Method filter

xds/src/main/java/io/grpc/xds/AddressFilter.java:69–83

Returns the next level hierarchical addresses derived from the given hierarchical addresses with the given filter name (any non-hierarchical addresses in the input will be ignored). This method does not modify the input addresses.

(List<EquivalentAddressGroup> addresses, String name)

   * This method does not modify the input addresses.
   */
  static List<EquivalentAddressGroup> filter(List<EquivalentAddressGroup> addresses, String name) {
    checkNotNull(addresses, "addresses");
    checkNotNull(name, "name");
    List<EquivalentAddressGroup> filteredAddresses = new ArrayList<>();
    for (EquivalentAddressGroup address : addresses) {
      PathChain pathChain = address.getAttributes().get(PATH_CHAIN_KEY);
      if (pathChain != null && pathChain.name.equals(name)) {
        Attributes filteredAddressAttrs =
            address.getAttributes().toBuilder().set(PATH_CHAIN_KEY, pathChain.next).build();
        filteredAddresses.add(
            new EquivalentAddressGroup(address.getAddresses(), filteredAddressAttrs));
      }
    }
    return Collections.unmodifiableList(filteredAddresses);
  }

  static final class PathChain {
    final String name;