From 055e803851e73bb94d341c3b4f25f52be167fef7 Mon Sep 17 00:00:00 2001
From: Shea Levy <shea@shealevy.com>
Date: Thu, 29 Mar 2012 18:20:31 +0200
Subject: [PATCH] Add the '--show-progress' flag to nix-copy-closure

---
 doc/manual/nix-copy-closure.xml |  8 ++++++++
 perl/lib/Nix/CopyClosure.pm     |  7 ++++---
 scripts/nix-copy-closure.in     | 10 ++++++++--
 3 files changed, 20 insertions(+), 5 deletions(-)

diff --git a/doc/manual/nix-copy-closure.xml b/doc/manual/nix-copy-closure.xml
index 45cfc0f34..4b5ce755c 100644
--- a/doc/manual/nix-copy-closure.xml
+++ b/doc/manual/nix-copy-closure.xml
@@ -26,6 +26,7 @@
     <arg><option>--gzip</option></arg>
     <arg><option>--bzip2</option></arg>
     <arg><option>--xz</option></arg>
+    <arg><option>--show-progress</option></arg>
     <arg><option>--include-outputs</option></arg>
     <arg choice='plain'>
       <replaceable>user@</replaceable><replaceable>machine</replaceable>
@@ -110,6 +111,13 @@ those paths.  If this bothers you, use
 
   </varlistentry>
 
+  <varlistentry><term><option>--show-progress</option></term>
+
+    <listitem><para>Show the progress of each path's transfer as it's made.
+    This requires the <command>pv</command> utility to be in <envar>PATH</envar>.</para></listitem>
+
+  </varlistentry>
+
   <varlistentry><term><option>--include-outputs</option></term>
   
   <listitem><para>Also copy the outputs of store derivations included
diff --git a/perl/lib/Nix/CopyClosure.pm b/perl/lib/Nix/CopyClosure.pm
index 08573b2ab..4794fed9d 100644
--- a/perl/lib/Nix/CopyClosure.pm
+++ b/perl/lib/Nix/CopyClosure.pm
@@ -6,11 +6,12 @@ use Nix::Store;
 
 
 sub copyTo {
-    my ($sshHost, $sshOpts, $storePaths, $compressor, $decompressor, $includeOutputs, $dryRun, $sign) = @_;
+    my ($sshHost, $sshOpts, $storePaths, $compressor, $decompressor, $includeOutputs, $dryRun, $sign, $progressViewer) = @_;
 
     $compressor = "$compressor |" if $compressor ne "";
     $decompressor = "$decompressor |" if $decompressor ne "";
-    
+    $progressViewer = "$progressViewer |" if $progressViewer ne "";
+
     # Get the closure of this path.
     my @closure = reverse(topoSortPaths(computeFSClosure(0, $includeOutputs,
         map { followLinksToStorePath $_ } @{$storePaths})));
@@ -34,7 +35,7 @@ sub copyTo {
     if (scalar @missing > 0) {
         print STDERR "copying ", scalar @missing, " missing paths to ‘$sshHost’...\n";
         unless ($dryRun) {
-            open SSH, "| $compressor ssh $sshHost @{$sshOpts} '$decompressor nix-store --import' > /dev/null" or die;
+            open SSH, "| $progressViewer $compressor ssh $sshHost @{$sshOpts} '$decompressor nix-store --import' > /dev/null" or die;
             exportPaths(fileno(SSH), $sign, @missing);
             close SSH or die "copying store paths to remote machine `$sshHost' failed: $?";
         }
diff --git a/scripts/nix-copy-closure.in b/scripts/nix-copy-closure.in
index 1ed24d285..a38a31a8b 100755
--- a/scripts/nix-copy-closure.in
+++ b/scripts/nix-copy-closure.in
@@ -23,6 +23,8 @@ my $sign = 0;
 my $compressor = "";
 my $decompressor = "";
 
+my $progressViewer = "";
+
 my $toMode = 1;
 
 my $includeOutputs = 0;
@@ -60,6 +62,9 @@ while (@ARGV) {
     elsif ($arg eq "--include-outputs") {
         $includeOutputs = 1;
     }
+    elsif ($arg eq "--show-progress") {
+        $progressViewer = "pv";
+    }
     elsif ($arg eq "--dry-run") {
         $dryRun = 1;
     }
@@ -76,7 +81,7 @@ openSSHConnection $sshHost or die "$0: unable to start SSH\n";
 
 
 if ($toMode) { # Copy TO the remote machine.
-    Nix::CopyClosure::copyTo($sshHost, [ @sshOpts ], [ @storePaths ], $compressor, $decompressor, $includeOutputs, $dryRun, $sign);
+    Nix::CopyClosure::copyTo($sshHost, [ @sshOpts ], [ @storePaths ], $compressor, $decompressor, $includeOutputs, $dryRun, $sign, $progressViewer);
 }
 
 else { # Copy FROM the remote machine.
@@ -101,9 +106,10 @@ else { # Copy FROM the remote machine.
         print STDERR "copying ", scalar @missing, " missing paths from ‘$sshHost’...\n";
         $compressor = "| $compressor" if $compressor ne "";
         $decompressor = "$decompressor |" if $decompressor ne "";
+	$progressViewer = "$progressViewer |" if $progressViewer ne "";
         unless ($dryRun) {
             my $extraOpts = $sign ? "--sign" : "";
-            system("set -f; ssh $sshHost @sshOpts 'nix-store --export $extraOpts @missing $compressor' | $decompressor $Nix::Config::binDir/nix-store --import > /dev/null") == 0
+            system("set -f; ssh $sshHost @sshOpts 'nix-store --export $extraOpts @missing $compressor' | $decompressor $progressViewer $Nix::Config::binDir/nix-store --import > /dev/null") == 0
                 or die "copying store paths from remote machine `$sshHost' failed: $?";
         }
     }