From 099125435fc5ada63365a94ca153c711e706e225 Mon Sep 17 00:00:00 2001
From: Eelco Dolstra <eelco.dolstra@logicblox.com>
Date: Mon, 9 Jul 2012 10:57:28 -0400
Subject: [PATCH] download-from-binary-cache: add nix.conf options

---
 doc/manual/conf-file.xml                 | 20 ++++++++++++++++++++
 perl/lib/Nix/Config.pm.in                |  6 +++---
 scripts/download-from-binary-cache.pl.in | 10 +++++++---
 3 files changed, 30 insertions(+), 6 deletions(-)

diff --git a/doc/manual/conf-file.xml b/doc/manual/conf-file.xml
index 25a009de9d..e2890b1031 100644
--- a/doc/manual/conf-file.xml
+++ b/doc/manual/conf-file.xml
@@ -288,6 +288,26 @@ build-use-chroot = /dev /proc /bin</programlisting>
   </varlistentry>
 
 
+  <varlistentry><term><literal>binary-caches</literal></term>
+
+    <listitem><para>A list of URLs of binary caches, separated by
+    whitespace.  It can be overriden through the environment variable
+    <envar>NIX_BINARY_CACHES</envar>.  The default is
+    <literal>http://nixos.org/binary-cache</literal>.</para></listitem>
+
+  </varlistentry>
+  
+
+  <varlistentry><term><literal>binary-caches-parallel-connections</literal></term>
+
+    <listitem><para>The maximum number of parallel HTTP connections
+    used by the binary cache substituter to get NAR info files.  This
+    number should be high to minimise latency.  It defaults to
+    150.</para></listitem>
+
+  </varlistentry>
+  
+
   <varlistentry><term><literal>system</literal></term>
 
     <listitem><para>This option specifies the canonical Nix system
diff --git a/perl/lib/Nix/Config.pm.in b/perl/lib/Nix/Config.pm.in
index 64aaccd7cd..57751b6b40 100644
--- a/perl/lib/Nix/Config.pm.in
+++ b/perl/lib/Nix/Config.pm.in
@@ -14,16 +14,16 @@ $curl = "@curl@";
 
 $useBindings = "@perlbindings@" eq "yes";
 
+%config = ();
+
 sub readConfig {
-    my %config;
-    my $config = "@sysconfdir@/nix/nix.conf";
+    my $config = "$confDir/nix.conf";
     return unless -f $config;
     
     open CONFIG, "<$config" or die "cannot open `$config'";
     while (<CONFIG>) {
         /^\s*([\w|-]+)\s*=\s*(.*)$/ or next;
         $config{$1} = $2;
-        print "|$1| -> |$2|\n";
     }
     close CONFIG;
 }
diff --git a/scripts/download-from-binary-cache.pl.in b/scripts/download-from-binary-cache.pl.in
index 37f8db0a99..f062d17e6e 100644
--- a/scripts/download-from-binary-cache.pl.in
+++ b/scripts/download-from-binary-cache.pl.in
@@ -10,9 +10,13 @@ use WWW::Curl::Multi;
 use strict;
 
 
-my @binaryCacheUrls = map { s/\/+$//; $_ } split(/ /, ($ENV{"NIX_BINARY_CACHES"} || ""));
+Nix::Config::readConfig;
 
-my $maxParallelRequests = 150;
+my @binaryCacheUrls = map { s/\/+$//; $_ } split(/ /,
+    ($ENV{"NIX_BINARY_CACHES"} // $Nix::Config::config{"binary-caches"} // "http://nixos.org/binary-cache"));
+
+my $maxParallelRequests = int($Nix::Config::config{"binary-caches-parallel-connections"} // 150);
+$maxParallelRequests = 1 if $maxParallelRequests < 1;
 
 my ($dbh, $insertNAR, $queryNAR, $insertNegativeNAR, $queryNegativeNAR);
 my %cacheIds;
@@ -22,7 +26,7 @@ my $activeRequests = 0;
 my $curlIdCount = 1;
 my %requests;
 my %scheduled;
-my $caBundle = $ENV{"CURL_CA_BUNDLE"} || $ENV{"OPENSSL_X509_CERT_FILE"};
+my $caBundle = $ENV{"CURL_CA_BUNDLE"} // $ENV{"OPENSSL_X509_CERT_FILE"};
 
 
 sub addRequest {