public CompletionFieldsProducer(SegmentReadState state) throws IOException {
String suggestFSTFile =
IndexFileNames.segmentFileName(state.segmentInfo.name, state.segmentSuffix, EXTENSION);
IndexInput input = state.directory.openInput(suggestFSTFile, state.context);
if (state.segmentInfo.getVersion().onOrAfter(Version.LUCENE_6_2_0)) {
// Lucene 6.2.0+ requires all index files to use index header, but prior to that we used an
// ordinary codec header:
version =
CodecUtil.checkIndexHeader(
input,
CODEC_NAME,
SUGGEST_CODEC_VERSION,
SUGGEST_VERSION_CURRENT,
state.segmentInfo.getId(),
state.segmentSuffix);
} else {
version =
CodecUtil.checkHeader(
input, CODEC_NAME, SUGGEST_CODEC_VERSION, SUGGEST_VERSION_CURRENT);
}
FieldsProducer delegateProducer = null;
boolean success = false;
try {
PostingsFormat delegatePostingsFormat = PostingsFormat.forName(input.readString());
String providerName = input.readString();
CompletionLookupProvider completionLookupProvider = providers.get(providerName);
if (completionLookupProvider == null) {
throw new IllegalStateException(
"no provider with name [" + providerName + "] registered");
}
// TODO: we could clone the ReadState and make it always forward IOContext.MERGE to prevent
// unecessary heap usage?
delegateProducer = delegatePostingsFormat.fieldsProducer(state);
/*
* If we are merging we don't load the FSTs at all such that we
* don't consume so much memory during merge
*/
if (state.context.context != Context.MERGE) {
// TODO: maybe we can do this in a fully lazy fashion based on some configuration
// eventually we should have some kind of curciut breaker that prevents us from going OOM
// here
// with some configuration
this.lookupFactory = completionLookupProvider.load(input);
} else {
this.lookupFactory = null;
}
this.delegateProducer = delegateProducer;
success = true;
} finally {
if (!success) {
IOUtils.closeWhileHandlingException(delegateProducer, input);
} else {
IOUtils.close(input);
}
}
}
static {
final CompletionLookupProvider provider =
new AnalyzingCompletionLookupProvider(true, true, false);
providers = Collections.singletonMap(provider.getName(), provider);
}