[Kstars-devel] branches/kstars/summer/kdeedu/kstars/kstars/skycomponents
Akarsh Simha
akarshsimha at gmail.com
Wed Jun 4 00:42:10 CEST 2008
SVN commit 816465 by asimha:
StarObject objects for unnamed stars are now created by memcpy()-ing a
template object and then filling in the data, instead of using the
constructor.
Also replacing call to skyMesh::indexStar(...) by a simple method of
obtaining the trixel ID. [Works only for level 3 HTM]
This seems to have brought down the time to load each star by a factor
of 6!! On my system, it now takes about 225 seconds on an average to
load 41560 stars, as against ~1745 seconds earlier. The timing code is
currently left as it is, for testing this out.
Some of the newly implemented code could be dangerous, as it uses
pointers at a very low level. This code is almost surely going to
result in a segmentation fault when we implement storage and retrieval
of observing log data and user-added links!
I didn't realise it would be so easy to do this - I thought I'd have
to modify all classes in the inheritance tree starting from SkyPoint!
Many thanks to James, who rightly pointed out that it was the stack of
constructors (and the SkyMesh::indexStar()) that were eating away most
of the time.
CCMAIL: kstars-devel at kde.org
M +89 -133 starcomponent.cpp
--- branches/kstars/summer/kdeedu/kstars/kstars/skycomponents/starcomponent.cpp #816464:816465
@@ -342,24 +342,25 @@
{
// TODO: We may want to remove the newMagnitude argument. Currently, it is deprecated
- // We break from Qt / KDE API and use traditional file handling here, to obtain speed
+ // We break from Qt / KDE API and use traditional file handling here, to obtain speed.
+ // We also avoid C++ constructors for the same reason.
FILE *dataFile, *nameFile;
bool swapBytes = false;
- dms RA, Dec;
BinFileHelper dataReader, nameReader;
unsigned long nrecords;
QString name, gname, visibleName;
+ StarObject *star;
- // DEPRECATED : only load star data if the new magnitude is fainter than we've seen so far.
- // We now load all stars the first time this method is called and load nothing during subsequent calls
+
+ // We now load all stars the first time this method is called and load nothing during subsequent calls:
if ( newMagnitude <= m_FaintMagnitude || newMagnitude > 8.0 ) return; // TODO: Create the solution to handle > 8.0 mag stars
- //float currentMag = m_FaintMagnitude;
m_FaintMagnitude = 8.00; // TODO: Find out if there could be a solution to load shallow stars dynamically
// prepare to index stars to this date
m_skyMesh->setKSNumbers( &m_reindexNum );
+ /* Open the data files */
if((dataFile = dataReader.openFile("shallowstars.dat")) == NULL) {
kDebug() << "Could not open data file shallowstars.dat" << endl;
return;
@@ -380,177 +381,132 @@
return;
}
+ // TODO: Implement a solution to load nameFile completely into memory, to avoid disk seeks
fseek(nameFile, nameReader.getDataOffset(), SEEK_SET);
long int nstars = 0;
Trixel expectedTrixelId = -1;
+ QTime t;
+ /* Create a template for plain ("unnamed") stars, from which we can do a memcpy()
+ *
+ * CAUTION: We avoid trying to construct StarObjects using the constructors [The C++ way]
+ * in order to gain speed. Instead, one template StarObject is constructed and
+ * all other unnamed stars are created by doing a raw copy from this using memcpy()
+ * and then calling StarObject::init() to replace the default data with the correct
+ * data.
+ * This means that this section of the code plays around with pointers to a great
+ * extend and has a chance of breaking down / causing segfaults.
+ */
+ stardata.mag = 0;
+ stardata.spec_type[0] = 'A';
+ stardata.spec_type[1] = '0';
+ visibleName = "";
+ stardata.dRA = 0;
+ stardata.dDec = 0;
+ stardata.parallax = 0;
+ stardata.flags = 0;
+ StarObject *plainStarTemplate = new StarObject(0, 0, stardata.mag/100.0, "", visibleName,
+ QByteArray(stardata.spec_type, 2),
+ stardata.dRA/10.0, stardata.dDec/10.0, stardata.parallax/10.0,
+ stardata.flags & 0x02, stardata.flags & 0x04 );
+
+
+ /* TODO : Remove timing code when we are done with all possible optimizations */
+ t.start();
+
+ /* Start reading the data file */
+ fseek(dataFile, dataReader.getDataOffset(), SEEK_SET);
+
+ /* Recurse over trixels */
for(int i = 0; i < m_skyMesh -> size(); ++i) {
+ // The following code is not required, because we are anyway reading the file sequentially, and hence is commented out.
+ /*
if(fseek(dataFile, dataReader.getOffset(i), SEEK_SET))
kDebug() << "ERROR: Could not seek to offset " << dataReader.getOffset(i) << " to find trixel #" << i << endl;
+ */
- for(unsigned j = 0; j < (unsigned long)dataReader.getRecordCount(i); ++j) {
-
+ /* Recurse over stars in each trixel */
+ for(unsigned long j = 0; j < (unsigned long)dataReader.getRecordCount(i); ++j) {
+
+ /* Read star data */
if(!fread(&stardata, sizeof(starData), 1, dataFile)){
kDebug() << "ERROR: Could not read starData structure for star #" << j << " under trixel #" << i << endl;
}
-
+
+
// TODO: Add byteswapping code
-
- RA.setH(stardata.RA/1000000.0);
- Dec.setD(stardata.Dec/100000.0);
-
+
gname = "";
name = "";
visibleName = "";
+ bool named = false;
+
if(stardata.flags & 0x01) {
- // Named Star - Read one Name
+ /* Named Star - Read the nameFile */
if(!fread(&starname, sizeof(starName), 1, nameFile))
kDebug() << "ERROR: fread() call on nameFile failed in trixel " << i << " star " << j << endl;
name = QByteArray(starname.longName, 32);
gname = QByteArray(starname.bayerName, 8);
if ( ! gname.isEmpty() && gname.at(0) != '.')
visibleName = gname;
+ if(! name.isEmpty() ) {
+ // HEV: look up star name in internationalization filesource
+ name = i18nc("star name", name.toLocal8Bit().data());
+ }
+ else
+ name = i18n("star");
+ named = true;
}
- // HEV: look up star name in internationalization filesource
- if ( name.isEmpty() ) name = i18n("star");
- name = i18nc("star name", name.toLocal8Bit().data());
-
- StarObject *star = new StarObject( RA, Dec, stardata.mag/100.0, name, visibleName, QByteArray(stardata.spec_type, 2),
- stardata.dRA/10.0, stardata.dDec/10.0, stardata.parallax/10.0,
- stardata.flags & 0x02, stardata.flags & 0x04 );
+ /* Create the new StarObject */
+ if ( named ) {
+ star = new StarObject( stardata.RA/1000000.0, stardata.Dec/100000.0, stardata.mag/100.0, name, visibleName,
+ QByteArray(stardata.spec_type, 2), stardata.dRA/10.0, stardata.dDec/10.0,
+ stardata.parallax/10.0, stardata.flags & 0x02, stardata.flags & 0x04 );
+ }
+ else {
+ // DANGEROUS CODE. Lots of pointer work!
+ /* Make a copy of the star template and set up the data in it */
+ star = (StarObject *)malloc(sizeof(StarObject));
+ star = (StarObject *)memcpy(star, plainStarTemplate, sizeof(StarObject));
+ star -> init(stardata.RA/1000000.0, stardata.Dec/100000.0, stardata.mag/100.0,
+ QByteArray(stardata.spec_type, 2), stardata.dRA/10.0, stardata.dDec/10.0,
+ stardata.parallax/10.0, stardata.flags & 0x02, stardata.flags & 0x04);
+ }
star->EquatorialToHorizontal( data()->lst(), data()->geo()->lat() );
++nstars;
-
- if ( ! gname.isEmpty() ) m_genName.insert( gname, star );
- if ( ! name.isEmpty() && name != i18n("star") ) {
- objectNames(SkyObject::STAR).append( name );
+ if( named ) {
+ if ( ! gname.isEmpty() ) m_genName.insert( gname, star );
+
+ if ( ! name.isEmpty() ) {
+ objectNames(SkyObject::STAR).append( name );
+ }
+ if ( ! gname.isEmpty() && gname != name ) {
+ objectNames(SkyObject::STAR).append( star -> gname(false) );
+ }
+
}
- if ( ! gname.isEmpty() && gname != name ) {
- objectNames(SkyObject::STAR).append( star -> gname(false) );
- }
-
- objectList().append( star );
- Trixel trixel = m_skyMesh->indexStar( star );
+ objectList().append( star );
+
+ Trixel trixel = ((i >= 256) ? (i - 256):(i + 256));
m_starIndex->at( trixel )->append( star );
double pm = star->pmMagnitude();
- if(j == 0)
- expectedTrixelId = trixel;
- else
- if(expectedTrixelId != trixel)
- kDebug() << "ERROR: Expected trixel Id = " << expectedTrixelId << " but found " << trixel << " instead at trixel #" << i <<", star #" << j << endl;
-
for (int j = 0; j < m_highPMStars.size(); j++ ) {
HighPMStarList* list = m_highPMStars.at( j );
- if ( list->append( trixel, star, pm ) ) break;
+ if ( list->append( 512 - i, star, pm ) ) break;
}
-
}
}
dataReader.closeFile();
nameReader.closeFile();
- kDebug() << "Loaded " << nstars << " stars" << endl;
+ kDebug() << "Loaded " << nstars << " stars in " << t.elapsed() << " ms" << endl;
}
-
-// DEPRECATED
-/*
-StarObject* StarComponent::processStar( const QString &line ) {
- QString name, gname, SpType, visibleName;
- int rah, ram, ras, ras2, dd, dm, ds, ds2;
- bool mult(false), var(false);
- QChar sgn;
- double mag, bv, dmag, vper;
- double pmra, pmdec, plx;
-
- //parse coordinates
- rah = line.mid( 0, 2 ).toInt();
- ram = line.mid( 2, 2 ).toInt();
- ras = int(line.mid( 4, 5 ).toDouble());
- ras2 = int(60.0*(line.mid( 4, 5 ).toDouble()-ras) + 0.5); //add 0.5 to get nearest integer with int()
-
- sgn = line.at(10);
- dd = line.mid(11, 2).toInt();
- dm = line.mid(13, 2).toInt();
- ds = int(line.mid(15, 4).toDouble());
- ds2 = int(60.0*(line.mid( 15, 5 ).toDouble()-ds) + 0.5); //add 0.5 to get nearest integer with int()
-
- //parse proper motion and parallax
- pmra = line.mid( 20, 9 ).toDouble();
- pmdec = line.mid( 29, 9 ).toDouble();
- plx = line.mid( 38, 7 ).toDouble();
-
- //parse magnitude, B-V color, and spectral type
- mag = line.mid( 46, 5 ).toDouble();
- bv = line.mid( 51, 5 ).toDouble();
- SpType = line.mid(56, 2);
-
- //parse multiplicity
- mult = line.mid( 59, 1 ).toInt();
-
- //parse variablility...currently not using dmag or var
- var = false; dmag = 0.0; vper = 0.0;
- if ( line.length() > 60 && line.at( 62 ) == '.' ) {
- var = true;
- dmag = line.mid( 61, 4 ).toDouble();
- vper = line.mid( 66, 6 ).toDouble();
- }
-
- //parse name(s)
- if ( line.length() > 72 )
- name = line.mid( 72 ).trimmed(); //the rest of the line
-
- if ( ! name.isEmpty() ) {
- if (name.at(0) == ',') { // new format: "; gname; name"
- gname = name.mid(1, 8).trimmed();
- if ( name.length() > 10)
- name = (name.at(9) == ',') ? name.mid(10).trimmed() : "";
- else
- name = "";
- }
- else { // old format: "name : gname"
- if (name.contains( ':' )) { //genetive form exists
- gname = name.mid( name.indexOf(':') + 1 ).trimmed();
- name = name.mid( 0, name.indexOf(':') ).trimmed();
- }
- }
-
- if ( ! gname.isEmpty() && gname.at(0) != '.')
- visibleName = gname;
- }
-
- //if ( ! gname.isEmpty() && gname.at(0) == '.') kDebug() << gname;
-
- // HEV: look up star name in internationalization filesource
- if ( name.isEmpty() ) name = i18n("star");
- name = i18nc("star name", name.toLocal8Bit().data());
-
- dms r;
- r.setH(rah, ram, ras, ras2);
- dms d(dd, dm, ds, ds2);
-
-if ( sgn == '-' ) { d.setD( -1.0*d.Degrees() ); }
-
- StarObject *o = new StarObject( r, d, mag, name, visibleName, SpType, pmra, pmdec, plx, mult, var );
- o->EquatorialToHorizontal( data()->lst(), data()->geo()->lat() );
-
- if ( ! gname.isEmpty() ) m_genName.insert( gname, o );
-
- if ( ! name.isEmpty() && name != i18n("star") ) {
- objectNames(SkyObject::STAR).append( name );
- }
- if ( ! gname.isEmpty() && gname != name ) {
- objectNames(SkyObject::STAR).append( o->gname(false) );
- }
- return o;
-}
-*/
-
SkyObject* StarComponent::findStarByGenetiveName( const QString name ) {
return m_genName.value( name );
}
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