From 3978a308a586e3a671807eb3716ba7c7596af21f Mon Sep 17 00:00:00 2001 From: Richard Jones Date: Tue, 31 Aug 2010 17:04:52 +0100 Subject: [PATCH] ocaml: bindings to progress callback. --- ocaml/guestfs_c.c | 93 +++++++++++++++++++++++++++++++++++++++++++++++++++++-- src/generator.ml | 29 +++++++++++++++++ 2 files changed, 120 insertions(+), 2 deletions(-) diff --git a/ocaml/guestfs_c.c b/ocaml/guestfs_c.c index 71f416a..7648ba9 100644 --- a/ocaml/guestfs_c.c +++ b/ocaml/guestfs_c.c @@ -1,5 +1,5 @@ /* libguestfs - * Copyright (C) 2009 Red Hat Inc. + * Copyright (C) 2009-2010 Red Hat Inc. * * This library is free software; you can redistribute it and/or * modify it under the terms of the GNU Lesser General Public @@ -30,9 +30,14 @@ #include #include #include +#include +#include #include "guestfs_c.h" +static void clear_progress_callback (guestfs_h *g); +static void progress_callback (guestfs_h *g, void *data, int proc_nr, int serial, uint64_t position, uint64_t total); + /* This macro was added in OCaml 3.10. Backport for earlier versions. */ #ifndef CAMLreturnT #define CAMLreturnT(type, result) do{ \ @@ -45,13 +50,18 @@ /* These prototypes are solely to quiet gcc warning. */ CAMLprim value ocaml_guestfs_create (void); CAMLprim value ocaml_guestfs_close (value gv); +CAMLprim value ocaml_guestfs_set_progress_callback (value gv, value closure); +CAMLprim value ocaml_guestfs_clear_progress_callback (value gv); /* Allocate handles and deal with finalization. */ static void guestfs_finalize (value gv) { guestfs_h *g = Guestfs_val (gv); - if (g) guestfs_close (g); + if (g) { + clear_progress_callback (g); + guestfs_close (g); + } } static struct custom_operations guestfs_custom_operations = { @@ -162,3 +172,82 @@ ocaml_guestfs_free_strings (char **argv) free (argv[i]); free (argv); } + +#define PROGRESS_ROOT_KEY "_ocaml_progress_root" + +/* Guestfs.set_progress_callback */ +CAMLprim value +ocaml_guestfs_set_progress_callback (value gv, value closure) +{ + CAMLparam2 (gv, closure); + + guestfs_h *g = Guestfs_val (gv); + clear_progress_callback (g); + + value *root = guestfs_safe_malloc (g, sizeof *root); + *root = closure; + + /* XXX This global root is generational, but we cannot rely on every + * user having the OCaml 3.11 version which supports this. + */ + caml_register_global_root (root); + + guestfs_set_private (g, PROGRESS_ROOT_KEY, root); + + guestfs_set_progress_callback (g, progress_callback, root); + + CAMLreturn (Val_unit); +} + +/* Guestfs.clear_progress_callback */ +CAMLprim value +ocaml_guestfs_clear_progress_callback (value gv) +{ + CAMLparam1 (gv); + + guestfs_h *g = Guestfs_val (gv); + clear_progress_callback (g); + + CAMLreturn (Val_unit); +} + +static void +clear_progress_callback (guestfs_h *g) +{ + guestfs_set_progress_callback (g, NULL, NULL); + + value *root = guestfs_get_private (g, PROGRESS_ROOT_KEY); + if (root) { + caml_remove_global_root (root); + free (root); + guestfs_set_private (g, PROGRESS_ROOT_KEY, NULL); + } +} + +static void +progress_callback (guestfs_h *g, void *root, + int proc_nr, int serial, uint64_t position, uint64_t total) +{ + CAMLparam0 (); + CAMLlocal5 (proc_nrv, serialv, positionv, totalv, rv); + + proc_nrv = Val_int (proc_nr); + serialv = Val_int (serial); + positionv = caml_copy_int64 (position); + totalv = caml_copy_int64 (total); + + value args[4] = { proc_nrv, serialv, positionv, totalv }; + + caml_leave_blocking_section (); + rv = caml_callbackN_exn (*(value*)root, 4, args); + caml_enter_blocking_section (); + + /* Callbacks shouldn't throw exceptions. There's not much we can do + * except to print it. + */ + if (Is_exception_result (rv)) + fprintf (stderr, "libguestfs: uncaught OCaml exception in progress callback: %s", + caml_format_exception (Extract_exception (rv))); + + CAMLreturn0; +} diff --git a/src/generator.ml b/src/generator.ml index f298d2e..b2f777a 100755 --- a/src/generator.ml +++ b/src/generator.ml @@ -8930,6 +8930,28 @@ val close : t -> unit unreferenced, but callers can call this in order to provide predictable cleanup. *) +type progress_cb = int -> int -> int64 -> int64 -> unit + +val set_progress_callback : t -> progress_cb -> unit +(** [set_progress_callback g f] sets [f] as the progress callback function. + For some long-running functions, [f] will be called repeatedly + during the function with progress updates. + + The callback is [f proc_nr serial position total]. See + the description of [guestfs_set_progress_callback] in guestfs(3) + for the meaning of these four numbers. + + Note that if the closure captures a reference to the handle, + this reference will prevent the handle from being + automatically closed by the garbage collector. There are + three ways to avoid this: be careful not to capture the handle + in the closure, or use a weak reference, or call + {!Guestfs.clear_progress_callback} to remove the reference. *) + +val clear_progress_callback : t -> unit +(** [clear_progress_callback g] removes any progress callback function + associated with the handle. See {!Guestfs.set_progress_callback}. *) + "; generate_ocaml_structure_decls (); @@ -8954,6 +8976,13 @@ exception Handle_closed of string external create : unit -> t = \"ocaml_guestfs_create\" external close : t -> unit = \"ocaml_guestfs_close\" +type progress_cb = int -> int -> int64 -> int64 -> unit + +external set_progress_callback : t -> progress_cb -> unit + = \"ocaml_guestfs_set_progress_callback\" +external clear_progress_callback : t -> unit + = \"ocaml_guestfs_clear_progress_callback\" + (* Give the exceptions names, so they can be raised from the C code. *) let () = Callback.register_exception \"ocaml_guestfs_error\" (Error \"\"); -- 1.8.3.1