# Advanced User Guide

## Additional Features

The main [Tutorial - User Guide](../tutorial/index.md){.internal-link target=_blank} should be enough to give you a tour through all the main features of **FastAPI**.

In the next sections you will see other options, configurations, and additional features.

/// tip

The next sections are **not necessarily "advanced"**.

And it's possible that for your use case, the solution is in one of them.

///

	SunOS)
		ARCH=$(isainfo -k)
		;;
	esac
}

## FIXME:
## In OSX, 'readlink -f' option does not exist, hence
## we have our own readlink -f behavior here.
## Once OSX has the option, below function is good enough.
##
## readlink() {
##     return /bin/readlink -f "$1"
## }
##
readlink() {
	TARGET_FILE=$1

	cd $(dirname $TARGET_FILE)
	TARGET_FILE=$(basename $TARGET_FILE)

	// Offset and out size cannot be negative.
	if offset < 0 || length < 0 {
		return 0, errUnexpected
	}

	// Do we have enough blocks?
	if len(enBlocks) < dataBlocks {
		return 0, reedsolomon.ErrTooFewShards
	}

	// Do we have enough data?
	if int64(getDataBlockLen(enBlocks, dataBlocks)) < length {
		return 0, reedsolomon.ErrShortData
	}

	// Counter to decrement total left to write.

  // +optional
  optional string selectedNode = 1;

  // PotentialNodes lists nodes where the Pod might be able to run.
  //
  // The size of this field is limited to 128. This is large enough for
  // many clusters. Larger clusters may need more attempts to find a node
  // that suits all pending resources. This may get increased in the
  // future, but not reduced.
  //
  // +listType=set
  // +optional

> Ideally, we structure `drain period` such that it is long enough to meet our application requirements, but short enough that we can fully terminate

 */
@GwtCompatible
@ElementTypesAreNonnullByDefault
final class Hashing {
  private Hashing() {}

  /*
   * These should be ints, but we need to use longs to force GWT to do the multiplications with
   * enough precision.
   */
  private static final long C1 = 0xcc9e2d51;
  private static final long C2 = 0x1b873593;

  /*
   * This method was rewritten in Java from an intermediate step of the Murmur hash function in

)

// errOutOfEntropy indicates that the a source of randomness (PRNG) wasn't able
// to produce enough random data. This is fatal error and should cause a panic.

      added += q.drainTo(buffer, numElements - added);
      if (added < numElements) { // not enough elements immediately available; will have to poll
        E e = q.poll(deadline - System.nanoTime(), NANOSECONDS);
        if (e == null) {
          break; // we already waited enough, and there are no more elements in sight
        }
        buffer.add(e);
        added++;
      }
    }

  }

  /**
   * Creates a {@code CompactLinkedHashMap} instance, with a high enough "initial capacity" that it
   * <i>should</i> hold {@code expectedSize} elements without rebuilding internal data structures.
   *
   * @param expectedSize the number of elements you expect to add to the returned set
   * @return a new, empty {@code CompactLinkedHashMap} with enough capacity to hold {@code
   *     expectedSize} elements without resizing

        If you are unable to do so, please ensure you have collected the relevant debugging information manually and attached below;
        issue without enough information will not be resolvable.
  - type: checkboxes
    id: area
    attributes:
      label: Affected product area
      options:
      - label: "Ambient"
      - label: "Docs"
      - label: "Dual Stack"