From 00473c6ac09d85a6b6e1ce0cbe132e31407a2d00 Mon Sep 17 00:00:00 2001
From: Laszlo Ersek <lersek@redhat.com>
Date: Thu, 6 Jan 2022 15:09:08 +0100
Subject: [PATCH] convert/libosinfo_utils: introduce
 "string_of_osinfo_device_list"

For debugging purposes, we'll want to print the list of devices returned
by the previously introduced "osinfo_os#get_devices" method.

Format the device list as a nice table.

Bugzilla: https://bugzilla.redhat.com/show_bug.cgi?id=1942325
Signed-off-by: Laszlo Ersek <lersek@redhat.com>
Message-Id: <20220106140910.13695-8-lersek@redhat.com>
Acked-by: Richard W.M. Jones <rjones@redhat.com>
---
 convert/libosinfo_utils.ml  | 35 +++++++++++++++++++++++++++++++++++
 convert/libosinfo_utils.mli |  3 +++
 2 files changed, 38 insertions(+)

diff --git a/convert/libosinfo_utils.ml b/convert/libosinfo_utils.ml
index 1fc138cc..d5eb082b 100644
--- a/convert/libosinfo_utils.ml
+++ b/convert/libosinfo_utils.ml
@@ -42,3 +42,38 @@ let string_of_osinfo_device_driver { Libosinfo.architecture; location;
     (if signed then "signed" else "unsigned")
     priority
     (String.concat " " files)
+
+let string_of_osinfo_device_list dev_list =
+
+  (* Turn the fields of an "osinfo_device" record into a list. *)
+  let listify { Libosinfo.id; vendor; vendor_id; product; product_id; name;
+                class_; bus_type; subsystem } =
+    [ id; vendor; vendor_id; product; product_id; name;
+      class_; bus_type; subsystem ]
+
+  (* Given a list of strings, and a list of previously known maximum widths,
+   * "increase" each width, if necessary, to the length of the corresponding
+   * string.
+   *)
+  and grow_widths = List.map2 (fun s -> max (String.length s))
+  in
+
+  (* Compute the maximum width for each field in "dev_list". *)
+  let max_widths =
+    List.fold_right grow_widths (List.map listify dev_list)
+      [ 0; 0; 0; 0; 0; 0; 0; 0; 0 ]
+
+  (* Given a list of strings and a list of field widths, format "string1 |
+   * string2 | ... | stringN" such that each field is right-padded to the
+   * corresponding width.
+   *)
+  and columnate strings widths =
+    String.concat " | " (List.map2 (Printf.sprintf "%-*s") widths strings)
+  in
+
+  (* Format "dev_list" as a table by (a) printing one "osinfo_device" record
+   * per line, and (b) right-padding each field of each "osinfo_device" record
+   * to the maximum width of that field.
+   *)
+  String.concat "\n"
+    (List.map (fun dev -> columnate (listify dev) max_widths) dev_list)
diff --git a/convert/libosinfo_utils.mli b/convert/libosinfo_utils.mli
index b3714d22..5a703334 100644
--- a/convert/libosinfo_utils.mli
+++ b/convert/libosinfo_utils.mli
@@ -27,3 +27,6 @@ val get_os_by_short_id : string -> Libosinfo.osinfo_os
 
 val string_of_osinfo_device_driver : Libosinfo.osinfo_device_driver -> string
 (** Convert a [osinfo_device_driver] to a printable string for debugging. *)
+
+val string_of_osinfo_device_list : Libosinfo.osinfo_device list -> string
+(** Convert an [osinfo_device] list to a printable string for debugging. *)
-- 
2.31.1