diff mbox

qemu-img: sort block formats in help message

Message ID 1399997268-9889-1-git-send-email-ncmike@ncultra.org
State New
Headers show

Commit Message

Mike D. Day May 13, 2014, 4:07 p.m. UTC 
The help message for qemu-img lists the supported block formats, of
which there are 27 as of version 2.0.50. The formats are printed in
the order of their driver's position in a linked list, which appears
random. This patch prints the formats in sorted order, making it
easier to read and to find a specific format in the list.

[Added suggestions from Fam Zheng <famz@redhat.com> to declare variables
at the top of the scope in help() and to omit explicit cast for void*
opaque.
--Stefan]

[Removed call to g_sequence_lookup because it breaks the build on
 machines with glib < 2.28.
--Mike]

Signed-off-by: Mike Day <ncmike@ncultra.org>
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
---
 qemu-img.c | 25 ++++++++++++++++++++++---
 1 file changed, 22 insertions(+), 3 deletions(-)

Comments

Markus Armbruster May 13, 2014, 5:48 p.m. UTC | #1 
Mike Day <ncmike@ncultra.org> writes:

> The help message for qemu-img lists the supported block formats, of
> which there are 27 as of version 2.0.50. The formats are printed in
> the order of their driver's position in a linked list, which appears
> random. This patch prints the formats in sorted order, making it
> easier to read and to find a specific format in the list.

Patch revision notes like these

> [Added suggestions from Fam Zheng <famz@redhat.com> to declare variables
> at the top of the scope in help() and to omit explicit cast for void*
> opaque.
> --Stefan]
>
> [Removed call to g_sequence_lookup because it breaks the build on
>  machines with glib < 2.28.
> --Mike]
>
> Signed-off-by: Mike Day <ncmike@ncultra.org>
> Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
> ---

... go here, below the '---'.

Furthermore, your previous patch went in already.  We need an
incremental patch to get rid of the dependency on non-ancient glib.
Kevin Wolf May 14, 2014, 7:50 a.m. UTC | #2 
Am 13.05.2014 um 18:07 hat Mike Day geschrieben:
> The help message for qemu-img lists the supported block formats, of
> which there are 27 as of version 2.0.50. The formats are printed in
> the order of their driver's position in a linked list, which appears
> random. This patch prints the formats in sorted order, making it
> easier to read and to find a specific format in the list.
> 
> [Added suggestions from Fam Zheng <famz@redhat.com> to declare variables
> at the top of the scope in help() and to omit explicit cast for void*
> opaque.
> --Stefan]
> 
> [Removed call to g_sequence_lookup because it breaks the build on
>  machines with glib < 2.28.
> --Mike]
> 
> Signed-off-by: Mike Day <ncmike@ncultra.org>
> Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>

What happened here? This patch seems to be already applied, and you
included Stefan's SoB as well.

Kevin
Fam Zheng May 14, 2014, 8:09 a.m. UTC | #3 
On Wed, 05/14 09:50, Kevin Wolf wrote:
> Am 13.05.2014 um 18:07 hat Mike Day geschrieben:
> > The help message for qemu-img lists the supported block formats, of
> > which there are 27 as of version 2.0.50. The formats are printed in
> > the order of their driver's position in a linked list, which appears
> > random. This patch prints the formats in sorted order, making it
> > easier to read and to find a specific format in the list.
> > 
> > [Added suggestions from Fam Zheng <famz@redhat.com> to declare variables
> > at the top of the scope in help() and to omit explicit cast for void*
> > opaque.
> > --Stefan]
> > 
> > [Removed call to g_sequence_lookup because it breaks the build on
> >  machines with glib < 2.28.
> > --Mike]
> > 
> > Signed-off-by: Mike Day <ncmike@ncultra.org>
> > Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
> 
> What happened here? This patch seems to be already applied, and you
> included Stefan's SoB as well.
> 

Mike, please fix on top of current master, instead of squashing the removing of
g_sequence_lookup into your already merged patch.

Fam
Stefan Hajnoczi May 14, 2014, 1:02 p.m. UTC | #4 
On Wed, May 14, 2014 at 04:09:14PM +0800, Fam Zheng wrote:
> On Wed, 05/14 09:50, Kevin Wolf wrote:
> > Am 13.05.2014 um 18:07 hat Mike Day geschrieben:
> > > The help message for qemu-img lists the supported block formats, of
> > > which there are 27 as of version 2.0.50. The formats are printed in
> > > the order of their driver's position in a linked list, which appears
> > > random. This patch prints the formats in sorted order, making it
> > > easier to read and to find a specific format in the list.
> > > 
> > > [Added suggestions from Fam Zheng <famz@redhat.com> to declare variables
> > > at the top of the scope in help() and to omit explicit cast for void*
> > > opaque.
> > > --Stefan]
> > > 
> > > [Removed call to g_sequence_lookup because it breaks the build on
> > >  machines with glib < 2.28.
> > > --Mike]
> > > 
> > > Signed-off-by: Mike Day <ncmike@ncultra.org>
> > > Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
> > 
> > What happened here? This patch seems to be already applied, and you
> > included Stefan's SoB as well.
> > 
> 
> Mike, please fix on top of current master, instead of squashing the removing of
> g_sequence_lookup into your already merged patch.

Yes, we cannot change the git commit history once a commit is in the
public qemu.git repository.  The only options are to:

1. Add a patch on top that fixes the issue.
2. Use git-revert(1) to undo your commit entirely (this adds a new patch
   on top the applies the reverse diff).

In this case #1 seems like a good choice.

Stefan
Mike D. Day May 14, 2014, 1:28 p.m. UTC | #5 
On Wed, May 14, 2014 at 9:02 AM, Stefan Hajnoczi <stefanha@gmail.com> wrote:
> Yes, we cannot change the git commit history once a commit is in the
> public qemu.git repository.  The only options are to:
>
> 1. Add a patch on top that fixes the issue.
> 2. Use git-revert(1) to undo your commit entirely (this adds a new patch
>    on top the applies the reverse diff).
>
> In this case #1 seems like a good choice.

I followed your advice and went with #1, I think its already been pulled.

Mike
diff mbox

Patch

diff --git a/qemu-img.c b/qemu-img.c
index 96f4463..93e51d1 100644
--- a/qemu-img.c
+++ b/qemu-img.c
@@ -32,6 +32,7 @@ 
 #include "block/block_int.h"
 #include "block/qapi.h"
 #include <getopt.h>
+#include <glib.h>
 
 #define QEMU_IMG_VERSION "qemu-img version " QEMU_VERSION \
                           ", Copyright (c) 2004-2008 Fabrice Bellard\n"
@@ -55,9 +56,22 @@  typedef enum OutputFormat {
 #define BDRV_O_FLAGS BDRV_O_CACHE_WB
 #define BDRV_DEFAULT_CACHE "writeback"
 
-static void format_print(void *opaque, const char *name)
+static gint compare_data(gconstpointer a, gconstpointer b, gpointer user)
 {
-    printf(" %s", name);
+    return g_strcmp0(a, b);
+}
+
+static void print_format(gpointer data, gpointer user)
+{
+    printf(" %s", (char *)data);
+}
+
+static void add_format_to_seq(void *opaque, const char *fmt_name)
+{
+    GSequence *seq = opaque;
+
+    g_sequence_insert_sorted(seq, (gpointer)fmt_name,
+                             compare_data, NULL);
 }
 
 static void QEMU_NORETURN GCC_FMT_ATTR(1, 2) error_exit(const char *fmt, ...)
@@ -142,10 +156,15 @@  static void QEMU_NORETURN help(void)
            "  '-f' first image format\n"
            "  '-F' second image format\n"
            "  '-s' run in Strict mode - fail on different image size or sector allocation\n";
+    GSequence *seq;
 
     printf("%s\nSupported formats:", help_msg);
-    bdrv_iterate_format(format_print, NULL);
+    seq = g_sequence_new(NULL);
+    bdrv_iterate_format(add_format_to_seq, seq);
+    g_sequence_foreach(seq, print_format, NULL);
     printf("\n");
+    g_sequence_free(seq);
+
     exit(EXIT_SUCCESS);
 }