Process binary caches in order of priority

Binary caches can now specify a priority in their nix-cache-info file.
The binary cache substituter checks caches in order of priority.  This
is to ensure that fast, static caches like nixos.org/binary-cache are
processed before slow, dynamic caches like hydra.nixos.org.
This commit is contained in:
Eelco Dolstra 2012-11-06 17:45:20 +01:00
parent 3a95e1a17c
commit bbc107ef1e
2 changed files with 25 additions and 7 deletions

View file

@ -210,6 +210,7 @@ properties. Heres an example:
<screen>
StoreDir: /nix/store
WantMassQuery: 1
Priority: 10
</screen>
The properties that are currently supported are:
@ -246,6 +247,16 @@ The properties that are currently supported are:
</varlistentry>
<varlistentry><term><literal>Priority</literal></term>
<listitem><para>Each binary cache has a priority (defaulting to
50). Binary caches are checked for binaries in order of ascending
priority; thus a higher number denotes a lower priority. The
binary cache <uri>http://nixos.org/binary-cache</uri> has priority
40.</para></listitem>
</varlistentry>
</variablelist>
</para>

View file

@ -102,7 +102,9 @@ sub processRequests {
sub initCache {
my $dbPath = "$Nix::Config::stateDir/binary-cache-v1.sqlite";
my $dbPath = "$Nix::Config::stateDir/binary-cache-v2.sqlite";
unlink "$Nix::Config::stateDir/binary-cache-v1.sqlite";
# Open/create the database.
$dbh = DBI->connect("dbi:SQLite:dbname=$dbPath", "", "")
@ -120,7 +122,8 @@ sub initCache {
url text unique not null,
timestamp integer not null,
storeDir text not null,
wantMassQuery integer not null
wantMassQuery integer not null,
priority integer not null
);
EOF
@ -156,7 +159,7 @@ EOF
$dbh->do("create index if not exists NARExistenceByExistTimestamp on NARExistence (exist, timestamp)");
$queryCache = $dbh->prepare("select id, storeDir, wantMassQuery from BinaryCaches where url = ?") or die;
$queryCache = $dbh->prepare("select id, storeDir, wantMassQuery, priority from BinaryCaches where url = ?") or die;
$insertNAR = $dbh->prepare(
"insert or replace into NARs(cache, storePath, url, compression, fileHash, fileSize, narHash, " .
@ -220,7 +223,7 @@ sub getAvailableCaches {
my $res = $queryCache->fetchrow_hashref();
if (defined $res) {
next if $res->{storeDir} ne $Nix::Config::storeDir;
push @caches, { id => $res->{id}, url => $url, wantMassQuery => $res->{wantMassQuery} };
push @caches, { id => $res->{id}, url => $url, wantMassQuery => $res->{wantMassQuery}, priority => $res->{priority} };
next;
}
@ -236,6 +239,7 @@ sub getAvailableCaches {
my $storeDir = "/nix/store";
my $wantMassQuery = 0;
my $priority = 50;
foreach my $line (split "\n", $request->{content}) {
unless ($line =~ /^(.*): (.*)$/) {
print STDERR "bad cache info file $request->{url}\n";
@ -243,15 +247,18 @@ sub getAvailableCaches {
}
if ($1 eq "StoreDir") { $storeDir = $2; }
elsif ($1 eq "WantMassQuery") { $wantMassQuery = int($2); }
elsif ($1 eq "Priority") { $priority = int($2); }
}
$dbh->do("insert into BinaryCaches(url, timestamp, storeDir, wantMassQuery) values (?, ?, ?, ?)",
{}, $url, time(), $storeDir, $wantMassQuery);
$dbh->do("insert into BinaryCaches(url, timestamp, storeDir, wantMassQuery, priority) values (?, ?, ?, ?, ?)",
{}, $url, time(), $storeDir, $wantMassQuery, $priority);
my $id = $dbh->last_insert_id("", "", "", "");
next if $storeDir ne $Nix::Config::storeDir;
push @caches, { id => $id, url => $url, wantMassQuery => $wantMassQuery };
push @caches, { id => $id, url => $url, wantMassQuery => $wantMassQuery, priority => $priority };
}
@caches = sort { $a->{priority} <=> $b->{priority} } @caches;
expireNegative();
}