FGFS-4.1/simgear
3
0
Fork 0
Code Issues Pull Requests Packages Projects Releases Wiki Activity

Terrasync: implement HTTP service lookup via DNS

Browse Source 
Let terrasync use the http repository if
  /sim/terrasync/http-server == "automatic"
  resolve DNS NAPTR RR for terrasync.flightgear.org with service "ws20"
  and flags "U". Pick one of the returned entries with lowest order
  and preference. If more than one entry  with the same order and
  preference is returned, pick a random entry of those returned.

or if
  /sim/terrasync/http-server != "automatic"
  explicitly use the value of that property as the http server

if
  /sim/terrasync/http-server is empty, fall back to the legacy
  SVN repository
This commit is contained in:
Torsten Dreyer
2016-05-03 12:11:38 +02:00
parent 5e7b5cbf68
commit 9a29f54f8a
1 changed files with 65 additions and 1 deletions
Download Patch File Download Diff File Expand all files Collapse all files

66
simgear/scene/tsync/terrasync.cxx
View File

@@ -61,7 +61,9 @@
#include <simgear/io/HTTPClient.hxx>
#include <simgear/io/SVNRepository.hxx>
#include <simgear/io/HTTPRepository.hxx>
#include <simgear/io/DNSClient.hxx>
#include <simgear/structure/exception.hxx>
#include <simgear/math/sg_random.h>
static const bool svn_built_in_available = true;
@@ -507,7 +509,67 @@ void SGTerraSync::SvnThread::run()
initCompletedTilesPersistentCache();
{
if (_svn_server.empty()) {
if (_httpServer == "automatic" ) {
//TODO: make DN and service settable from properties
DNS::NAPTRRequest * naptrRequest = new DNS::NAPTRRequest("terrasync.flightgear.org");
naptrRequest->qservice = "ws20";
naptrRequest->qflags = "U";
DNS::Request_ptr r(naptrRequest);
DNS::Client dnsClient;
dnsClient.makeRequest(r);
while( !r->isComplete() && !r->isTimeout() )
dnsClient.update(0);
if( naptrRequest->entries.empty() ) {
SG_LOG(SG_TERRASYNC, SG_ALERT, "ERROR: automatic terrasync http-server requested, but no DNS entry found.");
_httpServer = "";
} else {
// walk through responses, they are ordered by 1. order and 2. preference
// For now, only take entries with lowest order
// TODO: try all available servers in the order given by preferenc and order
int order = naptrRequest->entries[0]->order;
// get all servers with this order and the same (for now only lowest preference)
DNS::NAPTRRequest::NAPTR_list availableServers;
for( DNS::NAPTRRequest::NAPTR_list::const_iterator it = naptrRequest->entries.begin();
it != naptrRequest->entries.end();
++it ) {
if( (*it)->order != order )
continue;
string regex = (*it)->regexp;
if( false == simgear::strutils::starts_with( (*it)->regexp, "!^.*$!" ) ) {
SG_LOG(SG_TERRASYNC,SG_WARN, "ignoring unsupported regexp: " << (*it)->regexp );
continue;
}
if( false == simgear::strutils::ends_with( (*it)->regexp, "!" ) ) {
SG_LOG(SG_TERRASYNC,SG_WARN, "ignoring unsupported regexp: " << (*it)->regexp );
continue;
}
// always use first entry
if( availableServers.empty() || (*it)->preference == availableServers[0]->preference) {
SG_LOG(SG_TERRASYNC,SG_DEBUG, "available server regexp: " << (*it)->regexp );
availableServers.push_back( *it );
}
}
// now pick a random entry from the available servers
DNS::NAPTRRequest::NAPTR_list::size_type idx = sg_random() * availableServers.size();
_httpServer = availableServers[idx]->regexp;
_httpServer = _httpServer.substr( 6, _httpServer.length()-7 ); // strip search pattern and separators
SG_LOG(SG_TERRASYNC,SG_INFO, "picking entry # " << idx << ", server is " << _httpServer );
}
}
}
if( _httpServer.empty() ) { // don't resolve SVN server is HTTP server is set
if ( _svn_server.empty()) {
SG_LOG(SG_TERRASYNC,SG_INFO, "Querying closest TerraSync server");
ServerSelectQuery* ssq = new ServerSelectQuery;
HTTP::Request_ptr req = ssq;
@@ -527,8 +589,10 @@ void SGTerraSync::SvnThread::run()
}
if (_svn_server.empty()) {
#if WE_HAVE_A_DEFAULT_SERVER_BUT_WE_DONT_THIS_URL_IS_NO_LONGER_VALID
// default value
_svn_server = "http://foxtrot.mgras.net:8080/terrascenery/trunk/data/Scenery";
#endif
}
}