From c0c2a0f9f5229063cdb92d94493b225c1c62323e Mon Sep 17 00:00:00 2001
From: Daniel Manrique <roadmr@ubuntu.com>
Date: Thu, 4 Sep 2014 08:14:26 -0400
Subject: providers:checkbox: Improved memory size presentation in
 memory_compare

---
 bin/memory_compare | 48 ++++++++++++++++++++++++++++++++++++++++--------
 1 file changed, 40 insertions(+), 8 deletions(-)

(limited to 'bin')

diff --git a/bin/memory_compare b/bin/memory_compare
index 4143673..2c26f67 100755
--- a/bin/memory_compare
+++ b/bin/memory_compare
@@ -24,6 +24,7 @@
 
 import os
 import sys
+from math import log, copysign
 from subprocess import check_output, PIPE
 
 from checkbox_support.parsers.lshwjson import LshwJsonParser
@@ -81,6 +82,32 @@ def get_threshold(installed_memory):
         return 10
 
 
+def bytes_to_human(my_bytes):
+    """ Convert my_bytes to a scaled representation with a
+    suffix
+    """
+    if my_bytes == 0:
+        return "0 bytes"
+
+    suffixes = ["bytes", "KiB", "MiB", "GiB", "TiB",
+                "PiB", "EiB", "ZiB", "YiB"]
+
+    try:
+        sign = copysign(1, my_bytes)
+    except OverflowError as excp:
+        return "(Number too large: {})".format(excp)
+    my_bytes = abs(my_bytes)
+    # my_bytes' base-1024 logarithm.
+    exponent = log(my_bytes, 1024)
+    try:
+        suffix = suffixes[int(exponent)]
+    except IndexError:
+        return "(Number too large)"
+    scalar = my_bytes / (1024**int(exponent))
+
+    return "{:.2f} {}".format(sign * scalar, suffix)
+
+
 def main():
     if os.geteuid() != 0:
         print("This script must be run as root.", file=sys.stderr)
@@ -95,9 +122,11 @@ def main():
         percentage = difference / installed_memory * 100
     except ZeroDivisionError:
         print("Results:")
-        print("\t/proc/meminfo reports:\t%s kB" % (visible_memory / 1024),
+        print("\t/proc/meminfo reports:\t{}".format(
+              bytes_to_human(visible_memory)),
               file=sys.stderr)
-        print("\tlshw reports:\t%s kB" % (installed_memory / 1024),
+        print("\tlshw reports:\t{}".format(
+              bytes_to_human(installed_memory)),
               file=sys.stderr)
         print("\nFAIL: Either lshw or /proc/meminfo returned a memory size "
               "of 0 kB", file=sys.stderr)
@@ -105,17 +134,20 @@ def main():
 
     if percentage <= threshold:
         print("Results:")
-        print("\t/proc/meminfo reports:\t%s kB" % (visible_memory / 1024))
-        print("\tlshw reports:\t%s kB" % (installed_memory / 1024))
-        print("\nPASS: Meminfo reports %d bytes less than lshw, a "
+        print("\t/proc/meminfo reports:\t{}".format(
+              bytes_to_human(visible_memory)))
+        print("\tlshw reports:\t{}".format(bytes_to_human(installed_memory)))
+        print("\nPASS: Meminfo reports %s less than lshw, a "
               "difference of %.2f%%. This is less than the "
-              "%d%% variance allowed." % (difference, percentage, threshold))
+              "%d%% variance allowed." % (bytes_to_human(difference),
+                                          percentage, threshold))
         return 0
     else:
         print("Results:", file=sys.stderr)
-        print("\t/proc/meminfo reports:\t%s kB" % (visible_memory / 1024),
+        print("\t/proc/meminfo reports:\t{}".format(
+              bytes_to_human(visible_memory)),
               file=sys.stderr)
-        print("\tlshw reports:\t%s kB" % (installed_memory / 1024),
+        print("\tlshw reports:\t{}".format(bytes_to_human(installed_memory)),
               file=sys.stderr)
         print("\nFAIL: Meminfo reports %d bytes less than lshw, "
               "a difference of %.2f%%. Only a variance of %d%% in "
-- 
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