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+=head1 NAME
+
+Git - Perl interface to the Git version control system
+
+=cut
+
+
+package Git;
+
+use strict;
+
+
+BEGIN {
+
+our ($VERSION, @ISA, @EXPORT, @EXPORT_OK);
+
+# Totally unstable API.
+$VERSION = '0.01';
+
+
+=head1 SYNOPSIS
+
+ use Git;
+
+ my $version = Git::command_oneline('version');
+
+ git_cmd_try { Git::command_noisy('update-server-info') }
+ '%s failed w/ code %d';
+
+ my $repo = Git->repository (Directory => '/srv/git/cogito.git');
+
+
+ my @revs = $repo->command('rev-list', '--since=last monday', '--all');
+
+ my ($fh, $c) = $repo->command_output_pipe('rev-list', '--since=last monday', '--all');
+ my $lastrev = <$fh>; chomp $lastrev;
+ $repo->command_close_pipe($fh, $c);
+
+ my $lastrev = $repo->command_oneline( [ 'rev-list', '--all' ],
+ STDERR => 0 );
+
+ my $sha1 = $repo->hash_and_insert_object('file.txt');
+ my $tempfile = tempfile();
+ my $size = $repo->cat_blob($sha1, $tempfile);
+
+=cut
+
+
+require Exporter;
+
+@ISA = qw(Exporter);
+
+@EXPORT = qw(git_cmd_try);
+
+# Methods which can be called as standalone functions as well:
+@EXPORT_OK = qw(command command_oneline command_noisy
+ command_output_pipe command_input_pipe command_close_pipe
+ command_bidi_pipe command_close_bidi_pipe
+ version exec_path hash_object git_cmd_try
+ remote_refs
+ temp_acquire temp_release temp_reset temp_path);
+
+
+=head1 DESCRIPTION
+
+This module provides Perl scripts easy way to interface the Git version control
+system. The modules have an easy and well-tested way to call arbitrary Git
+commands; in the future, the interface will also provide specialized methods
+for doing easily operations which are not totally trivial to do over
+the generic command interface.
+
+While some commands can be executed outside of any context (e.g. 'version'
+or 'init'), most operations require a repository context, which in practice
+means getting an instance of the Git object using the repository() constructor.
+(In the future, we will also get a new_repository() constructor.) All commands
+called as methods of the object are then executed in the context of the
+repository.
+
+Part of the "repository state" is also information about path to the attached
+working copy (unless you work with a bare repository). You can also navigate
+inside of the working copy using the C<wc_chdir()> method. (Note that
+the repository object is self-contained and will not change working directory
+of your process.)
+
+TODO: In the future, we might also do
+
+ my $remoterepo = $repo->remote_repository (Name => 'cogito', Branch => 'master');
+ $remoterepo ||= Git->remote_repository ('http://git.or.cz/cogito.git/');
+ my @refs = $remoterepo->refs();
+
+Currently, the module merely wraps calls to external Git tools. In the future,
+it will provide a much faster way to interact with Git by linking directly
+to libgit. This should be completely opaque to the user, though (performance
+increase notwithstanding).
+
+=cut
+
+
+use Carp qw(carp croak); # but croak is bad - throw instead
+use Error qw(:try);
+use Cwd qw(abs_path);
+use IPC::Open2 qw(open2);
+use Fcntl qw(SEEK_SET SEEK_CUR);
+}
+
+
+=head1 CONSTRUCTORS
+
+=over 4
+
+=item repository ( OPTIONS )
+
+=item repository ( DIRECTORY )
+
+=item repository ()
+
+Construct a new repository object.
+C<OPTIONS> are passed in a hash like fashion, using key and value pairs.
+Possible options are:
+
+B<Repository> - Path to the Git repository.
+
+B<WorkingCopy> - Path to the associated working copy; not strictly required
+as many commands will happily crunch on a bare repository.
+
+B<WorkingSubdir> - Subdirectory in the working copy to work inside.
+Just left undefined if you do not want to limit the scope of operations.
+
+B<Directory> - Path to the Git working directory in its usual setup.
+The C<.git> directory is searched in the directory and all the parent
+directories; if found, C<WorkingCopy> is set to the directory containing
+it and C<Repository> to the C<.git> directory itself. If no C<.git>
+directory was found, the C<Directory> is assumed to be a bare repository,
+C<Repository> is set to point at it and C<WorkingCopy> is left undefined.
+If the C<$GIT_DIR> environment variable is set, things behave as expected
+as well.
+
+You should not use both C<Directory> and either of C<Repository> and
+C<WorkingCopy> - the results of that are undefined.
+
+Alternatively, a directory path may be passed as a single scalar argument
+to the constructor; it is equivalent to setting only the C<Directory> option
+field.
+
+Calling the constructor with no options whatsoever is equivalent to
+calling it with C<< Directory => '.' >>. In general, if you are building
+a standard porcelain command, simply doing C<< Git->repository() >> should
+do the right thing and setup the object to reflect exactly where the user
+is right now.
+
+=cut
+
+sub repository {
+ my $class = shift;
+ my @args = @_;
+ my %opts = ();
+ my $self;
+
+ if (defined $args[0]) {
+ if ($#args % 2 != 1) {
+ # Not a hash.
+ $#args == 0 or throw Error::Simple("bad usage");
+ %opts = ( Directory => $args[0] );
+ } else {
+ %opts = @args;
+ }
+ }
+
+ if (not defined $opts{Repository} and not defined $opts{WorkingCopy}) {
+ $opts{Directory} ||= '.';
+ }
+
+ if ($opts{Directory}) {
+ -d $opts{Directory} or throw Error::Simple("Directory not found: $!");
+
+ my $search = Git->repository(WorkingCopy => $opts{Directory});
+ my $dir;
+ try {
+ $dir = $search->command_oneline(['rev-parse', '--git-dir'],
+ STDERR => 0);
+ } catch Git::Error::Command with {
+ $dir = undef;
+ };
+
+ if ($dir) {
+ $dir =~ m#^/# or $dir = $opts{Directory} . '/' . $dir;
+ $opts{Repository} = $dir;
+
+ # If --git-dir went ok, this shouldn't die either.
+ my $prefix = $search->command_oneline('rev-parse', '--show-prefix');
+ $dir = abs_path($opts{Directory}) . '/';
+ if ($prefix) {
+ if (substr($dir, -length($prefix)) ne $prefix) {
+ throw Error::Simple("rev-parse confused me - $dir does not have trailing $prefix");
+ }
+ substr($dir, -length($prefix)) = '';
+ }
+ $opts{WorkingCopy} = $dir;
+ $opts{WorkingSubdir} = $prefix;
+
+ } else {
+ # A bare repository? Let's see...
+ $dir = $opts{Directory};
+
+ unless (-d "$dir/refs" and -d "$dir/objects" and -e "$dir/HEAD") {
+ # Mimick git-rev-parse --git-dir error message:
+ throw Error::Simple('fatal: Not a git repository');
+ }
+ my $search = Git->repository(Repository => $dir);
+ try {
+ $search->command('symbolic-ref', 'HEAD');
+ } catch Git::Error::Command with {
+ # Mimick git-rev-parse --git-dir error message:
+ throw Error::Simple('fatal: Not a git repository');
+ }
+
+ $opts{Repository} = abs_path($dir);
+ }
+
+ delete $opts{Directory};
+ }
+
+ $self = { opts => \%opts };
+ bless $self, $class;
+}
+
+=back
+
+=head1 METHODS
+
+=over 4
+
+=item command ( COMMAND [, ARGUMENTS... ] )
+
+=item command ( [ COMMAND, ARGUMENTS... ], { Opt => Val ... } )
+
+Execute the given Git C<COMMAND> (specify it without the 'git-'
+prefix), optionally with the specified extra C<ARGUMENTS>.
+
+The second more elaborate form can be used if you want to further adjust
+the command execution. Currently, only one option is supported:
+
+B<STDERR> - How to deal with the command's error output. By default (C<undef>)
+it is delivered to the caller's C<STDERR>. A false value (0 or '') will cause
+it to be thrown away. If you want to process it, you can get it in a filehandle
+you specify, but you must be extremely careful; if the error output is not
+very short and you want to read it in the same process as where you called
+C<command()>, you are set up for a nice deadlock!
+
+The method can be called without any instance or on a specified Git repository
+(in that case the command will be run in the repository context).
+
+In scalar context, it returns all the command output in a single string
+(verbatim).
+
+In array context, it returns an array containing lines printed to the
+command's stdout (without trailing newlines).
+
+In both cases, the command's stdin and stderr are the same as the caller's.
+
+=cut
+
+sub command {
+ my ($fh, $ctx) = command_output_pipe(@_);
+
+ if (not defined wantarray) {
+ # Nothing to pepper the possible exception with.
+ _cmd_close($fh, $ctx);
+
+ } elsif (not wantarray) {
+ local $/;
+ my $text = <$fh>;
+ try {
+ _cmd_close($fh, $ctx);
+ } catch Git::Error::Command with {
+ # Pepper with the output:
+ my $E = shift;
+ $E->{'-outputref'} = \$text;
+ throw $E;
+ };
+ return $text;
+
+ } else {
+ my @lines = <$fh>;
+ defined and chomp for @lines;
+ try {
+ _cmd_close($fh, $ctx);
+ } catch Git::Error::Command with {
+ my $E = shift;
+ $E->{'-outputref'} = \@lines;
+ throw $E;
+ };
+ return @lines;
+ }
+}
+
+
+=item command_oneline ( COMMAND [, ARGUMENTS... ] )
+
+=item command_oneline ( [ COMMAND, ARGUMENTS... ], { Opt => Val ... } )
+
+Execute the given C<COMMAND> in the same way as command()
+does but always return a scalar string containing the first line
+of the command's standard output.
+
+=cut
+
+sub command_oneline {
+ my ($fh, $ctx) = command_output_pipe(@_);
+
+ my $line = <$fh>;
+ defined $line and chomp $line;
+ try {
+ _cmd_close($fh, $ctx);
+ } catch Git::Error::Command with {
+ # Pepper with the output:
+ my $E = shift;
+ $E->{'-outputref'} = \$line;
+ throw $E;
+ };
+ return $line;
+}
+
+
+=item command_output_pipe ( COMMAND [, ARGUMENTS... ] )
+
+=item command_output_pipe ( [ COMMAND, ARGUMENTS... ], { Opt => Val ... } )
+
+Execute the given C<COMMAND> in the same way as command()
+does but return a pipe filehandle from which the command output can be
+read.
+
+The function can return C<($pipe, $ctx)> in array context.
+See C<command_close_pipe()> for details.
+
+=cut
+
+sub command_output_pipe {
+ _command_common_pipe('-|', @_);
+}
+
+
+=item command_input_pipe ( COMMAND [, ARGUMENTS... ] )
+
+=item command_input_pipe ( [ COMMAND, ARGUMENTS... ], { Opt => Val ... } )
+
+Execute the given C<COMMAND> in the same way as command_output_pipe()
+does but return an input pipe filehandle instead; the command output
+is not captured.
+
+The function can return C<($pipe, $ctx)> in array context.
+See C<command_close_pipe()> for details.
+
+=cut
+
+sub command_input_pipe {
+ _command_common_pipe('|-', @_);
+}
+
+
+=item command_close_pipe ( PIPE [, CTX ] )
+
+Close the C<PIPE> as returned from C<command_*_pipe()>, checking
+whether the command finished successfully. The optional C<CTX> argument
+is required if you want to see the command name in the error message,
+and it is the second value returned by C<command_*_pipe()> when
+called in array context. The call idiom is:
+
+ my ($fh, $ctx) = $r->command_output_pipe('status');
+ while (<$fh>) { ... }
+ $r->command_close_pipe($fh, $ctx);
+
+Note that you should not rely on whatever actually is in C<CTX>;
+currently it is simply the command name but in future the context might
+have more complicated structure.
+
+=cut
+
+sub command_close_pipe {
+ my ($self, $fh, $ctx) = _maybe_self(@_);
+ $ctx ||= '<unknown>';
+ _cmd_close($fh, $ctx);
+}
+
+=item command_bidi_pipe ( COMMAND [, ARGUMENTS... ] )
+
+Execute the given C<COMMAND> in the same way as command_output_pipe()
+does but return both an input pipe filehandle and an output pipe filehandle.
+
+The function will return return C<($pid, $pipe_in, $pipe_out, $ctx)>.
+See C<command_close_bidi_pipe()> for details.
+
+=cut
+
+sub command_bidi_pipe {
+ my ($pid, $in, $out);
+ $pid = open2($in, $out, 'git', @_);
+ return ($pid, $in, $out, join(' ', @_));
+}
+
+=item command_close_bidi_pipe ( PID, PIPE_IN, PIPE_OUT [, CTX] )
+
+Close the C<PIPE_IN> and C<PIPE_OUT> as returned from C<command_bidi_pipe()>,
+checking whether the command finished successfully. The optional C<CTX>
+argument is required if you want to see the command name in the error message,
+and it is the fourth value returned by C<command_bidi_pipe()>. The call idiom
+is:
+
+ my ($pid, $in, $out, $ctx) = $r->command_bidi_pipe('cat-file --batch-check');
+ print "000000000\n" $out;
+ while (<$in>) { ... }
+ $r->command_close_bidi_pipe($pid, $in, $out, $ctx);
+
+Note that you should not rely on whatever actually is in C<CTX>;
+currently it is simply the command name but in future the context might
+have more complicated structure.
+
+=cut
+
+sub command_close_bidi_pipe {
+ local $?;
+ my ($pid, $in, $out, $ctx) = @_;
+ foreach my $fh ($in, $out) {
+ unless (close $fh) {
+ if ($!) {
+ carp "error closing pipe: $!";
+ } elsif ($? >> 8) {
+ throw Git::Error::Command($ctx, $? >>8);
+ }
+ }
+ }
+
+ waitpid $pid, 0;
+
+ if ($? >> 8) {
+ throw Git::Error::Command($ctx, $? >>8);
+ }
+}
+
+
+=item command_noisy ( COMMAND [, ARGUMENTS... ] )
+
+Execute the given C<COMMAND> in the same way as command() does but do not
+capture the command output - the standard output is not redirected and goes
+to the standard output of the caller application.
+
+While the method is called command_noisy(), you might want to as well use
+it for the most silent Git commands which you know will never pollute your
+stdout but you want to avoid the overhead of the pipe setup when calling them.
+
+The function returns only after the command has finished running.
+
+=cut
+
+sub command_noisy {
+ my ($self, $cmd, @args) = _maybe_self(@_);
+ _check_valid_cmd($cmd);
+
+ my $pid = fork;
+ if (not defined $pid) {
+ throw Error::Simple("fork failed: $!");
+ } elsif ($pid == 0) {
+ _cmd_exec($self, $cmd, @args);
+ }
+ if (waitpid($pid, 0) > 0 and $?>>8 != 0) {
+ throw Git::Error::Command(join(' ', $cmd, @args), $? >> 8);
+ }
+}
+
+
+=item version ()
+
+Return the Git version in use.
+
+=cut
+
+sub version {
+ my $verstr = command_oneline('--version');
+ $verstr =~ s/^git version //;
+ $verstr;
+}
+
+
+=item exec_path ()
+
+Return path to the Git sub-command executables (the same as
+C<git --exec-path>). Useful mostly only internally.
+
+=cut
+
+sub exec_path { command_oneline('--exec-path') }
+
+
+=item repo_path ()
+
+Return path to the git repository. Must be called on a repository instance.
+
+=cut
+
+sub repo_path { $_[0]->{opts}->{Repository} }
+
+
+=item wc_path ()
+
+Return path to the working copy. Must be called on a repository instance.
+
+=cut
+
+sub wc_path { $_[0]->{opts}->{WorkingCopy} }
+
+
+=item wc_subdir ()
+
+Return path to the subdirectory inside of a working copy. Must be called
+on a repository instance.
+
+=cut
+
+sub wc_subdir { $_[0]->{opts}->{WorkingSubdir} ||= '' }
+
+
+=item wc_chdir ( SUBDIR )
+
+Change the working copy subdirectory to work within. The C<SUBDIR> is
+relative to the working copy root directory (not the current subdirectory).
+Must be called on a repository instance attached to a working copy
+and the directory must exist.
+
+=cut
+
+sub wc_chdir {
+ my ($self, $subdir) = @_;
+ $self->wc_path()
+ or throw Error::Simple("bare repository");
+
+ -d $self->wc_path().'/'.$subdir
+ or throw Error::Simple("subdir not found: $!");
+ # Of course we will not "hold" the subdirectory so anyone
+ # can delete it now and we will never know. But at least we tried.
+
+ $self->{opts}->{WorkingSubdir} = $subdir;
+}
+
+
+=item config ( VARIABLE )
+
+Retrieve the configuration C<VARIABLE> in the same manner as C<config>
+does. In scalar context requires the variable to be set only one time
+(exception is thrown otherwise), in array context returns allows the
+variable to be set multiple times and returns all the values.
+
+This currently wraps command('config') so it is not so fast.
+
+=cut
+
+sub config {
+ my ($self, $var) = _maybe_self(@_);
+
+ try {
+ my @cmd = ('config');
+ unshift @cmd, $self if $self;
+ if (wantarray) {
+ return command(@cmd, '--get-all', $var);
+ } else {
+ return command_oneline(@cmd, '--get', $var);
+ }
+ } catch Git::Error::Command with {
+ my $E = shift;
+ if ($E->value() == 1) {
+ # Key not found.
+ return;
+ } else {
+ throw $E;
+ }
+ };
+}
+
+
+=item config_bool ( VARIABLE )
+
+Retrieve the bool configuration C<VARIABLE>. The return value
+is usable as a boolean in perl (and C<undef> if it's not defined,
+of course).
+
+This currently wraps command('config') so it is not so fast.
+
+=cut
+
+sub config_bool {
+ my ($self, $var) = _maybe_self(@_);
+
+ try {
+ my @cmd = ('config', '--bool', '--get', $var);
+ unshift @cmd, $self if $self;
+ my $val = command_oneline(@cmd);
+ return undef unless defined $val;
+ return $val eq 'true';
+ } catch Git::Error::Command with {
+ my $E = shift;
+ if ($E->value() == 1) {
+ # Key not found.
+ return undef;
+ } else {
+ throw $E;
+ }
+ };
+}
+
+=item config_int ( VARIABLE )
+
+Retrieve the integer configuration C<VARIABLE>. The return value
+is simple decimal number. An optional value suffix of 'k', 'm',
+or 'g' in the config file will cause the value to be multiplied
+by 1024, 1048576 (1024^2), or 1073741824 (1024^3) prior to output.
+It would return C<undef> if configuration variable is not defined,
+
+This currently wraps command('config') so it is not so fast.
+
+=cut
+
+sub config_int {
+ my ($self, $var) = _maybe_self(@_);
+
+ try {
+ my @cmd = ('config', '--int', '--get', $var);
+ unshift @cmd, $self if $self;
+ return command_oneline(@cmd);
+ } catch Git::Error::Command with {
+ my $E = shift;
+ if ($E->value() == 1) {
+ # Key not found.
+ return undef;
+ } else {
+ throw $E;
+ }
+ };
+}
+
+=item get_colorbool ( NAME )
+
+Finds if color should be used for NAMEd operation from the configuration,
+and returns boolean (true for "use color", false for "do not use color").
+
+=cut
+
+sub get_colorbool {
+ my ($self, $var) = @_;
+ my $stdout_to_tty = (-t STDOUT) ? "true" : "false";
+ my $use_color = $self->command_oneline('config', '--get-colorbool',
+ $var, $stdout_to_tty);
+ return ($use_color eq 'true');
+}
+
+=item get_color ( SLOT, COLOR )
+
+Finds color for SLOT from the configuration, while defaulting to COLOR,
+and returns the ANSI color escape sequence:
+
+ print $repo->get_color("color.interactive.prompt", "underline blue white");
+ print "some text";
+ print $repo->get_color("", "normal");
+
+=cut
+
+sub get_color {
+ my ($self, $slot, $default) = @_;
+ my $color = $self->command_oneline('config', '--get-color', $slot, $default);
+ if (!defined $color) {
+ $color = "";
+ }
+ return $color;
+}
+
+=item remote_refs ( REPOSITORY [, GROUPS [, REFGLOBS ] ] )
+
+This function returns a hashref of refs stored in a given remote repository.
+The hash is in the format C<refname =\> hash>. For tags, the C<refname> entry
+contains the tag object while a C<refname^{}> entry gives the tagged objects.
+
+C<REPOSITORY> has the same meaning as the appropriate C<git-ls-remote>
+argument; either an URL or a remote name (if called on a repository instance).
+C<GROUPS> is an optional arrayref that can contain 'tags' to return all the
+tags and/or 'heads' to return all the heads. C<REFGLOB> is an optional array
+of strings containing a shell-like glob to further limit the refs returned in
+the hash; the meaning is again the same as the appropriate C<git-ls-remote>
+argument.
+
+This function may or may not be called on a repository instance. In the former
+case, remote names as defined in the repository are recognized as repository
+specifiers.
+
+=cut
+
+sub remote_refs {
+ my ($self, $repo, $groups, $refglobs) = _maybe_self(@_);
+ my @args;
+ if (ref $groups eq 'ARRAY') {
+ foreach (@$groups) {
+ if ($_ eq 'heads') {
+ push (@args, '--heads');
+ } elsif ($_ eq 'tags') {
+ push (@args, '--tags');
+ } else {
+ # Ignore unknown groups for future
+ # compatibility
+ }
+ }
+ }
+ push (@args, $repo);
+ if (ref $refglobs eq 'ARRAY') {
+ push (@args, @$refglobs);
+ }
+
+ my @self = $self ? ($self) : (); # Ultra trickery
+ my ($fh, $ctx) = Git::command_output_pipe(@self, 'ls-remote', @args);
+ my %refs;
+ while (<$fh>) {
+ chomp;
+ my ($hash, $ref) = split(/\t/, $_, 2);
+ $refs{$ref} = $hash;
+ }
+ Git::command_close_pipe(@self, $fh, $ctx);
+ return \%refs;
+}
+
+
+=item ident ( TYPE | IDENTSTR )
+
+=item ident_person ( TYPE | IDENTSTR | IDENTARRAY )
+
+This suite of functions retrieves and parses ident information, as stored
+in the commit and tag objects or produced by C<var GIT_type_IDENT> (thus
+C<TYPE> can be either I<author> or I<committer>; case is insignificant).
+
+The C<ident> method retrieves the ident information from C<git var>
+and either returns it as a scalar string or as an array with the fields parsed.
+Alternatively, it can take a prepared ident string (e.g. from the commit
+object) and just parse it.
+
+C<ident_person> returns the person part of the ident - name and email;
+it can take the same arguments as C<ident> or the array returned by C<ident>.
+
+The synopsis is like:
+
+ my ($name, $email, $time_tz) = ident('author');
+ "$name <$email>" eq ident_person('author');
+ "$name <$email>" eq ident_person($name);
+ $time_tz =~ /^\d+ [+-]\d{4}$/;
+
+=cut
+
+sub ident {
+ my ($self, $type) = _maybe_self(@_);
+ my $identstr;
+ if (lc $type eq lc 'committer' or lc $type eq lc 'author') {
+ my @cmd = ('var', 'GIT_'.uc($type).'_IDENT');
+ unshift @cmd, $self if $self;
+ $identstr = command_oneline(@cmd);
+ } else {
+ $identstr = $type;
+ }
+ if (wantarray) {
+ return $identstr =~ /^(.*) <(.*)> (\d+ [+-]\d{4})$/;
+ } else {
+ return $identstr;
+ }
+}
+
+sub ident_person {
+ my ($self, @ident) = _maybe_self(@_);
+ $#ident == 0 and @ident = $self ? $self->ident($ident[0]) : ident($ident[0]);
+ return "$ident[0] <$ident[1]>";
+}
+
+
+=item hash_object ( TYPE, FILENAME )
+
+Compute the SHA1 object id of the given C<FILENAME> considering it is
+of the C<TYPE> object type (C<blob>, C<commit>, C<tree>).
+
+The method can be called without any instance or on a specified Git repository,
+it makes zero difference.
+
+The function returns the SHA1 hash.
+
+=cut
+
+# TODO: Support for passing FILEHANDLE instead of FILENAME
+sub hash_object {
+ my ($self, $type, $file) = _maybe_self(@_);
+ command_oneline('hash-object', '-t', $type, $file);
+}
+
+
+=item hash_and_insert_object ( FILENAME )
+
+Compute the SHA1 object id of the given C<FILENAME> and add the object to the
+object database.
+
+The function returns the SHA1 hash.
+
+=cut
+
+# TODO: Support for passing FILEHANDLE instead of FILENAME
+sub hash_and_insert_object {
+ my ($self, $filename) = @_;
+
+ carp "Bad filename \"$filename\"" if $filename =~ /[\r\n]/;
+
+ $self->_open_hash_and_insert_object_if_needed();
+ my ($in, $out) = ($self->{hash_object_in}, $self->{hash_object_out});
+
+ unless (print $out $filename, "\n") {
+ $self->_close_hash_and_insert_object();
+ throw Error::Simple("out pipe went bad");
+ }
+
+ chomp(my $hash = <$in>);
+ unless (defined($hash)) {
+ $self->_close_hash_and_insert_object();
+ throw Error::Simple("in pipe went bad");
+ }
+
+ return $hash;
+}
+
+sub _open_hash_and_insert_object_if_needed {
+ my ($self) = @_;
+
+ return if defined($self->{hash_object_pid});
+
+ ($self->{hash_object_pid}, $self->{hash_object_in},
+ $self->{hash_object_out}, $self->{hash_object_ctx}) =
+ command_bidi_pipe(qw(hash-object -w --stdin-paths));
+}
+
+sub _close_hash_and_insert_object {
+ my ($self) = @_;
+
+ return unless defined($self->{hash_object_pid});
+
+ my @vars = map { 'hash_object_' . $_ } qw(pid in out ctx);
+
+ command_close_bidi_pipe(@$self{@vars});
+ delete @$self{@vars};
+}
+
+=item cat_blob ( SHA1, FILEHANDLE )
+
+Prints the contents of the blob identified by C<SHA1> to C<FILEHANDLE> and
+returns the number of bytes printed.
+
+=cut
+
+sub cat_blob {
+ my ($self, $sha1, $fh) = @_;
+
+ $self->_open_cat_blob_if_needed();
+ my ($in, $out) = ($self->{cat_blob_in}, $self->{cat_blob_out});
+
+ unless (print $out $sha1, "\n") {
+ $self->_close_cat_blob();
+ throw Error::Simple("out pipe went bad");
+ }
+
+ my $description = <$in>;
+ if ($description =~ / missing$/) {
+ carp "$sha1 doesn't exist in the repository";
+ return -1;
+ }
+
+ if ($description !~ /^[0-9a-fA-F]{40} \S+ (\d+)$/) {
+ carp "Unexpected result returned from git cat-file";
+ return -1;
+ }
+
+ my $size = $1;
+
+ my $blob;
+ my $bytesRead = 0;
+
+ while (1) {
+ my $bytesLeft = $size - $bytesRead;
+ last unless $bytesLeft;
+
+ my $bytesToRead = $bytesLeft < 1024 ? $bytesLeft : 1024;
+ my $read = read($in, $blob, $bytesToRead, $bytesRead);
+ unless (defined($read)) {
+ $self->_close_cat_blob();
+ throw Error::Simple("in pipe went bad");
+ }
+
+ $bytesRead += $read;
+ }
+
+ # Skip past the trailing newline.
+ my $newline;
+ my $read = read($in, $newline, 1);
+ unless (defined($read)) {
+ $self->_close_cat_blob();
+ throw Error::Simple("in pipe went bad");
+ }
+ unless ($read == 1 && $newline eq "\n") {
+ $self->_close_cat_blob();
+ throw Error::Simple("didn't find newline after blob");
+ }
+
+ unless (print $fh $blob) {
+ $self->_close_cat_blob();
+ throw Error::Simple("couldn't write to passed in filehandle");
+ }
+
+ return $size;
+}
+
+sub _open_cat_blob_if_needed {
+ my ($self) = @_;
+
+ return if defined($self->{cat_blob_pid});
+
+ ($self->{cat_blob_pid}, $self->{cat_blob_in},
+ $self->{cat_blob_out}, $self->{cat_blob_ctx}) =
+ command_bidi_pipe(qw(cat-file --batch));
+}
+
+sub _close_cat_blob {
+ my ($self) = @_;
+
+ return unless defined($self->{cat_blob_pid});
+
+ my @vars = map { 'cat_blob_' . $_ } qw(pid in out ctx);
+
+ command_close_bidi_pipe(@$self{@vars});
+ delete @$self{@vars};
+}
+
+
+{ # %TEMP_* Lexical Context
+
+my (%TEMP_FILEMAP, %TEMP_FILES);
+
+=item temp_acquire ( NAME )
+
+Attempts to retreive the temporary file mapped to the string C<NAME>. If an
+associated temp file has not been created this session or was closed, it is
+created, cached, and set for autoflush and binmode.
+
+Internally locks the file mapped to C<NAME>. This lock must be released with
+C<temp_release()> when the temp file is no longer needed. Subsequent attempts
+to retrieve temporary files mapped to the same C<NAME> while still locked will
+cause an error. This locking mechanism provides a weak guarantee and is not
+threadsafe. It does provide some error checking to help prevent temp file refs
+writing over one another.
+
+In general, the L<File::Handle> returned should not be closed by consumers as
+it defeats the purpose of this caching mechanism. If you need to close the temp
+file handle, then you should use L<File::Temp> or another temp file faculty
+directly. If a handle is closed and then requested again, then a warning will
+issue.
+
+=cut
+
+sub temp_acquire {
+ my $temp_fd = _temp_cache(@_);
+
+ $TEMP_FILES{$temp_fd}{locked} = 1;
+ $temp_fd;
+}
+
+=item temp_release ( NAME )
+
+=item temp_release ( FILEHANDLE )
+
+Releases a lock acquired through C<temp_acquire()>. Can be called either with
+the C<NAME> mapping used when acquiring the temp file or with the C<FILEHANDLE>
+referencing a locked temp file.
+
+Warns if an attempt is made to release a file that is not locked.
+
+The temp file will be truncated before being released. This can help to reduce
+disk I/O where the system is smart enough to detect the truncation while data
+is in the output buffers. Beware that after the temp file is released and
+truncated, any operations on that file may fail miserably until it is
+re-acquired. All contents are lost between each release and acquire mapped to
+the same string.
+
+=cut
+
+sub temp_release {
+ my ($self, $temp_fd, $trunc) = _maybe_self(@_);
+
+ if (exists $TEMP_FILEMAP{$temp_fd}) {
+ $temp_fd = $TEMP_FILES{$temp_fd};
+ }
+ unless ($TEMP_FILES{$temp_fd}{locked}) {
+ carp "Attempt to release temp file '",
+ $temp_fd, "' that has not been locked";
+ }
+ temp_reset($temp_fd) if $trunc and $temp_fd->opened;
+
+ $TEMP_FILES{$temp_fd}{locked} = 0;
+ undef;
+}
+
+sub _temp_cache {
+ my ($self, $name) = _maybe_self(@_);
+
+ _verify_require();
+
+ my $temp_fd = \$TEMP_FILEMAP{$name};
+ if (defined $$temp_fd and $$temp_fd->opened) {
+ if ($TEMP_FILES{$$temp_fd}{locked}) {
+ throw Error::Simple("Temp file with moniker '",
+ $name, "' already in use");
+ }
+ } else {
+ if (defined $$temp_fd) {
+ # then we're here because of a closed handle.
+ carp "Temp file '", $name,
+ "' was closed. Opening replacement.";
+ }
+ my $fname;
+
+ my $tmpdir;
+ if (defined $self) {
+ $tmpdir = $self->repo_path();
+ }
+
+ ($$temp_fd, $fname) = File::Temp->tempfile(
+ 'Git_XXXXXX', UNLINK => 1, DIR => $tmpdir,
+ ) or throw Error::Simple("couldn't open new temp file");
+
+ $$temp_fd->autoflush;
+ binmode $$temp_fd;
+ $TEMP_FILES{$$temp_fd}{fname} = $fname;
+ }
+ $$temp_fd;
+}
+
+sub _verify_require {
+ eval { require File::Temp; require File::Spec; };
+ $@ and throw Error::Simple($@);
+}
+
+=item temp_reset ( FILEHANDLE )
+
+Truncates and resets the position of the C<FILEHANDLE>.
+
+=cut
+
+sub temp_reset {
+ my ($self, $temp_fd) = _maybe_self(@_);
+
+ truncate $temp_fd, 0
+ or throw Error::Simple("couldn't truncate file");
+ sysseek($temp_fd, 0, SEEK_SET) and seek($temp_fd, 0, SEEK_SET)
+ or throw Error::Simple("couldn't seek to beginning of file");
+ sysseek($temp_fd, 0, SEEK_CUR) == 0 and tell($temp_fd) == 0
+ or throw Error::Simple("expected file position to be reset");
+}
+
+=item temp_path ( NAME )
+
+=item temp_path ( FILEHANDLE )
+
+Returns the filename associated with the given tempfile.
+
+=cut
+
+sub temp_path {
+ my ($self, $temp_fd) = _maybe_self(@_);
+
+ if (exists $TEMP_FILEMAP{$temp_fd}) {
+ $temp_fd = $TEMP_FILEMAP{$temp_fd};
+ }
+ $TEMP_FILES{$temp_fd}{fname};
+}
+
+sub END {
+ unlink values %TEMP_FILEMAP if %TEMP_FILEMAP;
+}
+
+} # %TEMP_* Lexical Context
+
+=back
+
+=head1 ERROR HANDLING
+
+All functions are supposed to throw Perl exceptions in case of errors.
+See the L<Error> module on how to catch those. Most exceptions are mere
+L<Error::Simple> instances.
+
+However, the C<command()>, C<command_oneline()> and C<command_noisy()>
+functions suite can throw C<Git::Error::Command> exceptions as well: those are
+thrown when the external command returns an error code and contain the error
+code as well as access to the captured command's output. The exception class
+provides the usual C<stringify> and C<value> (command's exit code) methods and
+in addition also a C<cmd_output> method that returns either an array or a
+string with the captured command output (depending on the original function
+call context; C<command_noisy()> returns C<undef>) and $<cmdline> which
+returns the command and its arguments (but without proper quoting).
+
+Note that the C<command_*_pipe()> functions cannot throw this exception since
+it has no idea whether the command failed or not. You will only find out
+at the time you C<close> the pipe; if you want to have that automated,
+use C<command_close_pipe()>, which can throw the exception.
+
+=cut
+
+{
+ package Git::Error::Command;
+
+ @Git::Error::Command::ISA = qw(Error);
+
+ sub new {
+ my $self = shift;
+ my $cmdline = '' . shift;
+ my $value = 0 + shift;
+ my $outputref = shift;
+ my(@args) = ();
+
+ local $Error::Depth = $Error::Depth + 1;
+
+ push(@args, '-cmdline', $cmdline);
+ push(@args, '-value', $value);
+ push(@args, '-outputref', $outputref);
+
+ $self->SUPER::new(-text => 'command returned error', @args);
+ }
+
+ sub stringify {
+ my $self = shift;
+ my $text = $self->SUPER::stringify;
+ $self->cmdline() . ': ' . $text . ': ' . $self->value() . "\n";
+ }
+
+ sub cmdline {
+ my $self = shift;
+ $self->{'-cmdline'};
+ }
+
+ sub cmd_output {
+ my $self = shift;
+ my $ref = $self->{'-outputref'};
+ defined $ref or undef;
+ if (ref $ref eq 'ARRAY') {
+ return @$ref;
+ } else { # SCALAR
+ return $$ref;
+ }
+ }
+}
+
+=over 4
+
+=item git_cmd_try { CODE } ERRMSG
+
+This magical statement will automatically catch any C<Git::Error::Command>
+exceptions thrown by C<CODE> and make your program die with C<ERRMSG>
+on its lips; the message will have %s substituted for the command line
+and %d for the exit status. This statement is useful mostly for producing
+more user-friendly error messages.
+
+In case of no exception caught the statement returns C<CODE>'s return value.
+
+Note that this is the only auto-exported function.
+
+=cut
+
+sub git_cmd_try(&$) {
+ my ($code, $errmsg) = @_;
+ my @result;
+ my $err;
+ my $array = wantarray;
+ try {
+ if ($array) {
+ @result = &$code;
+ } else {
+ $result[0] = &$code;
+ }
+ } catch Git::Error::Command with {
+ my $E = shift;
+ $err = $errmsg;
+ $err =~ s/\%s/$E->cmdline()/ge;
+ $err =~ s/\%d/$E->value()/ge;
+ # We can't croak here since Error.pm would mangle
+ # that to Error::Simple.
+ };
+ $err and croak $err;
+ return $array ? @result : $result[0];
+}
+
+
+=back
+
+=head1 COPYRIGHT
+
+Copyright 2006 by Petr Baudis E<lt>pasky@suse.czE<gt>.
+
+This module is free software; it may be used, copied, modified
+and distributed under the terms of the GNU General Public Licence,
+either version 2, or (at your option) any later version.
+
+=cut
+
+
+# Take raw method argument list and return ($obj, @args) in case
+# the method was called upon an instance and (undef, @args) if
+# it was called directly.
+sub _maybe_self {
+ UNIVERSAL::isa($_[0], 'Git') ? @_ : (undef, @_);
+}
+
+# Check if the command id is something reasonable.
+sub _check_valid_cmd {
+ my ($cmd) = @_;
+ $cmd =~ /^[a-z0-9A-Z_-]+$/ or throw Error::Simple("bad command: $cmd");
+}
+
+# Common backend for the pipe creators.
+sub _command_common_pipe {
+ my $direction = shift;
+ my ($self, @p) = _maybe_self(@_);
+ my (%opts, $cmd, @args);
+ if (ref $p[0]) {
+ ($cmd, @args) = @{shift @p};
+ %opts = ref $p[0] ? %{$p[0]} : @p;
+ } else {
+ ($cmd, @args) = @p;
+ }
+ _check_valid_cmd($cmd);
+
+ my $fh;
+ if ($^O eq 'MSWin32') {
+ # ActiveState Perl
+ #defined $opts{STDERR} and
+ # warn 'ignoring STDERR option - running w/ ActiveState';
+ $direction eq '-|' or
+ die 'input pipe for ActiveState not implemented';
+ # the strange construction with *ACPIPE is just to
+ # explain the tie below that we want to bind to
+ # a handle class, not scalar. It is not known if
+ # it is something specific to ActiveState Perl or
+ # just a Perl quirk.
+ tie (*ACPIPE, 'Git::activestate_pipe', $cmd, @args);
+ $fh = *ACPIPE;
+
+ } else {
+ my $pid = open($fh, $direction);
+ if (not defined $pid) {
+ throw Error::Simple("open failed: $!");
+ } elsif ($pid == 0) {
+ if (defined $opts{STDERR}) {
+ close STDERR;
+ }
+ if ($opts{STDERR}) {
+ open (STDERR, '>&', $opts{STDERR})
+ or die "dup failed: $!";
+ }
+ _cmd_exec($self, $cmd, @args);
+ }
+ }
+ return wantarray ? ($fh, join(' ', $cmd, @args)) : $fh;
+}
+
+# When already in the subprocess, set up the appropriate state
+# for the given repository and execute the git command.
+sub _cmd_exec {
+ my ($self, @args) = @_;
+ if ($self) {
+ $self->repo_path() and $ENV{'GIT_DIR'} = $self->repo_path();
+ $self->wc_path() and chdir($self->wc_path());
+ $self->wc_subdir() and chdir($self->wc_subdir());
+ }
+ _execv_git_cmd(@args);
+ die qq[exec "@args" failed: $!];
+}
+
+# Execute the given Git command ($_[0]) with arguments ($_[1..])
+# by searching for it at proper places.
+sub _execv_git_cmd { exec('git', @_); }
+
+# Close pipe to a subprocess.
+sub _cmd_close {
+ my ($fh, $ctx) = @_;
+ if (not close $fh) {
+ if ($!) {
+ # It's just close, no point in fatalities
+ carp "error closing pipe: $!";
+ } elsif ($? >> 8) {
+ # The caller should pepper this.
+ throw Git::Error::Command($ctx, $? >> 8);
+ }
+ # else we might e.g. closed a live stream; the command
+ # dying of SIGPIPE would drive us here.
+ }
+}
+
+
+sub DESTROY {
+ my ($self) = @_;
+ $self->_close_hash_and_insert_object();
+ $self->_close_cat_blob();
+}
+
+
+# Pipe implementation for ActiveState Perl.
+
+package Git::activestate_pipe;
+use strict;
+
+sub TIEHANDLE {
+ my ($class, @params) = @_;
+ # FIXME: This is probably horrible idea and the thing will explode
+ # at the moment you give it arguments that require some quoting,
+ # but I have no ActiveState clue... --pasky
+ # Let's just hope ActiveState Perl does at least the quoting
+ # correctly.
+ my @data = qx{git @params};
+ bless { i => 0, data => \@data }, $class;
+}
+
+sub READLINE {
+ my $self = shift;
+ if ($self->{i} >= scalar @{$self->{data}}) {
+ return undef;
+ }
+ my $i = $self->{i};
+ if (wantarray) {
+ $self->{i} = $#{$self->{'data'}} + 1;
+ return splice(@{$self->{'data'}}, $i);
+ }
+ $self->{i} = $i + 1;
+ return $self->{'data'}->[ $i ];
+}
+
+sub CLOSE {
+ my $self = shift;
+ delete $self->{data};
+ delete $self->{i};
+}
+
+sub EOF {
+ my $self = shift;
+ return ($self->{i} >= scalar @{$self->{data}});
+}
+
+
+1; # Famous last words