private static void assertSplitAtFractionBinary()

in sdk/src/main/java/com/google/cloud/dataflow/sdk/testing/SourceTestUtils.java [451:503]
45 lines of code
8 McCabe index (conditional complexity)

  private static <T> void assertSplitAtFractionBinary(
      BoundedSource<T> source,
      List<T> expectedItems,
      int numItemsToBeReadBeforeSplit,
      double leftFraction,
      SplitAtFractionResult leftResult,
      double rightFraction,
      SplitAtFractionResult rightResult,
      PipelineOptions options,
      SplitFractionStatistics stats)
      throws Exception {
    if (rightFraction - leftFraction < 0.001) {
      // Do not recurse too deeply. Otherwise we will end up in infinite
      // recursion, e.g., while trying to find the exact minimal fraction s.t.
      // split succeeds. A precision of 0.001 when looking for such a fraction
      // ought to be enough for everybody.
      return;
    }
    double middleFraction = (rightFraction + leftFraction) / 2;
    if (leftResult == null) {
      leftResult = assertSplitAtFractionBehaviorImpl(
          source, expectedItems, numItemsToBeReadBeforeSplit, leftFraction,
          ExpectedSplitOutcome.MUST_BE_CONSISTENT_IF_SUCCEEDS, options);
    }
    if (rightResult == null) {
      rightResult = assertSplitAtFractionBehaviorImpl(
          source, expectedItems, numItemsToBeReadBeforeSplit, rightFraction,
          ExpectedSplitOutcome.MUST_BE_CONSISTENT_IF_SUCCEEDS, options);
    }
    SplitAtFractionResult middleResult = assertSplitAtFractionBehaviorImpl(
        source, expectedItems, numItemsToBeReadBeforeSplit, middleFraction,
        ExpectedSplitOutcome.MUST_BE_CONSISTENT_IF_SUCCEEDS, options);
    if (middleResult.numResidualItems != -1) {
      stats.successfulFractions.add(middleFraction);
    }
    if (middleResult.numResidualItems > 0) {
      stats.nonTrivialFractions.add(middleFraction);
    }
    // Two split fractions are equivalent if they yield the same number of
    // items in primary vs. residual source. Left and right are already not
    // equivalent. Recurse into [left, middle) and [right, middle) respectively
    // if middle is not equivalent to left or right.
    if (leftResult.numPrimaryItems != middleResult.numPrimaryItems) {
      assertSplitAtFractionBinary(
          source, expectedItems, numItemsToBeReadBeforeSplit,
          leftFraction, leftResult, middleFraction, middleResult, options, stats);
    }
    if (rightResult.numPrimaryItems != middleResult.numPrimaryItems) {
      assertSplitAtFractionBinary(
          source, expectedItems, numItemsToBeReadBeforeSplit,
          middleFraction, middleResult, rightFraction, rightResult, options, stats);
    }
  }