1#!/bin/perl
2#
3# This tool will print vaguely pretty information about a pack. It
4# expects the output of "git-verify-pack -v" as input on stdin.
5#
6# $ git-verify-pack -v | packinfo.pl
7#
8# This prints some full-pack statistics; currently "all sizes", "all
9# path sizes", "tree sizes", "tree path sizes", and "depths".
10#
11# * "all sizes" stats are across every object size in the file;
12# full sizes for base objects, and delta size for deltas.
13# * "all path sizes" stats are across all object's "path sizes".
14# A path size is the sum of the size of the delta chain, including the
15# base object. In other words, it's how many bytes need be read to
16# reassemble the file from deltas.
17# * "tree sizes" are object sizes grouped into delta trees.
18# * "tree path sizes" are path sizes grouped into delta trees.
19# * "depths" should be obvious.
20#
21# When run as:
22#
23# $ git-verify-pack -v | packinfo.pl -tree
24#
25# the trees of objects are output along with the stats. This looks
26# like:
27#
28# 0 commit 031321c6... 803 803
29#
30# 0 blob 03156f21... 1767 1767
31# 1 blob f52a9d7f... 10 1777
32# 2 blob a8cc5739... 51 1828
33# 3 blob 660e90b1... 15 1843
34# 4 blob 0cb8e3bb... 33 1876
35# 2 blob e48607f0... 311 2088
36# size: count 6 total 2187 min 10 max 1767 mean 364.50 median 51 std_dev 635.85
37# path size: count 6 total 11179 min 1767 max 2088 mean 1863.17 median 1843 std_dev 107.26
38#
39# The first number after the sha1 is the object size, the second
40# number is the path size. The statistics are across all objects in
41# the previous delta tree. Obviously they are omitted for trees of
42# one object.
43#
44# When run as:
45#
46# $ git-verify-pack -v | packinfo.pl -tree -filenames
47#
48# it adds filenames to the tree. Getting this information is slow:
49#
50# 0 blob 03156f21... 1767 1767 Documentation/git-lost-found.txt @ tags/v1.2.0~142
51# 1 blob f52a9d7f... 10 1777 Documentation/git-lost-found.txt @ tags/v1.5.0-rc1~74
52# 2 blob a8cc5739... 51 1828 Documentation/git-lost+found.txt @ tags/v0.99.9h^0
53# 3 blob 660e90b1... 15 1843 Documentation/git-lost+found.txt @ master~3222^2~2
54# 4 blob 0cb8e3bb... 33 1876 Documentation/git-lost+found.txt @ master~3222^2~3
55# 2 blob e48607f0... 311 2088 Documentation/git-lost-found.txt @ tags/v1.5.2-rc3~4
56# size: count 6 total 2187 min 10 max 1767 mean 364.50 median 51 std_dev 635.85
57# path size: count 6 total 11179 min 1767 max 2088 mean 1863.17 median 1843 std_dev 107.26
58#
59# When run as:
60#
61# $ git-verify-pack -v | packinfo.pl -dump
62#
63# it prints out "sha1 size pathsize depth" for each sha1 in lexical
64# order.
65#
66# 000079a2eaef17b7eae70e1f0f635557ea67b644 30 472 7
67# 00013cafe6980411aa6fdd940784917b5ff50f0a 44 1542 4
68# 000182eacf99cde27d5916aa415921924b82972c 499 499 0
69# ...
70#
71# This is handy for comparing two packs. Adding "-filenames" will add
72# filenames, as per "-tree -filenames" above.
73use strict;
75use Getopt::Long;
76my $filenames = 0;
78my $tree = 0;
79my $dump = 0;
80GetOptions("tree" => \$tree,
81 "filenames" => \$filenames,
82 "dump" => \$dump);
83my %parents;
85my %children;
86my %sizes;
87my @roots;
88my %paths;
89my %types;
90my @commits;
91my %names;
92my %depths;
93my @depths;
94while (<STDIN>) {
96 my ($sha1, $type, $size, $offset, $depth, $parent) = split(/\s+/, $_);
97 next unless ($sha1 =~ /^[0-9a-f]{40}$/);
98 $depths{$sha1} = $depth || 0;
99 push(@depths, $depth || 0);
100 push(@commits, $sha1) if ($type eq 'commit');
101 push(@roots, $sha1) unless $parent;
102 $parents{$sha1} = $parent;
103 $types{$sha1} = $type;
104 push(@{$children{$parent}}, $sha1);
105 $sizes{$sha1} = $size;
106}
107if ($filenames && ($tree || $dump)) {
109 open(NAMES, "git-name-rev --all|");
110 while (<NAMES>) {
111 if (/^(\S+)\s+(.*)$/) {
112 my ($sha1, $name) = ($1, $2);
113 $names{$sha1} = $name;
114 }
115 }
116 close NAMES;
117 for my $commit (@commits) {
119 my $name = $names{$commit};
120 open(TREE, "git-ls-tree -t -r $commit|");
121 print STDERR "Plumbing tree $name\n";
122 while (<TREE>) {
123 if (/^(\S+)\s+(\S+)\s+(\S+)\s+(.*)$/) {
124 my ($mode, $type, $sha1, $path) = ($1, $2, $3, $4);
125 $paths{$sha1} = "$path @ $name";
126 }
127 }
128 close TREE;
129 }
130}
131sub stats {
133 my @data = sort {$a <=> $b} @_;
134 my $min = $data[0];
135 my $max = $data[$#data];
136 my $total = 0;
137 my $count = scalar @data;
138 for my $datum (@data) {
139 $total += $datum;
140 }
141 my $mean = $total / $count;
142 my $median = $data[int(@data / 2)];
143 my $diff_sum = 0;
144 for my $datum (@data) {
145 $diff_sum += ($datum - $mean)**2;
146 }
147 my $std_dev = sqrt($diff_sum / $count);
148 return ($count, $total, $min, $max, $mean, $median, $std_dev);
149}
150sub print_stats {
152 my $name = shift;
153 my ($count, $total, $min, $max, $mean, $median, $std_dev) = stats(@_);
154 printf("%s: count %s total %s min %s max %s mean %.2f median %s std_dev %.2f\n",
155 $name, $count, $total, $min, $max, $mean, $median, $std_dev);
156}
157my @sizes;
159my @path_sizes;
160my @all_sizes;
161my @all_path_sizes;
162my %path_sizes;
163sub dig {
165 my ($sha1, $depth, $path_size) = @_;
166 $path_size += $sizes{$sha1};
167 push(@sizes, $sizes{$sha1});
168 push(@all_sizes, $sizes{$sha1});
169 push(@path_sizes, $path_size);
170 push(@all_path_sizes, $path_size);
171 $path_sizes{$sha1} = $path_size;
172 if ($tree) {
173 printf("%3d%s %6s %s %8d %8d %s\n",
174 $depth, (" " x $depth), $types{$sha1},
175 $sha1, $sizes{$sha1}, $path_size, $paths{$sha1});
176 }
177 for my $child (@{$children{$sha1}}) {
178 dig($child, $depth + 1, $path_size);
179 }
180}
181my @tree_sizes;
183my @tree_path_sizes;
184for my $root (@roots) {
186 undef @sizes;
187 undef @path_sizes;
188 dig($root, 0, 0);
189 my ($aa, $sz_total) = stats(@sizes);
190 my ($bb, $psz_total) = stats(@path_sizes);
191 push(@tree_sizes, $sz_total);
192 push(@tree_path_sizes, $psz_total);
193 if ($tree) {
194 if (@sizes > 1) {
195 print_stats(" size", @sizes);
196 print_stats("path size", @path_sizes);
197 }
198 print "\n";
199 }
200}
201if ($dump) {
203 for my $sha1 (sort keys %sizes) {
204 print "$sha1 $sizes{$sha1} $path_sizes{$sha1} $depths{$sha1} $paths{$sha1}\n";
205 }
206} else {
207 print_stats(" all sizes", @all_sizes);
208 print_stats(" all path sizes", @all_path_sizes);
209 print_stats(" tree sizes", @tree_sizes);
210 print_stats("tree path sizes", @tree_path_sizes);
211 print_stats(" depths", @depths);
212}