public TokenRange mergeWith()

in core/src/main/java/com/datastax/oss/driver/internal/core/metadata/token/TokenRangeBase.java [219:260]

29 lines of code
14 McCabe index (conditional complexity)


  public TokenRange mergeWith(@NonNull TokenRange that) {
    if (this.equals(that)) {
      return this;
    }

    if (!(this.intersects(that)
        || this.end.equals(that.getStart())
        || that.getEnd().equals(this.start))) {
      throw new IllegalArgumentException(
          String.format(
              "Can't merge %s with %s because they neither intersect nor are adjacent",
              this, that));
    }

    if (this.isEmpty()) {
      return that;
    }

    if (that.isEmpty()) {
      return this;
    }

    // That's actually "starts in or is adjacent to the end of"
    boolean thisStartsInThat = contains(that, this.start, true) || this.start.equals(that.getEnd());
    boolean thatStartsInThis =
        contains(this, that.getStart(), true) || that.getStart().equals(this.end);

    // This takes care of all the cases that return the full ring, so that we don't have to worry
    // about them below
    if (thisStartsInThat && thatStartsInThis) {
      return fullRing();
    }

    // Starting at this.start, see how far we can go while staying in at least one of the ranges.
    Token mergedEnd =
        (thatStartsInThis && !contains(this, that.getEnd(), false)) ? that.getEnd() : this.end;

    // Repeat in the other direction.
    Token mergedStart = thisStartsInThat ? that.getStart() : this.start;

    return newTokenRange(mergedStart, mergedEnd);
  }