Update payload library + command-line tool
An initial implementation of a Python module for parsing, checking and
applying a Chrome OS update payload. Comes with a command-line tool
(paycheck.py) for applying such operations on payload files, and a test
script (test_paycheck.sh) for ensuring that the library and tool are
working correctly.
Since update_payload is introduced as a package, we're moving some
previously merged utilities into the package's directory.
(Unit testing for this code will be uploaded on a separate CL; see
chromium-os:39663)
BUG=chromium-os:34911,chromium-os:33607,chromium-os:7597
TEST=test_paycheck.sh successful on MP-signed payloads
CQ-DEPEND=I5746a1d80e822a575f0d96f94d0b4e765fc64507
Change-Id: I77123a1fffbb2059c239b7145c6922968fdffb6a
Reviewed-on: https://gerrit.chromium.org/gerrit/43041
Reviewed-by: Gilad Arnold <garnold@chromium.org>
Tested-by: Gilad Arnold <garnold@chromium.org>
Reviewed-by: Chris Sosa <sosa@chromium.org>
Reviewed-by: Jay Srinivasan <jaysri@chromium.org>
Reviewed-by: Don Garrett <dgarrett@chromium.org>
Commit-Queue: Gilad Arnold <garnold@chromium.org>
diff --git a/scripts/update_payload/format_utils.py b/scripts/update_payload/format_utils.py
new file mode 100644
index 0000000..2c82f32
--- /dev/null
+++ b/scripts/update_payload/format_utils.py
@@ -0,0 +1,93 @@
+# Copyright (c) 2013 The Chromium OS Authors. All rights reserved.
+# Use of this source code is governed by a BSD-style license that can be
+# found in the LICENSE file.
+
+"""Various formatting functions."""
+
+
+def NumToPercent(num, total, min_precision=1, max_precision=5):
+ """Returns the percentage (string) of |num| out of |total|.
+
+ If the percentage includes a fraction, it will be computed down to the least
+ precision that yields a non-zero and ranging between |min_precision| and
+ |max_precision|. Values are always rounded down. All arithmetic operations
+ are integer built-ins. Examples (using default precision):
+
+ (1, 1) => 100%
+ (3, 10) => 30%
+ (3, 9) => 33.3%
+ (3, 900) => 0.3%
+ (3, 9000000) => 0.00003%
+ (3, 900000000) => 0%
+ (5, 2) => 250%
+
+ Args:
+ num: the value of the part
+ total: the value of the whole
+ min_precision: minimum precision for fractional percentage
+ max_precision: maximum precision for fractional percentage
+ Returns:
+ Percentage string.
+
+ """
+ percent = 0
+ precision = min(min_precision, max_precision)
+ factor = 10 ** precision
+ while precision <= max_precision:
+ percent = num * 100 * factor / total
+ if percent:
+ break
+ factor *= 10
+ precision += 1
+
+ whole, frac = divmod(percent, factor)
+ while frac and not frac % 10:
+ frac /= 10
+ precision -= 1
+
+ return '%d%s%%' % (whole, '.%0*d' % (precision, frac) if frac else '')
+
+
+def BytesToHumanReadable(size, precision=1, decimal=False):
+ """Returns a human readable representation of a given |size|.
+
+ The returned string includes unit notations in either binary (KiB, MiB, etc)
+ or decimal (kB, MB, etc), based on the value of |decimal|. The chosen unit is
+ the largest that yields a whole (or mixed) number. It may contain up to
+ |precision| fractional digits. Values are always rounded down. Largest unit
+ is an exabyte. All arithmetic operations are integer built-ins. Examples
+ (using default precision and binary units):
+
+ 4096 => 4 KiB
+ 5000 => 4.8 KiB
+ 500000 => 488.2 KiB
+ 5000000 => 4.7 MiB
+
+ Args:
+ size: the size in bytes
+ precision: the number of digits past the decimal point
+ decimal: whether to compute/present decimal or binary units
+ Returns:
+ Readable size string, or None if no conversion is applicable (i.e. size is
+ less than the smallest unit).
+
+ """
+ constants = (
+ (('KiB', 'MiB', 'GiB', 'TiB', 'PiB', 'EiB'), 1024),
+ (('kB', 'MB', 'GB', 'TB', 'PB', 'EB'), 1000)
+ )
+ suffixes, base = constants[decimal]
+ exp, magnitude = 0, 1
+ while exp < len(suffixes):
+ next_magnitude = magnitude * base
+ if size < next_magnitude:
+ break
+ exp += 1
+ magnitude = next_magnitude
+
+ if exp != 0:
+ whole = size / magnitude
+ frac = (size % magnitude) * (10 ** precision) / magnitude
+ while frac and not frac % 10:
+ frac /= 10
+ return '%d%s %s' % (whole, '.%d' % frac if frac else '', suffixes[exp - 1])