Merge pull request #43 from djs55/epoch-open

API changes for clone-on-boot

Author: djs55

generator/src/control.ml

@@ -60,7 +60,11 @@ let api =
             "protocols, he list should be sorted into descending order of ";
             "desirability. Xapi will open the most desirable URI for which it has ";
             "an available datapath plugin.";
-          ]
+          ];
+          "keys", Dict(String, Basic String), String.concat " " [
+            "A lit of key=value pairs which have been stored in the Volume ";
+            "metadata. These should not be interpreted by the Volume plugin.";
+          ];
         ]
       )) in
   let volume = Type.Name "volume" in
@@ -210,6 +214,8 @@ let api =
                 "[snapshot sr volume] creates a new volue which is a ";
                 "snapshot of [volume] in [sr]. Snapshots should never be";
                 "written to; they are intended for backup/restore only.";
+                "Note the name and description are copied but any extra";
+                "metadata associated by [set] is not copied.";
               ];
               inputs = [
                 sr;
@@ -225,7 +231,8 @@ let api =
               Method.name = "clone";
               description = String.concat " " [
                 "[clone sr volume] creates a new volume which is a writable";
-                "clone of [volume] in [sr].";
+                "clone of [volume] in [sr]. Note the name and description are";
+                "copied but any extra metadata associated by [set] is not copied.";
               ];
               inputs = [
                 sr;
@@ -276,6 +283,44 @@ let api =
             ];
               outputs = [
               ];
+            }; {
+              Method.name = "set";
+              description = String.concat " " [
+                "[set sr volume key value] associates [key] with [value] in the metadata of [volume]";
+                "Note these keys and values are not interpreted by the plugin; they are intended for";
+                "the higher-level software only.";
+              ];
+              inputs = [
+                sr;
+                key;
+                { Arg.name = "k";
+                  ty = Basic String;
+                  description = "Key"
+                }; {
+                  Arg.name = "v";
+                  ty = Basic String;
+                  description = "Value"
+                }
+            ];
+              outputs = [
+              ];
+            }; {
+              Method.name = "unset";
+              description = String.concat " " [
+                "[unset sr volume key] removes [key] and any value associated with it from the metadata of [volume]";
+                "Note these keys and values are not interpreted by the plugin; they are intended for";
+                "the higher-level software only.";
+              ];
+              inputs = [
+                sr;
+                key;
+                { Arg.name = "k";
+                  ty = Basic String;
+                  description = "Key"
+                }
+            ];
+              outputs = [
+              ];
             }; {
               Method.name = "resize";
               description = String.concat " " [

generator/src/data.ml

@@ -18,6 +18,16 @@ let backend = {
   description = "The Xen block backend configuration."
 }
 
+let persistent = {
+  Arg.name = "persistent";
+  ty = Type.(Basic Boolean);
+  description = String.concat "" [
+    "True means the disk data is persistent and should be preserved when the datapath ";
+    "is closed i.e. when a VM is shutdown or rebooted. False means the data should be ";
+    "thrown away when the VM is shutdown or rebooted.";
+  ]
+}
+
 let implementation = Type.Variant (
   ("Blkback", Type.(Basic String), "use kernel blkback with the given 'params' key"), [
    "Tapdisk3", Type.(Basic String), "use userspace tapdisk3 with the given 'params' key";
@@ -95,6 +105,20 @@ let api =
          ];
         methods = [
           {
+            Method.name = "open";
+            description = String.concat " "[
+              "[open uri persistent] is called before a disk is attached to a VM. If";
+              "persistent is true then care should be taken to persist all writes to the";
+              "disk. If persistent is false then the implementation should configure";
+              "a temporary location for writes so they can be thrown away on [close]."
+            ];
+            inputs = [
+              uri;
+              persistent;
+            ];
+            outputs = [
+            ];
+          }; {
             Method.name = "attach";
             description = String.concat " "[
               "[attach uri domain] prepares a connection between the storage";
@@ -164,6 +188,17 @@ let api =
             ];
             outputs = [
             ];
+          }; {
+            Method.name = "close";
+            description = String.concat " "[
+              "[close uri] is called after a disk is detached and a VM shutdown.";
+              "This is an opportunity to throw away writes if the disk is not persistent.";
+            ];
+            inputs = [
+              uri;
+            ];
+            outputs = [
+            ];
           }
         ]
       }

generator/src/ocaml.ml

@@ -14,6 +14,12 @@ let rec lines_of_t t =
 
 let string_of_ts ts = String.concat "\n" (List.concat (List.map lines_of_t ts))
 
+let keywords = [
+  "open";
+]
+
+let escape_keywords x = if List.mem x keywords then "_" ^ x else x
+
 open Printf
 
 let rec typeof ?(expand_aliases=false) env t =
@@ -315,7 +321,7 @@ let skeleton_method unimplemented env i m =
   let unimplemented_error =
     sprintf "return (`Error (Unimplemented \"%s.%s\"))" i.Interface.name m.Method.name in
   [
-    Line (sprintf "let %s x =" m.Method.name);
+    Line (sprintf "let %s x =" (escape_keywords m.Method.name));
     Block [
       Line (sprintf "let open Types.%s.%s in" i.Interface.name (String.capitalize m.Method.name));
       Line "let open Types in";
@@ -365,7 +371,7 @@ let example_stub env is i m =
     ];
     Line "end)";
     Line "";
-    Line (sprintf "let result = Client.%s %s;;" m.Method.name (String.concat " " (List.map (fun a -> sprintf "~%s:%s" a.Arg.name (example_value_of env a.Arg.ty)) m.Method.inputs)));
+    Line (sprintf "let result = Client.%s %s;;" (escape_keywords m.Method.name) (String.concat " " (List.map (fun a -> sprintf "~%s:%s" a.Arg.name (example_value_of env a.Arg.ty)) m.Method.inputs)));
   ]
 
 let skeleton_of_interface unimplemented suffix env i =
@@ -381,7 +387,7 @@ let skeleton_of_interface unimplemented suffix env i =
 let signature_of_interface env i =
   let signature_of_method m =
     Line (sprintf "val %s: Types.%s.%s.In.t -> (Types.%s.%s.Out.t, exn) Result.t t"
-            m.Method.name
+            (escape_keywords m.Method.name)
             i.Interface.name (String.capitalize m.Method.name)
             i.Interface.name (String.capitalize m.Method.name)
          ) in
@@ -402,7 +408,7 @@ let server_of_interface env i =
     [
       Line (sprintf "| Types.%s.In.%s x ->" i.Interface.name (String.capitalize m.Method.name));
       Block [
-        Line (sprintf "Impl.%s x" m.Method.name);
+        Line (sprintf "Impl.%s x" (escape_keywords m.Method.name));
         Line ">>= fun result ->";
         Line "return (Result.(>>=) result (fun ok ->";
         Block [
@@ -441,17 +447,17 @@ let server_of_interface env i =
 let client_of_interfaces env is =
   let client_of_method env i m =
     [
-      Line (sprintf "let %s_r x =" m.Method.name);
+      Line (sprintf "let %s_r x =" (escape_keywords m.Method.name));
       Block [
         Line (sprintf "let call = Types.%s.In.call_of (Types.%s.In.%s x) in" i.Interface.name i.Interface.name (String.capitalize m.Method.name));
         Line "RPC.rpc call >>= fun response ->";
         Line (sprintf "let result = Result.(>>=) (result_of_response response) (fun x -> Result.return (Types.%s.%s.Out.t_of_rpc x)) in" i.Interface.name (String.capitalize m.Method.name));
         Line "return result";
       ];
-      Line (sprintf "let %s %s =" m.Method.name (String.concat " " (List.map (fun i -> sprintf "~%s" i.Arg.name) m.Method.inputs)));
+      Line (sprintf "let %s %s =" (escape_keywords m.Method.name) (String.concat " " (List.map (fun i -> sprintf "~%s" i.Arg.name) m.Method.inputs)));
       Block [
         Line (sprintf "let r = Types.%s.%s.In.({ %s }) in" i.Interface.name (String.capitalize m.Method.name) (String.concat "; " (List.map (fun i -> sprintf "%s = %s" i.Arg.name i.Arg.name) m.Method.inputs)));
-        Line (sprintf "%s_r r" m.Method.name);
+        Line (sprintf "%s_r r" (escape_keywords m.Method.name));
       ]
     ] in
   let client_of_interface env i =

generator/src/python.ml

@@ -14,6 +14,13 @@ let rec lines_of_t t =
 
 let string_of_ts ts = String.concat "\n" (List.concat (List.map lines_of_t ts))
 
+(* generate a fresh id *)
+let fresh_id =
+  let counter = ref 0 in
+  fun () ->
+    incr counter;
+    "tmp_" ^ (string_of_int !counter)
+
 (** [typecheck ty v] returns a python fragment which checks 
     	[v] has type [ty] *)
 let rec typecheck env ty v =
@@ -47,20 +54,22 @@ let rec typecheck env ty v =
       ] in
     (member true hd) @ (List.concat (List.map (member false) tl))
   | Array t ->
+    let id = fresh_id () in
     [
       Line (sprintf "if type(%s) <> type([]):" v);
       Block [ raise_type_error ];
-      Line (sprintf "for x in %s:" v);
-      Block (typecheck env t "x")
+      Line (sprintf "for %s in %s:" id v);
+      Block (typecheck env t id)
     ]
   | Dict (key, va) ->
+    let id = fresh_id () in
     [
       Line (sprintf "if type(%s) <> type({}):" v);
       Block [ raise_type_error ];
-      Line (sprintf "for x in %s.keys():" v);
-      Block (typecheck env (Basic key) "x");
-      Line (sprintf "for x in %s.values():" v);
-      Block (typecheck env va "x")
+      Line (sprintf "for %s in %s.keys():" id v);
+      Block (typecheck env (Basic key) id);
+      Line (sprintf "for %s in %s.values():" id v);
+      Block (typecheck env va id)
     ]
   | Name x ->
     let ident =

python/Makefile

@@ -16,3 +16,6 @@ install: build
 .PHONY: uninstall
 uninstall:
 	echo "I don't know how to uninstall python code"
+
+.PHONY: reinstall
+reinstall: install