Function applyFacetsTree

worker/task.go:2291–2358

applyFacetsTree : we return error only when query has some problems. like Or has 3 arguments, argument facet val overflows integer. returns true if postingFacets can be included.

(postingFacets []*api.Facet, ftree *facetsTree)

// like Or has 3 arguments, argument facet val overflows integer.
// returns true if postingFacets can be included.
func applyFacetsTree(postingFacets []*api.Facet, ftree *facetsTree) (bool, error) {
	if ftree == nil {
		return true, nil
	}
	if ftree.function != nil {
		var fc *api.Facet
		for _, fci := range postingFacets {
			if fci.Key == ftree.function.key {
				fc = fci
				break
			}
		}
		if fc == nil { // facet is not there
			return false, nil
		}

		switch ftree.function.fnType {
		case compareAttrFn: // lt, gt, le, ge, eq
			fVal, err := facets.ValFor(fc)
			if err != nil {
				return false, err
			}

			v, ok := ftree.function.typesToVal[fVal.Tid]
			if !ok {
				// Not found in map and hence convert it here.
				v, err = types.Convert(ftree.function.val, fVal.Tid)
				if err != nil {
					// ignore facet if not of appropriate type.
					return false, nil
				}
			}

			return types.CompareVals(ftree.function.name, fVal, v), nil

		case standardFn: // allofterms, anyofterms
			facetType, err := facets.TypeIDFor(fc)
			if err != nil {
				return false, err
			}
			if facetType != types.StringID {
				return false, nil
			}
			return filterOnStandardFn(ftree.function.name, fc.Tokens, ftree.function.tokens)
		}
		return false, errors.Errorf("Fn %s not supported in facets filtering.", ftree.function.name)
	}

	res := make([]bool, 0, 2) // We can have max two children for a node.
	for _, c := range ftree.children {
		r, err := applyFacetsTree(postingFacets, c)
		if err != nil {
			return false, err
		}
		res = append(res, r)
	}

	// we have already checked for number of children in preprocessFilter