Commit f767b5c8 authored by Michal Privoznik's avatar Michal Privoznik

examples: Introduce vol-sparse.pl

Signed-off-by: 's avatarMichal Privoznik <mprivozn@redhat.com>
parent b6a368b3
......@@ -11,6 +11,7 @@ Revision history for perl module Sys::Virt
- Introduce Stream::sparse_send_all()
- Register VOL_DOWNLOAD_SPARSE_STREAM &
VOL_UPLOAD_SPARSE_STREAM constants
- Add vol-sparse.pl example
3.3.0 2017-05-08
......
#!/usr/bin/perl
use strict;
use warnings;
use Sys::Virt;
use Fcntl;
my $FILE;
sub download_handler {
my $st = shift;
my $data = shift;
my $nbytes = shift;
return syswrite FILE, $data, $nbytes;
}
sub download_hole_handler {
my $st = shift;
my $offset = shift;
my $pos = sysseek FILE, $offset, Fcntl::SEEK_CUR or die "Unable to seek in $FILE: $!";
truncate FILE, $pos;
}
sub download {
my $vol = shift;
my $st = shift;
my $filename = shift;
my $offset = 0;
my $length = 0;
open FILE, ">$filename" or die "unable to create $filename: $!";
eval {
$vol->download($st, $offset, $length, Sys::Virt::StorageVol::VOL_DOWNLOAD_SPARSE_STREAM);
$st->sparse_recv_all(\&download_handler, \&download_hole_handler);
$st->finish();
};
if ($@) {
unlink $filename if $@;
close FILE;
die $@;
}
close FILE or die "cannot save $filename: $!"
}
sub upload_handler {
my $st = $_[0];
my $nbytes = $_[2];
return sysread FILE, $_[1], $nbytes;
}
sub upload_hole_handler {
my $st = shift;
my $in_data;
my $section_len;
# HACK, Perl lacks SEEK_DATA and SEEK_HOLE.
my $SEEK_DATA = 3;
my $SEEK_HOLE = 4;
my $cur = sysseek FILE, 0, Fcntl::SEEK_CUR;
eval {
my $data = sysseek FILE, $cur, $SEEK_DATA;
# There are three options:
# 1) $data == $cur; $cur is in data
# 2) $data > $cur; $cur is in a hole, next data at $data
# 3) $data < 0; either $cur is in trailing hole, or $cur is beyond EOF.
if (!defined($data)) {
# case 3
$in_data = 0;
my $end = sysseek FILE, 0, Fcntl::SEEK_END or die "Unable to get EOF position: $!";
$section_len = $end - $cur;
} elsif ($data > $cur) {
#case 2
$in_data = 0;
$section_len = $data - $cur;
} else {
#case 1
my $hole = sysseek FILE, $data, $SEEK_HOLE;
if (!defined($hole) or $hole eq $data) {
die "Blah";
}
$in_data = 1;
$section_len = $hole - $data;
}
};
die "Blah" if ($@);
# reposition file back
sysseek FILE, $cur, Fcntl::SEEK_SET;
return ($in_data, $section_len);
}
sub upload_skip_handler {
my $st = shift;
my $offset = shift;
sysseek FILE, $offset, Fcntl::SEEK_CUR or die "Unable to seek in $FILE";
return 0;
}
sub upload {
my $vol = shift;
my $st = shift;
my $filename = shift;
my $offset = 0;
my $length = 0;
open FILE, "<$filename" or die "unable to open $filename: $!";
eval {
$vol->upload($st, $offset, $length, Sys::Virt::StorageVol::VOL_UPLOAD_SPARSE_STREAM);
$st->sparse_send_all(\&upload_handler, \&upload_hole_handler, \&upload_skip_handler);
$st->finish();
};
if ($@) {
close FILE;
die $@;
}
close FILE or die "cannot close $filename: $!"
}
die "syntax: $0 URI --download/--upload VOLUME FILE" unless int(@ARGV) == 4;
my $uri = shift @ARGV;
my $action = shift @ARGV;
my $volpath = shift @ARGV;
my $filename = shift @ARGV;
my $c = Sys::Virt->new(uri => $uri) or die "Unable to connect to $uri";
my $vol = $c->get_storage_volume_by_key($volpath) or die "No such volume";
my $st = $c->new_stream();
if ($action eq "--download") {
download($vol, $st, $filename);
} elsif ($action eq "--upload") {
upload($vol, $st, $filename);
} else {
die "unknown action $action";
}
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