final Document doc(int n, FieldSelector fieldSelector) throws IOException {
indexStream.seek(n * 8L);
long position = indexStream.readLong();
fieldsStream.seek(position);
Document doc = new Document();
int numFields = fieldsStream.readVInt();
for (int i = 0; i < numFields; i++) {
int fieldNumber = fieldsStream.readVInt();
FieldInfo fi = fieldInfos.fieldInfo(fieldNumber);
FieldSelectorResult acceptField =
fieldSelector == null ? FieldSelectorResult.LOAD : fieldSelector.accept(fi.name);
byte bits = fieldsStream.readByte();
boolean compressed = (bits & FieldsWriter.FIELD_IS_COMPRESSED) != 0;
boolean tokenize = (bits & FieldsWriter.FIELD_IS_TOKENIZED) != 0;
boolean binary = (bits & FieldsWriter.FIELD_IS_BINARY) != 0;
// TODO: Find an alternative approach here if this list continues to grow beyond the
// list of 5 or 6 currently here. See Lucene 762 for discussion
if (acceptField.equals(FieldSelectorResult.LOAD)) {
addField(doc, fi, binary, compressed, tokenize);
} else if (acceptField.equals(FieldSelectorResult.LOAD_FOR_MERGE)) {
addFieldForMerge(doc, fi, binary, compressed, tokenize);
} else if (acceptField.equals(FieldSelectorResult.LOAD_AND_BREAK)) {
addField(doc, fi, binary, compressed, tokenize);
break; // Get out of this loop
} else if (acceptField.equals(FieldSelectorResult.LAZY_LOAD)) {
addFieldLazy(doc, fi, binary, compressed, tokenize);
} else if (acceptField.equals(FieldSelectorResult.SIZE)) {
skipField(binary, compressed, addFieldSize(doc, fi, binary, compressed));
} else if (acceptField.equals(FieldSelectorResult.SIZE_AND_BREAK)) {
addFieldSize(doc, fi, binary, compressed);
break;
} else {
skipField(binary, compressed);
}
}
return doc;
}
public MultiFieldSelector add(FieldSelector fs) {
fss.put(fs.getDescriptor(), fs);
return this;
}
