[libvirt] [PATCH] virsh-domain-monitor: add human readable output for 'domblkinfo'.

[Julio Faracco]

The virsh command 'domblkinfo' returns the capacity, allocation and phisycal
size of the devices attached in a domain. Usually, this sizes are very big
and hard to understand and calculate. This commits introduce a human readable
support to check the size of each field easilly.

For example, the command today:

virsh # domblkinfo my_domain hda
Capacity:       21474836480
Allocation:     14875545600
Physical:       21474836480

After this patch:

virsh # domblkinfo my_domain hda --human
Capacity:       20.0G
Allocation:     13.9G
Physical:       20.0G

This commit supports Bytes, KiB and MiB too.

Resolves: https://bugzilla.redhat.com/show_bug.cgi?id=1330940

Signed-off-by: Julio Faracco <jcfaracco at gmail.com>
---
 tools/virsh-domain-monitor.c | 41 ++++++++++++++++++++++++++++++++++++++---
 tools/virsh.pod              |  5 +++--
 2 files changed, 41 insertions(+), 5 deletions(-)

diff --git a/tools/virsh-domain-monitor.c b/tools/virsh-domain-monitor.c
index 3db4795..755d740 100644
--- a/tools/virsh-domain-monitor.c
+++ b/tools/virsh-domain-monitor.c
@@ -396,6 +396,10 @@ static const vshCmdOptDef opts_domblkinfo[] = {
      .flags = VSH_OFLAG_REQ,
      .help = N_("block device")
     },
+    {.name = "human",
+     .type = VSH_OT_BOOL,
+     .help = N_("Human readable output")
+    },
     {.name = NULL}
 };
 
@@ -405,6 +409,7 @@ cmdDomblkinfo(vshControl *ctl, const vshCmd *cmd)
     virDomainBlockInfo info;
     virDomainPtr dom;
     bool ret = false;
+    bool human = false;
     const char *device = NULL;
 
     if (!(dom = virshCommandOptDomain(ctl, cmd, NULL)))
@@ -416,9 +421,39 @@ cmdDomblkinfo(vshControl *ctl, const vshCmd *cmd)
     if (virDomainGetBlockInfo(dom, device, &info, 0) < 0)
         goto cleanup;
 
-    vshPrint(ctl, "%-15s %llu\n", _("Capacity:"), info.capacity);
-    vshPrint(ctl, "%-15s %llu\n", _("Allocation:"), info.allocation);
-    vshPrint(ctl, "%-15s %llu\n", _("Physical:"), info.physical);
+    human = vshCommandOptBool(cmd, "human");
+
+    if (!human) {
+        vshPrint(ctl, "%-15s %llu\n", _("Capacity:"), info.capacity);
+        vshPrint(ctl, "%-15s %llu\n", _("Allocation:"), info.allocation);
+        vshPrint(ctl, "%-15s %llu\n", _("Physical:"), info.physical);
+    } else {
+        double sizeCapacity = 1;
+        const char *sizeStr = "B";
+
+        /* Check if capacity can be in K. */
+        if (info.capacity >= 1024) {
+            sizeCapacity = 1024.0;
+            sizeStr = "K";
+        }
+        /* Check if capacity can be in M. */
+        if (info.capacity >= 1048576) {
+            sizeCapacity = 1048576.0;
+            sizeStr = "M";
+        }
+        /* Check if capacity can be in G. */
+        if (info.capacity >= 1073741824) {
+            sizeCapacity = 1073741824.0;
+            sizeStr = "G";
+        }
+
+        vshPrint(ctl, "%-15s %.1f%s\n", _("Capacity:"),
+                                info.capacity/sizeCapacity, sizeStr);
+        vshPrint(ctl, "%-15s %.1f%s\n", _("Allocation:"),
+                                info.allocation/sizeCapacity, sizeStr);
+        vshPrint(ctl, "%-15s %.1f%s\n", _("Physical:"),
+                                info.physical/sizeCapacity, sizeStr);
+    }
 
     ret = true;
 
diff --git a/tools/virsh.pod b/tools/virsh.pod
index e16f62f..9f67de2 100644
--- a/tools/virsh.pod
+++ b/tools/virsh.pod
@@ -841,12 +841,13 @@ B<domstate> command says that a domain was paused due to I/O error.
 The B<domblkerror> command lists all block devices in error state and
 the error seen on each of them.
 
-=item B<domblkinfo> I<domain> I<block-device>
+=item B<domblkinfo> I<domain> I<block-device> [I<--human>]
 
 Get block device size info for a domain.  A I<block-device> corresponds
 to a unique target name (<target dev='name'/>) or source file (<source
 file='name'/>) for one of the disk devices attached to I<domain> (see
-also B<domblklist> for listing these names).
+also B<domblklist> for listing these names). If I<--human> is set, the
+output will have a human readable design.
 
 =item B<domblklist> I<domain> [I<--inactive>] [I<--details>]
 
-- 
2.7.4