) -> Result<()> {
+        match self {
+            StorageBackend::Standalone(fs) => fs.delete_object(bucket, key).await,
+            StorageBackend::Clustered(ds) => ds.delete_object(bucket, key).await,
+        }
+    }
+
+    pub async fn copy_object(
+        &self,
+        src_bucket: &str,
+        src_key: &str,
+        dest_bucket: &str,
+        dest_key: &str,
+        metadata_directive: &str,
+        new_metadata: Option<HashMap<String, String>>,
+    ) -> Result<CopyResult> {
+        match self {
+            StorageBackend::Standalone(fs) => {
+                fs.copy_object(src_bucket, src_key, dest_bucket, dest_key, metadata_directive, new_metadata).await
+            }
+            StorageBackend::Clustered(ds) => {
+                ds.copy_object(src_bucket, src_key, dest_bucket, dest_key, metadata_directive, new_metadata).await
+            }
+        }
+    }
+
+    pub async fn list_objects(
+        &self,
+        bucket: &str,
+        prefix: &str,
+        delimiter: &str,
+        max_keys: usize,
+        continuation_token: Option<&str>,
+    ) -> Result<ListObjectsResult> {
+        match self {
+            StorageBackend::Standalone(fs) => {
+                fs.list_objects(bucket, prefix, delimiter, max_keys, continuation_token).await
+            }
+            StorageBackend::Clustered(ds) => {
+                ds.list_objects(bucket, prefix, delimiter, max_keys, continuation_token).await
+            }
+        }
+    }
+
+    pub async fn initiate_multipart(
+        &self,
+        bucket: &str,
+        key: &str,
+        metadata: HashMap<String, String>,
+    ) -> Result<String> {
+        match self {
+            StorageBackend::Standalone(fs) => fs.initiate_multipart(bucket, key, metadata).await,
+            StorageBackend::Clustered(ds) => ds.initiate_multipart(bucket, key, metadata).await,
+        }
+    }
+
+    pub async fn upload_part(
+        &self,
+        upload_id: &str,
+        part_number: u32,
+        body: Incoming,
+    ) -> Result<(String, u64)> {
+        match self {
+            StorageBackend::Standalone(fs) => fs.upload_part(upload_id, part_number, body).await,
+            StorageBackend::Clustered(ds) => ds.upload_part(upload_id, part_number, body).await,
+        }
+    }
+
+    pub async fn complete_multipart(
+        &self,
+        upload_id: &str,
+        parts: &[(u32, String)],
+    ) -> Result<CompleteMultipartResult> {
+        match self {
+            StorageBackend::Standalone(fs) => fs.complete_multipart(upload_id, parts).await,
+            StorageBackend::Clustered(ds) => ds.complete_multipart(upload_id, parts).await,
+        }
+    }
+
+    pub async fn abort_multipart(&self, upload_id: &str) -> Result<()> {
+        match self {
+            StorageBackend::Standalone(fs) => fs.abort_multipart(upload_id).await,
+            StorageBackend::Clustered(ds) => ds.abort_multipart(upload_id).await,
+        }
+    }
+
+    pub async fn list_multipart_uploads(
+        &self,
+        bucket: &str,
+    ) -> Result<Vec<MultipartUploadInfo>> {
+        match self {
+            StorageBackend::Standalone(fs) => fs.list_multipart_uploads(bucket).await,
+            StorageBackend::Clustered(ds) => ds.list_multipart_uploads(bucket).await,
+        }
+    }
+}
+
 // ============================
 // Key encoding (identity on Linux)
 // ============================