[libvirt] [PATCH 02/21] util: Introduce virPrettySize

[Martin Kletzander]

We can't output better memory sizes if we want to be compatible with libvirt
older than the one which introduced /memory/unit, but for new things we can just
output nicer capacity to the user if available.  And this function enables that.

Signed-off-by: Martin Kletzander <mkletzan at redhat.com>
---
 src/libvirt_private.syms |  1 +
 src/util/virutil.c       | 50 ++++++++++++++++++++++++++++++++++++++++++++++++
 src/util/virutil.h       |  3 +++
 3 files changed, 54 insertions(+)

diff --git a/src/libvirt_private.syms b/src/libvirt_private.syms
index 36cd5b55b249..d4bae6150bb8 100644
--- a/src/libvirt_private.syms
+++ b/src/libvirt_private.syms
@@ -2954,6 +2954,7 @@ virParseNumber;
 virParseOwnershipIds;
 virParseVersionString;
 virPipeReadUntilEOF;
+virPrettySize;
 virScaleInteger;
 virSetBlocking;
 virSetCloseExec;
diff --git a/src/util/virutil.c b/src/util/virutil.c
index 170e921920ef..dcfb65262aff 100644
--- a/src/util/virutil.c
+++ b/src/util/virutil.c
@@ -1993,3 +1993,53 @@ virMemoryMaxValue(bool capped)
     else
         return LLONG_MAX;
 }
+
+
+/**
+ * virPrettySize
+ *
+ * @val: Value in bytes to be shortened
+ * @unit: unit to be used
+ *
+ * Similar to vshPrettyCapacity, but operates on integers and not doubles
+ *
+ * Returns shortened value that can be used with @unit.
+ */
+unsigned long long
+virPrettySize(unsigned long long val, const char **unit)
+{
+    unsigned long long limit = 1024;
+
+    if (val % limit || val == 0) {
+        *unit = "B";
+        return val;
+    }
+    limit *= 1024;
+    if (val % limit) {
+        *unit = "KiB";
+        return val / (limit / 1024);
+    }
+    limit *= 1024;
+    if (val % limit) {
+        *unit = "MiB";
+        return val / (limit / 1024);
+    }
+    limit *= 1024;
+    if (val % limit) {
+        *unit = "GiB";
+        return val / (limit / 1024);
+    }
+    limit *= 1024;
+    if (val % limit) {
+        *unit = "TiB";
+        return val / (limit / 1024);
+    }
+    limit *= 1024;
+    if (val % limit) {
+        *unit = "PiB";
+        return val / (limit / 1024);
+    }
+    limit *= 1024;
+    *unit = "EiB";
+    return val / (limit / 1024);
+}
diff --git a/src/util/virutil.h b/src/util/virutil.h
index ff89d1aaaa5f..72e35fc9a607 100644
--- a/src/util/virutil.h
+++ b/src/util/virutil.h
@@ -222,4 +222,7 @@ unsigned long long virMemoryMaxValue(bool ulong) ATTRIBUTE_NOINLINE;
 # define VIR_ASSIGN_IS_OVERFLOW(lvalue, rvalue) \
     (((lvalue) = (rvalue)) != (rvalue))
 
+unsigned long long
+virPrettySize(unsigned long long val, const char **unit);
+
 #endif /* __VIR_UTIL_H__ */
-- 
2.15.0