p4.pm #22

package VCP::Utils::p4 ;

=head1 NAME

VCP::Utils::p4 - utilities for dealing with the p4 command

=head1 SYNOPSIS

   use base qw( ... VCP::Utils::p4 ) ;

=head1 DESCRIPTION

A mix-in class providing methods shared by VCP::Source::p4 and VCP::Dest::p4,
mostly wrappers for calling the p4 command.

=cut

use strict ;

use VCP::Debug qw( debug debugging ) ;
use VCP::Utils qw( profile profiling );

=head1 METHODS

=over

=item repo_client

The p4 client name. This is an accessor for a data member in each class.
The data member should be part of VCP::Utils::p4, but the fields pragma
does not support multiple inheritance, so the accessor is here but all
derived classes supporting this accessor must provide for a key named
"P4_REPO_CLIENT".

=cut

sub repo_client {
   my $self = shift ;

   $self->{P4_REPO_CLIENT} = shift if @_ ;
   return $self->{P4_REPO_CLIENT} ;
}


=item p4

Calls the p4 command with the appropriate user, client, port, and password.

=cut

sub p4 {
   my $self = shift ;

   my $p4_command = "";
   if ( profiling ) {
      for( @{$_[0]} ) {
         unless ( /^-/ ) {
            $p4_command = $_;
            last;
         }
      }

      profile "BEG p4 $p4_command";
   }

   local $ENV{P4PASSWD} = $self->repo_password if defined $self->repo_password ;
   unshift @{$_[0]}, '-p', $self->repo_server  if defined $self->repo_server ;
   unshift @{$_[0]}, '-c', $self->repo_client  if defined $self->repo_client ;
   unshift @{$_[0]}, '-u', $self->repo_user    if defined $self->repo_user ;

   ## TODO: Specify an empty 

   ## localizing this was giving me some grief.  Can't recall what.
   ## PWD must be cleared because, unlike all other Unix utilities I
   ## know of, p4 looks at it and bases it's path calculations on it.
   my $tmp = $ENV{PWD} ;
   delete $ENV{PWD} ;

   my $args = shift ;
#if ( $ENV{UHOH} && grep( /^client$/, @$args ) && grep( /^-o$/, @$args ) ) {
#  warn( ">>>>>>>>>>>>>p4.exe @$args > bah1" );
#  system( "p4.exe @$args > bah1" );
#  system( "p4.exe @$args > bah2" );
#}

   $self->run_safely( [ "p4", @$args ], @_ ) ;
   $ENV{PWD} = $tmp if defined $tmp ;

   profile "END p4 $p4_command" if profiling;
}


=item parse_p4_form

   my %form = $self->parse_p4_form( $form );
   my %form = $self->parse_p4_form( \@command_to_emit_form );

Parses a p4 form and returns a list containing the form's data elements
in the order that they were accumulated.  This is suitable for initializing
a hash if order's not important, or an array if it is.

You can pass the form in verbatim, or a reference to a command to run
to get the form.  If the first parameter is an ARRAY reference, all
parameters will be passed to C<$self->p4> with stdout redirected to
a temporary variable.

Multiline fields will have trailing C<\n>s in the data, single-line fields
won't.  All fields have leading spaces on each line removed.

Comments are tagged with a field name of "#", blank (containing only spaces
if that) are tagged with a " ".  This is to allow accurate reproduction
of the file if reemitted.

NOTE: This does not implement 100% compatible p4 forms parsing; it should
be upwards compatible and one day we should implement full forms parsing.

=cut

## this simulates the real C++ tokenizer built in to p4.  That tokenizes
## p4 forms with a state machine that knows about quoting, text blocks,
## etc.  Some layer above the parser informs the parser about whether or
## not the current field is a text block.  This parser tries to emulate that
## tokenizer's behavior without implementing a low level state machine.

sub parse_p4_form {
   my $self = shift;

   my $form;
   
   if ( ref $_[0] eq "ARRAY" ) {
      $self->p4( $_[0], ">", \$form, @_[1..$#_] )
   }
   else {
      $form = shift;
   }

   my @lines = split /\r?\n/, $form;

   my @entries;
   my $cat;  ## Set when catenating lines together in a comment or value
   my $blanks = 0;

   for ( @lines ) {
      ++$blanks, next if /^$/;
      next if /^#/;

#      if ( s/^\s*#\s*(.*)/$1/ ) {
#         $blanks = 0;
#         unless ( @entries && $entries[-2] eq "#" ) {
#            chomp $entries[-1] if $cat;
#            push @entries, ( "#", "" );
#            $cat = 1;
#         }
#      }
#      elsif ( /^([A-Za-z]+):[ \t]*(?:(\S.*))?\z/ ) {
      if ( /^([A-Za-z]+):[ \t]*(?:(\S.*))?\z/ ) {
         chomp $entries[-1] if $cat;
         $cat = undef;
         $blanks = 0;

         push @entries, $1;
         if ( defined $2 ) {
            local $_ = $2;
            s/(^|[ \t]+)#.*//;
            push @entries, length $_ ? "$_\n" : "";
         }
         else {
            push @entries, "";
         }
         $cat = 1;
         next;
      }

      if ( $cat ) {
         s/^\s//;  ## This may be too general.  May need to trim the same
                    ## number of characters from each line.
         $entries[-1] .= "\n" x $blanks;
         $blanks = 0;
         s/(^|[ \t]+)#.*//;
         $entries[-1] .= $_ . "\n";
      }
      elsif ( ! length ) {
         next;
      }
      else {
         ## We warn instead of dieing in case p4 can output things we don't
         ## expect.  TODO: This could be bad, change to die() with a
         ## syntax error.
         warn "Ignoring '$_' from p4 output\n";
      }
   }
   chomp $entries[-1] if $cat;

   return @entries;
}


=item build_p4_form

   my $form = $self->build_p4_form( @form_fields );
   my $form = $self->build_p4_form( %form_fields );
   $self->build_p4_form( ..., \@command_to_emit_form );

Builds a p4 form and either returns it or submits it to the indicated command.

=cut

sub build_p4_form {
   my $self = shift;

   my @form;
   
   while ( @_ ) {
      last if ref $_[0] eq "ARRAY";  ## rest is a command.
      my ( $name, $value ) = ( shift, shift );

      if ( $name eq "#" ) {
         $value =~ s/^/# /mg;
         chomp $value;
         push @form, $value, "\n\n";
         next;
      }

      push @form, ( $name, ":" );

      if ( $value =~ tr/\n// ) {
         push @form, "\n";
         $value =~ s/^(?!$)/\t/gm;
         chomp $value;
         push @form, $value, "\n\n";
      }
      else {
         push @form, ( " ", $value, "\n\n" );
      }
   }

   my $form = join "", @form;
   @form = ();

   $self->p4( $_[0], "<", \$form, @_[1..$#_] ) if @_;

   return $form;
}


=item parse_p4_repo_spec

Calls $self->parse_repo_spec, the post-processes the repo_user in to a user
name and a client view. If the user specified no client name, then a client
name of "vcp_tmp_$$" is used by default.

This also initializes the client to have a mapping to a working directory
under /tmp, and arranges for the current client definition to be restored
or deleted on exit.

=cut

sub parse_p4_repo_spec {
   my $self = shift ;
   my ( $spec ) = @_ ;

   my $parsed_spec = $self->parse_repo_spec( $spec ) ;

   my ( $user, $client ) ;
   ( $user, $client ) = $self->repo_user =~ m/([^()]*)(?:\((.*)\))?/
      if defined $self->repo_user ;
   $client = "vcp_tmp_$$" unless defined $client && length $client ;

   $self->repo_user( $user ) ;
   $self->repo_client( $client ) ;

   if ( $self->can( "min" ) ) {
      my $filespec = $self->repo_filespec ;

      ## If a change range was specified, we need to list the files in
      ## each change.  p4 doesn't allow an @ range in the filelog command,
      ## for wataver reason, so we must parse it ourselves and call lots
      ## of filelog commands.  Even if it did, we need to chunk the list
      ## so that we don't consume too much memory or need a temporary file
      ## to contain one line per revision per file for an entire large
      ## repo.
      my ( $name, $min, $comma, $max ) ;
      ( $name, $min, $comma, $max ) =
	 $filespec =~ m/^([^@]*)(?:@(-?\d+)(?:(\D|\.\.)((?:\d+|#head)))?)?$/i
	 or die "Unable to parse p4 filespec '$filespec'\n";

      die "'$comma' should be ',' in change_id range in '$filespec'\n"
	 if defined $comma && $comma ne ',' ;

      if ( ! defined $min ) {
	 $min = 1 ;
	 $max = '#head' ;
      }

      if ( ! defined $max ) {
	 $max = $min ;
      }
      elsif ( lc( $max ) eq '#head' ) {
	 $self->p4( [qw( counter change )], \$max ) ;
	 chomp $max ;
      }

      if ( $max == 0 ) {
         ## TODO: make this a "normal exit"
         die "Current change number is 0, no work to do\n";
      }

      if ( $min < 0 ) {
	 $min = $max + $min ;
      }

      $self->repo_filespec( $name ) ;
      $self->min( $min ) ;
      $self->max( $max ) ;
   }

   return $parsed_spec ;
}


=item init_p4_view

   $self->init_p4_view

Borrows or creates a client with the right view.  Only called from
VCP::Dest::p4, since VCP::Source::p4 uses non-view oriented commands.

=cut

sub init_p4_view {
   my $self = shift ;

   my $client = $self->repo_client ;

   $self->repo_client( undef ) ;
   my $client_exists = grep $_ eq $client, $self->p4_clients ;
   debug "p4: client '$client' exists" if $client_exists && debugging $self ;
   $self->repo_client( $client ) ;
   my $client_spec = $self->p4_get_client_spec ;
## work around a wierd intermittant failure on Win32.  The
## Options: line *should* end in nomodtime normdir
## instead it looks like:
##
## Options:	noallwrite noclobber nocompress unlocked nom+
##
## but only occasionally!
$client_spec = $self->p4_get_client_spec
    if $^O =~ /Win32/ && $client_spec =~ /[\x80-\xFF]/;

   $self->queue_p4_restore_client_spec( $client_exists ? $client_spec : undef );

   my $p4_spec = $self->repo_filespec ;
   $p4_spec =~ s{(/(\.\.\.)?)?$}{/...} ;
   my $work_dir = $self->work_root ;

   $client_spec =~ s{^Root.*}{Root:\t$work_dir}m ;
   $client_spec =~ s{^View.*}{View:\n\t$p4_spec\t//$client/...\n}ms ;
   debug "p4: using client spec", $client_spec if debugging $self ;
   $client_spec =~ s{^(Options:.*)}{$1 nocrlf}m 
      if $^O =~ /Win32/ ;
   $client_spec =~ s{^LineEnd.*}{LineEnd:\tunix}mi ;

   debug "p4: using client spec", $client_spec if debugging $self ;

   $self->p4_set_client_spec( $client_spec ) ;

}

=item p4_clients

Returns a list of known clients.

=cut

sub p4_clients {
   my $self = shift ;

   my $clients ;
   $self->p4( [ "clients", ], ">", \$clients ) ;
   return map { /^Client (\S*)/ ; $1 } split /\n/m, $clients ;
}

=item p4_get_client_spec

Returns the current client spec for the named client. The client may or may not
exist first, grep the results from L</p4_clients> to see if it already exists.

=cut

sub p4_get_client_spec {
   my $self = shift ;
   my $client_spec ;
   $self->p4( [ "client", "-o" ], ">", \$client_spec ) ;
   return $client_spec ;
}


=item queue_p4_restore_client_spec

   $self->queue_p4_restore_client_spec( $client_spec ) ;

Saves a copy of the named p4 client and arranges for it's restoral on exit
(assuming END blocks run). Used when altering a user-specified client that
already exists.

If $client_spec is undefined, then the named client will be deleted on
exit.

Note that END blocks may be skipped in certain cases, like coredumps,
kill -9, or a call to POSIX::exit().  None of these should happen except
in debugging, but...

=cut

my @client_backups ;
my @p4ds_to_kill;

END {
   my $child_exit;
   {
      local $?;  ## Protect this; we're about to run a child process and
                 ## we want to exit with the appropriate value.
      for ( @client_backups ) {
         my ( $object, $name, $spec ) = @$_ ;
         my $tmp_name = $object->repo_client ;
         $object->repo_client( $name ) ;
         if ( defined $spec ) {
            $object->p4_set_client_spec( $spec ) ;
         }
         else {
            my $out ;
            $object->p4( [ "client", "-df", $object->repo_client ], ">", \$out);
            warn "vcp: unexpected stdout from p4:\np4: ", $out
               unless $out =~ /^Client\s.*\sdeleted./ ;
            $child_exit = $?;
         }
         $object->repo_client( $tmp_name ) ;
         $_ = undef ;
      }
      @client_backups = () ;
   }
   $? = $child_exit if $child_exit && ! $?;

   __PACKAGE__->kill_all_vcp_p4ds;
}


sub queue_p4_restore_client_spec {
   my $self = shift ;
   my ( $client_spec ) = @_ ;
   push @client_backups, [ $self, $self->repo_client, $client_spec ] ;
}

=item p4_set_client_spec

   $self->p4_set_client_spec( $client_spec ) ;

Writes a client spec to the repository.

=cut


sub p4_set_client_spec {
   my $self = shift ;
   my ( $client_spec ) = @_ ;

   ## Capture stdout so it doesn't leak.
   my $out ;
   $self->p4( [ "client", "-i" ], "<", \$client_spec, ">", \$out ) ;

   die "vcp: unexpected stdout from p4:\np4: ", $out
      unless $out =~ /^Client\s.*\ssaved.$/ ;
}

=item run_p4d

=cut
   

sub run_p4d {
   my $self = shift;

   my ( $dir, $port ) = split ":", $self->repo_server, 2;

   $port = $self->launch_p4d( $dir, $port );
   $self->repo_server( "localhost:$port" );
}



=item launch_p4d

VCP can use its own p4d, this sub is used to launch it and queue its
demise when the program exits.

The $p4root argument is required.  The $p4port is optional; if
undefined, a random p4 port is chosen.

The return value is the p4 port.

TODO: Make VCP.pm kill things when the transfer is over and only use
END{} subs if that fails.

=cut

sub launch_p4d {
   my $self = shift;
   my ( $p4root, $p4port ) = @_;

   require VCP::Utils;
   require IPC::Run;

   my $h ;

   # use a random port if the caller hasn't provided one
   until ( defined $p4port ) {
      ## 30_000 is because I vaguely recall some TCP stack that had problems
      ## with listening on really high ports.  2048 is because I vaguely recall
      ## that some OS required root privs up to 2047 instead of 1023.
      $p4port = ( rand( 65536 ) % 30_000 ) + 2048 ;
      $p4port = undef if $p4port == 1666;
   }

   my @p4d = ( "p4d", "-f", "-r", $p4root, "-p", $p4port ) ;
   warn "vcp\$ ", VCP::Utils::shell_quote( @p4d ), "\n" ;

   ## Ok, this is wierd: we need to fork & run p4d in foreground mode so that
   ## we can capture it's PID and kill it later.  There doesn't seem to be
   ## the equivalent of a 'p4d.pid' file. If we let it daemonize, then I
   ## don't know how to get it's PID.

   $h = IPC::Run::start( \@p4d );
   ## Wait for p4d to start.  'twould be better to wait for P4PORT to
   ## be seen.
   sleep 1 ;
 
   ## The child process will have died if the port is taken or due
   ## to other errors.
   unless ( $h->pumpable ) {
      $h->finish;
      die VCP::Utils::shell_quote( @p4d ), ", failed to start, aborting\n";
   }

   push @{p4ds_to_kill}, $h;

   return $p4port;
}


=item kill_all_vcp_p4ds

Kills all p4ds that have been started by this VCP process.

=cut

sub kill_all_vcp_p4ds {
   for my $h ( @p4ds_to_kill ) {
      warn "vcp: killing p4d\n";
      eval { $h->kill_kill; 1 } or warn "vcp: $@ killing p4d\n";
      $? = 0;  ## p4d exits with a "15", which becomes our exit code
               ## if we don't clear this.
   }
}

=back

=head1 COPYRIGHT

Copyright 2000, Perforce Software, Inc.  All Rights Reserved.

This module and the VCP package are licensed according to the terms given in
the file LICENSE accompanying this distribution, a copy of which is included in
L<vcp>.

=cut

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