hydra/src/lib/Hydra/Plugin/PathInput.pm
2013-09-07 13:28:53 +02:00

82 lines
2.6 KiB
Perl

package Hydra::Plugin::PathInput;
use strict;
use parent 'Hydra::Plugin';
use POSIX qw(strftime);
use Hydra::Helper::Nix;
use Nix::Store;
sub supportedInputTypes {
my ($self, $inputTypes) = @_;
$inputTypes->{'path'} = 'Local path';
}
sub fetchInput {
my ($self, $type, $name, $value) = @_;
return undef if $type ne "path";
my $uri = $value;
my $timestamp = time;
my $sha256;
my $storePath;
# Some simple caching: don't check a path more than once every N seconds.
(my $cachedInput) = $self->{db}->resultset('CachedPathInputs')->search(
{srcpath => $uri, lastseen => {">", $timestamp - 30}},
{rows => 1, order_by => "lastseen DESC"});
if (defined $cachedInput && isValidPath($cachedInput->storepath)) {
$storePath = $cachedInput->storepath;
$sha256 = $cachedInput->sha256hash;
$timestamp = $cachedInput->timestamp;
} else {
print STDERR "copying input ", $name, " from $uri\n";
if ( $uri =~ /^\// ) {
$storePath = `nix-store --add "$uri"`
or die "cannot copy path $uri to the Nix store.\n";
} else {
$storePath = `PRINT_PATH=1 nix-prefetch-url "$uri" | tail -n 1`
or die "cannot fetch $uri to the Nix store.\n";
}
chomp $storePath;
$sha256 = (queryPathInfo($storePath, 0))[1] or die;
($cachedInput) = $self->{db}->resultset('CachedPathInputs')->search(
{srcpath => $uri, sha256hash => $sha256});
# Path inputs don't have a natural notion of a "revision", so
# we simulate it by using the timestamp that we first saw this
# path have this SHA-256 hash. So if the contents of the path
# changes, we get a new "revision", but if it doesn't change
# (or changes back), we don't get a new "revision".
if (!defined $cachedInput) {
txn_do($self->{db}, sub {
$self->{db}->resultset('CachedPathInputs')->update_or_create(
{ srcpath => $uri
, timestamp => $timestamp
, lastseen => $timestamp
, sha256hash => $sha256
, storepath => $storePath
});
});
} else {
$timestamp = $cachedInput->timestamp;
txn_do($self->{db}, sub {
$cachedInput->update({lastseen => time});
});
}
}
return
{ uri => $uri
, storePath => $storePath
, sha256hash => $sha256
, revision => strftime "%Y%m%d%H%M%S", gmtime($timestamp)
};
}
1;