+++ /dev/null
-(* This is a virtual machine graphical viewer tool.
- * Written by Richard W.M. Jones, Sept. 2009.
- *
- * It demonstrates some complex programming techniques: OCaml, Gtk+,
- * threads, and use of both libguestfs and libvirt from threads.
- *
- * You will need the following installed in order to compile it:
- * - ocaml (http://caml.inria.fr/)
- * - ocamlfind (http://projects.camlcity.org/projects/findlib.html/)
- * - extlib (http://code.google.com/p/ocaml-extlib/)
- * - lablgtk2 (http://wwwfun.kurims.kyoto-u.ac.jp/soft/lsl/lablgtk.html
- * - xml-light (http://tech.motion-twin.com/xmllight.html)
- * - cduce and ocamlduce (http://cduce.org/)
- * - ocaml-libvirt (http://libvirt.org/ocaml)
- * - ocaml-libguestfs
- *
- * Note that most/all of these are available as packages via Fedora,
- * Debian, Ubuntu or GODI. You won't need to compile them from source.
- *
- * You will also need to configure libguestfs:
- * ./configure --enable-ocaml-viewer
- *
- * All programs in the ocaml/examples subdirectory, including this
- * one, may be freely copied without any restrictions.
- *)
-
-(* Architecturally, there is one main thread which does all the Gtk
- * calls, and one slave thread which executes all libguestfs and
- * libvirt calls. The main thread sends commands to the slave thread,
- * which are delivered in a queue and acted on in sequence. Responses
- * are delivered back to the main thread as commands finish.
- *
- * The commands are just OCaml objects (type: Slave.command). The
- * queue of commands is an OCaml Queue. The responses are sent by adding
- * idle events to the glib main loop[1].
- *
- * If a command fails, it causes the input queue to be cleared. In
- * this case, a failure response is sent to the main loop which
- * causes the display to be reset and possibly an error message to
- * be shown.
- *
- * The global variables [conn], [dom] and [g] are the libvirt
- * connection, current domain, and libguestfs handle respectively.
- * Because these can be accessed by both threads, they are
- * protected from the main thread by access methods which
- * (a) prevent the main thread from using them unlocked, and
- * (b) prevent the main thread from doing arbitrary / long-running
- * operations on them (the main thread must send a command instead).
- *
- * [1] http://library.gnome.org/devel/gtk-faq/stable/x499.html
- *)
-
-open Printf
-open ExtList
-
-let (//) = Filename.concat
-
-(* Short names for commonly used modules. *)
-module C = Libvirt.Connect
-module Cd = Condition
-module D = Libvirt.Domain
-module G = Guestfs
-module M = Mutex
-module Q = Queue
-
-let verbose = ref false (* Verbose mode. *)
-
-let debug fs =
- let f str = if !verbose then ( prerr_string str; prerr_newline () ) in
- ksprintf f fs
-
-(*----------------------------------------------------------------------*)
-(* Slave thread. The signature describes what operations the main
- * thread can perform, and protects the locked internals of the
- * slave thread.
- *)
-module Slave : sig
- type 'a callback = 'a -> unit
-
- type partinfo = {
- pt_name : string; (** device / LV name *)
- pt_size : int64; (** in bytes *)
- pt_content : string; (** the output of the 'file' command *)
- pt_statvfs : G.statvfs option; (** None if not mountable *)
- }
-
- val no_callback : 'a callback
- (** Use this as the callback if you don't want a callback. *)
-
- val set_failure_callback : exn callback -> unit
- (** Set the function that is called in the main thread whenever
- there is a command failure in the slave. The command queue
- is cleared before this is sent. [exn] is the exception
- associated with the failure. *)
-
- val set_busy_callback : [`Busy|`Idle] callback -> unit
- (** Set the function that is called in the main thread whenever
- the slave thread goes busy or idle. *)
-
- val exit_thread : unit -> unit
- (** [exit_thread ()] causes the slave thread to exit. *)
-
- val connect : string option -> string option callback -> unit
- (** [connect uri cb] connects to libvirt [uri], and calls [cb]
- if it completes successfully. Any previous connection is
- automatically cleaned up and disconnected. *)
-
- val get_domains : string list callback -> unit
- (** [get_domains cb] gets the list of active domains from libvirt,
- and calls [cb domains] with the names of those domains. *)
-
- val open_domain : string -> partinfo list callback -> unit
- (** [open_domain dom cb] sets the domain [dom] as the current
- domain, and launches a libguestfs handle for it. Any previously
- current domain and libguestfs handle is closed. Once the
- libguestfs handle is opened (which usually takes some time),
- callback [cb] is called with the list of partitions found
- in the guest. *)
-
- val slave_loop : unit -> unit
- (** The slave thread's main loop, running in the slave thread. *)
-
-end = struct
- type partinfo = {
- pt_name : string;
- pt_size : int64;
- pt_content : string;
- pt_statvfs : G.statvfs option;
- }
-
- (* Commands sent by the main thread to the slave thread. When
- * [cmd] is successfully completed, [callback] will be delivered
- * (in the main thread). If [cmd] fails, then the global error
- * callback will be delivered in the main thread.
- *)
- type command =
- | Exit_thread
- | Connect of string option * string option callback
- | Get_domains of string list callback
- | Open_domain of string * partinfo list callback
- and 'a callback = 'a -> unit
-
- let string_of_command = function
- | Exit_thread -> "Exit_thread"
- | Connect (None, _) -> "Connect [no uri]"
- | Connect (Some uri, _) -> "Connect " ^ uri
- | Get_domains _ -> "Get_domains"
- | Open_domain (name, _) -> "Open_domain " ^ name
-
- let no_callback _ = ()
-
- let failure_cb = ref (fun _ -> ())
- let set_failure_callback cb = failure_cb := cb
-
- let busy_cb = ref (fun _ -> ())
- let set_busy_callback cb = busy_cb := cb
-
- (* Execute a function, while holding a mutex. If the function
- * fails, ensure we release the mutex before rethrowing the
- * exception.
- *)
- type ('a, 'b) choice = Either of 'a | Or of 'b
- let with_lock m f =
- M.lock m;
- let r = try Either (f ()) with exn -> Or exn in
- M.unlock m;
- match r with
- | Either r -> r
- | Or exn -> raise exn
-
- let q = Q.create () (* queue of commands *)
- let q_lock = M.create ()
- let q_cond = Cd.create ()
-
- (* Send a command message to the slave thread. *)
- let send_to_slave c =
- debug "sending to slave: %s" (string_of_command c);
- with_lock q_lock (
- fun () ->
- Q.push c q;
- Cd.signal q_cond
- )
-
- let exit_thread () =
- with_lock q_lock (fun () -> Q.clear q);
- send_to_slave Exit_thread
-
- let connect uri cb =
- send_to_slave (Connect (uri, cb))
-
- let get_domains cb =
- send_to_slave (Get_domains cb)
-
- let open_domain dom cb =
- send_to_slave (Open_domain (dom, cb))
-
- (* These are not protected by a mutex because we don't allow
- * any references to these objects to escape from the slave
- * thread.
- *)
- let conn = ref None (* libvirt connection *)
- let dom = ref None (* libvirt domain *)
- let g = ref None (* libguestfs handle *)
-
- let quit = ref false
-
- let rec slave_loop () =
- debug "Slave.slave_loop: waiting for a command";
- let c =
- with_lock q_lock (
- fun () ->
- while Q.is_empty q do
- Cd.wait q_cond q_lock
- done;
- Q.pop q
- ) in
-
- (try
- debug "Slave.slave_loop: executing: %s" (string_of_command c);
- !busy_cb `Busy;
- exec_command c;
- !busy_cb `Idle;
- debug "Slave.slave_loop: command succeeded";
- with exn ->
- (* If an exception is thrown, it means the command failed. In
- * this case we clear the command queue and deliver the failure
- * callback in the main thread.
- *)
- debug "Slave.slave_loop: command failed";
-
- !busy_cb `Idle;
- with_lock q_lock (fun () -> Q.clear q);
- GtkThread.async !failure_cb exn
- );
-
- if !quit then Thread.exit ();
- slave_loop ()
-
- and exec_command = function
- | Exit_thread ->
- quit := true; (* quit first in case disconnect_all throws an exn *)
- disconnect_all ()
-
- | Connect (name, cb) ->
- disconnect_all ();
- conn := Some (C.connect_readonly ?name ());
- cb name
-
- | Get_domains cb ->
- let conn = Option.get !conn in
- let doms = D.get_domains conn [D.ListAll] in
- (* Only return the names, so that the libvirt objects
- * aren't leaked outside the slave thread.
- *)
- let doms = List.map D.get_name doms in
- cb doms
-
- | Open_domain (domname, cb) ->
- let conn = Option.get !conn in
- disconnect_dom ();
- dom := Some (D.lookup_by_name conn domname);
- let dom = Option.get !dom in
-
- (* Get the devices. *)
- let xml = D.get_xml_desc dom in
- let devs = get_devices_from_xml xml in
-
- (* Create the libguestfs handle and launch it. *)
- let g' = G.create () in
- List.iter (G.add_drive_ro g') devs;
- G.launch g';
- g := Some g';
-
- (* Get the list of partitions. *)
- let parts = Array.to_list (G.list_partitions g') in
- (* Remove any which are PVs. *)
- let pvs = Array.to_list (G.pvs g') in
- let parts = List.filter (fun part -> not (List.mem part pvs)) parts in
- let lvs = Array.to_list (G.lvs g') in
- let parts = parts @ lvs in
-
- let parts = List.map (
- fun part ->
- (* Find out the size of each partition. *)
- let size = G.blockdev_getsize64 g' part in
-
- (* Find out what's on each partition. *)
- let content = G.file g' part in
-
- (* Try to mount it. *)
- let statvfs =
- try
- G.mount_ro g' part "/";
- Some (G.statvfs g' "/")
- with _ -> None in
- G.umount_all g';
-
- { pt_name = part; pt_size = size; pt_content = content;
- pt_statvfs = statvfs }
- ) parts in
-
- (* Call the callback. *)
- cb parts
-
- (* Close all libvirt/libguestfs handles. *)
- and disconnect_all () =
- disconnect_dom ();
- (match !conn with Some conn -> C.close conn | None -> ());
- conn := None
-
- (* Close dom and libguestfs handles. *)
- and disconnect_dom () =
- (match !g with Some g -> G.close g | None -> ());
- g := None;
- (match !dom with Some dom -> D.free dom | None -> ());
- dom := None
-
- and get_devices_from_xml xml =
- (* Lengthy discussion of the merits or otherwise of this code here:
- * http://groups.google.com/group/fa.caml/browse_thread/thread/48e05d49b0f21b8a/5296bceb31ebfff3
- *)
- let xml = Xmllight_loader.from_string xml in
- let xs = {{ [xml] }} in
- let xs = {{ (((xs.(<domain..>_)) / .(<devices..>_)) / .(<disk..>_)) / }} in
- let xs = {{ map xs with
- | <source dev=(Latin1 & s) ..>_
- | <source file=(Latin1 & s) ..>_ -> [s]
- | _ -> [] }} in
- {: xs :}
-end
-(* End of slave thread code. *)
-(*----------------------------------------------------------------------*)
-
-(* Display state. *)
-type display_state = {
- window : GWindow.window;
- vmlist_set : string list -> unit;
- throbber_set : [`Busy|`Idle] -> unit;
- da : GMisc.drawing_area;
- draw : GDraw.drawable;
- drawing_area_repaint : unit -> unit;
- set_statusbar : string -> unit;
- clear_statusbar : unit -> unit;
- pango_large_context : GPango.context_rw;
- pango_small_context : GPango.context_rw;
-}
-
-(* This is called in the main thread whenever a command fails in the
- * slave thread. The command queue has been cleared before this is
- * called, so our job here is to reset the main window, and if
- * necessary to turn the exception into an error message.
- *)
-let failure ds exn =
- let title = "Error" in
- let msg = Printexc.to_string exn in
- debug "failure callback: %s" msg;
- let icon = GMisc.image () in
- icon#set_stock `DIALOG_ERROR;
- icon#set_icon_size `DIALOG;
- GToolbox.message_box ~title ~icon msg
-
-(* This is called in the main thread when the slave thread transitions
- * to busy or idle.
- *)
-let busy ds state = ds.throbber_set state
-
-(* Main window and callbacks from menu etc. *)
-let main_window opened_domain repaint =
- let window_title = "Virtual machine graphical viewer" in
- let window = GWindow.window ~width:800 ~height:600 ~title:window_title () in
- let vbox = GPack.vbox ~packing:window#add () in
-
- (* Do the menus. *)
- let menubar = GMenu.menu_bar ~packing:vbox#pack () in
- let factory = new GMenu.factory menubar in
- let accel_group = factory#accel_group in
- let connect_menu = factory#add_submenu "_Connect" in
-
- let factory = new GMenu.factory connect_menu ~accel_group in
- let quit_item = factory#add_item "E_xit" ~key:GdkKeysyms._Q in
-
- (* Quit. *)
- let quit _ = GMain.quit (); false in
- ignore (window#connect#destroy ~callback:GMain.quit);
- ignore (window#event#connect#delete ~callback:quit);
- ignore (quit_item#connect#activate
- ~callback:(fun () -> ignore (quit ()); ()));
-
- (* Top status area. *)
- let hbox = GPack.hbox ~border_width:4 ~packing:vbox#pack () in
- ignore (GMisc.label ~text:"Guest: " ~packing:hbox#pack ());
-
- (* List of VMs. *)
- let vmcombo = GEdit.combo_box_text ~packing:hbox#pack () in
- let vmlist_set names =
- let combo, (model, column) = vmcombo in
- model#clear ();
- List.iter (
- fun name ->
- let row = model#append () in
- model#set ~row ~column name
- ) names
- in
-
- (* Throbber, http://faq.pygtk.org/index.py?req=show&file=faq23.037.htp *)
- let static = Throbber.static () in
- (*let animation = Throbber.animation () in*)
- let throbber =
- GMisc.image ~pixbuf:static ~packing:(hbox#pack ~from:`END) () in
- let throbber_set = function
- | `Busy -> (*throbber#set_pixbuf animation*)
- (* Workaround because no binding for GdkPixbufAnimation: *)
- let file = Filename.dirname Sys.argv.(0) // "Throbber.gif" in
- throbber#set_file file
- | `Idle -> throbber#set_pixbuf static
- in
-
- (* Drawing area. *)
- let da = GMisc.drawing_area ~packing:(vbox#pack ~expand:true ~fill:true) () in
- da#misc#realize ();
- let draw = new GDraw.drawable da#misc#window in
- window#set_geometry_hints ~min_size:(80,80) (da :> GObj.widget);
-
- (* Calling this can be used to force a redraw of the drawing area. *)
- let drawing_area_repaint () = GtkBase.Widget.queue_draw da#as_widget in
-
- (* Pango contexts used to draw large and small text. *)
- let pango_large_context = da#misc#create_pango_context in
- pango_large_context#set_font_description (Pango.Font.from_string "Sans 12");
- let pango_small_context = da#misc#create_pango_context in
- pango_small_context#set_font_description (Pango.Font.from_string "Sans 8");
-
- (* Status bar at the bottom of the screen. *)
- let set_statusbar =
- let statusbar = GMisc.statusbar ~packing:vbox#pack () in
- let context = statusbar#new_context ~name:"Standard" in
- ignore (context#push window_title);
- fun msg ->
- context#pop ();
- ignore (context#push msg)
- in
- let clear_statusbar () = set_statusbar "" in
-
- (* Display the window and enter Gtk+ main loop. *)
- window#show ();
- window#add_accel_group accel_group;
-
- (* display_state which is threaded through all the other callbacks,
- * allowing callbacks to update the window.
- *)
- let ds =
- { window = window; vmlist_set = vmlist_set; throbber_set = throbber_set;
- da = da; draw = draw; drawing_area_repaint = drawing_area_repaint;
- set_statusbar = set_statusbar; clear_statusbar = clear_statusbar;
- pango_large_context = pango_large_context;
- pango_small_context = pango_small_context; } in
-
- (* Set up some callbacks which require access to the display_state. *)
- ignore (
- let combo, (model, column) = vmcombo in
- combo#connect#changed
- ~callback:(
- fun () ->
- match combo#active_iter with
- | None -> ()
- | Some row ->
- let name = model#get ~row ~column in
- ds.set_statusbar (sprintf "Opening %s ..." name);
- Slave.open_domain name (opened_domain ds))
- );
-
- ignore (da#event#connect#expose ~callback:(repaint ds));
-
- ds
-
-(* Partition info for the current domain, if one is loaded. *)
-let parts = ref None
-
-(* This is called in the main thread when we've connected to libvirt. *)
-let rec connected ds uri =
- debug "connected callback";
- let msg =
- match uri with
- | None -> "Connected to libvirt"
- | Some uri -> sprintf "Connected to %s" uri in
- ds.set_statusbar msg;
- Slave.get_domains (got_domains ds)
-
-(* This is called in the main thread when we've got the list of domains. *)
-and got_domains ds doms =
- debug "got_domains callback: (%s)" (String.concat " " doms);
- ds.vmlist_set doms
-
-(* This is called when we have opened a domain. *)
-and opened_domain ds parts' =
- debug "opened_domain callback";
- ds.clear_statusbar ();
- parts := Some parts';
- ds.drawing_area_repaint ()
-
-and repaint ds _ =
- (match !parts with
- | None -> ()
- | Some parts ->
- real_repaint ds parts
- );
- false
-
-and real_repaint ds parts =
- let width, height = ds.draw#size in
- ds.draw#set_background `WHITE;
- ds.draw#set_foreground `WHITE;
- ds.draw#rectangle ~x:0 ~y:0 ~width ~height ~filled:true ();
-
- let sum = List.fold_left Int64.add 0L in
- let totsize = sum (List.map (fun { Slave.pt_size = size } -> size) parts) in
-
- let scale = (float height -. 16.) /. Int64.to_float totsize in
-
- (* Calculate the height in pixels of each partition, if we were to
- * display it at a true relative size.
- *)
- let parts =
- List.map (
- fun ({ Slave.pt_size = size } as part) ->
- let h = scale *. Int64.to_float size in
- (h, part)
- ) parts in
-
- (*
- if !verbose then (
- eprintf "real_repaint: before borrowing:\n";
- List.iter (
- fun (h, part) ->
- eprintf "%s\t%g pix\n" part.Slave.pt_name h
- ) parts
- );
- *)
-
- (* Now adjust the heights of small partitions so they "borrow" some
- * height from the larger partitions.
- *)
- let min_h = 32. in
- let rec borrow needed = function
- | [] -> 0., []
- | (h, part) :: parts ->
- let spare = h -. min_h in
- if spare >= needed then (
- needed, (h -. needed, part) :: parts
- ) else if spare > 0. then (
- let needed = needed -. spare in
- let spare', parts = borrow needed parts in
- spare +. spare', (h -. spare, part) :: parts
- ) else (
- let spare', parts = borrow needed parts in
- spare', (h, part) :: parts
- )
- in
- let rec loop = function
- | parts, [] -> List.rev parts
- | prev, ((h, part) :: parts) ->
- let needed = min_h -. h in
- let h, prev, parts =
- if needed > 0. then (
- (* Find some spare height in a succeeding partition(s). *)
- let spare, parts = borrow needed parts in
- (* Or if not, in a preceeding partition(s). *)
- let spare, prev =
- if spare = 0. then borrow needed prev else spare, prev in
- h +. spare, prev, parts
- ) else (
- h, prev, parts
- ) in
- loop (((h, part) :: prev), parts)
- in
- let parts = loop ([], parts) in
-
- (*
- if !verbose then (
- eprintf "real_repaint: after borrowing:\n";
- List.iter (
- fun (h, part) ->
- eprintf "%s\t%g pix\n" part.Slave.pt_name h
- ) parts
- );
- *)
-
- (* Calculate the proportion space used in each partition. *)
- let parts = List.map (
- fun (h, part) ->
- let used =
- match part.Slave.pt_statvfs with
- | None -> 0.
- | Some { G.bavail = bavail; blocks = blocks } ->
- let num = Int64.to_float (Int64.sub blocks bavail) in
- let denom = Int64.to_float blocks in
- num /. denom in
- (h, used, part)
- ) parts in
-
- (* Draw it. *)
- ignore (
- List.fold_left (
- fun y (h, used, part) ->
- (* This partition occupies pixels 8+y .. 8+y+h-1 *)
- let yb = 8 + int_of_float y
- and yt = 8 + int_of_float (y +. h) in
-
- ds.draw#set_foreground `WHITE;
- ds.draw#rectangle ~x:8 ~y:yb ~width:(width-16) ~height:(yt-yb)
- ~filled:true ();
-
- let col =
- if used < 0.6 then `NAME "grey"
- else if used < 0.8 then `NAME "pink"
- else if used < 0.9 then `NAME "hot pink"
- else `NAME "red" in
- ds.draw#set_foreground col;
- let w = int_of_float (used *. (float width -. 16.)) in
- ds.draw#rectangle ~x:8 ~y:yb ~width:w ~height:(yt-yb) ~filled:true ();
-
- ds.draw#set_foreground `BLACK;
- ds.draw#rectangle ~x:8 ~y:yb ~width:(width-16) ~height:(yt-yb) ();
-
- (* Large text - the device name. *)
- let txt = ds.pango_large_context#create_layout in
- Pango.Layout.set_text txt part.Slave.pt_name;
- let fore = `NAME "dark slate grey" in
- ds.draw#put_layout ~x:12 ~y:(yb+4) ~fore txt;
-
- let { Pango.height = txtheight; Pango.width = txtwidth } =
- Pango.Layout.get_pixel_extent txt in
-
- (* Small text below - the content. *)
- let txt = ds.pango_small_context#create_layout in
- Pango.Layout.set_text txt part.Slave.pt_content;
- let fore = `BLACK in
- ds.draw#put_layout ~x:12 ~y:(yb+4+txtheight) ~fore txt;
-
- (* Small text right - size. *)
- let size =
- match part.Slave.pt_statvfs with
- | None -> printable_size part.Slave.pt_size
- | Some { G.blocks = blocks; bsize = bsize } ->
- let bytes = Int64.mul blocks bsize in
- let pc = 100. *. used in
- sprintf "%s (%.1f%% used)" (printable_size bytes) pc in
- let txt = ds.pango_small_context#create_layout in
- Pango.Layout.set_text txt size;
- ds.draw#put_layout ~x:(16+txtwidth) ~y:(yb+4) ~fore txt;
-
- (y +. h)
- ) 0. parts
- )
-
-and printable_size bytes =
- if bytes < 16_384L then sprintf "%Ld bytes" bytes
- else if bytes < 16_777_216L then
- sprintf "%Ld KiB" (Int64.div bytes 1024L)
- else if bytes < 17_179_869_184L then
- sprintf "%Ld MiB" (Int64.div bytes 1_048_576L)
- else
- sprintf "%Ld GiB" (Int64.div bytes 1_073_741_824L)
-
-let default_uri = ref ""
-
-let argspec = Arg.align [
- "-verbose", Arg.Set verbose, "Verbose mode";
- "-connect", Arg.Set_string default_uri, "Connect to libvirt URI";
-]
-
-let anon_fun _ =
- failwith (sprintf "%s: unknown command line argument"
- (Filename.basename Sys.executable_name))
-
-let usage_msg =
- sprintf "\
-
-%s: graphical virtual machine disk usage viewer
-
-Options:"
- (Filename.basename Sys.executable_name)
-
-let main () =
- Arg.parse argspec anon_fun usage_msg;
-
- (* Start up the slave thread. *)
- let slave = Thread.create Slave.slave_loop () in
-
- (* Set up the display. *)
- let ds = main_window opened_domain repaint in
-
- Slave.set_failure_callback (failure ds);
- Slave.set_busy_callback (busy ds);
- let uri = match !default_uri with "" -> None | s -> Some s in
- Slave.connect uri (connected ds);
-
- (* Run the main thread. When this returns, the application has been closed. *)
- GtkThread.main ();
-
- (* Tell the slave thread to exit and wait for it to do so. *)
- Slave.exit_thread ();
- Thread.join slave
-
-let () =
- main ()
git.annexia.org / libguestfs.git / commitdiff
