@GET
@Path("{userID}")
@Produces({MediaType.TEXT_PLAIN, CSVMessageBodyWriter.TEXT_CSV, MediaType.APPLICATION_JSON})
public List<IDValue> get(
@PathParam("userID") String userID,
@DefaultValue("10") @QueryParam("howMany") int howMany,
@DefaultValue("0") @QueryParam("offset") int offset)
throws OryxServingException {
check(howMany > 0, "howMany must be positive");
check(offset >= 0, "offset must be nonnegative");
ALSServingModel model = getALSServingModel();
float[] userVector = model.getUserVector(userID);
checkExists(userVector != null, userID);
List<Pair<String, float[]>> knownItemVectors = model.getKnownItemVectorsForUser(userID);
if (knownItemVectors == null || knownItemVectors.isEmpty()) {
return Collections.emptyList();
}
Iterator<Pair<String, Double>> idDots =
knownItemVectors
.stream()
.map(
itemIDVector ->
new Pair<>(
itemIDVector.getFirst(),
VectorMath.dot(userVector, itemIDVector.getSecond())))
.iterator();
Ordering<Pair<?, Double>> ordering =
Ordering.from((p1, p2) -> p1.getSecond().compareTo(p2.getSecond()));
return toIDValueResponse(ordering.leastOf(idDots, howMany + offset), howMany, offset);
}
