solver: initial Perl implementation

This will lookup git blobs from associated git source code
repositories.  If the blobs can't be found, an attempt to
"solve" them via patch application will be performed.

Eventually, this may become the basis of a type-agnostic
frontend similar to "git show"

3 files changed, 148 insertions, 0 deletions

diff --git a/t/solve/0001-simple-mod.patch b/t/solve/0001-simple-mod.patch
new file mode 100644
index 00000000..c6bb1575
--- /dev/null
+++ b/t/solve/0001-simple-mod.patch
@@ -0,0 +1,20 @@
+From: WEB DESIGN EXPERT <BOFH@YHBT.net>
+To: meta@public-inbox.org
+Subject: [PATCH] TODO: take expert web design advice
+Date: Mon, 1 Apr 2019 08:15:20 +0000
+Message-Id: <20190401081523.16213-1-BOFH@YHBT.net>
+
+---
+ TODO | 2 ++
+ 1 file changed, 2 insertions(+)
+
+diff --git a/TODO b/TODO
+index 605013e..69df7d5 100644
+--- a/TODO
++++ b/TODO
+@@ -109,3 +109,5 @@ all need to be considered for everything we introduce)
+ 
+   * Optional history squashing to reduce commit and intermediate
+     tree objects
++
++  * Make use of <blink> and <marquee> tags
diff --git a/t/solve/0002-rename-with-modifications.patch b/t/solve/0002-rename-with-modifications.patch
new file mode 100644
index 00000000..aa415e01
--- /dev/null
+++ b/t/solve/0002-rename-with-modifications.patch
@@ -0,0 +1,37 @@
+From: POLITICAL CORRECTNESS EXPERT <BOFH@YHBT.net>
+To: meta@public-inbox.org
+Subject: [PATCH] POLITICALLY CORRECT FILE NAMING
+Date: Mon, 1 Apr 2019 08:15:20 +0000
+Message-Id: <20190401081523.16213-2-BOFH@YHBT.net>
+
+HACKING MIGHT GET US REPORTED TO EFF-BEE-EYE
+AND USE MARKDOWN CUZ MOAR FLAVORS == BETTER
+---
+ HACKING => CONTRIBUTING.md | 6 +++---
+ 1 file changed, 3 insertions(+), 3 deletions(-)
+ rename HACKING => CONTRIBUTING.md (94%)
+
+diff --git a/HACKING b/CONTRIBUTING.md
+similarity index 94%
+rename from HACKING
+rename to CONTRIBUTING.md
+index 3435775..0a92431 100644
+--- a/HACKING
++++ b/CONTRIBUTING.md
+@@ -1,5 +1,5 @@
+-hacking public-inbox
+---------------------
++contributing to public-inbox
++----------------------------
+ 
+ Send all patches and "git request-pull"-formatted emails to our
+ self-hosting inbox at meta@public-inbox.org
+@@ -15,7 +15,7 @@ Please consider our goals in mind:
+         Decentralization, Accessibility, Compatibility, Performance
+ 
+ These goals apply to everyone: users viewing over the web or NNTP,
+-sysadmins running public-inbox, and other hackers working public-inbox.
++sysadmins running public-inbox, and other contributors working public-inbox.
+ 
+ We will reject any feature which advocates or contributes to any
+ particular instance of a public-inbox becoming a single point of failure.
diff --git a/t/solver_git.t b/t/solver_git.t
new file mode 100644
index 00000000..fe322eab
--- /dev/null
+++ b/t/solver_git.t
@@ -0,0 +1,91 @@
+# Copyright (C) 2019 all contributors <meta@public-inbox.org>
+# License: AGPL-3.0+ <https://www.gnu.org/licenses/agpl-3.0.txt>
+use strict;
+use warnings;
+use Test::More;
+use File::Temp qw(tempdir);
+use Cwd qw(abs_path);
+require './t/common.perl';
+require_git(2.6);
+
+my @mods = qw(DBD::SQLite Search::Xapian HTTP::Request::Common Plack::Test
+                URI::Escape Plack::Builder);
+foreach my $mod (@mods) {
+        eval "require $mod";
+        plan skip_all => "$mod missing for $0" if $@;
+}
+chomp(my $git_dir = `git rev-parse --git-dir 2>/dev/null`);
+plan skip_all => "$0 must be run from a git working tree" if $?;
+$git_dir = abs_path($git_dir);
+
+use_ok "PublicInbox::$_" for (qw(Inbox V2Writable MIME Git SolverGit));
+
+my $mainrepo = tempdir('pi-solver-XXXXXX', TMPDIR => 1, CLEANUP => 1);
+my $opts = {
+        mainrepo => $mainrepo,
+        name => 'test-v2writable',
+        version => 2,
+        -primary_address => 'test@example.com',
+};
+my $ibx = PublicInbox::Inbox->new($opts);
+my $im = PublicInbox::V2Writable->new($ibx, 1);
+$im->{parallel} = 0;
+
+sub deliver_patch ($) {
+        open my $fh, '<', $_[0] or die "open: $!";
+        my $mime = PublicInbox::MIME->new(do { local $/; <$fh> });
+        $im->add($mime);
+        $im->done;
+}
+
+deliver_patch('t/solve/0001-simple-mod.patch');
+
+my $gits = [ PublicInbox::Git->new($git_dir) ];
+my $solver = PublicInbox::SolverGit->new($gits, [ $ibx ]);
+open my $log, '+>>', "$mainrepo/solve.log" or die "open: $!";
+my $res = $solver->solve($log, '69df7d5', {});
+ok($res, 'solved a blob!');
+my $wt_git = $res->[0];
+is(ref($wt_git), 'PublicInbox::Git', 'got a git object for the blob');
+my $expect = '69df7d565d49fbaaeb0a067910f03dc22cd52bd0';
+is($res->[1], $expect, 'resolved blob to unabbreviated identifier');
+is($res->[2], 'blob', 'type specified');
+is($res->[3], 4405, 'size returned');
+
+is(ref($wt_git->cat_file($res->[1])), 'SCALAR', 'wt cat-file works');
+is_deeply([$expect, 'blob', 4405],
+          [$wt_git->check($res->[1])], 'wt check works');
+
+if (0) { # TODO: check this?
+        seek($log, 0, 0);
+        my $z = do { local $/; <$log> };
+        diag $z;
+}
+
+$res = undef;
+my $wt_git_dir = $wt_git->{git_dir};
+$wt_git = undef;
+ok(!-d $wt_git_dir, 'no references to WT held');
+
+$res = $solver->solve($log, '0'x40, {});
+is($res, undef, 'no error on z40');
+
+my $git_v2_20_1_tag = '7a95a1cd084cb665c5c2586a415e42df0213af74';
+$res = $solver->solve($log, $git_v2_20_1_tag, {});
+is($res, undef, 'no error on a tag not in our repo');
+
+deliver_patch('t/solve/0002-rename-with-modifications.patch');
+$res = $solver->solve($log, '0a92431', {});
+ok($res, 'resolved without hints');
+
+my $hints = {
+        oid_a => '3435775',
+        path_a => 'HACKING',
+        path_b => 'CONTRIBUTING'
+};
+my $hinted = $solver->solve($log, '0a92431', $hints);
+# don't compare ::Git objects:
+shift @$res; shift @$hinted;
+is_deeply($res, $hinted, 'hints work (or did not hurt :P');
+
+done_testing();