5:23 a.m.
On Tuesday, 3 January 2017 11:18:55 CET Cédric Bosdonnat wrote:
There is already a libosinfo reading function located in src folder
to
get the iso informations. Provide a similar but more generic function
to be used in ocaml tools.
---
I'd rather avoid duplicating the logic used for reading the osinfo-db,
especially that
a) it was touched recently to support the newer osinfo-db, the newer
internal libosinfo-db, and the old internal libosinfo-db
b) we might support more from the osinfo-db spec in the future (e.g.
OSINFO_LOCAL_DIR and OSINFO_USER_DIR), especially since they are
declared "MUST"
A way to do this could be the following (at least IMHO):
1) adapt the current C code (src/osinfo.c) to use a callback (with
void *opaque) to parse each XML file -- in short, adding a new
parameter to read_osinfo_db_xml
2) separate osinfo.c in two parts:
2.a) what reads the osinfo-db and invokes a callback
2.b) the libguestfs DB (osinfo_db, osinfo_db_size) with
read_osinfo_db_xml as callback to fill it
3) expose (2.a) to OCaml, with an implementation similar to what Rich
did recently for the visit API -- see cat/visit.c, mllib/visit-c.c,
and mllib/visit.ml
4) build & use (2.b) + (3) in virt-builder
This way we would have just the OCaml callback to read the XML file,
and just collecting the list of short-id's.
+ fun os_file ->
+ let file_path = distro_path // os_file in
+ let xml = read_whole_file file_path in
+ let doc = Xml.parse_memory xml in
Hmm I've seen this pattern already, and IMHO it's time to change it:
the Xml module needs also a parse_file method to parse an existing
file, instead of keeping it all in memory. Other users of this new
parse_file are in v2v/input_ova.ml, and
v2v/test-harness/v2v_test_harness.ml.
+let osinfo_read_db filter =
+ let path = try
+ Sys.getenv "OSINFO_SYSTEM_DIR"
+ with Not_found -> "/usr/share/osinfo" in
+
+ try osinfo_db_read_three_levels (path // "os") filter with
+ | _ ->
+ try osinfo_db_read_three_levels (osinfopath // "os") filter with
+ | _ ->
+ try osinfo_db_read_flat (osinfopath // "oses") filter with
+ | _ -> []
Note that this chain of try..with is too "coarse", and swallows also
errors which needs to be considered fatal (I/O errors, XML issues).
diff --git a/mllib/osinfo.mli b/mllib/osinfo.mli
new file mode 100644
index 000000000..4b881408e
--- /dev/null
+++ b/mllib/osinfo.mli
@@ -0,0 +1,21 @@
+(* virt-builder
+ * Copyright (C) 2016 - SUSE Inc.
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License along
+ * with this program; if not, write to the Free Software Foundation, Inc.,
+ * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
+ *)
+
+val osinfo_read_db : (Xml.xpathctx -> 'a) -> 'a list
+(** [osinfo_read_db filter] runs the [filter] function on the
+ XPath context of every osinfo os description XML file. *)
diff --git a/mllib/osinfopath.ml b/mllib/osinfopath.ml
new file mode 100644
index 000000000..a58b8d60f
--- /dev/null
+++ b/mllib/osinfopath.ml
@@ -0,0 +1 @@
+let osinfopath = "/usr/local/share/libosinfo/db"
Note that a generated file should not be in the patch, and needs to be
added to the top level .gitignore.
Thanks,
--
Pino Toscano