Bug 1424155 - Write scripts to import/export attachments to disk

1 files changed, 123 insertions, 0 deletions

diff --git a/Bugzilla/Attachment/Archive.pm b/Bugzilla/Attachment/Archive.pm
new file mode 100644
index 000000000..ccedf1da4
--- /dev/null
+++ b/Bugzilla/Attachment/Archive.pm
@@ -0,0 +1,123 @@
+# This Source Code Form is subject to the terms of the Mozilla Public
+# License, v. 2.0. If a copy of the MPL was not distributed with this
+# file, You can obtain one at http://mozilla.org/MPL/2.0/.
+#
+# This Source Code Form is "Incompatible With Secondary Licenses", as
+# defined by the Mozilla Public License, v. 2.0.
+
+package Bugzilla::Attachment::Archive;
+
+use 5.10.1;
+use Moo;
+use Digest::SHA qw(sha256_hex);
+use Carp;
+use IO::File;
+
+use constant HEADER_SIZE   => 45;
+use constant HEADER_FORMAT => 'ANNNH64';
+
+has 'file'      => ( is => 'ro',   required  => 1 );
+has 'input_fh'  => ( is => 'lazy', predicate => 'has_input_fh' );
+has 'output_fh' => ( is => 'lazy', predicate => 'has_output_fh' );
+has 'checksum'  => ( is => 'lazy', clearer   => 'reset_checksum' );
+
+sub read_member {
+    my ($self) = @_;
+    my $header = $self->_read_header();
+    my ($type, $bug_id, $attach_id, $data_len, $hash) = unpack HEADER_FORMAT, $header;
+    if ( $type eq 'D' ) {
+        $self->checksum->add($header);
+        my $data = $self->_read_data( $data_len, $hash );
+        return {
+            bug_id    => $bug_id,
+            attach_id => $attach_id,
+            data_len  => $data_len,
+            hash      => $hash,
+            data      => $data,
+        };
+    }
+    elsif ($type eq 'C') {
+        die "bad overall checksum\n" unless $hash eq $self->checksum->hexdigest;
+        $self->reset_checksum;
+        return undef;
+    }
+    else {
+        die "unknown member type: $type\n";
+    }
+}
+
+sub write_attachment {
+    my ( $self, $attachment ) = @_;
+    my $data      = $attachment->data;
+    my $bug_id    = $attachment->bug_id;
+    my $attach_id = $attachment->id;
+
+    if (defined $data && length($data) == $attachment->datasize) {
+        my $header = pack HEADER_FORMAT, 'D', $bug_id, $attach_id, length($data), sha256_hex($data);
+        $self->checksum->add($header);
+        $self->output_fh->print($header, $data);
+    }
+}
+
+sub write_checksum {
+    my ($self) = @_;
+    my $header = pack HEADER_FORMAT, 'C', 0, 0, 0, $self->checksum->hexdigest;
+    $self->output_fh->print($header);
+    $self->reset_checksum;
+    $self->output_fh->flush;
+}
+
+sub _build_checksum {
+    my ($self) = @_;
+    return Digest::SHA->new(256);
+}
+
+sub _build_input_fh {
+    my ($self) = @_;
+    if ($self->has_output_fh) {
+        croak "I will not read and write a file at the same time";
+    }
+    my $file = $self->file;
+    return IO::File->new( $self->file, '<:bytes' ) or die "cannot read $file: $!";
+}
+
+sub _build_output_fh {
+    my ($self) = @_;
+    if ($self->has_input_fh) {
+        croak "I will not read and write a file at the same time";
+    }
+    my $file = $self->file;
+    if (-e $file) {
+        croak "I will not overwrite a file (file $file already exists)";
+    }
+    return IO::File->new( $file, '>:bytes' ) or die "cannot write $file: $!";
+}
+
+sub _read_header {
+    my ($self) = @_;
+    my $header     = '' x HEADER_SIZE;
+    my $header_len = $self->input_fh->read($header, HEADER_SIZE);
+    if ( !$header_len || $header_len != HEADER_SIZE ) {
+        die "bad header\n";
+    }
+    return $header;
+}
+
+sub _read_data {
+    my ($self, $data_len, $hash) = @_;
+
+    my $data = '' x $data_len;
+    my $read_data_len = $self->input_fh->read($data, $data_len);
+
+    unless ( $read_data_len == $data_len ) {
+        die "bad data\n";
+    }
+
+    unless ( $hash eq sha256_hex($data) ) {
+        die "bad checksum:\n\t$hash\n\t" . sha226_hex($data) . "\n";
+    }
+
+    return $data;
+}
+
+1;
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