Don't pass use_installed to every package handler function.

use_installed is a global variable (defined in febootstrap_cmdline.mli)
so there's not much point in passing it around to every function that
needs it.  This commit removes the optional argument in favour of just
using the global variable in each package handler.

However we still need a place where we can bail if the --use-installed
flag is used for package handlers which don't support this yet.

Thus add a ph_init function is called after the right package handler
has been detected but before it is used.  This is a convenient place
to put the --use-installed checking and any other initialization that
is required.

6 files changed, 40 insertions, 29 deletions

diff --git a/src/febootstrap.ml b/src/febootstrap.ml
index 3afb1bb..7e48206 100644
--- a/src/febootstrap.ml
+++ b/src/febootstrap.ml
@@ -67,7 +67,7 @@ let () =
     List.flatten (
       List.map (
         fun pkg ->
-          let files = ph.ph_list_files ~use_installed pkg in
+          let files = ph.ph_list_files pkg in
           List.map (fun (filename, ft) -> filename, ft, pkg) files
       ) packages
     ) in
@@ -320,7 +320,7 @@ let () =
        * original file from the package.
        *)
       else if config then (
-        let outfile = ph.ph_get_file_from_package ~use_installed pkg path in
+        let outfile = ph.ph_get_file_from_package pkg path in
 
         (* Note that the output config file might not be a regular file. *)
         let statbuf = lstat outfile in
diff --git a/src/febootstrap_debian.ml b/src/febootstrap_debian.ml
index e7fcffd..e4b42af 100644
--- a/src/febootstrap_debian.ml
+++ b/src/febootstrap_debian.ml
@@ -45,6 +45,9 @@ let debian_detect () =
   file_exists "/etc/debian_version" &&
     Config.aptitude <> "no" && Config.apt_cache <> "no" && Config.dpkg <> "no"
 
+let debian_init () =
+  ()
+
 let rec debian_resolve_dependencies_and_download names =
   let cmd =
     sprintf "%s depends --recurse -i %s | grep -v '^[<[:space:]]'"
@@ -191,14 +194,14 @@ let debian_list_files_installed pkg =
   ) lines in
   files
 
-let debian_list_files ?(use_installed=false) pkg =
+let debian_list_files pkg =
   if use_installed && List.exists ((=) pkg) (get_installed_pkgs ()) then
     debian_list_files_installed pkg
   else
     debian_list_files_downloaded pkg
 
 (* Easy because we already unpacked the archive above. *)
-let debian_get_file_from_package ?(use_installed=false) pkg file =
+let debian_get_file_from_package pkg file =
   if use_installed && List.exists (fun p -> p = pkg) (get_installed_pkgs ())
   then
     file
@@ -208,6 +211,7 @@ let debian_get_file_from_package ?(use_installed=false) pkg file =
 let () =
   let ph = {
     ph_detect = debian_detect;
+    ph_init = debian_init;
     ph_resolve_dependencies_and_download =
       debian_resolve_dependencies_and_download;
     ph_list_files = debian_list_files;
diff --git a/src/febootstrap_package_handlers.ml b/src/febootstrap_package_handlers.ml
index f627d2f..0d5cc72 100644
--- a/src/febootstrap_package_handlers.ml
+++ b/src/febootstrap_package_handlers.ml
@@ -24,9 +24,10 @@ open Febootstrap_cmdline
 
 type package_handler = {
   ph_detect : unit -> bool;
+  ph_init : unit -> unit;
   ph_resolve_dependencies_and_download : string list -> string list;
-  ph_list_files : ?use_installed:bool -> string -> (string * file_type) list;
-  ph_get_file_from_package : ?use_installed:bool -> string -> string -> string
+  ph_list_files : string -> (string * file_type) list;
+  ph_get_file_from_package : string -> string -> string
 }
 and file_type = {
   ft_dir : bool;
@@ -46,14 +47,15 @@ let register_package_handler name ph =
 
 let handler = ref None
 
-let check_system () =
+let rec check_system () =
   try
     handler := Some (
       List.find (
         fun (_, ph) ->
           ph.ph_detect ()
       ) !handlers
-    )
+    );
+    (get_package_handler ()).ph_init ()
   with Not_found ->
     eprintf "\
 febootstrap: could not detect package manager used by this system or distro.
@@ -65,14 +67,14 @@ then it may be that the package detection code is not working.
 ";
     exit 1
 
-let rec get_package_handler () =
+and get_package_handler () =
   match !handler with
   | Some (_, ph) -> ph
   | None ->
       check_system ();
       get_package_handler ()
 
-let rec get_package_handler_name () =
+and get_package_handler_name () =
   match !handler with
   | Some (name, _) -> name
   | None ->
diff --git a/src/febootstrap_package_handlers.mli b/src/febootstrap_package_handlers.mli
index ebf0386..88916ad 100644
--- a/src/febootstrap_package_handlers.mli
+++ b/src/febootstrap_package_handlers.mli
@@ -20,7 +20,14 @@
 
 type package_handler = {
   ph_detect : unit -> bool;
-  (** Detect if the current system uses this package manager. *)
+  (** Detect if the current system uses this package manager.  This is
+      called in turn on each package handler, until one returns [true]. *)
+
+  ph_init : unit -> unit;
+  (** After a package handler is selected, this function is called
+      which can optionally do any initialization that is required.
+      This is only called on the package handler if it has returned
+      [true] from {!ph_detect}. *)
 
   ph_resolve_dependencies_and_download : string list -> string list;
   (** [ph_resolve_dependencies_and_download pkgs]
@@ -31,11 +38,11 @@ type package_handler = {
 
       Note this should also process the [excludes] list. *)
 
-  ph_list_files : ?use_installed:bool -> string -> (string * file_type) list;
+  ph_list_files : string -> (string * file_type) list;
   (** [ph_list_files pkg] lists the files and file metadata in the
       package called [pkg] (a package file). *)
 
-  ph_get_file_from_package : ?use_installed:bool -> string -> string -> string;
+  ph_get_file_from_package : string -> string -> string;
   (** [ph_get_file_from_package pkg file] extracts the
       single named file [file] from [pkg].  The path of the
       extracted file is returned. *)
diff --git a/src/febootstrap_pacman.ml b/src/febootstrap_pacman.ml
index bd12f69..7fbb72b 100644
--- a/src/febootstrap_pacman.ml
+++ b/src/febootstrap_pacman.ml
@@ -32,6 +32,10 @@ let pacman_detect () =
   file_exists "/etc/arch-release" &&
     Config.pacman <> "no"
 
+let pacman_init () =
+  if use_installed then
+    failwith "pacman driver doesn't support --use-installed"
+
 let pacman_resolve_dependencies_and_download names =
   let cmd =
     sprintf "(for p in %s; do pactree -u $p; done) | awk '{print $1}' | sort -u"
@@ -71,10 +75,7 @@ let pacman_resolve_dependencies_and_download names =
 
   List.sort compare pkgs
 
-let pacman_list_files ?(use_installed=false) pkg =
-  if use_installed then
-    failwith "pacman driver doesn't support --use-installed";
-
+let pacman_list_files pkg =
   debug "unpacking %s ..." pkg;
 
   (* We actually need to extract the file in order to get the
@@ -119,15 +120,13 @@ let pacman_list_files ?(use_installed=false) pkg =
   files
 
 (* Easy because we already unpacked the archive above. *)
-let pacman_get_file_from_package ?(use_installed=false) pkg file =
-  if use_installed then
-    failwith "pacman driver doesn't support --use-installed";
-
+let pacman_get_file_from_package pkg file =
   tmpdir // pkg ^ ".d" // file
 
 let () =
   let ph = {
     ph_detect = pacman_detect;
+    ph_init = pacman_init;
     ph_resolve_dependencies_and_download =
       pacman_resolve_dependencies_and_download;
     ph_list_files = pacman_list_files;
diff --git a/src/febootstrap_yum_rpm.ml b/src/febootstrap_yum_rpm.ml
index 815c5ba..bfda11e 100644
--- a/src/febootstrap_yum_rpm.ml
+++ b/src/febootstrap_yum_rpm.ml
@@ -32,6 +32,10 @@ let yum_rpm_detect () =
   (file_exists "/etc/redhat-release" || file_exists "/etc/fedora-release") &&
     Config.yum <> "no" && Config.rpm <> "no"
 
+let yum_rpm_init () =
+  if use_installed then
+    failwith "yum_rpm driver doesn't support --use-installed"
+
 let yum_rpm_resolve_dependencies_and_download names =
   (* Liberate this data from python. *)
   let tmpfile = tmpdir // "names.tmp" in
@@ -172,10 +176,7 @@ if verbose:
       sprintf "%s/%s-%s-%s.%s.rpm" tmpdir name version release arch
   ) pkgs
 
-let rec yum_rpm_list_files ?(use_installed=false) pkg =
-  if use_installed then
-    failwith "yum_rpm driver doesn't support --use-installed";
-
+let rec yum_rpm_list_files pkg =
   (* Run rpm -qlp with some extra magic. *)
   let cmd =
     sprintf "rpm -q --qf '[%%{FILENAMES} %%{FILEFLAGS:fflags} %%{FILEMODES} %%{FILESIZES}\\n]' -p %s"
@@ -231,10 +232,7 @@ let rec yum_rpm_list_files ?(use_installed=false) pkg =
 
   files
 
-let yum_rpm_get_file_from_package ?(use_installed=false) pkg file =
-  if use_installed then
-    failwith "yum_rpm driver doesn't support --use-installed";
-
+let yum_rpm_get_file_from_package pkg file =
   debug "extracting %s from %s ..." file (Filename.basename pkg);
 
   let outfile = tmpdir // file in
@@ -247,6 +245,7 @@ let yum_rpm_get_file_from_package ?(use_installed=false) pkg file =
 let () =
   let ph = {
     ph_detect = yum_rpm_detect;
+    ph_init = yum_rpm_init;
     ph_resolve_dependencies_and_download =
       yum_rpm_resolve_dependencies_and_download;
     ph_list_files = yum_rpm_list_files;