async-ify xenstore and xenclient

libs/xen/xenstore/src/client.rs

@@ -35,85 +35,71 @@ impl XsPermission {
     }
 }
 
+#[allow(async_fn_in_trait)]
 pub trait XsdInterface {
-    fn list(&mut self, path: &str) -> Result<Vec<String>>;
-    fn read(&mut self, path: &str) -> Result<Vec<u8>>;
-    fn read_string(&mut self, path: &str) -> Result<String>;
-    fn write(&mut self, path: &str, data: Vec<u8>) -> Result<bool>;
-    fn write_string(&mut self, path: &str, data: &str) -> Result<bool>;
-    fn mkdir(&mut self, path: &str) -> Result<bool>;
-    fn rm(&mut self, path: &str) -> Result<bool>;
-    fn set_perms(&mut self, path: &str, perms: &[XsPermission]) -> Result<bool>;
+    async fn list(&mut self, path: &str) -> Result<Vec<String>>;
+    async fn read(&mut self, path: &str) -> Result<Option<Vec<u8>>>;
+    async fn read_string(&mut self, path: &str) -> Result<Option<String>>;
+    async fn write(&mut self, path: &str, data: Vec<u8>) -> Result<bool>;
+    async fn write_string(&mut self, path: &str, data: &str) -> Result<bool>;
+    async fn mkdir(&mut self, path: &str) -> Result<bool>;
+    async fn rm(&mut self, path: &str) -> Result<bool>;
+    async fn set_perms(&mut self, path: &str, perms: &[XsPermission]) -> Result<bool>;
 
-    fn mknod(&mut self, path: &str, perms: &[XsPermission]) -> Result<bool> {
-        let result1 = self.write_string(path, "")?;
-        let result2 = self.set_perms(path, perms)?;
+    async fn mknod(&mut self, path: &str, perms: &[XsPermission]) -> Result<bool> {
+        let result1 = self.write_string(path, "").await?;
+        let result2 = self.set_perms(path, perms).await?;
         Ok(result1 && result2)
     }
-
-    fn read_string_optional(&mut self, path: &str) -> Result<Option<String>> {
-        Ok(match self.read_string(path) {
-            Ok(value) => Some(value),
-            Err(error) => {
-                if error.is_noent_response() {
-                    None
-                } else {
-                    return Err(error);
-                }
-            }
-        })
-    }
-
-    fn list_any(&mut self, path: &str) -> Result<Vec<String>> {
-        Ok(match self.list(path) {
-            Ok(value) => value,
-            Err(error) => {
-                if error.is_noent_response() {
-                    Vec::new()
-                } else {
-                    return Err(error);
-                }
-            }
-        })
-    }
 }
 
 impl XsdClient {
-    pub fn open() -> Result<XsdClient> {
-        let socket = XsdSocket::dial()?;
+    pub async fn open() -> Result<XsdClient> {
+        let socket = XsdSocket::open().await?;
         Ok(XsdClient { socket })
     }
 
-    fn list(&mut self, tx: u32, path: &str) -> Result<Vec<String>> {
+    async fn list(&mut self, tx: u32, path: &str) -> Result<Vec<String>> {
         trace!("list tx={tx} path={path}");
-        let response = self.socket.send_single(tx, XSD_DIRECTORY, path)?;
+        let response = self.socket.send_single(tx, XSD_DIRECTORY, path).await?;
         response.parse_string_vec()
     }
 
-    fn read(&mut self, tx: u32, path: &str) -> Result<Vec<u8>> {
+    async fn read(&mut self, tx: u32, path: &str) -> Result<Option<Vec<u8>>> {
         trace!("read tx={tx} path={path}");
-        let response = self.socket.send_single(tx, XSD_READ, path)?;
-        Ok(response.payload)
+        match self.socket.send_single(tx, XSD_READ, path).await {
+            Ok(response) => Ok(Some(response.payload)),
+            Err(error) => {
+                if error.is_noent_response() {
+                    Ok(None)
+                } else {
+                    Err(error)
+                }
+            }
+        }
     }
 
-    fn write(&mut self, tx: u32, path: &str, data: Vec<u8>) -> Result<bool> {
+    async fn write(&mut self, tx: u32, path: &str, data: Vec<u8>) -> Result<bool> {
         trace!("write tx={tx} path={path} data={:?}", data);
         let mut buffer = Vec::new();
         let path = CString::new(path)?;
         buffer.extend_from_slice(path.as_bytes_with_nul());
         buffer.extend_from_slice(data.as_slice());
-        let response = self.socket.send(tx, XSD_WRITE, buffer.as_slice())?;
+        let response = self.socket.send(tx, XSD_WRITE, buffer.as_slice()).await?;
         response.parse_bool()
     }
 
-    fn mkdir(&mut self, tx: u32, path: &str) -> Result<bool> {
+    async fn mkdir(&mut self, tx: u32, path: &str) -> Result<bool> {
         trace!("mkdir tx={tx} path={path}");
-        self.socket.send_single(tx, XSD_MKDIR, path)?.parse_bool()
+        self.socket
+            .send_single(tx, XSD_MKDIR, path)
+            .await?
+            .parse_bool()
     }
 
-    fn rm(&mut self, tx: u32, path: &str) -> Result<bool> {
+    async fn rm(&mut self, tx: u32, path: &str) -> Result<bool> {
         trace!("rm tx={tx} path={path}");
-        let result = self.socket.send_single(tx, XSD_RM, path);
+        let result = self.socket.send_single(tx, XSD_RM, path).await;
         if let Err(error) = result {
             if error.is_noent_response() {
                 return Ok(true);
@@ -123,7 +109,7 @@ impl XsdClient {
         result.unwrap().parse_bool()
     }
 
-    fn set_perms(&mut self, tx: u32, path: &str, perms: &[XsPermission]) -> Result<bool> {
+    async fn set_perms(&mut self, tx: u32, path: &str, perms: &[XsPermission]) -> Result<bool> {
         trace!("set_perms tx={tx} path={path} perms={:?}", perms);
         let mut items: Vec<String> = Vec::new();
         items.push(path.to_string());
@@ -131,36 +117,46 @@ impl XsdClient {
             items.push(perm.encode()?);
         }
         let items_str: Vec<&str> = items.iter().map(|x| x.as_str()).collect();
-        let response = self.socket.send_multiple(tx, XSD_SET_PERMS, &items_str)?;
+        let response = self
+            .socket
+            .send_multiple(tx, XSD_SET_PERMS, &items_str)
+            .await?;
         response.parse_bool()
     }
 
-    pub fn transaction(&mut self) -> Result<XsdTransaction> {
+    pub async fn transaction(&mut self) -> Result<XsdTransaction> {
         trace!("transaction start");
-        let response = self.socket.send_single(0, XSD_TRANSACTION_START, "")?;
+        let response = self
+            .socket
+            .send_single(0, XSD_TRANSACTION_START, "")
+            .await?;
         let str = response.parse_string()?;
         let tx = str.parse::<u32>()?;
         Ok(XsdTransaction { client: self, tx })
     }
 
-    pub fn get_domain_path(&mut self, domid: u32) -> Result<String> {
-        let response =
-            self.socket
-                .send_single(0, XSD_GET_DOMAIN_PATH, domid.to_string().as_str())?;
+    pub async fn get_domain_path(&mut self, domid: u32) -> Result<String> {
+        let response = self
+            .socket
+            .send_single(0, XSD_GET_DOMAIN_PATH, domid.to_string().as_str())
+            .await?;
         response.parse_string()
     }
 
-    pub fn introduce_domain(&mut self, domid: u32, mfn: u64, evtchn: u32) -> Result<bool> {
+    pub async fn introduce_domain(&mut self, domid: u32, mfn: u64, evtchn: u32) -> Result<bool> {
         trace!("introduce domain domid={domid} mfn={mfn} evtchn={evtchn}");
-        let response = self.socket.send_multiple(
-            0,
-            XSD_INTRODUCE,
-            &[
-                domid.to_string().as_str(),
-                mfn.to_string().as_str(),
-                evtchn.to_string().as_str(),
-            ],
-        )?;
+        let response = self
+            .socket
+            .send_multiple(
+                0,
+                XSD_INTRODUCE,
+                &[
+                    domid.to_string().as_str(),
+                    mfn.to_string().as_str(),
+                    evtchn.to_string().as_str(),
+                ],
+            )
+            .await?;
         response.parse_bool()
     }
 }
@@ -171,89 +167,104 @@ pub struct XsdTransaction<'a> {
 }
 
 impl XsdInterface for XsdClient {
-    fn list(&mut self, path: &str) -> Result<Vec<String>> {
-        self.list(0, path)
+    async fn list(&mut self, path: &str) -> Result<Vec<String>> {
+        self.list(0, path).await
     }
 
-    fn read(&mut self, path: &str) -> Result<Vec<u8>> {
-        self.read(0, path)
+    async fn read(&mut self, path: &str) -> Result<Option<Vec<u8>>> {
+        self.read(0, path).await
     }
 
-    fn read_string(&mut self, path: &str) -> Result<String> {
-        Ok(String::from_utf8(self.read(0, path)?)?)
+    async fn read_string(&mut self, path: &str) -> Result<Option<String>> {
+        match self.read(0, path).await {
+            Ok(value) => match value {
+                Some(value) => Ok(Some(String::from_utf8(value)?)),
+                None => Ok(None),
+            },
+            Err(error) => Err(error),
+        }
     }
 
-    fn write(&mut self, path: &str, data: Vec<u8>) -> Result<bool> {
-        self.write(0, path, data)
+    async fn write(&mut self, path: &str, data: Vec<u8>) -> Result<bool> {
+        self.write(0, path, data).await
     }
 
-    fn write_string(&mut self, path: &str, data: &str) -> Result<bool> {
-        self.write(0, path, data.as_bytes().to_vec())
+    async fn write_string(&mut self, path: &str, data: &str) -> Result<bool> {
+        self.write(0, path, data.as_bytes().to_vec()).await
     }
 
-    fn mkdir(&mut self, path: &str) -> Result<bool> {
-        self.mkdir(0, path)
+    async fn mkdir(&mut self, path: &str) -> Result<bool> {
+        self.mkdir(0, path).await
     }
 
-    fn rm(&mut self, path: &str) -> Result<bool> {
-        self.rm(0, path)
+    async fn rm(&mut self, path: &str) -> Result<bool> {
+        self.rm(0, path).await
     }
 
-    fn set_perms(&mut self, path: &str, perms: &[XsPermission]) -> Result<bool> {
-        self.set_perms(0, path, perms)
+    async fn set_perms(&mut self, path: &str, perms: &[XsPermission]) -> Result<bool> {
+        self.set_perms(0, path, perms).await
     }
 }
 
 impl XsdInterface for XsdTransaction<'_> {
-    fn list(&mut self, path: &str) -> Result<Vec<String>> {
-        self.client.list(self.tx, path)
+    async fn list(&mut self, path: &str) -> Result<Vec<String>> {
+        self.client.list(self.tx, path).await
     }
 
-    fn read(&mut self, path: &str) -> Result<Vec<u8>> {
-        self.client.read(self.tx, path)
+    async fn read(&mut self, path: &str) -> Result<Option<Vec<u8>>> {
+        self.client.read(self.tx, path).await
     }
 
-    fn read_string(&mut self, path: &str) -> Result<String> {
-        Ok(String::from_utf8(self.client.read(self.tx, path)?)?)
+    async fn read_string(&mut self, path: &str) -> Result<Option<String>> {
+        match self.client.read(self.tx, path).await {
+            Ok(value) => match value {
+                Some(value) => Ok(Some(String::from_utf8(value)?)),
+                None => Ok(None),
+            },
+            Err(error) => Err(error),
+        }
     }
 
-    fn write(&mut self, path: &str, data: Vec<u8>) -> Result<bool> {
-        self.client.write(self.tx, path, data)
+    async fn write(&mut self, path: &str, data: Vec<u8>) -> Result<bool> {
+        self.client.write(self.tx, path, data).await
     }
 
-    fn write_string(&mut self, path: &str, data: &str) -> Result<bool> {
-        self.client.write(self.tx, path, data.as_bytes().to_vec())
+    async fn write_string(&mut self, path: &str, data: &str) -> Result<bool> {
+        self.client
+            .write(self.tx, path, data.as_bytes().to_vec())
+            .await
     }
 
-    fn mkdir(&mut self, path: &str) -> Result<bool> {
-        self.client.mkdir(self.tx, path)
+    async fn mkdir(&mut self, path: &str) -> Result<bool> {
+        self.client.mkdir(self.tx, path).await
     }
 
-    fn rm(&mut self, path: &str) -> Result<bool> {
-        self.client.rm(self.tx, path)
+    async fn rm(&mut self, path: &str) -> Result<bool> {
+        self.client.rm(self.tx, path).await
     }
 
-    fn set_perms(&mut self, path: &str, perms: &[XsPermission]) -> Result<bool> {
-        self.client.set_perms(self.tx, path, perms)
+    async fn set_perms(&mut self, path: &str, perms: &[XsPermission]) -> Result<bool> {
+        self.client.set_perms(self.tx, path, perms).await
     }
 }
 
 impl XsdTransaction<'_> {
-    pub fn end(&mut self, abort: bool) -> Result<bool> {
+    pub async fn end(&mut self, abort: bool) -> Result<bool> {
         let abort_str = if abort { "F" } else { "T" };
 
         trace!("transaction end abort={}", abort);
         self.client
             .socket
-            .send_single(self.tx, XSD_TRANSACTION_END, abort_str)?
+            .send_single(self.tx, XSD_TRANSACTION_END, abort_str)
+            .await?
             .parse_bool()
     }
 
-    pub fn commit(&mut self) -> Result<bool> {
-        self.end(false)
+    pub async fn commit(&mut self) -> Result<bool> {
+        self.end(false).await
     }
 
-    pub fn abort(&mut self) -> Result<bool> {
-        self.end(true)
+    pub async fn abort(&mut self) -> Result<bool> {
+        self.end(true).await
     }
 }