#### Caching

Config translation typically takes the overwhelming majority of Istiod's resource usage. In particular, protobuf encoding. As a result, caching has been introduced, storing the already encoded `protobuf.Any` for a given resource.

  /**
   * Various scenarios to be generated for each method under test. The actual scenario generation
   * (determining which scenarios are applicable to which methods and what the outcome should be)
   * takes place in {@link #addTests(TestSuite, Method)}.
   */
  private enum Scenario {
    SATISFIED_AND_UNOCCUPIED_BEFORE_ENTERING,
    UNSATISFIED_AND_UNOCCUPIED_BEFORE_ENTERING,
    SATISFIED_AND_OCCUPIED_BEFORE_ENTERING,

	var buffer []byte
	switch size := data.Size(); {
	case size == 0:
		buffer = make([]byte, 1) // Allocate at least a byte to reach EOF
	case size == -1:
		if size := data.ActualSize(); size > 0 && size < fi.Erasure.BlockSize {
			// Account for padding and forced compression overhead and encryption.
			buffer = make([]byte, data.ActualSize()+256+32+32, data.ActualSize()*2+512)
		} else {

          return new FutureAsCancellable(immediateCancelledFuture());
        }
        // We reschedule ourselves with a lock held for two reasons. 1. we want to make sure that
        // cancel calls cancel on the correct future. 2. we want to make sure that the assignment
        // to currentFuture doesn't race with itself so that currentFuture is assigned in the
        // correct order.
        Throwable scheduleFailure = null;

	// The approach here is to write 8 byte sizes if needed without
	// adding a zip64 extra in the local header (too late anyway).
	var buf []byte
	if w.isZip64() {
		buf = make([]byte, dataDescriptor64Len)
	} else {
		buf = make([]byte, dataDescriptorLen)
	}
	b := writeBuf(buf)
	b.uint32(dataDescriptorSignature) // de-facto standard, required by OS X
	b.uint32(w.CRC32)
	if w.isZip64() {

* A new client `k8s.io/client-go/metadata.Client` has been added for accessing objects generically. This client makes it easier to retrieve only the metadata (the `metadata` sub-section) from resources on the cluster in an efficient manner for use cases that deal with objects generically, like the garbage collector, quota, or the namespace controller. The client asks...

#
# The original version of this file is located in the https://github.com/istio/common-files repo.
# If you're looking at this file in a different repo and want to make a change, please go to the
# common-files repo, make the change there and check it in. Then come back to this repo and run
# "make update-common".

# Copyright Istio Authors
#
# Licensed under the Apache License, Version 2.0 (the "License");

 * a {@code Map<R, Map<C, V>>}. A method call like {@code column(columnKey).get(rowKey)} still runs
 * quickly, since the row key is provided. However, {@code column(columnKey).size()} takes longer,
 * since an iteration across all row keys occurs.
 *
 * <p>Because a {@code TreeBasedTable} has unique sorted values for a given row, both {@code

	}()
	// TODO(http://golang.org/issue/51462): We should rely on the append-make
	// pattern so that the compiler can call runtime.growslice. For example:
	//	return append(b, make([]byte, n)...)
	// This avoids unnecessary zero-ing of the first len(b) bytes of the
	// allocated slice, but this pattern causes b to escape onto the heap.
	//
	// Instead use the append-make pattern with a nil slice to ensure that

Call             Type T     Result

make(T, n)       slice      slice of type T with length n and capacity n
make(T, n, m)    slice      slice of type T with length n and capacity m

make(T)          map        map of type T
make(T, n)       map        map of type T with initial space for approximately n elements

make(T)          channel    unbuffered channel of type T