[libvirt] [PATCH] qemu_driver.c: factor out more duplication

[Jim Meyering]

Charles Duffy wrote:
>>From 3c4f6568623ed420a9e71da33b9ce74abda289a8 Mon Sep 17 00:00:00 2001
> From: Charles Duffy <Charles_Duffy at dell.com>
> Date: Wed, 9 Sep 2009 15:53:25 -0500
> Subject: [PATCH] Reintroduce support for lzop compression
>
> lzop was removed due to some confusion over whether it provided functional
> advantages distinct from xz. This has been addressed in the mailing list post
> archived at http://permalink.gmane.org/gmane.comp.emulators.libvirt/16487, and
> support for lzop is re-added here.
>
> lzop is added to the enum after xz, leaving xz at the position lzma was
> originally in (which is appropriate, as it should handle decompression of
> lzma-format files) and giving lzop back its prior position.
>
> Documentation in qemu.conf is amended to remove references to lzma and add
> suggestions regarding the tradeoffs made by various compressors.
>
> Signed-off-by: Charles Duffy <charles at dyfis.net>
> ---
>  libvirt.spec.in   |    1 +
>  src/qemu.conf     |    7 ++++---
>  src/qemu_driver.c |    9 ++++++---
>  3 files changed, 11 insertions(+), 6 deletions(-)
...
>  struct qemud_save_header {
>      char magic[sizeof(QEMUD_SAVE_MAGIC)-1];
> @@ -4384,6 +4385,8 @@ static int qemudDomainRestore(virConnectPtr conn,
>              intermediate_argv[0] = "bzip2";
>          else if (header.compressed == QEMUD_SAVE_FORMAT_XZ)
>              intermediate_argv[0] = "xz";
> +        else if (header.compressed == QEMUD_SAVE_FORMAT_LZOP)
> +            intermediate_argv[0] = "lzop";
>          else if (header.compressed != QEMUD_SAVE_FORMAT_RAW) {
>              qemudReportError(conn, NULL, NULL, VIR_ERR_OPERATION_FAILED,
>                               _("Unknown compressed save format %d"),

Thanks for that patch.
I'm glad I read it, since it made me realize my clean-up
from yesterday was incomplete.  You should not have had to add
the literal, "lzop", in two places.

This completes the job:

>From 05b3f087b7ac29cebd22dfdf099f8fb36a31c86a Mon Sep 17 00:00:00 2001
From: Jim Meyering <meyering at redhat.com>
Date: Thu, 10 Sep 2009 11:26:00 +0200
Subject: [PATCH] qemu_driver.c: factor out more duplication

* src/qemu_driver.c (qemudDomainRestore): Use the new ...TypeToString
function here, too.

(qemudSaveCompressionTypeToString): Declare.
---
 src/qemu_driver.c |   18 +++++++-----------
 1 files changed, 7 insertions(+), 11 deletions(-)

diff --git a/src/qemu_driver.c b/src/qemu_driver.c
index 5c2a8ec..256e8e7 100644
--- a/src/qemu_driver.c
+++ b/src/qemu_driver.c
@@ -4379,21 +4379,17 @@ static int qemudDomainRestore(virConnectPtr conn,

     if (header.version == 2) {
         const char *intermediate_argv[3] = { NULL, "-dc", NULL };
-        if (header.compressed == QEMUD_SAVE_FORMAT_GZIP)
-            intermediate_argv[0] = "gzip";
-        else if (header.compressed == QEMUD_SAVE_FORMAT_BZIP2)
-            intermediate_argv[0] = "bzip2";
-        else if (header.compressed == QEMUD_SAVE_FORMAT_XZ)
-            intermediate_argv[0] = "xz";
-        else if (header.compressed == QEMUD_SAVE_FORMAT_LZOP)
-            intermediate_argv[0] = "lzop";
-        else if (header.compressed != QEMUD_SAVE_FORMAT_RAW) {
+        const char *prog = qemudSaveCompressionTypeToString(header.compressed);
+        if (prog == NULL) {
             qemudReportError(conn, NULL, NULL, VIR_ERR_OPERATION_FAILED,
-                             _("Unknown compressed save format %d"),
+                             _("Invalid compressed save format %d"),
                              header.compressed);
             goto cleanup;
         }
-        if (intermediate_argv[0] != NULL) {
+
+        if (header.compressed != QEMUD_SAVE_FORMAT_RAW)
+            intermediate_argv[0] = prog;
+        else {
             intermediatefd = fd;
             fd = -1;
             if (virExec(conn, intermediate_argv, NULL, NULL,
--
1.6.5.rc0.164.g5f6b0