X-Git-Url: http://git.shadowcat.co.uk/gitweb/gitweb.cgi?p=catagits%2FGitalist.git;a=blobdiff_plain;f=local-lib5%2Flib%2Fperl5%2FGit%2FPurePerl%2FPackIndex%2FVersion1.pm;fp=local-lib5%2Flib%2Fperl5%2FGit%2FPurePerl%2FPackIndex%2FVersion1.pm;h=302ef71509c0e4e57499f0322e555aa76fea2dac;hp=0000000000000000000000000000000000000000;hb=3fea05b9fbf95091f4522528b9980a33e0235603;hpb=af746827daa7a8feccee889e1d12ebc74cc9201e

diff --git a/local-lib5/lib/perl5/Git/PurePerl/PackIndex/Version1.pm b/local-lib5/lib/perl5/Git/PurePerl/PackIndex/Version1.pm
new file mode 100644
index 0000000..302ef71
--- /dev/null
+++ b/local-lib5/lib/perl5/Git/PurePerl/PackIndex/Version1.pm
@@ -0,0 +1,72 @@
+package Git::PurePerl::PackIndex::Version1;
+use Moose;
+use MooseX::StrictConstructor;
+use namespace::autoclean;
+
+extends 'Git::PurePerl::PackIndex';
+
+my $FanOutCount   = 256;
+my $SHA1Size      = 20;
+my $IdxOffsetSize = 4;
+my $OffsetSize    = 4;
+my $CrcSize       = 4;
+my $OffsetStart   = $FanOutCount * $IdxOffsetSize;
+my $SHA1Start     = $OffsetStart + $OffsetSize;
+my $EntrySize     = $OffsetSize + $SHA1Size;
+my $EntrySizeV2   = $SHA1Size + $CrcSize + $OffsetSize;
+
+sub global_offset {
+    return 0;
+}
+
+sub all_sha1s {
+    my ( $self, $want_sha1 ) = @_;
+    my $fh = $self->fh;
+    my @sha1s;
+
+    my $pos = $OffsetStart;
+    $fh->seek( $pos, 0 ) || die $!;
+    foreach my $i ( 1 .. $self->size ) {
+        $fh->read( my $data, $OffsetSize ) || die $!;
+        my $offset = unpack( 'N', $data );
+        $fh->read( $data, $SHA1Size ) || die $!;
+        my $sha1 = unpack( 'H*', $data );
+        push @sha1s, $sha1;
+        $pos += $EntrySize;
+    }
+    return @sha1s;
+}
+
+sub get_object_offset {
+    my ( $self, $want_sha1 ) = @_;
+    my @offsets = $self->offsets;
+    my $fh      = $self->fh;
+
+    my $slot = unpack( 'C', pack( 'H*', $want_sha1 ) );
+    return unless defined $slot;
+
+    my ( $first, $last ) = @offsets[ $slot, $slot + 1 ];
+
+    while ( $first < $last ) {
+        my $mid = int( ( $first + $last ) / 2 );
+        $fh->seek( $SHA1Start + $mid * $EntrySize, 0 ) || die $!;
+        $fh->read( my $data, $SHA1Size ) || die $!;
+        my $midsha1 = unpack( 'H*', $data );
+        if ( $midsha1 lt $want_sha1 ) {
+            $first = $mid + 1;
+        } elsif ( $midsha1 gt $want_sha1 ) {
+            $last = $mid;
+        } else {
+            my $pos = $OffsetStart + $mid * $EntrySize;
+            $fh->seek( $pos, 0 ) || die $!;
+            $fh->read( my $data, $OffsetSize ) || die $!;
+            my $offset = unpack( 'N', $data );
+            return $offset;
+        }
+    }
+
+    return;
+}
+
+__PACKAGE__->meta->make_immutable;
+