public FileFlatField(FileAccessor accessor, CacheStrategy strategy) throws VisADException {
super(accessor.getFunctionType(), getNullDomainSet(accessor.getFunctionType().getDomain()));
fileAccessor = accessor;
cacheStrategy = strategy;
// '0' is in legal range of adaptedFlatFieldIndex,
// but not owned by this
adaptedFlatFieldIndex = 0;
}
private FlatField getAdaptedFlatField() {
// if owner array is null,
// assume this object got serialized & unserialized
if (adaptedFlatFieldOwner == null) {
return null;
}
synchronized (adaptedFlatFields) {
for (int ii = 0; ii < MAX_FILE_FLAT_FIELDS; ii++) {
if (this == adaptedFlatFieldOwner[ii]) {
// mark time of most recent access
adaptedFlatFieldTimes[ii] = System.currentTimeMillis();
return adaptedFlatFields[ii];
}
}
// this FileFlatField does not own a cache entry, so invoke
// CahceStrategy.allocate to allocate one, possibly by taking
// one, possibly by taking one from another FileFlatField;
// this will be an area for lots of thought and experimentation;
adaptedFlatFieldIndex =
cacheStrategy.allocate(
adaptedFlatFields, adaptedFlatFieldDirty,
adaptedFlatFieldSizes, adaptedFlatFieldTimes);
// flush cache entry, if dirty
if (adaptedFlatFieldDirty[adaptedFlatFieldIndex]) {
try {
adaptedFlatFieldOwner[adaptedFlatFieldIndex].flushCache();
} catch (VisADException e) {
System.out.println(e.getMessage());
}
}
// create a new entry in adaptedFlatFields at adaptedFlatFieldIndex
// and read data values from fileAccessor at fileLocation
try {
adaptedFlatFields[adaptedFlatFieldIndex] = fileAccessor.getFlatField();
} catch (VisADException e1) {
System.out.println(e1.getMessage());
} catch (RemoteException e2) {
System.out.println(e2.getMessage());
}
// mark cache entry as belonging to this FileFlatField
adaptedFlatFieldOwner[adaptedFlatFieldIndex] = this;
// get size of adapted FlatField
// (by calling a method that currently does not exist)
/*adaptedFlatFields[adaptedFlatFieldIndex].getSize(); */
adaptedFlatFieldTimes[adaptedFlatFieldIndex] = System.currentTimeMillis();
return adaptedFlatFields[adaptedFlatFieldIndex];
}
}