builder: Use pxzcat (optionally) to speed up xzcat step.

README

@@ -170,6 +170,9 @@ The full requirements are described below.
 | gpg          |             | O | Used by virt-builder for digital        |
 |              |             |   | signatures                              |
 +--------------+-------------+---+-----------------------------------------+
+| pxzcat       |             | O | Can be used by virt-builder for fast    |
+|              |             |   | uncompression of templates.             |
++--------------+-------------+---+-----------------------------------------+
 | findlib      |             | O | For the OCaml bindings.                 |
 +--------------+-------------+---+-----------------------------------------+
 | ocaml-gettext|             | O | For localizing OCaml virt-* tools.      |

builder/builder.ml

@@ -301,9 +301,11 @@ let main () =
 
       output, Some size, format, delete_output_file, do_resize, true in
 
-  (* Create xzcat command to uncompress from input to output. *)
+  (* Create xzcat/pxzcat command to uncompress from input to output. *)
   let xzcat_command input output =
-    sprintf "%s %s > %s" Config.xzcat input output
+    match Config.pxzcat with
+    | None -> sprintf "%s %s > %s" Config.xzcat input output
+    | Some pxzcat -> sprintf "%s %s -o %s" pxzcat input output
   in
 
   if not do_resize then (

configure.ac

@@ -702,6 +702,9 @@ dnl Check for xzcat (required).
 AC_PATH_PROGS([XZCAT],[xzcat],[no])
 test "x$XZCAT" = "xno" && AC_MSG_ERROR([xzcat must be installed])
 
+dnl Check for pxzcat (optional).
+AC_PATH_PROGS([PXZCAT],[pxzcat],[no])
+
 dnl Check for QEMU for running binaries on this $host_cpu, fall
 dnl back to basic 'qemu'.  Allow the user to override it.
 qemu_system="$(

mllib/config.ml.in

@@ -20,3 +20,7 @@ let package_name = "@PACKAGE_NAME@"
 let package_version = "@PACKAGE_VERSION@"
 
 let xzcat = "@XZCAT@"
+let pxzcat =
+  match "@PXZCAT@" with
+  | "no" -> None
+  | path -> Some path