factor out runsh

A common function to run shell commands, with a nice little optimisation
for "true" and "false". That optimisation speeds up "mr list" by 2 seconds
here.

diff --git a/debian/changelog b/debian/changelog
index fa4b5d9949bb8b0be8354cb6ac2902aad808877e..e35f338f95f5bcd9e1f2fcb8fcda25dc49806ca3 100644 (file)
--- a/debian/changelog
+++ b/debian/changelog
@@ -8,6 +8,7 @@ mr (1.07) UNRELEASED; urgency=low
     paths with more than one path segment. (Thanks, Adam Spiers)
   * Support _append to add on to the existing value of a parameter.
     (Thanks, Adam Spiers)
+  * Optimizations.
 
  -- Joey Hess <joeyh@debian.org>  Tue, 29 Nov 2011 18:15:51 -0400
 

diff --git a/mr b/mr
index f14ba4dddebfd38fb55f9a823e7cea2e7050b2b2..38bf2b779306063440b13aeb5fd487c714c93c99 100755 (executable)
--- a/mr
+++ b/mr
@@ -539,6 +539,42 @@ my (@ok, @failed, @skipped);
 
 main();
 
+sub shellquote {
+       my $i=shift;
+       $i=~s/'/'"'"'/g;
+       return "'$i'";
+}
+
+# Runs a shell command using a supplied function.
+# The lib will be included in the shell command line, and any params
+# will be available in the shell as $1, $2, etc.
+my $lastlib;
+sub runsh {
+       my ($action, $topdir, $subdir, $command, $params, $runner) = @_;
+
+       # optimisation: avoid running the shell for true and false
+       if ($command =~ /^\s*true\s*$/) {
+               $?=0;
+               return 0;
+       }
+       elsif ($command =~ /^\s*false\s*$/) {
+               $?=0;
+               return 1;
+       }
+       
+       my $quotedparams=join(" ", (map { shellquote($_) } @$params));
+       my $lib=exists $config{$topdir}{$subdir}{lib} ?
+                      $config{$topdir}{$subdir}{lib}."\n" : "";
+       if ($verbose && (! defined $lastlib || $lastlib ne $lib)) {
+               print "mr library now: >>$lib<<\n";
+               $lastlib=$lib;
+       }
+       my $shellcode="set -e;".$lib.
+               "my_sh(){ $command\n }; my_sh $quotedparams";
+       print "mr $action: running $action >>$command<<\n" if $verbose;
+       $runner->($shellcode);
+}
+
 my %vcs;
 sub vcs_test {
        my ($action, $dir, $topdir, $subdir) = @_;
@@ -547,7 +583,7 @@ sub vcs_test {
                return $vcs{$dir};
        }
 
-       my $test="set -e\n";
+       my $test="";
        foreach my $vcs_test (
                        sort {
                                length $a <=> length $b 
@@ -558,12 +594,13 @@ sub vcs_test {
                $test="my_$vcs_test() {\n$config{$topdir}{$subdir}{$vcs_test}\n}\n".$test;
                $test.="if my_$vcs_test; then echo $vcs; fi\n";
        }
-       $test=$config{$topdir}{$subdir}{lib}."\n".$test
-               if exists $config{$topdir}{$subdir}{lib};
-       
-       print "mr $action: running vcs test >>$test<<\n" if $verbose;
-       my $vcs=`$test`;
-       chomp $vcs;
+
+       my $vcs=runsh "vcs test", $topdir, $subdir, $test, [], sub {
+               my $sh=shift;
+               my $ret=`$sh`;
+               chomp $ret;
+               return $ret;
+       };
        if ($vcs=~/\n/s) {
                $vcs=~s/\n/, /g;
                print STDERR "mr $action: found multiple possible repository types ($vcs) for ".fulldir($topdir, $subdir)."\n";
@@ -609,8 +646,6 @@ sub action {
        my $fulldir=fulldir($topdir, $subdir);
 
        $ENV{MR_CONFIG}=$configfiles{$topdir};
-       my $lib=exists $config{$topdir}{$subdir}{lib} ?
-                      $config{$topdir}{$subdir}{lib}."\n" : "";
        my $is_checkout=($action eq 'checkout');
        my $is_update=($action =~ /update/);
 
@@ -621,10 +656,9 @@ sub action {
                my $testcommand=findcommand($testname, $dir, $topdir, $subdir, $is_checkout);
 
                if (defined $testcommand) {
-                       my $test="set -e;".$lib.
-                               "my_action(){ $testcommand\n }; my_action '$action'";
-                       print "mr $action: running $testname test >>$test<<\n" if $verbose;
-                       my $ret=system($test);
+                       my $ret=runsh "$testname test", $topdir, $subdir,
+                               $testcommand, [$action],
+                               sub { system(shift()) };
                        if ($ret != 0) {
                                if (($? & 127) == 2) {
                                        print STDERR "mr $action: interrupted\n";
@@ -701,22 +735,22 @@ sub action {
                my $hookret=hook("pre_$action", $topdir, $subdir);
                return $hookret if $hookret != OK;
 
-               $command="set -e; ".$lib.
-                       "my_action(){ $command\n }; my_action ".
-                       join(" ", map { s/\\/\\\\/g; s/"/\"/g; '"'.$_.'"' } @ARGV);
-               print "mr $action: running >>$command<<\n" if $verbose;
-               my $ret;
-               if ($quiet) {
-                       my $output = qx/$command 2>&1/;
-                       $ret = $?;
-                       if ($ret != 0) {
-                               print "$actionmsg\n";
-                               print STDERR $output;
-                       }
-               }
-               else {
-                       $ret=system($command);
-               }
+               my $ret=runsh $action, $topdir, $subdir,
+                       $command, \@ARGV, sub {
+                               my $sh=shift;
+                               if ($quiet) {
+                                       my $output = qx/$sh 2>&1/;
+                                       my $ret = $?;
+                                       if ($ret != 0) {
+                                               print "$actionmsg\n";
+                                               print STDERR $output;
+                                       }
+                                       return $ret;
+                               }
+                               else {
+                                       system($sh);
+                               }
+                       };
                if ($ret != 0) {
                        if (($? & 127) == 2) {
                                print STDERR "mr $action: interrupted\n";
@@ -767,22 +801,20 @@ sub hook {
 
        my $command=$config{$topdir}{$subdir}{$hook};
        return OK unless defined $command;
-       my $lib=exists $config{$topdir}{$subdir}{lib} ?
-                      $config{$topdir}{$subdir}{lib}."\n" : "";
-       my $shell="set -e;".$lib.
-               "my_hook(){ $command\n }; my_hook";
-       print "mr $hook: running >>$shell<<\n" if $verbose;
-       my $ret;
-       if ($quiet) {
-               my $output = qx/$shell 2>&1/;
-               $ret = $?;
-               if ($ret != 0) {
-                       print STDERR $output;
-               }
-       }
-       else {
-               $ret=system($shell);
-       }
+       my $ret=runsh $hook, $topdir, $subdir, $command, [], sub {
+                       my $sh=shift;
+                       if ($quiet) {
+                               my $output = qx/$sh 2>&1/;
+                               my $ret = $?;
+                               if ($ret != 0) {
+                                       print STDERR $output;
+                               }
+                               return $ret;
+                       }
+                       else {
+                               system($sh);
+                       }
+               };
        if ($ret != 0) {
                if (($? & 127) == 2) {
                        print STDERR "mr $hook: interrupted\n";