[PATCH v3 1/2] git-p4: print size values in appropriate units

From: Joel Holdsworth <jholdsworth@nvidia.com>
Date: Jan 4, 2022, 12:43 UTC
Message-ID: <20220104124307.2524-2-jholdsworth@nvidia.com>
In-Reply-To: <20220104124307.2524-1-jholdsworth@nvidia.com>

The git-p4 script reports file sizes in various log messages. Previously, in each case the script would print them as the number of bytes divided by 1048576 i.e. the size in mebibytes, rounded down to an integer. This resulted in small files being described as having a size of "0 MB".

This patch replaces the existing behaviour with a new helper function: format_size_human_readable, which takes a number of bytes (or any other quantity), and computes the appropriate prefix to use: none, Ki, Mi, Gi, Ti, Pi, Ei, Zi, Yi.

For example, a size of 123456 will now be printed as "120.6 KiB" greatly improving the readability of the log output.

Large valued prefixes such as pebi, exbi, zebi and yobi are included for completeness, though they not expected to appear in any real-world Perforce repository!

Signed-off-by: Joel Holdsworth <jholdsworth@nvidia.com>
---
 git-p4.py | 24 +++++++++++++++++++-----
 1 file changed, 19 insertions(+), 5 deletions(-)

diff --git a/git-p4.py b/git-p4.py
index 2b4500226a..74834736fa 100755
--- a/git-p4.py
+++ b/git-p4.py
@@ -56,6 +56,18 @@
 
 p4_access_checked = False
 
+def format_size_human_readable(num):
+    """ Returns a number of units (typically bytes) formatted as a human-readable
+        string.
+    """
+    if num < 1024:
+        return '{:d} B'.format(num)
+    for unit in ["Ki", "Mi", "Gi", "Ti", "Pi", "Ei", "Zi"]:
+        num /= 1024.0
+        if num < 1024.0:
+            return "{:3.1f} {}B".format(num, unit)
+    return "{:.1f} YiB".format(num)
+
 def p4_build_cmd(cmd):
     """Build a suitable p4 command line.
 
@@ -2966,7 +2978,8 @@ def streamOneP4File(self, file, contents):
                 size = int(self.stream_file['fileSize'])
             else:
                 size = 0 # deleted files don't get a fileSize apparently
-            sys.stdout.write('\r%s --> %s (%i MB)\n' % (file_path, relPath, size/1024/1024))
+            sys.stdout.write('\r%s --> %s (%s)\n' % (
+                file_path, relPath, format_size_human_readable(size)))
             sys.stdout.flush()
 
         (type_base, type_mods) = split_p4_type(file["type"])
@@ -3064,9 +3077,8 @@ def streamP4FilesCb(self, marshalled):
         if not err and 'fileSize' in self.stream_file:
             required_bytes = int((4 * int(self.stream_file["fileSize"])) - calcDiskFree())
             if required_bytes > 0:
-                err = 'Not enough space left on %s! Free at least %i MB.' % (
-                    os.getcwd(), required_bytes/1024/1024
-                )
+                err = 'Not enough space left on %s! Free at least %s.' % (
+                    os.getcwd(), format_size_human_readable(required_bytes))
 
         if err:
             f = None
@@ -3110,7 +3122,9 @@ def streamP4FilesCb(self, marshalled):
             size = int(self.stream_file["fileSize"])
             if size > 0:
                 progress = 100*self.stream_file['streamContentSize']/size
-                sys.stdout.write('\r%s %d%% (%i MB)' % (self.stream_file['depotFile'], progress, int(size/1024/1024)))
+                sys.stdout.write('\r%s %d%% (%s)' % (
+                    self.stream_file['depotFile'], progress,
+                    format_size_human_readable(size)))
                 sys.stdout.flush()
 
         self.stream_have_file_info = True

-- 
2.34.1