Vivian Meazza wrote:
> Only a minute eh? Under Cygwin cvs takes nearly 5 minutes - time for
> a brew a coffee - and that's on a pretty powerful machine.
Time from execution to fade in of the cockpit display is about 10
seconds on my laptop (1.8GHz Athlon64). I started trying to hunt this
down.
One issue that had been discovered earlier is that an AI-related patch
to the the airport loading code in February causes the startup routine
to try to load a rwyuse.xml and parking.xml file in every one of 24597
potential directories under $FG_ROOT/Aiports/AI.
Attached is a patch that pre-reads the directory contents ahead of
time (currently that is a list of length zero) to avoid having to hit
the kernel (twice!) for every airport.
Under Linux, this doesn't provide much speedup. But Windows (and
especially the cygwin libraries) has a somewhat less robust I/O system
in the face of many tiny operations. Hopefully it will help there.
Can someone on each of cygwin, mingw and/or MSVC try this out and see
if it helps?
Unfortunately, because there is no actual parking/runway AI data in
the base package, much of this is currently "dead code" that cannot be
tested. I can't promise I didn't break anything, because I have no
way of knowing whether it worked in the first place. :)
Andy
Index: src/Airports/simple.hxx
===================================================================
RCS file: /var/cvs/FlightGear-0.9/source/src/Airports/simple.hxx,v
retrieving revision 1.12
diff -u -r1.12 simple.hxx
--- src/Airports/simple.hxx 10 Feb 2005 09:01:51 -0000 1.12
+++ src/Airports/simple.hxx 26 May 2005 20:47:33 -0000
@@ -42,10 +42,12 @@
#include STL_STRING
#include <map>
+#include <set>
#include <vector>
SG_USING_STD(string);
SG_USING_STD(map);
+SG_USING_STD(set);
SG_USING_STD(vector);
typedef vector<string> stringVec;
@@ -306,11 +308,12 @@
airport_map airports_by_id;
airport_list airports_array;
+ set < string > ai_dirs;
public:
// Constructor (new)
- FGAirportList() {}
+ FGAirportList();
// Destructor
~FGAirportList();
Index: src/Airports/simple.cxx
===================================================================
RCS file: /var/cvs/FlightGear-0.9/source/src/Airports/simple.cxx,v
retrieving revision 1.17
diff -u -r1.17 simple.cxx
--- src/Airports/simple.cxx 25 Feb 2005 19:41:53 -0000 1.17
+++ src/Airports/simple.cxx 26 May 2005 20:47:33 -0000
@@ -1149,6 +1149,26 @@
* FGAirportList
*****************************************************************************/
+// Populates a list of subdirectories of $FG_ROOT/Airports/AI so that
+// the add() method doesn't have to try opening 2 XML files in each of
+// thousands of non-existent directories. FIXME: should probably add
+// code to free this list after parsing of apt.dat is finished;
+// non-issue at the moment, however, as there are no AI subdirectories
+// in the base package.
+FGAirportList::FGAirportList()
+{
+ ulDir* d;
+ ulDirEnt* dent;
+ SGPath aid( globals->get_fg_root() );
+ aid.append( "/Airports/AI" );
+ if((d = ulOpenDir(aid.c_str())) == NULL)
+ return;
+ while((dent = ulReadDir(d)) != NULL) {
+ cerr << "Dent: " << dent->d_name; // DEBUG
+ ai_dirs.insert(dent->d_name);
+ }
+ ulCloseDir(d);
+}
// add an entry to the list
void FGAirportList::add( const string id, const double longitude,
@@ -1172,7 +1192,8 @@
rwyPrefPath.append( "/Airports/AI/" );
rwyPrefPath.append(id);
rwyPrefPath.append("rwyuse.xml");
- if (parkpath.exists())
+ if (ai_dirs.find(parkpath.str()) != ai_dirs.end()
+ && parkpath.exists())
{
try {
readXML(parkpath.str(),a);
@@ -1181,7 +1202,8 @@
//cerr << "unable to read " << parkpath.str() << endl;
}
}
- if (rwyPrefPath.exists())
+ if (ai_dirs.find(rwyPrefPath.str()) != ai_dirs.end()
+ && rwyPrefPath.exists())
{
try {
readXML(rwyPrefPath.str(), rwyPrefs);
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