feat: Implement RFC-0409 Accessor Capabilities

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

Author: Xuanwo

Cargo.toml

@@ -49,6 +49,7 @@ backon = { version = "0.0.2", optional = true }
 base64 = "0.13.0"
 bytes = "1.1.0"
 dotenv = { version = "0.15.0", optional = true }
+flagset = "0.4.3"
 futures = { version = "0.3.21", features = ["alloc"] }
 hdrs = { version = "0.1.4", optional = true, features = ["futures-io"] }
 http = "0.2.6"

src/accessor.rs

@@ -17,6 +17,8 @@ use std::io::Result;
 use std::sync::Arc;
 
 use async_trait::async_trait;
+use flagset::flags;
+use flagset::FlagSet;
 
 use crate::ops::OpCreate;
 use crate::ops::OpDelete;
@@ -148,6 +150,7 @@ pub struct AccessorMetadata {
     scheme: Scheme,
     root: String,
     name: String,
+    capabilities: FlagSet<AccessorCapability>,
 }
 
 impl AccessorMetadata {
@@ -185,4 +188,17 @@ impl AccessorMetadata {
         self.name = name.to_string();
         self
     }
+
+    pub(crate) fn set_capabilities(
+        &mut self,
+        capabilities: impl Into<FlagSet<AccessorCapability>>,
+    ) -> &mut Self {
+        self.capabilities = capabilities.into();
+        self
+    }
+}
+
+flags! {
+    /// AccessorCapability describes accessor's advanced capability.
+    pub(crate) enum AccessorCapability: u32 {}
 }

src/services/azblob/backend.rs

@@ -271,7 +271,8 @@ impl Accessor for Backend {
         let mut am = AccessorMetadata::default();
         am.set_scheme(Scheme::Azblob)
             .set_root(&self.root)
-            .set_name(&self.container);
+            .set_name(&self.container)
+            .set_capabilities(None);
 
         am
     }

src/services/fs/backend.rs

@@ -149,7 +149,9 @@ impl Backend {
 impl Accessor for Backend {
     fn metadata(&self) -> AccessorMetadata {
         let mut am = AccessorMetadata::default();
-        am.set_scheme(Scheme::Fs).set_root(&self.root);
+        am.set_scheme(Scheme::Fs)
+            .set_root(&self.root)
+            .set_capabilities(None);
 
         am
     }

src/services/hdfs/backend.rs

@@ -200,7 +200,9 @@ impl Backend {
 impl Accessor for Backend {
     fn metadata(&self) -> AccessorMetadata {
         let mut am = AccessorMetadata::default();
-        am.set_scheme(Scheme::Hdfs).set_root(&self.root);
+        am.set_scheme(Scheme::Hdfs)
+            .set_root(&self.root)
+            .set_capabilities(None);
 
         am
     }

src/services/http/backend.rs

@@ -215,7 +215,9 @@ impl Backend {
 impl Accessor for Backend {
     fn metadata(&self) -> AccessorMetadata {
         let mut ma = AccessorMetadata::default();
-        ma.set_scheme(Scheme::Http).set_root(&self.root);
+        ma.set_scheme(Scheme::Http)
+            .set_root(&self.root)
+            .set_capabilities(None);
 
         ma
     }

src/services/memory/backend.rs

@@ -80,7 +80,8 @@ impl Accessor for Backend {
         let mut am = AccessorMetadata::default();
         am.set_scheme(Scheme::Memory)
             .set_root("/")
-            .set_name("memory");
+            .set_name("memory")
+            .set_capabilities(None);
 
         am
     }

src/services/s3/backend.rs

@@ -821,7 +821,8 @@ impl Accessor for Backend {
         let mut am = AccessorMetadata::default();
         am.set_scheme(Scheme::S3)
             .set_root(&self.root)
-            .set_name(&self.bucket);
+            .set_name(&self.bucket)
+            .set_capabilities(None);
 
         am
     }