[pve-devel] [PATCH common v3] fix convert_size with decimal numbers and add tests

[Dominik Csapak]

converting from 0.5 gb to mb resulted in 0 mb
with this patch it correctly returns 512

also add tests and catch more errors

Signed-off-by: Dominik Csapak <d.csapak at proxmox.com>
---
changes from v2:
* unified up and down converting (with regards to ceil/floor)
* disallow empty/non-defined and '.' as value (has no real value)
* catch undefined to/from
* catch undefined variables i test
* added test cases for ceil/floor when converting to bigger unit
* added content of value to error message
* made condition for to/from check more readable
* added comment giving examples for allowed format of value
 src/PVE/Tools.pm          | 34 +++++++++++++++++----------
 test/Makefile             |  1 +
 test/convert_size_test.pl | 60 +++++++++++++++++++++++++++++++++++++++++++++++
 3 files changed, 82 insertions(+), 13 deletions(-)
 create mode 100755 test/convert_size_test.pl

diff --git a/src/PVE/Tools.pm b/src/PVE/Tools.pm
index 6d579d8..f43424b 100644
--- a/src/PVE/Tools.pm
+++ b/src/PVE/Tools.pm
@@ -1629,9 +1629,16 @@ sub encrypt_pw {
 }
 
 # intended usage: convert_size($val, "kb" => "gb")
-# on reduction (converting to a bigger unit) we round up by default if
-# information got lost. E.g. `convert_size(1023, "b" => "kb")` returns 1
+# we round up to the next integer by default
+# E.g. `convert_size(1023, "b" => "kb")` returns 1
 # use $no_round_up to switch this off, above example would then return 0
+# this is also true for converting down e.g. 0.0005 gb to mb returns 1
+# (0 if $no_round_up is true)
+# allowed formats for value:
+# 1234
+# 1234.
+# 1234.1234
+# .1234
 sub convert_size {
     my ($value, $from, $to, $no_round_up) = @_;
 
@@ -1644,21 +1651,22 @@ sub convert_size {
 	pb => 5,
     };
 
-    $from = lc($from); $to = lc($to);
+    die "no value given"
+	if !defined($value) || $value eq "";
+
+    $from = lc($from // ''); $to = lc($to // '');
     die "unknown 'from' and/or 'to' units ($from => $to)"
-	if !(defined($units->{$from}) && defined($units->{$to}));
+	if !defined($units->{$from}) || !defined($units->{$to});
 
-    my $shift_amount = $units->{$from} - $units->{$to};
+    die "value '$value' is not a valid, positive number"
+	if $value !~ m/^(?:[0-9]+\.?[0-9]*|[0-9]*\.[0-9]+)$/;
 
-    if ($shift_amount > 0) {
-	$value <<= ($shift_amount * 10);
-    } elsif ($shift_amount < 0) {
-	my $remainder = ($value & (1 << abs($shift_amount)*10) - 1);
-	$value >>= abs($shift_amount) * 10;
-	$value++ if $remainder && !$no_round_up;
-    }
+    my $shift_amount = ($units->{$from} - $units->{$to}) * 10;
+
+    $value *= 2**$shift_amount;
+    $value++ if !$no_round_up && ($value - int($value)) > 0.0;
 
-    return $value;
+    return int($value);
 }
 
 1;
diff --git a/test/Makefile b/test/Makefile
index 894093b..b6fe6e0 100644
--- a/test/Makefile
+++ b/test/Makefile
@@ -8,6 +8,7 @@ check:
 	for d in $(SUBDIRS); do $(MAKE) -C $$d check; done
 	./lock_file.pl
 	./calendar_event_test.pl
+	./convert_size_test.pl
 
 install: check
 distclean: clean
diff --git a/test/convert_size_test.pl b/test/convert_size_test.pl
new file mode 100755
index 0000000..93e88b1
--- /dev/null
+++ b/test/convert_size_test.pl
@@ -0,0 +1,60 @@
+#!/usr/bin/perl
+
+use lib '../src';
+use strict;
+use warnings;
+use Data::Dumper;
+use Test::More;
+
+use PVE::Tools;
+
+my $tests = [
+    [
+	1,           # input value
+	'gb',        # from
+	'kb',        # to
+	undef,       # no_round_up
+	1*1024*1024, # result
+	undef,       # error string
+    ],
+    [ -1, 'gb', 'kb', undef, 1*1024*1024, "value '-1' is not a valid, positive number" ],
+    [ 1.5, 'gb', 'kb', undef, 1.5*1024*1024 ],
+    [  0.0005, 'gb', 'mb', undef, 1 ],
+    [  0.0005, 'gb', 'mb', 1, 0 ],
+    [ '.5', 'gb', 'kb', undef, .5*1024*1024 ],
+    [ '1.', 'gb', 'kb', undef, 1.*1024*1024 ],
+    [  0.5, 'mb', 'gb', undef, 1, ],
+    [  0.5, 'mb', 'gb', 1, 0, ],
+    [ '.', 'gb', 'kb', undef, 0, "value '.' is not a valid, positive number" ],
+    [ '', 'gb', 'kb', undef, 0, "no value given" ],
+    [ '1.1.', 'gb', 'kb', undef, 0, "value '1.1.' is not a valid, positive number" ],
+    [ 500, 'kb', 'kb', undef, 500, ],
+    [ 500000, 'b', 'kb', undef, 489, ],
+    [ 500000, 'b', 'kb', 0, 489, ],
+    [ 500000, 'b', 'kb', 1, 488, ],
+    [ 128*1024 - 1, 'b', 'kb', 0, 128, ],
+    [ 128*1024 - 1, 'b', 'kb', 1, 127, ],
+    [ "abcdef", 'b', 'kb', 0, 0, "value 'abcdef' is not a valid, positive number" ],
+    [ undef, 'b', 'kb', 0, 0, "no value given" ],
+    [ 0, 'b', 'pb', 0, 0, ],
+    [ 0, 'b', 'yb', 0, 0, "unknown 'from' and/or 'to' units (b => yb)"],
+    [ 0, 'b', undef, 0, 0, "unknown 'from' and/or 'to' units (b => )"],
+];
+
+foreach my $test (@$tests) {
+    my ($input, $from, $to, $no_round_up, $expect, $error) = @$test;
+
+    my $result = eval { PVE::Tools::convert_size($input, $from, $to, $no_round_up); };
+    my $err = $@;
+    $input = $input // "";
+    $from = $from // "";
+    $to = $to // "";
+    if ($error) {
+	like($err, qr/^\Q$error\E/, "expected error for $input $from -> $to: $error");
+    } else {
+	my $round = $no_round_up ? 'floor' : 'ceil';
+	is($result, $expect, "$input $from converts to $expect $to ($round)");
+    }
+};
+
+done_testing();
-- 
2.11.0