feat: Allow kv services implemented without list support

src/adapters/kv/api.rs

@@ -16,8 +16,11 @@ use std::fmt::Debug;
 use std::io::Result;
 
 use async_trait::async_trait;
+use flagset::FlagSet;
 use futures::Stream;
 
+use crate::AccessorCapability;
+use crate::AccessorMetadata;
 use crate::Scheme;
 
 /// KvAdapter is the adapter to underlying kv services.
@@ -58,14 +61,20 @@ pub const INODE_ROOT: u64 = 0;
 pub struct Metadata {
     scheme: Scheme,
     name: String,
+    capabilities: FlagSet<AccessorCapability>,
 }
 
 impl Metadata {
     /// Create a new KeyValueAccessorMetadata.
-    pub fn new(scheme: Scheme, name: &str) -> Self {
+    pub fn new(
+        scheme: Scheme,
+        name: &str,
+        capabilities: impl Into<FlagSet<AccessorCapability>>,
+    ) -> Self {
         Self {
             scheme,
             name: name.to_string(),
+            capabilities: capabilities.into(),
         }
     }
 
@@ -78,6 +87,22 @@ impl Metadata {
     pub fn name(&self) -> &str {
         &self.name
     }
+
+    /// Get the capabilities.
+    pub fn capabilities(&self) -> FlagSet<AccessorCapability> {
+        self.capabilities
+    }
+}
+
+impl From<Metadata> for AccessorMetadata {
+    fn from(m: Metadata) -> AccessorMetadata {
+        let mut am = AccessorMetadata::default();
+        am.set_name(m.name());
+        am.set_scheme(m.scheme());
+        am.set_capabilities(m.capabilities());
+
+        am
+    }
 }
 
 /// KeyStream represents a stream of keys.

src/adapters/kv/backend.rs

@@ -54,7 +54,6 @@ use crate::path::get_basename;
 use crate::path::get_parent;
 use crate::path::normalize_root;
 use crate::Accessor;
-use crate::AccessorCapability;
 use crate::AccessorMetadata;
 use crate::BytesReader;
 use crate::ObjectEntry;
@@ -96,15 +95,9 @@ where
     S: Adapter,
 {
     fn metadata(&self) -> AccessorMetadata {
-        let mut am = AccessorMetadata::default();
+        let mut am: AccessorMetadata = self.kv.metadata().into();
         am.set_root(&self.root);
-        am.set_capabilities(
-            AccessorCapability::Read | AccessorCapability::Write | AccessorCapability::List,
-        );
 
-        let kvam = self.kv.metadata();
-        am.set_scheme(kvam.scheme());
-        am.set_name(kvam.name());
         am
     }
 

src/services/memory/backend.rs

@@ -30,6 +30,7 @@ use parking_lot::Mutex;
 use crate::adapters::kv;
 use crate::adapters::kv::next_prefix;
 use crate::Accessor;
+use crate::AccessorCapability;
 use crate::Scheme;
 
 /// Builder for memory backend
@@ -60,7 +61,11 @@ pub struct Adapter {
 #[async_trait]
 impl kv::Adapter for Adapter {
     fn metadata(&self) -> kv::Metadata {
-        kv::Metadata::new(Scheme::Memory, &format!("{:?}", &self.inner as *const _))
+        kv::Metadata::new(
+            Scheme::Memory,
+            &format!("{:?}", &self.inner as *const _),
+            AccessorCapability::Read | AccessorCapability::Write | AccessorCapability::List,
+        )
     }
 
     async fn next_id(&self) -> Result<u64> {

src/services/redis/backend.rs

@@ -45,6 +45,7 @@ use crate::adapters::kv;
 use crate::error::new_other_backend_error;
 use crate::path::normalize_root;
 use crate::Accessor;
+use crate::AccessorCapability;
 use crate::Scheme;
 
 const DEFAULT_REDIS_ENDPOINT: &str = "tcp://127.0.0.1:6379";
@@ -280,6 +281,7 @@ impl kv::Adapter for Adapter {
         kv::Metadata::new(
             Scheme::Redis,
             &self.client.get_connection_info().addr.to_string(),
+            AccessorCapability::Read | AccessorCapability::Write | AccessorCapability::List,
         )
     }