From a36f24feb5ed826146ac75c50f7489876190252c Mon Sep 17 00:00:00 2001
From: "Steinar H. Gunderson" <sgunderson@bigfoot.com>
Date: Fri, 2 Sep 2016 18:24:50 +0200
Subject: [PATCH] Send gRPC backends from the Perl code to the Node.js.

Makes it easier to keep all the config for one machine in one place.
---
 config.pm                |  2 ++
 remoteglot.pl            | 10 +++++++++-
 server/hash-lookup.js    | 16 ++++++++++++++++
 server/serve-analysis.js | 12 +++++++++++-
 4 files changed, 38 insertions(+), 2 deletions(-)

diff --git a/config.pm b/config.pm
index 8050adf..7de4407 100644
--- a/config.pm
+++ b/config.pm
@@ -45,6 +45,7 @@ our %engine_config = (
 	'Hash' => '1024',
 #	'MultiPV' => '2'
 );
+our $engine_grpc_backend = undef;  # Not used by us, but will be communicated to serve-analysis.js.
 
 # Separate engine for multi-PV; can be undef for none.
 our $engine2_cmdline = undef;
@@ -54,6 +55,7 @@ our %engine2_config = (
 	'Hash' => '1024',
 	'Threads' => '8',
 );
+our $engine2_grpc_backend = undef;  # Not used by us, but will be communicated to serve-analysis.js.
 
 our $uci_assume_full_compliance = 0;                    # dangerous :-)
 our $update_max_interval = 1.0;
diff --git a/remoteglot.pl b/remoteglot.pl
index 4b67496..9a1ee4c 100755
--- a/remoteglot.pl
+++ b/remoteglot.pl
@@ -67,7 +67,7 @@ select(TBLOG);
 $| = 1;
 
 select(STDOUT);
-umask 0022;
+umask 0027;  # analysis.json should not be served to users.
 
 # open the chess engine
 my $engine = open_engine($remoteglotconf::engine_cmdline, 'E1', sub { handle_uci(@_, 1); });
@@ -847,6 +847,14 @@ sub output_json {
 	if (defined($remoteglotconf::engine_details)) {
 		$json->{'engine'}{'details'} = $remoteglotconf::engine_details;
 	}
+	my @grpc_backends = ();
+	if (defined($remoteglotconf::engine_grpc_backend)) {
+		push @grpc_backends, $remoteglotconf::engine_grpc_backend;
+	}
+	if (defined($remoteglotconf::engine2_grpc_backend)) {
+		push @grpc_backends, $remoteglotconf::engine2_grpc_backend;
+	}
+	$json->{'internal'}{'grpc_backends'} = \@grpc_backends;
 	if (defined($remoteglotconf::move_source)) {
 		$json->{'move_source'} = $remoteglotconf::move_source;
 	}
diff --git a/server/hash-lookup.js b/server/hash-lookup.js
index b9d5f00..032b87b 100644
--- a/server/hash-lookup.js
+++ b/server/hash-lookup.js
@@ -7,11 +7,27 @@ var hashprobe_proto = grpc.load(PROTO_PATH).hashprobe;
 var board = new Chess();
 
 var clients = [];
+var current_servers = [];
+
+var need_reinit = function(servers) {
+	if (servers.length != current_servers.length) {
+		return true;
+	}
+	for (var i = 0; i < servers.length; ++i) {
+		if (servers[i] != current_servers[i]) {
+			return true;
+		}
+	}
+	return false;
+}
+exports.need_reinit = need_reinit;
 
 var init = function(servers) {
+	clients = [];
 	for (var i = 0; i < servers.length; ++i) {
 		clients.push(new hashprobe_proto.HashProbe(servers[i], grpc.credentials.createInsecure()));
 	}
+	current_servers = servers;
 }
 exports.init = init;
 
diff --git a/server/serve-analysis.js b/server/serve-analysis.js
index 22bc20d..ca9047f 100644
--- a/server/serve-analysis.js
+++ b/server/serve-analysis.js
@@ -93,8 +93,18 @@ var replace_json = function(new_json_contents, mtime) {
 		}
 	}
 
+	var parsed = JSON.parse(new_json_contents);
+
+	if (parsed['internal']) {
+		if (parsed['internal']['grpc_backends'] &&
+		    hash_lookup.need_reinit(parsed['internal']['grpc_backends'])) {
+			hash_lookup.init(parsed['internal']['grpc_backends']);
+		}
+		delete parsed['internal'];
+	}
+
 	var new_json = {
-		parsed: JSON.parse(new_json_contents),
+		parsed: parsed,
 		plain: new_json_contents,
 		last_modified: mtime
 	};
-- 
2.39.2